YULINK regulates vascular formation in zebrafish and HUVECs

BACKGROUND: The distinct arterial and venous cell fates are dictated by a combination of various genetic factors which form diverse types of blood vessels such as arteries, veins, and capillaries. We report here that YULINK protein is involved in vasculogenesis, especially venous formation. METHODS: In this manuscript, we employed gene knockdown, yeast two-hybrid, FLIM-FRET, immunoprecipitation, and various imaging technologies to investigate the role of YULINK gene in zebrafish and human umbilical vein endothelial cells (HUVECs). RESULTS: Knockdown of YULINK during the arterial-venous developmental stage of zebrafish embryos led to the defective venous formation and abnormal vascular plexus formation. Knockdown of YULINK in HUVECs impaired their ability to undergo cell migration and differentiation into a capillary-like tube formation. In addition, the phosphorylated EPHB4 was decreased in YULINK knockdown HUVECs. Yeast two-hybrid, FLIM-FRET, immunoprecipitation, as well as imaging technologies showed that YULINK colocalized with endosome related proteins (EPS15, RAB33B or TICAM2) and markers (Clathrin and RHOB). VEGF-induced VEGFR2 internalization was also compromised in YULINK knockdown HUVECs, demonstrating to the involvement of YULINK. CONCLUSION: This study suggests that YULINK regulates vasculogenesis, possibly through endocytosis in zebrafish and HUVECs. Key points Knockdown of YULINK with morpholino in embryos of double transgenic zebrafish exhibited abnormal venous formation. Tube formation and phosphorylated EPHB4 were decreased in YULINK knockdown HUVECs. FLIM-FRET, immunoprecipitation, as well as other imaging technologies showed that YULINK colocalized with endosome related proteins (EPS15, RAB33B and TICAM2) and endosome markers (Clathrin and RHOB). Knockdown of YULINK decreased the internalization of VEGF and VEGFR2 in HUVECs.

Optimized biotransformation of acid-treated water melon peel hydrolyzate into ethanol / Biotransformação otimizada de hidrolisado de casca de melancia tratada com ácido em etanol

Abstract Today, global focus of research is to explore the solution of energy crisis and environmental pollution. Like other agricultural countries, bulk quantities of watermelon peels (WMP) are disposed-off in environment as waste in Pakistan and appropriate management of this waste is the need of hour to save environment from pollution. The work emphasizes the role of ethanologenic yeasts to utilize significant sugars present in WMP for low-cost bioethanol fermentation. Dilute hydrochloric acid hydrolysis of WMP was carried out on optimized conditions employing RSM (response surface methodology) following central composite design (CCD). This experimental design is based on optimization of ethanologenesis involving some key independent parameters such as WMP hydrolysate and synthetic media ratio (X1), incubation temperature (X2) and incubation temperature (X3) for maximal ethanol yield exploiting standard (Saccharomyces cerevisiae K7) as well as experimental (Metchnikowia cibodasensisY34) yeasts. The results revealed that maximal ethanol yields obtained from S. cerevisiae K7 was 0.36±0.02 g/g of reducing sugars whereas M. cibodasensisY34, yielded 0.40±0.01 g ethanol/g of reducing sugars. The yeast isolate M. cibodasensisY34 appeared as promising ethanologen and embodies prospective potential for fermentative valorization of WMP-to-bioethanol.

Resumo Hoje, o foco global da pesquisa é explorar a solução da crise energética e da poluição ambiental. Como em outros países agrícolas, grandes quantidades de cascas de melancia (WMP) são descartadas como resíduos no meio ambiente no Paquistão, mas a gestão adequada desses resíduos é a mais recente solução para salvar o meio ambiente da poluição. O trabalho enfatiza o papel das leveduras etanologênicas para utilizar açúcares significativos presentes no WMP para fermentação de bioetanol de baixo custo. A hidrólise de ácido clorídrico diluído de WMP foi realizada em condições otimizadas empregando RSM (metodologia de superfície de resposta) e seguindo o projeto de composto central (CCD). Este projeto experimental é baseado na otimização da etanologenesis envolvendo alguns parâmetros independentes importantes, como hidrolisado de WMP e razão de meio sintético (X1), temperatura de incubação (X2) e temperatura de incubação (X3) para rendimento máximo de etanol explorando o padrão (Saccharomyces cerevisiae K7) também como leveduras experimentais (Metchnikowia cibodasensis Y34). Os resultados revelaram que os rendimentos máximos de etanol obtidos a partir de S. cerevisiae K7 foi de 0,36 ± 0,02 g / g de açúcares redutores, enquanto M. cibodasensis Y34 rendeu 0,40 ± 0,01 g de etanol / g de açúcares redutores. O isolado de levedura M. cibodasensis Y34 apareceu como um etanologeno promissor e incorpora um potencial prospectivo para a valorização fermentativa de WMP em bioetanol.

Homeopathy on cultures of Saccharomyces cerevisiaeand impact on fermentation

Studies have shownthat homeopathy modulates the activity of both single-and multi-celled organisms;therefore, we propose a study into the action of Arnica Montanaand S. cerevisiae fungus nosode on growth "in vitro", and on the fermentation of S. cerevisiaeon brewer's wort. Methods:250 µL of medication in 30% alcohol were placed in 5 mL of Sabouraud Broth (SB) or wort, with 20 µL of fungus ata McFarland standard of 0.5 and in a dilution of 1:100. Fungal growth was evaluated via spectrophotometry at 600 nm or a cell count in a Neubauer chamber in a kinetic of 1 to 5 days' incubation at 25ºC. The production of alcohol by the fungus was evaluated using the BRIX index in the samekinetic. 1x107fungi/mL were previously incubated with medication for 5 days and, afterwards, placed in 20 mL of fresh wort, incubated at 25ºC for 7 days and evaluated for growth and sugar consumption. Resultsand Discussion: The SB results revealed that after 2days incubation with Arnica30CH, an increase in fungal growth was observed (p<0.0001), whilewith nosode 6 and 30CH there was a reduction in growth after 2 and 5 days incubation (p<0.001). The fungi incubated with Arnica30CH exhibited increased sugar consumption after 2 and5 days incubation (p<0.05), while the nosode 30CH resulted in lower sugar consumption after 2 and 3 days incubation (p<0.05). The results for fungal growth and sugar consumption with the wort were similar to those using SB.The fungalcultures previously incubated with homeopathic medication and subsequent incubation with fresh wortindicated a loss of distinction, bothin terms of fungal growth and sugar consumption. This piece of data may suggest action by the homeopathic medication only when in contact with the cells. Conclusion: The treatment of the S. cerevisiae fungus using Arnica and the S. cerevisiae nosode produced a significant modulation in fungal growth and sugar consumption.

