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1.
J Environ Manage ; 362: 121351, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38838535

RESUMO

In this study, the growth of yeast and yeast-like fungi in the liquid digestate from vegetable wastes was investigated in order to remove nutrients and organic pollutants, and for their application as co-culture members with green microalgae. The studied yeast strains were characterized for their assimilative and enzymatic profiles as well as temperature requirements. In the first experimental stage, the growth dynamics of each strain were determined, allowing to select the best yeasts for further studies. In the subsequent stage, the ability of selectants to remove organic pollutants was assessed. Different cultivation media containing respectively 1:3, 1:1, 3:1 vol ratio of liquid digestate and the basal minimal medium were used. Among all tested yeast strains, Rhodotorula mucilaginosa DSM 70825 showed the most promising results, demonstrating the highest potential for removing organic substrates and nutrients. Depending on the medium, this strain achieved 50-80% sCOD, 45-60% tVFAs, 21-45% TN, 33-52% PO43- reduction rates. Similar results were obtained for the strain Candida sp. OR687571. The high nutrient and organics removal efficiency by these yeasts could likely be linked to their ability to assimilate xylose (being the main source of carbon in the liquid digestate). In culture media containing liquid digestate, both yeast strains achieved good viability and proliferation potential. In the liquid digestate medium, R. mucilaginosa and Candida sp. showed vitality at the level of 51.5% and 45.0%, respectively. These strains seem to be a good starting material for developing effective digestate treatment strategies involving monocultures and/or consortia with other yeasts or green microalgae.


Assuntos
Técnicas de Cocultura , Microalgas , Leveduras , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Leveduras/metabolismo , Leveduras/crescimento & desenvolvimento , Rhodotorula/metabolismo , Rhodotorula/crescimento & desenvolvimento , Nutrientes/metabolismo , Biodegradação Ambiental , Candida/crescimento & desenvolvimento , Candida/metabolismo
3.
J Agric Food Chem ; 72(21): 11871-11884, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38744727

RESUMO

Genome editing is a crucial technology for obtaining desired phenotypes in a variety of species, ranging from microbes to plants, animals, and humans. With the advent of CRISPR-Cas technology, it has become possible to edit the intended sequence by modifying the target recognition sequence in guide RNA (gRNA). By expressing multiple gRNAs simultaneously, it is possible to edit multiple targets at the same time, allowing for the simultaneous introduction of various functions into the cell. This can significantly reduce the time and cost of obtaining engineered microbial strains for specific traits. In this review, we investigate the resolution of multiplex genome editing and its application in engineering microorganisms, including bacteria and yeast. Furthermore, we examine how recent advancements in artificial intelligence technology could assist in microbial genome editing and engineering. Based on these insights, we present our perspectives on the future evolution and potential impact of multiplex genome editing technologies in the agriculture and food industry.


Assuntos
Bactérias , Sistemas CRISPR-Cas , Edição de Genes , Edição de Genes/métodos , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Leveduras/genética , Leveduras/metabolismo
4.
Environ Pollut ; 351: 124106, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38705445

RESUMO

Polyethylene terephthalate is a widely produced plastic polymer that exhibits considerable biodegradation resistance, making its derived microplastics ubiquitous environmental pollutants. In this study, a new yeast strain (Vanrija sp. SlgEBL5) was isolated and found to have lipase and esterase-positive capabilities for degrading polyethylene terephthalate microplastics. This isolate changed the microplastic surface charge from -19.3 to +31.0 mV and reduced more than 150 µm of its size in addition to reducing the intensity of the terephthalate, methylene, and ester bond functional groups of the polymer in 30 days. Tween 20 as a chemical auxiliary treatment combined with biodegradation increased the microplastic degradation rate from 10 to 16.6% and the thermal degradation rate from 85 to 89%. Releasing less potentially hazardous by-products like 1,2 diethyl-benzene despite the higher abundance of long-chain n-alkanes, including octadecane and tetracosane was also the result of the bio + chemical treatment. Altogether, the findings showed that Vanrija sp. SlgEBL5 has the potential as a biological treating agent for polyethylene terephthalate microplastics, and the simultaneous bio + chemical treatment enhanced the biodegradation rate and efficiency.


