Evaluation of mango residues to produce hyaluronic acid by Streptococcus zooepidemicus.

Mango processing generates significant amounts of residues (35-65%) that may represent environmental problems owed to improper disposal. The use of mango byproducts as substrates to produce hyaluronic acid (HA) is an attractive alternative to reduce the cost of substrate. In this study, we evaluated the potential of hydrolyzates from mango peels and seeds to produce HA by Streptococcus equi. subsp. zooepidemicus. The physicochemical characterization of mango residues showed that the seeds contain a higher amount of holocellulose (cellulose and hemicellulose), which amounts 54.2% (w/w) whereas it only represents 15.5% (w/w) in the peels. Mango peels, however, are composed mainly of hot water-extractives (62% w/w, that include sucrose, fructose, glucose and organic acids). A higher concentration of monosaccharides (39.8 g/L) was obtained from the enzymatic hydrolysis (with Macerex) of peels as compared to seeds (24.8 g/L with Celuzyme). From mango peels, hydrolyzates were obtained 0.6 g/L HA, while 0.9 g/L HA were obtained with hydrolyzates from mango seeds. These results demonstrate that mango byproducts have the potential to be used for production of HA.

Metabolomic Profiling of Phloem Sap from Different Pine Species and Implications on Black Capuchin.

In most commercial pine farms in southern Brazil, black capuchin causes damage to wood and financial losses when it removes bark from some pine species to feed upon underlying vascular tissues. Therefore, this study aimed to evaluate the variability of the primary metabolites of phloem saps from 10 different species of pine by NMR spectroscopy, as well as the aroma compounds using SPME-GC-MS. Each technique provided a different set of metabolites that we can correlate to monkey predilection. The PCA showed monosaccharide (detected by NMR) and α-pinene (pine-like and resinous flavor descriptors) as attractive compounds for monkeys. On the other hand, the low content of monosaccharide and the high content of ß-phellandrene (citrus odor descriptor) was observed in less attacked pine species (P. patula). The data fusion on primary metabolites and aroma compounds corroborated the individual analyses, complementing the comprehension of the monkey predilection. Thus, P. elliottii was an avoided tree even with high content of sugars possibly due to its high content of ß-phellandrene (citrus odor). The results are useful for further behavioral studies to determine the role that each highlighted metabolite plays in chemically mediated animal-plant interactions.

A novel mechanism of ß-glucosidase stimulation through a monosaccharide binding-induced conformational change.

It is urgent the transition from a fossil fuel-based economy to a sustainable bioeconomy based on bioconversion technologies using renewable plant biomass feedstocks to produce high chemicals, bioplastics, and biofuels. ß-Glucosidases are key enzymes responsible for degrading the plant cell wall polymers, as they cleave glucan-based oligo- and polysaccharides to generate glucose. Monosaccharide-tolerant or -stimulated ß-glucosidases have been reported in the past decade. Here, we describe a novel mechanism of ß-glucosidase stimulation by glucose and xylose. The glycoside hydrolase 1 family ß-glucosidase from Thermotoga petrophila (TpBgl1) displays a typical glucose stimulation mechanism based on an increased Vmax and decreased Km in response to glucose. Through molecular docking and dynamics analyses, we mapped putative monosaccharide binding regions (BRs) on the surface of TpBgl1. Our results indicate that after interaction with glucose or xylose at BR1 site, an adjacent loop region assumes an extended conformation, which increases the entrance to the TpBgl1 active site, improving product formation. Biochemical assays with TpBgl1 BR1 mutants, TpBgl1D49A/Y410A and TpBgl1D49K/Y410H, resulted in decreasing and abolishing monosaccharide stimulation, respectively. These mutations also impaired the BR1 looping extension responsible for monosaccharide stimulation. This study provides a molecular basis for the rational design of ß-glucosidases for biotechnological applications.