Caracterização do papel de Nop53 na montagem da subunidade ribossomal maior em Saccharomyces cerevisiae / Characterization of the role of Nop53 in the assembly of the large ribosomal subunit in Saccharomyces cerevisiae

Os ribossomos são complexos ribonucleoproteicos conservados formados por duas subunidades assimétricas (40S e 60S em eucariotos) responsáveis pela tradução da informação genética e catálise da síntese proteica. A montagem destes complexos em eucariotos é mais bem descrita em S. cerevisiae, constituindo um processo celular energeticamente dispendioso e com múltiplas etapas. Ela tem origem no nucléolo com a transcrição do pré-rRNA 35S e requer o recrutamento hierárquico e transiente de cerca de 200 fatores de montagem para garantir a formação correta dos centros funcionais aptos à tradução. Neste processo, que se estende no núcleo e citoplasma, 79 proteínas ribossomais associam-se gradativamente à medida que o prérRNA é dobrado, modificado e processado. O processamento do pré-rRNA 35S consiste na remoção progressiva de espaçadores internos (ITS1 e ITS2) e externos (5ETS e 3ETS), que separam e flanqueiam os rRNAs maduros componentes de ambas subunidades ribossomais. A clivagem do ITS1 separa as vias de maturação do pré-60S e do pré-40S. O ITS2, que, em associação a fatores de montagem, forma uma estrutura denominada ITS2-foot, é o último espaçador do pré-60S a ser removido. A composição do ITS2-foot permanece inalterada no nucléolo até a transição entre o estado E nucleolar e a formação da partícula Nog2 nuclear. Nesta etapa, a liberação do fator Erb1 permite o recrutamento do fator de montagem conservado e essencial Nop53. Na base do ITS2-foot, Nop53 recruta o exossomo via RNA helicase Mtr4 para a clivagem 3-5 exonucleolítica de parte do ITS2 levando à desmontagem do ITS2-foot. O fato de Nop53 atuar como ponte entre dois grandes complexos e apresentar uma estrutura flexível e estendida nos levou a aprofundar a caracterização de seu papel durante a maturação do pré60S. Neste trabalho, usando análise proteômica quantitativa label-free baseada em espectrometria de massas, caracterizou-se o interactoma de Nop53, e avaliou-se o impacto da depleção de Nop53 no interactoma da subunidade catalítica do exossomo Rrp6 e na composição de pré-ribossomos representativos de quase todas as etapas de maturação do pré-60S. Em paralelo, foram caracterizados mutantes truncados de Nop53 e avaliada por pull-down a interação de Nop53 com componentes do exossomo. Os resultados obtidos mostraram que Nop53 é capaz de interagir com o cofator do exossomo Mpp6, sugerindo pontos adicionais de interação durante o recrutamento do exossomo ao pré-60S. A análise do interactoma de Rrp6 mostrou uma associação precoce do exossomo aos intermediários pré-ribossomais nucleolares mais iniciais, anteriores aos previamente descritos. Mudanças na composição dos intermediários pré-60S revelaram que a depleção de Nop53 afeta a transição entre o estado E e a partícula Nog2, afetando eventos tardios de maturação como o recrutamento de Yvh1. Comparando-se o efeito da depleção de Nop53 com o de mutantes nop53 desprovidos da região de recrutamento do exossomo, obtivemos evidências bioquímicas do papel estrutural de Nop53 na base do ITS2- foot. Em conjunto, estas observações, à luz de estruturas de intermediários pré-ribossomais recentemente descritas, nos permitiram concluir que o recrutamento de Nop53 ao pré-60S contribui para a estabilização de eventos de remodelamento do rRNA que antecedem a formação da partícula Nog2

Ribosomes are conserved ribonucleoprotein complexes formed by two asymmetric subunits (the 40S and the 60S in eukaryotes) responsible for translating the genetic information and catalyzing protein synthesis. The assembly of these complexes in eukaryotes is best described in S. cerevisiae. It is an energetically demanding, multi-step cellular process, that starts in the nucleolus with the transcription of the 35S pre-rRNA. It requires the hierarchical and transient recruitment of about 200 assembly factors to ensure the correct formation of the functional centers suitable for translation. In this process, which extends into the nucleus and cytoplasm, 79 ribosomal proteins gradually associate as the pre-rRNA is folded, modified, and processed. The 35S pre-rRNA processing happens with the progressive removal of internal (ITS1 and ITS2) and external (5'ETS and 3'ETS) transcribed spacers, which separate and flank the mature rRNA components of both ribosomal subunits. The cleavage at the ITS1 separates the pre-60S and pre40S maturation pathways. The ITS2, which in association with assembly factors constitutes a structure called ITS2-foot, is the last pre-60S spacer to be removed. The composition of the ITS2- foot remains unchanged in the nucleolus until the transition between the nucleolar state E and the nuclear Nog2 particle. At this stage, the release of Erb1 allows the recruitment of the conserved and essential assembly factor Nop53. At the base of the ITS2-foot, Nop53 recruits the exosome via the RNA helicase Mtr4 for the ITS2 3'-5' exonucleolytic cleavage leading to the ITS2-foot disassembly. The fact that Nop53 acts as a bridge between these two large complexes and exhibits a flexible and extended structure led us to further characterize its role in the pre-60S maturation. In this work, using mass spectrometry-based label-free quantitative proteomics, we characterized the interactome of Nop53, as well as the impact of the depletion of Nop53 on the interactome of the exosome catalytic subunit Rrp6 and on the composition of pre-ribosomes representative of almost all pre-60S maturation stages. In parallel, we characterized nop53 truncated mutants and evaluated the interaction of Nop53 with exosome components by pulldown assays. The results showed that Nop53 can interact with the exosome cofactor Mpp6, suggesting the contribution of additional points of interaction during the exosome recruitment to the pre-60S. The analysis of the Rrp6 interactome revealed an early association of the exosome with pre-ribosomal intermediates at very early nucleolar stages, before those previously described. Changes in the composition of pre-60S intermediates revealed that Nop53 depletion affects the transition between the state E and the Nog2 particle, affecting late pre-60S maturation events, such as the Yvh1 recruitment. Comparing the effect of Nop53 depletion with that of nop53 mutants lacking the exosome interacting region, we obtained biochemical evidence of the structural role of Nop53 at the base of the ITS2-foot. Altogether, and in light of recently described structures of pre-ribosomal intermediates, these observations allowed us to conclude that the recruitment of Nop53 to the pre-60S contributes to the stabilization of rRNA remodeling events that precede the formation of the Nog2 particle