Assuntos
Biodegradação Ambiental , Microplásticos , Polietilenotereftalatos , Polissorbatos , Polietilenotereftalatos/metabolismo , Polietilenotereftalatos/química , Microplásticos/metabolismo , Polissorbatos/química , Leveduras/metabolismo
5.
J Cell Mol Med ; 28(10): e18343, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38760903

RESUMO

Fermented foods play a significant role in the human diet for their natural, highly nutritious and healthy attributes. Our aim was to study the effect of yeast extract, a fermented substance extracted from natural yeast, on colonic motility to better understand its potential therapeutic role. A yeast extract was given to rats by gavage for 3 days, and myogenic and neurogenic components of colonic motility were studied using spatiotemporal maps made from video recordings of the whole colon ex vivo. A control group received saline gavages. The yeast extract caused excitation of the musculature by increasing the propagation length and duration of long-distance contractions, the major propulsive activity of the rat colon. The yeast extract also evoked rhythmic propulsive motor complexes (RPMCs) which were antegrade in the proximal and mid-colon and retrograde in the distal colon. RPMC activity was evoked by distention-induced neural activity, but it was myogenic in nature since we showed it to be generated by bethanechol in the presence of tetrodotoxin. In conclusion, ingestion of yeast extract stimulates rat colon motility by exciting neurogenic and myogenic control mechanisms.


Assuntos
Colo , Motilidade Gastrointestinal , Animais , Colo/efeitos dos fármacos , Colo/fisiologia , Motilidade Gastrointestinal/efeitos dos fármacos , Ratos , Masculino , Leveduras , Ratos Sprague-Dawley , Tetrodotoxina/farmacologia
6.
Food Res Int ; 187: 114366, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38763646

RESUMO

In recent years, numerous studies have demonstrated the significant potential of non-Saccharomyces yeasts in aroma generation during fermentation. In this study, 134 strains of yeast were isolated from traditional fermented foods. Subsequently, through primary and tertiary screening, 28 strains of aroma-producing non-Saccharomyces yeast were selected for beer brewing. Headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and chemometrics were employed to analyze the volatile flavor substances in beer samples fermented using these strains. Chemometric analysis revealed that distinct species of non-Saccharomyces yeast had a unique influence on beer aroma, with strains from the same genus producing more similar flavor profiles. Accordingly, 2,6-nonadienal, 1-pentanol, phenyl ethanol, isoamyl acetate, ethyl caprate, butyl butyrate, ethyl propionate, furfuryl alcohol, phenethyl acetate, ethyl butyrate, ethyl laurate, acetic acid, and 3-methyl-4 heptanone were identified as the key aroma compounds for distinguishing among different non-Saccharomyces yeast species. This work provides useful insights into the aroma-producing characteristics of different non-Saccharomyces yeasts to reference the targeted improvement of beer aroma.


Assuntos
Cerveja , Fermentação , Alimentos Fermentados , Cromatografia Gasosa-Espectrometria de Massas , Odorantes , Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Leveduras , Cerveja/análise , Cerveja/microbiologia , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Alimentos Fermentados/microbiologia , Alimentos Fermentados/análise , Leveduras/isolamento & purificação , Leveduras/metabolismo , Microbiologia de Alimentos
7.
Microb Pathog ; 192: 106691, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38759933

RESUMO

Necrotic enteritis (NE) is a potentially fatal poultry disease that causes enormous economic losses in the poultry industry worldwide. The study aimed to evaluate the effects of dietary organic yeast-derived selenium (Se) on immune protection against experimental necrotic enteritis (NE) in commercial broilers. Chickens were fed basal diets supplemented with different Se levels (0.25, 0.50, and 1.00 Se mg/kg). To induce NE, Clostridium perfringens (C. perfringens) was orally administered at 14 days of age post hatch. The results showed that birds fed 0.25 Se mg/kg exhibited significantly increased body weight gain compared with the non-supplemented/infected birds. There were no significant differences in gut lesions between the Se-supplemented groups and the non-supplemented group. The antibody levels against α-toxin and NetB toxin increased with the increase between 0.25 Se mg/kg and 0.50 Se mg/kg. In the jejunal scrapings and spleen, the Se-supplementation groups up-regulated the transcripts for pro-inflammatory cytokines IL-1ß, IL-6, IL-8, iNOS, and LITAF and avian ß-defensin 6, 8, and 13 (AvBD6, 8 and 13). In conclusion, supplementation with organic yeast-derived Se alleviates the negative consequences and provides beneficial protection against experimental NE.