Low FODMAPs diet for functional abdominal pain disorders in children: critical review of current knowledge / Dieta com baixo teor de FODMAPs para distúrbios de dor abdominal funcional em crianças: revisão crítica do conhecimento atual

ABSTRACT Objective: This narrative review aimed to provide practitioners a synthesis of the current knowledge on the role of a low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in reducing symptoms associated with functional abdominal pain disorders in children. This review is focused on the pathophysiology, efficacy and criticism of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in children. Sources: Cochrane Database, Pubmed and Embase were searched using specific terms for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet interventions and functional abdominal pain disorders. Summary of the findings: In children, only one Randomized Control Trial and one open-label study reported positive results of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet; one Randomized Control Trial showed exacerbation of symptoms with fructans in children with Irritable Bowel Syndrome; no effect was found for the lactose-free diet whilst fructose-restricted diets were effective in 5/6 studies. Conclusions: In children there are few trials evaluating low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols in functional abdominal pain disorders, with encouraging data on the therapeutic efficacy particularly of fructose-restricted diet. Additional efforts are still needed to fill this research gap and clarify the most efficient way for tailoring dietary restrictions based on the patient's tolerance and/or identification of potential biomarkers of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols efficacy, to maintain nutritional adequacy and to simplify the adherence to diet by labeling Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols content in commercial products.

RESUMO Objetivo: Nos últimos anos, foram feitos esforços consideráveis para esclarecer o papel da dieta com baixo teor de oligossacarídeos fermentáveis, dissacarídeos, monossacarídeos e polióis (FODMAPs) para o tratamento de distúrbios gastrintestinais funcionais (DGIFs). Esta revisão narrativa teve como objetivo fornecer aos profissionais uma síntese do conhecimento atual sobre o papel de uma dieta com baixo teor de FODMAPs (BFM) na redução dos sintomas associados a distúrbios funcionais de dor abdominal (DFDA) em crianças. Esta revisão está focada na fisiopatologia, eficácia e crítica da dieta BFM em crianças. Fontes: O banco de dados Cochrane, Pubmed e Embase foram pesquisados com o uso dos termos específicos para intervenções na dieta FODMAP e DFDA. Resumo dos achados: Em crianças, apenas um estudo controlado randomizado e um estudo aberto relataram resultados positivos da dieta BFM; um estudo controlado randomizado mostrou exacerbação dos sintomas com frutanos em crianças com síndrome do intestino irritável; nenhum efeito foi encontrado para a dieta livre de lactose, enquanto dietas com restrição de frutose foram eficazes em 5/6 estudos. Conclusões: Existem poucos estudos que avaliam BFM em DFDA em crianças, com dados encorajadores sobre a eficácia terapêutica, particularmente de dietas com restrição de frutose. Esforços adicionais ainda são necessários para preencher essa lacuna de pesquisa e esclarecer a maneira mais eficiente de adaptar as restrições dietéticas com base na tolerância do paciente e/ou identificação de biomarcadores potenciais de eficácia da BFM, para manter a adequação nutricional e simplificar a adesão à dieta, ao incluir informações sobre conteúdo de FODMAPs em rótulos de produtos comerciais.

Sudangrass, an alternative lignocellulosic feedstock for bioenergy in Argentina.

Sudangrass, Sorghum sudanense (Piper) Stapf, is a vigorous forage crop that has also been used for biogas, paper, and electricity production. Due to the large biomass yields achieved by sudangrass and the large area of potential growth in Argentina seven sudangrass accessions from a collection of S. sudanense were analyzed to evaluate their potential as feedstocks for lignocellulosic bioethanol production, and to assess whether there is an association between the response to biotic and abiotic stresses and the composition of the biomass. The biomass composition was analyzed for major cell wall polymers, monosaccharides, and elemental composition. On average, 68% of stem lignocellulosic biomass was comprised of matrix polysaccharides and crystalline cellulose, representing a potential source of sugars for bioethanol production. Xylose was the predominant matrix polysaccharide monosaccharide comprising, on average, 45% of the total sugars, followed by arabinose, glucose, galactose, galacturonic acid, mannose, glucuronic acid, and fucose. Rhamnose was not detected in any of the biomasses analyzed. Silica was the most abundant element in sudangrass stem, followed by chloride, calcium, phosphorus and sulfur. We performed saccharification analyses after pretreatments. Alkaline pretreatment was more effective than water pretreatment. Sodium hydroxide pretreatment exposed different levels of recalcitrance among sudangrass accessions, whereas the water pretreatment did not. Phenological traits were also evaluated, showing significant variability among accessions. The comparison of major cell wall polymers and monosaccharide composition between tolerant and susceptible accessions to abiotic and biotic stresses suggests an association between the composition of the biomass and the response to stress.

Low FODMAPs diet for functional abdominal pain disorders in children: critical review of current knowledge.