Association between productive parameters and intestinal histomorphological findings in broilers supplemented with probiotics (Saccharomyces cerevisiae, Lactobacillus acidophilus and Bacillus subtilis) / Asociación entre parámetros productivos y hallazgos histomorfológicos en pollos de engorde suplementados con probióticos (Saccharomyces cerevisiae, Lactobacillus acidophilus y Bacillus subtilis)

SUMMARY: This study evaluates the effect of probiotics Saccharomyces cerevisiae, Lactobacillus acidophilus and Bacillus subtilis on production parameters and intestinal histomorphology of broilers of 45 days of age. Eleven 45-day-old Ross 500 broilers were used and classified as control group (CG) (n = 5) or supplemented with probiotics group (n = 8). Histopathological evaluation of duodenum, ileum, and jejunum was performed. The area of the villi height, base and apex were evaluated as well as the size and number of crypts. In addition, mucus production was quantified in different portions of the small intestine. The villi present duodenum of broilers supplemented with probiotics had a greater area (p = 0.0127), a greater basal width (p = 0.0049) and a greater apical width (p = 0.0024), as well as a greater crypt area (p = 0.0189). Significantly higher levels of mucus were noted in the duodenum (p = 0.0480) and jejunum (p = 0.0480) of broilers supplemented with probiotics. We suggest that probiotic supplementation improve the intestinal nutrients absorption.

RESUMEN: Este estudio evalúa el efecto del uso de probióticos como: Saccharomyces cerevisiae, Lactobacillus acidophilus, Bacillus subtilis en parámetros productivos e histomorfologia intestinal de pollos de engorde de 45 días de edad. Fueron usados 11, los cuales fueron clasificados en grupo control (CG) (n = 5) y grupo suplementado con probióticos (PG) (n = 8). Fue realizado análisis histopatológico de secciones de duodeno, íleon y yeyuno. Fue evaluado ancho, altura y área del ápice de la vellosidad, área y número de criptas. Además, fue estimada la producción de moco en los diferentes segmentos del intestino delgado. Fue observada mayor área de la vellosidad en duodeno, PG (p = 0.0127), ancho basal mayor en PG (p = 0.0049) ancho apical mayor en PG (p = 0.0024), así como mayor área de criptas en PG (p = 0.0189). No fueron encontradas diferencias significativas respecto a los segmentos de yeyuno e íleon. PG presentó mayor producción de moco en duodeno (p = 0.0480) y en yeyuno (p = 0.0480). Concluimos que la suplementación con probióticos en pollos de engorde genera cambios en la histomorfologia intestinal, evidenciables en áreas apicales y basales de las vellosidades intestinales. Soporte financiero: Dirección General de Investigaciones - Universidad de los Llanos.

Efecto radioprotector del ácido tánico y vinos de la var vitis vinífera L. cv tannat en Saccharomyces cerevisiae / Radioprotective effect of tannic acid and wines of the vitis vinifera L. cv tannat on Saccharomyces cerevisiae / Proteção contra radiação por vinho tinto var tannat e ácido tanico em Saccharomyces cerevisiae

El vino tinto variedad Vitis vinifera L. cv Tannat en los últimos años ha tomado relevancia por su alta concentración de polifenoles, esto le podría significar un rol protector sobre el genoma disminuyendo la formación de lesiones oxidativas. Los efectos a nivel celular de las radiaciones ionizantes en blancos como el ADN, componentes de cascadas de transducción de señales, resultan en lesiones letales, mutagénicas y recombinogénicas y en retardos en el ciclo celular. Se utilizó como modelo eucariota poblaciones de Saccharomyces cerevisiae en fase exponencial expuestas a radiación gamma (200 Gy) en presencia, o ausencia, de vino Tannat (10 % v/v) o de ácido tánico (60 µg/mL). Se estimaron las probabilidades de sobrevida y frecuencia mutagénica en distintas condiciones. Las muestras celulares expuestas a radiación ionizante presentaron una fracción de sobrevida de 0.21 ± 0.02 mientras que en las muestras irradiadas en presencia de vino Tannat o de ácido tánico la fracción de sobrevida fue de 0.33 ± 0.03 y 0.30 ± 0.03 respectivamente. Se observó en las poblaciones irradiadas un aumento significativo de la probabilidad de mutagénesis. En el caso de los tratamientos combinados se observó que la frecuencia mutagénica fue significativamente menor (gamma Tannat: 33%, gamma ácido tánico: 45% ). Estos resultados preliminares podrían indicar radioprotección moderada por parte de los compuestos estudiados, efecto que podría explicarse por las interacciones redox del ácido tánico y polifenoles contenidos en el vino con los radicales libres formados por las radiaciones ionizantes, además de la activación de vías de reparación genómica.

The red wine variety Vitis vinifera L. cv Tannat in recent years has gained relevance due to its high concentration of polyphenols, this could mean a protective role on the genome, reducing the formation of oxidative lesions. The effects at the cellular level of ionizing radiation on targets such as DNA, components of signal transduction cascades, result in lethal, mutagenic and recombinogenic lesions and delays in the cell cycle. Exponential phase populations of Saccharomyces cerevisiae exposed to gamma radiation (200 Gy) in the presence or absence of Tannat wine (10% v / v) or tannic acid (60 µg / ml) were used as a eukaryotic model. The probabilities of survival and mutagenic frequency in different conditions were estimated. Cellular samples exposed to ionizing radiation presented a survival fraction of 0.21 ± 0.02, while in samples irradiated in the presence of Tannat wine or tannic acid, the survival fraction was 0.33 ± 0.03 and 0.30 ± 0.03 respectively. A significant increase in the probability of mutagenesis was observed in irradiated populations. In the case of the combined treatments, it was observed that the mutagenic frequency was significantly lower (Tannat gamma: 33%, Tannic acid gamma: 45%). These preliminary results could indicate moderate radioprotection by the compounds studied, an effect that could be explained by the redox interactions of tannic acid and polyphenols contained in wine with the free radicals formed by ionizing radiation, in addition to the activation of genomic repair pathways.