Assuntos
Ração Animal , Galinhas , Infecções por Clostridium , Clostridium perfringens , Citocinas , Suplementos Nutricionais , Enterite , Doenças das Aves Domésticas , Selênio , Animais , Enterite/prevenção & controle , Enterite/veterinária , Enterite/imunologia , Enterite/microbiologia , Selênio/farmacologia , Selênio/administração & dosagem , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/imunologia , Clostridium perfringens/imunologia , Infecções por Clostridium/prevenção & controle , Infecções por Clostridium/veterinária , Infecções por Clostridium/imunologia , Citocinas/metabolismo , Toxinas Bacterianas/imunologia , Necrose , beta-Defensinas/metabolismo , Jejuno/efeitos dos fármacos , Jejuno/imunologia , Jejuno/microbiologia , Jejuno/patologia , Baço/imunologia , Leveduras , Óxido Nítrico Sintase Tipo II/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Interleucina-1beta/metabolismo , Anticorpos Antibacterianos/sangue
8.
J Am Soc Mass Spectrom ; 35(6): 1352-1362, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38742647

RESUMO

Mass spectrometry is commonly used in the identification of species present in microbial samples, but the high similarity in the peptide composition between strains of a single species has made analysis at the subspecies level challenging. Prior research in this area has employed methods such as Principal Component Analysis (PCA), the k-Nearest Neighbors' (kNN) algorithm, and Pearson correlation. Previously, 1D cross-correlation of mass spectra has been shown to be useful in the classification of small molecule compounds as well as in the identification of peptide sequences via the SEQUEST algorithm and its variants. While direct application of cross-correlation to mass spectral data has been shown to aid in the identification of many other types of compounds, this type of analysis has not been demonstrated in the literature for the purpose of LC-MS based identification of microbial strains. A method of identifying microbial strains is presented here that applies the principle of 2D cross-correlation to LC-MS data. For a set of N = 30 yeast isolate samples representing 5 yeast strains (K-97, S-33, T-58, US-05, WB-06), high-resolution LC-MS-Orbitrap data were collected. Reference spectra were then generated for each strain from the combined data of each sample of that strain. Sample strains were then predicted by computing the 2D cross-correlation of each sample against the reference spectra, followed by application of correction factors measuring the asymmetry of the 2D correlation functions.


Assuntos
Algoritmos , Espectrometria de Massas , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Leveduras/química , Leveduras/classificação , Leveduras/isolamento & purificação , Espectrometria de Massa com Cromatografia Líquida
9.
Food Chem ; 452: 139480, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38703738

RESUMO

This study aimed to investigate the correlation between the composition of volatile compounds, consumer acceptance, and drivers of (dis)liking of Protaetia brevitarsis larvae fermented using lactic acid bacteria and yeast. Volatile compounds were analyzed using HS-SPME-Arrow-GC-MS, and a sensory evaluation was conducted with 72 consumers. A total of 113 volatile compounds were detected, and principal component analysis indicated that the samples could be divided into three groups. The calculated relative odor activity values (ROAV) revealed the presence of 27 compounds (ROAV >1). Volatile compounds with high ROAV were predominantly found during yeast fermentation. The sensory evaluation results indicated a strong correlation between low levels of off-odor intensity and high odor liking, emphasizing that odor profile had a more direct association with consumer acceptance than odor intensity. These findings suggest that yeast fermentation using volatile compounds, which positively influences consumer acceptance, is appropriate for Protaetia brevitarsis larvae.


Assuntos
Fermentação , Lactobacillales , Larva , Odorantes , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/química , Animais , Larva/metabolismo , Larva/crescimento & desenvolvimento , Larva/microbiologia , Humanos , Odorantes/análise , Lactobacillales/metabolismo , Feminino , Paladar , Masculino , Saccharomyces cerevisiae/metabolismo , Leveduras/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Adulto , Comportamento do Consumidor
10.
J Photochem Photobiol B ; 256: 112945, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795655

RESUMO

In this study, for the first time, red LED light radiation was applied to the fermentation process of table olives using the Negrinha de Freixo variety. Photostimulation using LED light emission (630 ± 10 nm) is proposed to shorten and speed up this stage and reduce time to market. Several physical-chemical characteristics and microorganisms (total microbial count of mesophilic aerobic, molds, yeasts, and lactic acid bacteria) and their sequence during fermentation were monitored. The fermentation occurred for 122 days, with two irradiation periods for red LED light. The nutritional composition and sensory analysis were performed at the end of the process. Fermentation under red LED light increased the viable yeast and lactic acid bacteria (LAB) cell counts and decreased the total phenolics in olives. Even though significant differences were observed in some color parameters, the hue values were of the same order of magnitude and similar for both samples. Furthermore, the red LED light did not play a relevant change in the texture profile, preventing the softening of the fruit pulp. Similarly, LED light did not modify the existing type of microflora but increased species abundance, resulting in desirable properties and activities. The species identified were yeasts - Candida boidinii, Pichia membranifaciens, and Saccharomyces cerevisiae, and bacteria - Lactobacillus plantarum and Leuconostoc mesenteroides, being the fermentative process dominated by S. cerevisiae and L. plantarum. At the end of fermentation (122 days), the irradiated olives showed less bitterness and acidity, higher hardness, and lower negative sensory attributes than non-irradiated. Thus, the results of this study indicate that red LED light application can be an innovative technology for table olives production.


Assuntos
Fermentação , Luz , Olea , Olea/microbiologia , Olea/efeitos da radiação , Leveduras/efeitos da radiação , Leveduras/metabolismo , Fenóis/metabolismo , Fenóis/química , Fenóis/análise , Frutas/efeitos da radiação , Frutas/microbiologia , Microbiologia de Alimentos
11.
FEMS Microbiol Lett ; 3712024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38782713

RESUMO

Recent research has shown the potential of yeast-based biosensors (YBBs) for point-of-use detection of pathogens and target molecules in saliva, blood, and urine samples. The choice of output can greatly affect the sensitivity, dynamic range, detection time, and ease-of-use of a sensor. For visual detection without the need for additional reagents or machinery, colorimetric outputs have shown great potential. Here, we evaluated the inducible generation of prodeoxyviolacein and proviolacein as colorimetric YBB outputs and benchmarked these against lycopene. The outputs were induced via the yeast mating pathway and were compared on agar plates, in liquid culture, and on paper slips. We found that all three outputs produced comparable pigment intensity on agar plates, making them applicable for bioengineering settings. In liquid media and on paper slips, lycopene resulted in a higher intensity pigment and a decreased time-of-detection.


Assuntos
Técnicas Biossensoriais , Colorimetria , Saccharomyces cerevisiae , Técnicas Biossensoriais/métodos , Colorimetria/métodos , Saccharomyces cerevisiae/metabolismo , Licopeno/metabolismo , Leveduras/isolamento & purificação , Leveduras/metabolismo , Carotenoides/análise , Carotenoides/metabolismo , Sistemas Automatizados de Assistência Junto ao Leito
12.
Vitae (Medellín) ; 31(1): 1-11, 2024-05-03. Ilustraciones
Artigo em Inglês | LILACS, COLNAL | ID: biblio-1553606

RESUMO

Background: Mild Colombian coffees are recognized worldwide for their high-quality coffee cup. However, there have been some failures in post-harvest practices, such as coffee grain fermentation. These failures could occasionally lead to defects and inconsistencies in quality products and economic losses for coffee farmers. In Colombia, one of the fermentation methods most used by coffee growers is wet fermentation, conducted by submerging the de-pulped coffee beans for enough time in water tanks to remove the mucilage. Objectives: We evaluated the effect of the water (g)/de-pulped coffee (g) ratio (I: 0/25, II: 10/25, III: 20/25) and final fermentation time (24, 48, and 72 hours) on the total number of microbial groups. We also identified microorganisms of interest as starter cultures. Methods: We used a completely randomized experimental design with two factors; the effect of the water (g)/de-pulped coffee (g) ratio (I: 0/25, II: 10/25, III: 20/25) and final fermentation time (24, 48, and 72 hours), for 9 treatments with two replicates. During the coffee fermentation (1,950 g), the pH and °Brix were monitored. Total counts of different microbial groups (mesophiles, coliforms, lactic-acid bacteria, acetic-acid bacteria, and yeasts) were performed. Various isolates of microorganisms of interest as starter cultures (lactic-acid bacteria and yeasts) were identified using molecular sequencing techniques. Results: 21 lactic-acid bacteria (LAB) isolates and 22 yeasts were obtained from the different mini-batch fermentation systems. The most abundant lactic-acid bacteria species found were Lactiplantibacillus plantarum (46%) and Levilactobacillus brevis (31%). Pichia kluivery (39%) and Torulaspora delbrueckii (22%) were the most abundant yeast species. Conclusion The studied factors did not have effect over the microorganism's development. The identified bacterial and yeasts species have potential as starter cultures for better-quality coffees and in fermentation-related applications.