A variedade de vinho tinto Vitis vinifera L. cv Tannat nos últimos anos tem ganhado relevância devido à sua alta concentração de polifenóis, o que pode significar um papel protetor do genoma, reduzindo a formação de lesões oxidativas. Os efeitos no nível celular da radiação ionizante em alvos como o DNA, componentes de cascatas de transdução de sinal, resultam em lesões letais, mutagênicas e recombinogênicas e atrasos no ciclo celular. Populações de fase exponencial de Saccharomyces cerevisiae expostas à radiação gama (200 Gy) na presença ou ausência de vinho Tannat (10% v / v) ou ácido tânico (60 µg / ml) foram utilizadas como modelo eucariótico. Foram estimadas as probabilidades de sobrevivência e frequência mutagênica em diferentes condições. As amostras celulares expostas à radiação ionizante apresentaram uma fração de sobrevivência de 0,21 ± 0,02, enquanto nas amostras irradiadas na presença de vinho Tannat ou ácido tânico, a fração de sobrevivência foi de 0,33 ± 0,03 e 0,30 ± 0,03, respectivamente. Um aumento significativo na probabilidade de mutagênese foi observado nas populações irradiadas. No caso dos tratamentos combinados, observou-se que a frequência mutagênica foi significativamente menor (Tannat gama: 33%, ácido tânico gama: 45%). Esses resultados preliminares podem indicar radioproteção moderada pelos compostos estudados, efeito que pode ser explicado pelas interações redox do ácido tânico e polifenóis contidos no vinho com os radicais livres formados pela radiação ionizante, além da ativação de vias de reparo genômico.

Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro

BACKGROUND: Cecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1. RESULTS: The results indicated that the recombinant protein was about 5.5 kDa showed by Tricine­SDS­ PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain. CONCLUSIONS: Collectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.

Biological and Oxidative Effect of Ellagic Acid on Saccharomyces cerevisiae: A New Way for Culture Developing

Abstract In this study, the effects of Ellagic acid (EA) on protein expression in yeasts and cellular development were investigated. Four groups were formed. Groups: 1) Control group; yeast only cultivated group; 2) Ellagic Acid (EA) group: EA (10%) given group; 3) Hydrogen peroxide (H2O2) Group: The group given H2O2 (15 mM); 4) EA + H2O2 group: EA (10%) + H2O2 (15 mM) group. After sterilization, EA (10%) and H2O2 (15 mM) were added to the Saccharomyces cerevisiae (S. cerevisiae) cultures and the cultures were grown at 30 °C for 1 hour, 3 hours, 5 hours and 24 hours (overnight). S. cerevisiae cell growth, lipid peroxidation MDA (malondialdehyde) analysis and GSH (glutathione) level were analyzed by spectrophotometer. Total protein changes were determined by SDS-PAGE electrophoresis and measured by the Bradford method. According to the obtained results, compared with the H2O2 group, cell development (1, 3, 5 and 24 hours), GSH level and total protein synthesis (24 hours) were increased with EA, while MDA level (24 hours) decreased. These results show that EA reduces oxidative damage, increases cell growth and it has a protective effect to promote protein synthesis in S. cerevisiae culture.

Efeitos do probiótico Saccharomyces ceveriseae no tratamento da periodontite experimental em ratos submetidos à quimioterapia / Effects of the probiotic Saccharomyces Ceveriseae in the treatment of experimental periodontitis in rats undergoing chemotherapy

O presente estudo teve a finalidade de avaliar os efeitos do uso do probiótico (PRO) Saccharomyces ceveriseae coadjuvante à raspagem e alisamento radicular (RAR) no tratamento da periodontite experimental (PE) induzida em animais imunossuprimidos com o quimioterápico 5-Fluorouracil (5FU). Cento e oito animais foram submetidos à indução da PE por meio da instalação de um fio de algodão ao redor do primeiro molar inferior esquerdo ou direito. A imunossupressão foi obtida pela injeção intraperitoneal do 5FU aplicada em dois momentos: no ato da instalação da ligadura e após 48 horas. Sete dias após instalação a ligadura foi removida e os animais separados aleatoriamente em seis grupos experimentais que receberam os seguintes tratamentos: PE (n=18) - animais que não sofreram nenhum tratamento sistêmico ou local; SS (n=18) - animais que não sofreram tratamento local, apenas tratamento sistêmico com solução salina (SS); 5FU (n=18) - animais tratados sistemicamente com 5FU que não sofreram nenhum tratamento local; 5FU-PRO (n=18) - animais tratados sistemicamente com 5FU que receberam irrigação local com 0,6 ml de PRO; 5FURAR (n=18) - animais tratados sistemicamente com 5FU que receberam RAR e; 5FURAR-PRO (n=18) - animais tratados sistemicamente com 5FU, que receberam tratamento com RAR e irrigação local com 0,6 ml de PRO. Seis animais de cada período foram submetidos à eutanásia aos 7, 15 e 30 dias após os tratamentos. Os espécimes contendo a área interessada foram obtidos e processados para a análise histopatológica, histométrica da perda óssea alveolar (POA), porcentagem de tecido ósseo (PTO), porcentagem de osso vital (POV) e porcentagem de osso não vital (PONV), e análise imunoistoquímica (TRAP, RANKL e OPG). Os dados obtidos foram submetidos à análise estatística (α=5%). Os resultados histológicos demonstraram que nos espécimes tratados com 5FU houve agravamento da perda óssea na região de furca comparado com os animais sistemicamente saudáveis (grupos PE e SS); que o tratamento com PRO como monoterapia (grupo 5FU-PRO) promoveu redução do processo inflamatório, denotando estabilização da doença periodontal; que o tratamento com RAR (grupo 5FU-RAR) reduziu o volume do infiltrado inflamatório mostrando sinais de reparação e a associação PRO-RAR (grupo 5FU-RAR-PRO) evidenciou nítida reestruturação tecidual aos 15 dias e menor área de reabsorção óssea aos 30 dias. Observou-se na análise histométrica que a POA foi maior no grupo 5FU-PRO em relação ao grupo SS aos 30 dias (p<0,05); a PTO foi maior no grupo 5FU-RAR-PRO aos 30 dias em comparação aos grupos EP, SS, 5FU e 5FU-PRO (p<0,05) e a POV foi maior no grupo 5FU-RAR-PRO em comparação ao grupo 5FU aos 7 dias, e maior aos 30 dias em comparação a todos os grupos experimentais (p<0,05). Não houve diferença entre os grupos e períodos na imunomarcação das células TRAP positivas. A RANKL mostrou alto padrão de imunomarcação nos grupos PE, SS e 5FU em todos períodos, e aos 7 dias no grupo 5FU-PRO, 5FU-RAR e 5FURAR-PRO, moderado padrão de imunomarcação nos grupos 5FU, 5FU-PRO, 5FURAR, e 5FU-RAR-PRO, mantendo-se baixo padrão neste último grupo, no período de 30 dias. Houve baixo padrão de imunomarcação de OPG em todos os grupos e períodos, exceto no grupo 5FU-RAR-PRO que mostrou moderado padrão. Diante dos resultados obtidos pode ser concluído que o uso do quimioterápico 5FU agravou a PE; que o uso do Saccharomyces ceveriseae associado à RAR, minimizou os efeitos do quimioterápico nos tecidos periodontais reduzindo o processo inflamatório, e reduzindo a porcentagem de destruição de tecido ósseo na área de furca em animais imunossuprimidos(AU)