Antecedentes: Los cafés suaves lavados colombianos son reconocidos a nivel mundial por su buena puntuación sensorial; sin embargo, se han detectado fallas en las prácticas de postcosecha, como lo es la fermentación de los granos de café. Dichas fallas pueden causar defectos y carecer de consistencia en la calidad del producto, ocasionando pérdidas económicas para los caficultores. En Colombia, uno de los métodos más usados por los caficultores es la fermentación húmeda, la cual consiste en sumergir los granos de café despulpado en tanques con agua por un período de tiempo que permita la remoción del mucílago. Objetivos: La presente investigación evaluó la incidencia que tienen la proporción agua/granos despulpados de café (I: 0/25, II: 10/25, III: 20/25) y el tiempo final de fermentación (24, 48 y 72 horas) en el recuento final de grupos microbianos. Por otra parte, se identificaron taxonómicamente microorganismos de interés para su uso como cultivos iniciadores. Métodos: Mini-lotes consistieron en café despulpado (1950 g) puesto en recipientes de plástico abiertos y sumergidos en agua. Se aplicó un diseño experimental completamente aleatorizado de dos factores (proporción agua/ granos de café despulpado y tiempo) a tres niveles, para un total de nueve tratamientos con dos replicas. Durante las fermentaciones de café (1,950 g), el pH y los grados ºBrix, fueron monitoreados. Se realizaron los recuentos totales de los diferentes grupos microbianos: mesófilos, coliformes, bacterias ácido-lácticas, bacterias ácido-acéticas y levaduras. Se identificaron molecularmente diferentes aislados con potencial para ser usados como cultivos iniciadores (bacterias ácido-lácticas y levaduras). Resultados: Los resultados obtenidos mostraron que no hubo diferencia estádisticamente significativa entre los tratamientos aplicados y el recuento final de microorganismos. Un total de 21 aislados de bacterias ácido-lácticas (BAL) y 22 levaduras lograron obtenerse a partir de los diferentes sistemas de fermentación en mini-lote. Las especies de bacterias ácido-lácticas con mayor porcentaje acorde a su identificación taxonómica, corresponden a Lactiplantibacillus plantarum (46%), Levilactobacillus brevis (31%). Las especies de levaduras con mayor porcentaje acorde a su identificación taxonómica corresponden a Pichia kluivery (39%) y Torulaspora delbrueckii (22%). Conclusión Los factores estudiados no afectaron el crecimiento de ninguno de los grupos microbianos presentes en la fermentacion del café. Las especies de microorganismos identificados tienen potencial para se usados como cultivos starter o en aplicaciones dentro de las ciencias de fermentación.


Assuntos
Humanos , Fermentação , Leveduras , Técnicas Microbiológicas , Coffea , Lactobacillales
13.
Compr Rev Food Sci Food Saf ; 23(3): e13362, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38720585

RESUMO

Fermentation is a traditional method utilized for vegetable preservation, with microorganisms playing a crucial role in the process. Nowadays, traditional spontaneous fermentation methods are widely employed, which excessively depend on the microorganisms attached to the surface of raw materials, resulting in great difficulties in ideal control over the fermentation process. To achieve standardized production and improve product quality, it is essential to promote inoculated fermentation. In this way, starter cultures can dominate the fermentation processes successfully. Unfortunately, inoculated fermentation has not been thoroughly studied and applied. Therefore, this paper provides a systematic review of the potential upgrading strategy of vegetable fermentation technology. First, we disclose the microbial community structures and succession rules in some typical spontaneously fermented vegetables to comprehend the microbial fermentation processes well. Then, internal and external factors affecting microorganisms are explored to provide references for the selection of fermented materials and conditions. Besides, we widely summarize the potential starter candidates with various characteristics isolated from spontaneously fermented products. Subsequently, we exhibited the inoculated fermentation strategies with those isolations. To optimize the product quality, not only lactic acid bacteria that lead the fermentation, but also yeasts that contribute to aroma formation should be combined for inoculation. The inoculation order of the starter cultures also affects the microbial fermentation. It is equally important to choose a proper processing method to guarantee the activity and convenience of starter cultures. Only in this way can we achieve the transition from traditional spontaneous fermentation to modern inoculated fermentation.


Assuntos
Fermentação , Verduras , Bactérias , Alimentos Fermentados/microbiologia , Microbiologia de Alimentos/métodos , Microbiota , Verduras/microbiologia , Leveduras
14.
Biosensors (Basel) ; 14(5)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38785692

RESUMO

This study presents a biosensor fabricated based on integrated passive device (IPD) technology to measure microbial growth on solid media in real-time. Yeast (Pichia pastoris, strain GS115) is used as a model organism to demonstrate biosensor performance. The biosensor comprises an interdigital capacitor in the center with a helical inductive structure surrounding it. Additionally, 12 air bridges are added to the capacitor to increase the strength of the electric field radiated by the biosensor at the same height. Feasibility is verified by using a capacitive biosensor, and the change in capacitance values during the capacitance detection process with the growth of yeast indicates that the growth of yeast can induce changes in electrical parameters. The proposed IPD-based biosensor is used to measure yeast drop-added on a 3 mm medium for 100 h at an operating frequency of 1.84 GHz. The resonant amplitude of the biosensor varies continuously from 24 to 72 h due to the change in colony height during vertical growth of the yeast, with a maximum change of 0.21 dB. The overall measurement results also fit well with the Gompertz curve. The change in resonant amplitude between 24 and 72 h is then analyzed and reveals a linear relationship with time with a coefficient of determination of 0.9844, indicating that the biosensor is suitable for monitoring yeast growth. Thus, the proposed biosensor is proved to have potential in the field of microbial proliferation detection.


Assuntos
Técnicas Biossensoriais , Leveduras/crescimento & desenvolvimento
15.
Environ Microbiol Rep ; 16(3): e13213, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38738810

RESUMO

Since a significant proportion of plant matter is consumed by herbivores, a necessary adaptation for many phyllosphere microbes could be to survive through the guts of herbivores. While many studies explore the gut microbiome of herbivores by surveying the microbiome in their frass, few studies compare the phyllosphere microbiome to the gut microbiome of herbivores. High-throughput metabarcode sequencing was used to track the fungal community from milkweed (Asclepias spp.) leaves to monarch caterpillar frass. The most commonly identified fungal taxa that dominated the caterpillar frass after the consumption of leaves were yeasts, mostly belonging to the Basidiomycota phylum. While most fungal communities underwent significant bottlenecks and some yeast taxa increased in relative abundance, a consistent directional change in community structure was not identified from leaf to caterpillar frass. These results suggest that some phyllosphere fungi, especially diverse yeasts, can survive herbivory, but whether herbivory is a key stage of their life cycle remains uncertain. For exploring phyllosphere fungi and the potential coprophilous lifestyles of endophytic and epiphytic fungi, methods that target yeast and Basidiomycota fungi are recommended.


Assuntos
Asclepias , Fungos , Herbivoria , Folhas de Planta , Animais , Folhas de Planta/microbiologia , Asclepias/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/fisiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Micobioma , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/fisiologia , Basidiomycota/isolamento & purificação , Microbioma Gastrointestinal , Larva/microbiologia , Mariposas/microbiologia
16.
BMC Microbiol ; 24(1): 163, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745280

RESUMO

Spontaneous fermentation of cereals like millet involves a diverse population of microbes from various sources, including raw materials, processing equipment, fermenting receptacles, and the environment. Here, we present data on the predominant microbial species and their succession at each stage of the Hausa koko production process from five regions of Ghana. The isolates were enumerated using selective media, purified, and phenotypically characterised. The LAB isolates were further characterised by 16S rRNA Sanger sequencing, typed using (GTG)5 repetitive-PCR, and whole genome sequencing, while 28S rRNA Sanger sequencing was performed for yeast identification. The pH of the millet grains ranged from mean values of 6.02-6.53 to 3.51-3.99 in the final product, depending on the processors. The mean LAB and yeast counts increased during fermentation then fell to final counts of log 2.77-3.95 CFU/g for LAB and log 2.10-2.98 CFU/g for yeast in Hausa koko samples. At the various processing stages, the counts of LAB and yeast revealed significant variations (p < 0.0001). The species of LAB identified in this study were Limosilactobacillus pontis, Pediococcus acidilactici, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Schleiferilactobacillus harbinensis, and Weissella confusa. The yeasts were Saccharomyces cf. cerevisiae/paradoxus, Saccharomyces cerevisiae, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis. The identification and sequencing of these novel isolates and how they change during the fermentation process will pave the way for future controlled fermentation, safer starter cultures, and identifying optimal stages for starter culture addition or nutritional interventions. These LAB and yeast species are linked to many indigenous African fermented foods, potentially acting as probiotics in some cases. This result serves as the basis for further studies into the technological and probiotic potential of these Hausa koko microorganisms.