The present study aimed to evaluate the effects of using probiotic (PRO) Saccharomyces ceveriseae as an adjuvant of scaling and root planing (SRP) in the treatment of experimental periodontitis (EP) induced in immunosuppressed animals with chemotherapeutic 5-Fluorouracil (5FU). One hundred and eight animals were submitted to EP induction by installing a cotton thread around the lower left or right first molar. Immunosuppression was obtained by intraperitoneal injection of 5FU applied in two moments: at the time of installing the ligature and after 48 hours. Seven days after installation, the ligature was removed and the animals were randomly separated into six experimental groups that received the following treatments: EP (n = 18) - animals that did not receive any systemic or local treatment; SS (n = 18) - animals that did not receive local treatment, only systemic treatment with saline solution (SS); 5FU (n = 18) - animals treated systemically with 5FU that did not receive any local treatment; 5FUPRO (n = 18) - animals treated systemically with 5FU that received local irrigation with 0.6 ml of PRO; 5FU-SRP (n = 18) - animals treated systemically with 5FU that received RAR and; 5FU-SRP-PRO (n = 18) - animals treated systemically with 5FU, which received treatment with SRP and local irrigation with 0.6 ml of PRO. Six animals from each period were euthanized at 7, 15 and 30 days after treatments. The specimens containing the interested area were obtained and processed for histopathological, histometric analysis of alveolar bone loss (ABL), percentage of bone tissue (PBT), percentage of vital bone (PVB) and percentage of non-vital bone (PNVB), and immunohistochemical analysis (TRAP, RANKL and OPG). The data obtained were subjected to statistical analysis (α = 5%). The histological results showed that in the specimens treated with 5FU there was worsening of bone loss in the furcation region compared to healthy animals (EP and SS groups); that treatment with PRO as monotherapy (group 5FU-PRO) reduced the inflammatory process, denoting stabilization of periodontal disease; that treatment with SRP (5FU-SRP group) reduced the volume of the inflammatory infiltrate showing signs of repair and the PRO-SRP association (5FU-SRP-PRO group) showed a clear tissue restructuring at 15 days and a smaller area of bone resorption at 30 days. It was observed in the histometric analysis that ABL was higher in the 5FU-PRO group compared to SS group at 30 days (p <0.05); PTO was higher in 5FU-SRP-PRO group at 30 days compared to EP, SS, 5FU and 5FU-PRO groups (p <0.05) and PVB was higher in the 5FU-SRP-PRO group compared to 5FU group at 7 days, and greater at 30 days compared to all experimental groups (p <0.05). There was no difference between groups and periods in the immunostaining of TRAP positive cells. RANKL showed a high immunostaining pattern in the EP, SS and 5FU groups in all periods, and at 7 days in 5FU-PRO, 5FU-SRP and 5FU-SRP-PRO groups, a moderate immunostaining pattern in the 5FU, 5FU-PRO, 5FU-SRP and 5FU-SRP-PRO groups, maintaining a low standard in 5FU-SRP-PRO group, in the period of 30 days. There was a low pattern of OPG immunostaining in all groups and periods, except in 5FU-SRP-PRO group, which showed a moderate pattern. In view of the results obtained, it can be concluded that the use of 5FU chemotherapy has worsened the evolution of EP; that the use of Saccharomyces ceveriseae associated with RAR, minimized the effects of chemotherapy on periodontal tissues, reducing the inflammatory process, and reducing the percentage of bone tissue destruction in the furcation area in immunosuppressed animals(AU)

Prospective production of fructose and single cell protein from date palm waste

BACKGROUND: Fructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae. RESULTS: The effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0­5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained. CONCLUSIONS: Extension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes.

Eficácia da suplementação oral com 1, 3-1, 6 betaglucano proveniente de Saccharomyces cerevisiae no controle da mastite bovina / [Efficiency of oral supplementation of 1. 3-1. 6 beta-glucan from saccharomyces cerevisiae on the control of bovine mastitis]

A mastite bovina, uma das principais doenças do rebanho leiteiro, caracteriza-se por um processo inflamatório no úbere. A inviabilidade econômica, o impacto ambiental negativo e os resíduos antimicrobianos têm estimulado a pesquisa de outros tratamentos alternativos para a prevenção e o tratamento de doenças na bovinocultura leiteira. O betaglucano é um agente imunomodulador com potencial ação preventiva para doenças infecciosas, inclusive a mastite. Este estudo teve como objetivo avaliar a eficácia do uso do betaglucano, por meio de administração oral, em animais em lactação. Foram utilizadas 20 vacas lactantes, distribuídas em dois grupos, um controle e um tratamento, com 10 animais em cada grupo. O grupo tratamento recebeu 5g/dia, durante 60 dias, de 1,3-1,6 betaglucano isolado da parede celular de Saccharomyces cerevisiae diluído em ração após a ordenha, enquanto o grupo controle recebia somente a ração. Foram realizados os testes de California Mastitis Test (CMT), contagem de células somáticas (CCS), produção de leite e percentual de gordura e proteína no leite. Não houve diferença estatisticamente significativa entre os grupos quanto à CCS, ao CMT, à composição do leite ou produção. Não se observou, portanto, eficácia do uso do betaglucano purificado, administrado por via oral, no controle e na prevenção da mastite em vacas leiteiras, quando comparadas com o grupo controle. Atribuem-se esses resultados, principalmente, à degradação ruminal do produto testado. Sugerem-se, portanto, mais pesquisas utilizando o 1,3-1,6 betaglucano purificado de parede de S. cerevisiae por outras vias de administração, tais como intramamária e subcutânea.(AU)