Assuntos
Fermentação , Alimentos Fermentados , Microbiologia de Alimentos , Milhetes , Leveduras , Gana , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Leveduras/metabolismo , Alimentos Fermentados/microbiologia , Milhetes/microbiologia , Lactobacillales/classificação , Lactobacillales/isolamento & purificação , Lactobacillales/genética , Lactobacillales/metabolismo , RNA Ribossômico 16S/genética , Filogenia , Concentração de Íons de Hidrogênio , Grão Comestível/microbiologia
17.
Plant Foods Hum Nutr ; 79(2): 251-259, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38602651

RESUMO

Kombucha is a unique fermented beverage made from a symbiotic culture of yeast and bacteria. Kombucha is normally based on black tea added to water, then sugar is added as a substrate for fermentation in this beverage. This unique beverage is composed of amino acids, flavonoids, vitamins, and some active enzymes. Several beneficial health effects such as antioxidant, antimicrobial effects have been reported as a result of probiotics and prebiotics presence. These health effects of kombucha are attributed to its bioactive chemical and biological agents of probiotics bacteria e.g., Gluconobacter, Acetobacter and yeasts like Saccharomyces sps., along with glucuronic acid as the main sources of the health protection. This review focuses on the beneficial effects of Kombucha including antimicrobial, antioxidant, anti-cancer antidiabetic properties, as well as liver protection, treat of gastrointestinal problems, AIDS, gastric ulcers, obesity (and energy production), detoxification, and skin health.


Assuntos
Antioxidantes , Fermentação , Chá de Kombucha , Humanos , Antioxidantes/farmacologia , Prebióticos , Probióticos , Anti-Infecciosos/farmacologia , Hipoglicemiantes/farmacologia , Leveduras , Chá , Bebidas
18.
Braz J Microbiol ; 55(2): 1451-1463, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38656427

RESUMO

Antarctic temperature variations and long periods of freezing shaped the evolution of microorganisms with unique survival mechanisms. These resilient organisms exhibit several adaptations for life in extreme cold. In such ecosystems, microorganisms endure the absence of liquid water and exhibit resistance to freezing by producing water-binding molecules such as antifreeze proteins (AFP). AFPs modify the ice structure, lower the freezing point, and inhibit recrystallization. The objective of this study was to select and identify microorganisms isolated from different Antarctic ecosystems based on their resistance to temperatures below 0 °C. Furthermore, the study sought to characterize these microorganisms regarding their potential antifreeze adaptive mechanisms. Samples of soil, moss, permafrost, and marine sediment were collected on King George Island, located in the South Shetland archipelago, Antarctica. Bacteria and yeasts were isolated and subjected to freezing-resistance and ice recrystallization inhibition (IR) tests. A total of 215 microorganisms were isolated, out of which 118 were molecularly identified through molecular analysis using the 16S rRNA and ITS regions. Furthermore, our study identified 24 freezing-resistant isolates, including two yeasts and 22 bacteria. A total of 131 protein extracts were subjected to the IR test, revealing 14 isolates positive for AFP production. Finally, four isolates showed both freeze-resistance and IR activity (Arthrobacter sp. BGS04, Pseudomonas sp. BGS05, Cryobacterium sp. P64, and Acinetobacter sp. M1_25C). This study emphasizes the diversity of Antarctic microorganisms with the ability to tolerate freezing conditions. These microorganisms warrant further investigation to conduct a comprehensive analysis of their antifreeze capabilities, with the goal of exploring their potential for future biotechnological applications.