Bovine mastitis, one of the main diseases of dairy herds, is characterized by an inflammatory process in the udder. The economic and environmental impacts, as well as the residues of antimicrobial drugs have stimulated the research of novel alternative treatments for the prevention and treatment of diseases in dairy production cows. The beta-glucan is an immunomodulator agent, with potential preventive action for infectious diseases, including mastitis. This study aimed to assess the effectiveness of orally administered beta-glucan in lactating cows. 20 lactating cows were used, distributed into two groups, one control and one treatment, with 10 cows in each group. The treatment group received 5g of 1.3-1.6 betaglucan daily for 60 days, isolated from the cell-wall of Saccharomyces cerevisiae diluted into a grain meal, whereas the animals in the control group received only the ration. The California Mastitis Test (CMT), Somatic Cells Counting (SCC), daily production and assessments of fat and protein content in milk were done. There was no statistically significant difference between the groups concerning subclinical mastitis detected by CMT, SCC, milk production and composition regarding protein and fat content. It was not observed, therefore, the effectiveness of the use of purified beta-glucan orally administered on the control or prevention of mastitis in dairy cows. The results are attributed to the ruminal degradation of the product tested. It is, therefore, suggested that more research should be conducted using the 1.3-1.6 beta-glucan purified from the cell wall of S. cerevisiae by other administration means and ruminal protection technologies for the isolated beta-glucan.(AU)

Enhancement of ethanol production efficiency in repeated-batch fermentation from sweet sorghum stem juice: effect of initial sugar, nitrogen and aeration

BACKGROUND: Ethanol concentration (PE), ethanol productivity (QP) and sugar consumption (SC) are important values in industrial ethanol production. In this study, initial sugar and nitrogen (urea) concentrations in sweet sorghum stem juice (SSJ) were optimized for high PE (≥10%, v/v), QP, (≥2.5 g/L·h) and SC (≥90%) by Saccharomyces cerevisiae SSJKKU01. Then, repeated-batch fermentations under normal gravity (NG) and high gravity (HG) conditions were studied. RESULTS: The initial sugar at 208 g/L and urea at 2.75 g/L were the optimum values to meet the criteria. At the initial yeast cell concentration of ~1 × 108 cells/mL, the PE, QP and SC were 97.06 g/L, 3.24 g/L·h and 95.43%, respectively. Repeated-batch fermentations showed that the ethanol production efficiency of eight successive cycles with and without aeration were not significantly different when the initial sugar of cycles 2 to 8 was under NG conditions (~140 g/L). Positive effects of aeration were observed when the initial sugar from cycle 2 was under HG conditions (180­200 g/L). The PE and QP under no aeration were consecutively lower from cycle 1 to cycle 6. Additionally, aeration affected ergosterol formation in yeast cell membrane at high ethanol concentrations, whereas trehalose content under all conditions was not different. CONCLUSION: Initial sugar, sufficient nitrogen and appropriated aeration are necessary for promoting yeast growth and ethanol fermentation. The SSJ was successfully used as an ethanol production medium for a high level of ethanol production. Aeration was not essential for repeated-batch fermentation under NG conditions, but it was beneficial under HG conditions.

In vivo phagocytosis and hematology in Astyanax altiparanae, a potential model for surrogate technology / Fagocitose in vivo e hematologia em Astyanax altiparanae, um potencial modelo para tecnologia de propagação mediada

Abstract Although the potential of surrogate propagation technology for aquaculture and conservation of Neotropical fish, the poor understanding of the host immune system may results in rejection and destruction of the donor material. Thus, it is necessary to study and to develop methods to evaluate the effects of immunosuppressive drugs employment and to evaluate the immunocompatibility between donor and receptor. Thus, the present study aimed to optimize a methodology to assess in vivo phagocytosis in Astyanax altiparanae using Saccharomyces cerevisiae and to evaluate their hematological response resultant from the inflammatory induction. To this, S. cerevisiae were labeled with Congo red and injected in the coelomic cavity of A. altiparanae at the concentration of 2.5 x 106 cells mL-1. A PBS solution and a non-injected group were kept as control. Fish blood was sampled and the phagocytic capacity and index were determined at 1, 2, 3 and 6 h post-injection (hpi). The yeast injection successfully stimulated phagocytosis, with the best result for phagocytosis assessment after 2 hpi. Moreover, it was achieved a high traceability of phagocytized and non-phagocytized yeast under optic microscopy analysis due to the Congo red labeling. The hematological profile was similar to usually observed in early infections, indicating lymphocyte migration to inflammatory site and increase in number of circulating phagocytes due to natural response to inflammatory stimulus. In conclusion, our method was efficient to assess in vivo phagocytosis in A. altiparanae and will be an important tool to evaluate the efficacy of immunosuppressive drugs in this species. Additionally, these results may serve as support for further studies in fish immunocompetence, both in laboratory and in field conditions.

Resumo Apesar do potencial apresentado pela tecnologia de propagação mediada para a aquicultura e conservação de peixes Neotropicais, o pobre entendimento do sistema imune do hospedeiro pode resultar na rejeição e destruição do material do doador. Com isso, se fazem necessários o estudo e o desenvolvimento de métodos para análise tanto dos efeitos de drogas imunossupressoras quanto para a avaliação da imunocompatibilidade entre doadores e receptores. Logo, o presente estudo teve como objetivo aperfeiçoar um método para analisar a fagocitose in vivo em Astyanax altiparanae usando Saccharomyces cerevisiae marcado e avaliar seu perfil hematológico resultante da indução inflamatória. Para isso, S. cerevisiae foram marcados com vermelho Congo e injetados na cavidade celomática dos A. altiparanae na concentração de 2,5 x 106 células.mL-1. Peixes injetados com PBS e peixes não injetados foram mantidos como controle. Sangue foi colhido e a capacidade fagocítica e o índice fagocítico foram determinados após 1, 2, 3 e 6 horas após à injeção (hpi). A injeção de levedura estimulou a fagocitose com sucesso, com o melhor resultado atingido após 2 hpi. Ainda, foi observada uma alta rastreabilidade das leveduras fagocitadas e não fagocitadas sob microscopia óptica devido à marcação com vermelho Congo. O perfil hematológico foi similar ao observado usualmente em infecções recém-induzidas, indicando migração de linfócitos ao sítio inflamatório e aumento no número de fagócitos circulantes devido à resposta natural ao estímulo inflamatório. Como conclusão, nosso método foi eficiente para analisar a fagocitose in vivo em A. altiparanae e será uma ferramenta importante para a avaliação de eficácia de drogas imunossopressoras para esta espécie. Em adição, estes resultados podem contribuir para futuros estudos em imunocompetência em peixes, tanto em âmbito laboratorial quanto a campo.