Assuntos
Proteínas Anticongelantes , Bactérias , Congelamento , Regiões Antárticas , Proteínas Anticongelantes/metabolismo , Proteínas Anticongelantes/química , Proteínas Anticongelantes/genética , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Bactérias/isolamento & purificação , Ilhas , Filogenia , Leveduras/genética , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/metabolismo , RNA Ribossômico 16S/genética , Ecossistema
19.
Microb Cell Fact ; 23(1): 111, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622625

RESUMO

BACKGROUND: Ascomycetous budding yeasts are ubiquitous environmental microorganisms important in food production and medicine. Due to recent intensive genomic research, the taxonomy of yeast is becoming more organized based on the identification of monophyletic taxa. This includes genera important to humans, such as Kazachstania. Until now, Kazachstania humilis (previously Candida humilis) was regarded as a sourdough-specific yeast. In addition, any antibacterial activity has not been associated with this species. RESULTS: Previously, we isolated a yeast strain that impaired bio-hydrogen production in a dark fermentation bioreactor and inhibited the growth of Gram-positive and Gram-negative bacteria. Here, using next generation sequencing technologies, we sequenced the genome of this strain named K. humilis MAW1. This is the first genome of a K. humilis isolate not originating from a fermented food. We used novel phylogenetic approach employing the 18 S-ITS-D1-D2 region to show the placement of the K. humilis MAW1 among other members of the Kazachstania genus. This strain was examined by global phenotypic profiling, including carbon sources utilized and the influence of stress conditions on growth. Using the well-recognized bacterial model Escherichia coli AB1157, we show that K. humilis MAW1 cultivated in an acidic medium inhibits bacterial growth by the disturbance of cell division, manifested by filament formation. To gain a greater understanding of the inhibitory effect of K. humilis MAW1, we selected 23 yeast proteins with recognized toxic activity against bacteria and used them for Blast searches of the K. humilis MAW1 genome assembly. The resulting panel of genes present in the K. humilis MAW1 genome included those encoding the 1,3-ß-glucan glycosidase and the 1,3-ß-glucan synthesis inhibitor that might disturb the bacterial cell envelope structures. CONCLUSIONS: We characterized a non-sourdough-derived strain of K. humilis, including its genome sequence and physiological aspects. The MAW1, together with other K. humilis strains, shows the new organization of the mating-type locus. The revealed here pH-dependent ability to inhibit bacterial growth has not been previously recognized in this species. Our study contributes to the building of genome sequence-based classification systems; better understanding of K.humilis as a cell factory in fermentation processes and exploring bacteria-yeast interactions in microbial communities.


Assuntos
Antibacterianos , Saccharomycetales , Humanos , Filogenia , Antibacterianos/metabolismo , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Saccharomycetales/genética , Leveduras/metabolismo , Fermentação
20.
Int J Food Microbiol ; 417: 110688, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38615425

RESUMO

Taggiasca table olives are typical of Liguria, a Northwestern Italian region, produced with a spontaneous fermentation carried out by placing the raw drupes directly into brine with a salt concentration of 8-12 % w/v. Such concentrations limit the development of unwanted microbes and favor the growth of yeasts. This process usually lasts up to 8 months. Yeasts are found throughout the entire fermentation process and they are mainly involved in the production of volatile organic compounds, which strongly impact the quality of the final product. The aim of this study was to evaluate the dynamics of autochthonous yeasts in brines and olives in a spontaneous process with no lye pre-treatment or addition of acids in the fermenting brine with 10 % NaCl (w/v) in two batches during 2021 harvest. Three hundred seventy-three yeast colonies were isolated, characterized by rep-PCR and identified by the D1/D2 region of the 26S rRNA gene sequencing. Mycobiota was also studied by 26S rRNA gene metataxonomics, while metabolome was assessed through GC-MS analysis. Traditional culture-dependent methods showed the dominance of Candida diddensiae, Wickerhamomyces anomalus, Pichia membranifaciens and Aureobasidium pullulans, with differences in species distribution between batches, sampling time and type of sample (olives/brines). Amplicon-based sequencing confirmed the dominance of W. anomalus in batch 1 throughout the entire fermentation, while Cyteromyces nyonsensis and Aureobasidium spp. were most abundant in the fermentation in batch 2. Volatilome results were analyzed and correlated to the mycobiota data, confirming differences between fermentation stages. Given the high appreciation for this traditional food, this study helps elucidate the mycobiota associated to Taggiasca cv. table olives and its relationship with the quality of the final product.


Assuntos
Fermentação , Microbiologia de Alimentos , Olea , Compostos Orgânicos Voláteis , Leveduras , Olea/microbiologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo , Leveduras/metabolismo , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Itália , Sais
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