Saccharomyces cerevisiae as a probiotic agent and a possible aflatoxin B1 adsorbent in simulated fish intestinal tract conditions / Saccharomyces cerevisiae como agente probiótico e possível adsorvente de aflatoxina B1 em condições simuladas do trato intestinal de peixes

The aim of this study was to evaluate in vitro the probiotic potential and absorption of Saccharomyces cerevisiae for the aflatoxin B1 in simulated fish intestinal tract conditions. Three yeast strains were used, two from brewery: S. cerevisiae RC1 and S. cerevisiae RC3 and one from a fish farming environment: S. cerevisiae A8L2. The selected yeasts were subjected to the following in vitro tests: homologous inhibition, self-aggregation, co-aggregation, antibacterial activity, gastrointestinal conditions tolerance and adsorption of AFB1. All S. cerevisiae strains showed good capability of self-aggregation and co-aggregation with pathogenic bacteria. All yeast strains were able to survive the gastrointestinal conditions. In acidic conditions, the factors (strain vs. time) had interaction (P=0.0317), resulting in significant variation among the strains tested in the time periods analyzed. It was observed that there was also interaction (P=0.0062) in intestinal conditions, with an increased number of cells in the 12-hour period for all strains tested. In the adsorption test, the A8L2 strain was statistically more effective (P<0.005) for both AFB1 concentrations evaluated in this study (10 and 25ng/mL). Thus, it was observed that the strains of S. cerevisiae have potential probiotic and adsorbent of AFB1.(AU)

Objetivou-se, com esta pesquisa, avaliar in vitro o potencial probiótico e adsorvente de Saccharomyces cerevisiae para aflatoxina B1 em condições simuladas do trato intestinal de peixes. Foram utilizadas três cepas de leveduras, sendo duas provenientes de cervejaria: S. cerevisiae RC1 e S. cerevisiae RC3, e uma de ambiente de piscicultura: S. cerevisiae A8L2. As leveduras selecionadas foram submetidas aos seguintes testes in vitro: inibição homóloga, autoagregação, coagregação, atividade antibacteriana, viabilidade às condições gastrointestinais e adsorção de AFB1. Todas as estirpes de S. cerevisiae mostraram boa capacidade de autoagregação e coagregação com bactérias patogênicas. Todas as estirpes de levedura foram capazes de sobreviver às condições gastrointestinais. Em condições ácidas, os fatores (cepa x tempo) tiveram interação (P=0,0317), resultando em variações significativas entre as cepas testadas nos períodos de tempo analisados. Observou-se que também houve interação (P=0,0062) em condições intestinais, havendo um aumento do número de células no período de 12h para todas as cepas avaliadas. No ensaio de adsorção, a estirpe A8L2 foi a mais eficaz estatisticamente (P<0,005), para as duas concentrações de AFB1 avaliadas neste estudo (10 e 25ng. mL-1). Dessa forma, conclui-se que as cepas de Saccharomyces cerevisiae possuem potencial probiótico e adsorvente de AFB1.(AU)

Yeast culture in the diet of feedlot steers: performance, carcass traits and feeding behavior / Cultura de leveduras na dieta de novilhos confinados: desempenho, características da carcaça e comportamento ingestivo

This study aimed to evaluate the performance, apparent digestibility of diet, ingestive behavior which occurred in two moments, carcass traits, being evaluated constituent and non-carcass components, and also the effect the yeast culture could promote in the peripheral temperature of rumen, hull and body temperature. The diets consisted of a constant ratio of 50% forage (maize silage) and 50% concentrate. Thirty-six steers, ½ Angus Nelore, with average age of 11 months and average initial body weight of 339.5±10kg were used in the experiment. The inclusion of yeast culture promoted a higher daily dry matter intake (8.83 vs 9.35kg day-1) and, consequently, a better daily weight gain (1,143 vs. 1,325kg day-1) in the initial feedlot phase, with no difference in other periods. The apparent digestibility of the diet containing yeast culture was higher than the control diet (69.69 versus 68.32%, respectively), and its use did not interfere with the feeding behavior of the animals. Based on our findings, supplementation with yeast culture may bring positive results in the initial feedlot phase.(AU)

O objetivo deste estudo foi avaliar o desempenho; a digestibilidade aparente da dieta; o comportamento oral ingestivo, o qual ocorreu em dois momentos, as características de carcaça, sendo avaliados componentes integrantes e não integrantes da carcaça; bem como o efeito que a cultura de leveduras pudesse promover perante a temperatura periférica de rúmen, casco e temperatura corpórea, sendo aferida por meio da temperatura retal. As dietas foram constituídas em uma constante relação de 50% de volumoso (silagem de milho) e 50% de concentrado. Utilizaram-se no experimento 36 novilhos, ½ sangue Angus Nelore, com idade média de 11 meses e peso vivo médio inicial de 339,5 ± 10kg. O uso de cultura de leveduras promoveu maior consumo diário de matéria seca (8,83 contra 9,35 kg dia-1) e consequentemente melhor ganho de peso diário (1,143 contra 1,325kg dia-1) na fase inicial do confinamento, não havendo diferença nos demais períodos. A digestibilidade aparente da dieta que continha cultura de leveduras foi superior à da dieta controle (69,69 contra 68,32%, respectivamente), e seu uso não interferiu no comportamento ingestivo dos animais. Com base nos resultados do presente estudo, a suplementação com cultura de leveduras pode trazer resultados positivos na fase inicial de confinamento.(AU)

Fungemia following Saccharomyces cerevisiae var. boulardii probiotic treatment in an elderly patient / Fungemia posterior al tratamiento con Saccharomyces cerevisiae var. boulardii como probiótico en una paciente anosa

Abstract The yeast Saccharomyces cerevisiae var. boulardii is a biotherapeutic agent used for the prevention and treatment of several gastrointestinal diseases. We report a case of fungemia in a patient suffering from Clostridium difficile-associated diarrhea and treated with metronidazole and a probiotic containing S. cerevisiae var. boulardii. The yeasts isolated from the blood culture and capsules were identified by MALDI-TOF MS and API ID 32 C as S. cerevisiae, and showed the same appearance and color on CHROMAgar Candida. Treatment with fluconazole 400mg/day was initiated and the probiotic was stopped. The patient was discharged from hospital in good condition and was referred to a rehabilitation center. We suggest that the potential benefit of S. cerevisiae var. boulardii should be accurately evaluated, especially in elderly patients. Moreover, all physicians should be trained in the use of probiotic agents and enquire whether the use probiotics was included in the patients'medical histories. © 2019 Asociación Argentina de Microbiología. Published by Elsevier España, S.L.U. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Resumen Saccharomyces cerevisiae var. boulardii es un agente bioterapéutico usado en la prevención y el tratamiento de varias enfermedades gastrointestinales. Informamos de un caso de fungemia en una paciente con diarrea asociada a Clostridium difficile, y tratada con metron-idazol y un probiótico que contenía S. cerevisiae var. boulardii. Las levaduras aisladas a partir del hemocultivo y del contenido de las cápsulas tomadas por la paciente se identificaron como S. cerevisiae mediante MALDI-TOF MS y API® ID 32C, las colonias mostraron el mismo color y aspecto en el medio CHROMAgar™ Candida. Se instauró un tratamiento con fluconazol 400mg/día y se suspendió el probiótico. La paciente fue dada de alta del hospital en buenas condiciones, y remitida a un centro de rehabilitación. Sugerimos que el beneficio potencial del uso de S. cerevisiae var. boulardii debe ser evaluado en cada paciente, especialmente en personas añosas. El uso de probióticos debería incluirse en los interrogatorios orientados al diagnóstico y formar parte de la historia clínica. © 2019 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Disentangling the genetic bases of Saccharomyces cerevisiae nitrogen consumption and adaptation to low nitrogen environments in wine fermentation

The budding yeast Saccharomyces cerevisiae has been considered for more than 20 years as a premier model organ- ism for biological sciences, also being the main microorganism used in wide industrial applications, like alcoholic fermentation in the winemaking process. Grape juice is a challenging environment for S. cerevisiae , with nitrogen deficiencies impairing fermentation rate and yeast biomass production, causing stuck or sluggish fermentations, thus generating sizeable economic losses for wine industry. In the present review, we summarize some recent efforts in the search of causative genes that account for yeast adaptation to low nitrogen environments, specially focused in wine fermentation conditions. We start presenting a brief perspective of yeast nitrogen utilization under wine fermentative conditions, highlighting yeast preference for some nitrogen sources above others. Then, we give an outlook of S. cerevisiae genetic diversity studies, paying special attention to efforts in genome sequencing for population structure determination and presenting QTL mapping as a powerful tool for phenotype-genotype correlations. Finally, we do a recapitulation of S. cerevisiae natural diversity related to low nitrogen adaptation, specially showing how different studies have left in evidence the central role of the TORC1 signalling pathway in nitrogen utilization and positioned wild S. cerevisiae strains as a reservoir of beneficial alleles with potential industrial applications (e.g. improvement of industrial yeasts for wine production). More studies focused in disentangling the genetic bases of S. cerevisiae adaptation in wine fermentation will be key to determine the domestication effects over low nitrogen adaptation, as well as to definitely proof that wild S. cerevisiae strains have potential genetic determinants for better adaptation to low nitrogen conditions.

Bioremediation of heavy metals in food industry: application of Saccharomyces cerevisiae

Heavy metals are natural elements in the Earth's crust that can enter human food through industrial or agricultural processing, in the form of fertilizers and pesticides. These elements are not biodegradable. Some heavy metals are known as pollutants and are toxic, and their bioaccumulation in plant and animal tissues can cause undesirable effects for humans; therefore, their amount in water and food should always be under control. The aim of this study is to investigate the conditions for the bioremediation of heavy metals in foods. Various physical, chemical, and biological methods have been used to reduce the heavy metal content in the environment. During the last decades, bioremediation methods using plants and microorganisms have created interest to researchers for their advantages such as being more specific and environmentally friendly. The main pollutant elements in foods and beverages are lead, cadmium, arsenic, and mercury, which have their own permissible limits. Among the microorganisms that are capable of bioremediation of heavy metals, Saccharomyces cerevisiae is an interesting choice for its special characteristics and being safe for humans, which make it quite common and useful in the food industry. Its mass production as the byproduct of the fermentation industry and the low cost of culture media are the other advantages. The ability of this yeast to remove an individual separated element has also been widely investigated. In countries with high heavy metal pollution in wheat, the use of S. cerevisiae is a native solution for overcoming the problem of solution. This article summarizes the main conditions for heavy metal absorption by S. cerevisiae.

Effective diffusion coefficients and bioconversion rates of inhibitory compounds in flocs of Saccharomyces cerevisiae

Background: Fermentation strategies for bioethanol production that use flocculating Saccharomyces cerevisiae yeast need to account for the mechanism by which inhibitory compounds, generated in the hydrolysis of lignocellulosic materials, are tolerated and detoxified by a yeast floc. Results: Diffusion coefficients and first-order kinetic bioconversion rate coefficients were measured for three fermentation inhibitory compounds (furfural, hydroxymethylfurfural, and vanillin) in self-aggregated flocs of S. cerevisiae NRRL Y-265. Thièle-type moduli and internal effectiveness factors were obtained by simulating a simple steady-state spherical floc model. Conclusions: The obtained values for the Thiéle moduli and internal effectiveness factors showed that the bioconversion rate of the inhibitory compounds is the dominant phenomenon over mass transfer inside the flocs.

Co-production of ethanol and biodiesel from sweet sorghum juice in two consecutive fermentation steps

Background: Sugars from sweet sorghum stalks can be used to produce ethanol and also to grow oleaginous yeasts. Instead of two separate processes, in this paper we propose a different route producing ethanol and microbial oil in two consecutive fermentation steps. Results: Three yeasts were compared in the first ethanol producing step. In the second step four different oleaginous yeasts were tested. Sweet sorghum juice was first clarified and concentrated. High gravity ethanol fermentation was carried out with concentrated juice with 23.7 g/100 mL of total sugars and without added nutrients. Total sugars were 2.5 times more than the original clarified juice. One yeast gave the best overall response over the two other tested; relative high ethanol productivity, 1.44 g ethanol/L•h−1 , and 90% of sugar consumption. Aeration by flask agitation produced superior results than static flasks for all yeasts. Microbial oil production was done employing the residual liquid left after ethanol separation. The pooled residual liquid from the ethanol distillation contained 7.08 g/mL of total carbohydrates, rich in reducing sugars. Trichosporon oleaginosus and Lipomyces starkeyi produced higher dry biomass, total sugar consumption and oil productivity than the other two oleaginous yeasts tested; with values around 25 g/L, 80%, and 0.55 g oil/L•h−1 respectively. However, the biomass oil content in all yeasts was relatively low in the range of 14 to 16%. Conclusion: The two step process is viable and could be considered an integral part of a consolidated biorefinery from sweet sorghum.