OBJECTIVE: This narrative review aimed to provide practitioners a synthesis of the current knowledge on the role of a low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in reducing symptoms associated with functional abdominal pain disorders in children. This review is focused on the pathophysiology, efficacy and criticism of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in children. SOURCES: Cochrane Database, Pubmed and Embase were searched using specific terms for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet interventions and functional abdominal pain disorders. SUMMARY OF THE FINDINGS: In children, only one Randomized Control Trial and one open-label study reported positive results of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet; one Randomized Control Trial showed exacerbation of symptoms with fructans in children with Irritable Bowel Syndrome; no effect was found for the lactose-free diet whilst fructose-restricted diets were effective in 5/6 studies. CONCLUSIONS: In children there are few trials evaluating low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols in functional abdominal pain disorders, with encouraging data on the therapeutic efficacy particularly of fructose-restricted diet. Additional efforts are still needed to fill this research gap and clarify the most efficient way for tailoring dietary restrictions based on the patient's tolerance and/or identification of potential biomarkers of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols efficacy, to maintain nutritional adequacy and to simplify the adherence to diet by labeling Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols content in commercial products.

Effect of the in vitro gastrointestinal digestion on free-phenolic compounds and mono/oligosaccharides from Moringa oleifera leaves: Bioaccessibility, intestinal permeability and antioxidant capacity.

Moringa oleifera is a plant recognized for its compounds such as dietary fiber (oligosaccharides, amongst others) and polyphenols, with biological activities. These properties depend on bioactive compounds (BC) interactions with food matrix/digestion conditions, which have not been evaluated. Thus, the aim of this study was to evaluate the bioaccessibility, intestinal permeability and antioxidant capacity of BC (free-phenolic compounds (PC); and mono/oligosaccharides (MOS)) from Moringa oleifera leaves (ML) powder during in vitro gastrointestinal digestion. The gallic/caffeic acids, morin, kaempferol, mannose and stachyose showed the highest bioaccessibilities (~6-210%). The PC correlated with the antioxidant capacity (R2: 0.59-0.98, p < .05), whereas gallic/caffeic acids were the highest. The apparent permeability coefficients of bioactive compounds (0.62-36.65 × 10-4 cm/s) and water flux/glucose transport confirmed the model similarity to in vivo experiments. The results suggest that ML digestion dynamically modifies PC/MOS bioaccessibility/antioxidant capacity while most of them are not completely absorbed in the small intestine.

Glycosylation Profile of the Transferrin Receptor in Gestational Iron Deficiency and Early-Onset Severe Preeclampsia.

OBJECTIVE: To examine the expression of hypoxia-inducible factor-1α (HIF-1α), TfR1, and TfR1-attached terminal monosaccharides in placentas of women with IDAP and severe preeclampsia. METHODS: TfR1 and HIF-1α were detected by western blot. Immunoadsorption of TfR1 was performed to characterize the terminal monosaccharides by specific lectin binding. RESULTS: There was no difference in the expression of TfR1 and HIF-1α between groups. Lectin blot analysis pointed out an overexpression of galactose ß1-4 N-acetylglucosamine (Gal-GlcNAc) and mannose in severe preeclampsia. CONCLUSION: The increase in Gal-GlcNAc may be due to the increased presence of antennary structures and the mannose glycans of TfR1 may indicate the presence of misfolded or incomplete proteins. These findings may be associated with the low expression of placental TfR1 in women with preeclampsia.

Frucooligosaccharides purification: Complexing simple sugars with phenylboronic acid.

Prebiotic fructooligosaccharides (FOS) are currently obtained by enzymatic reaction with fructosyltransferases (FTFs) using sucrose as both donor and acceptor. In these reactions glucose results as the most abundant by-product, arising from each fructosyl transfer event and, together with fructose, because of the inherent hydrolytic activity of the FTFs. As FOS are mainly used as prebiotic in nutraceutical foods, the reduction or total elimination of monosaccharides is required. In this work the selective elimination of monosaccharides from a synthetic FOS mixture was achieved through the selective complexation of glucose and fructose with phenyl boronic acid (PBAc) followed by ethyl-acetate extraction. The process was applied to a complex mixture of FOS obtained in an enzymatic synthesis reaction containing 40% glucose, 15.8% fructose and 35% of FOS, elimination of the sugars was achieved through 3:1 molar reactions, resulting in a levan-type FOS product with 97% purity.

The characterization and comparison of exopolysaccharides from two benthic diatoms with different biofilm formation abilities.

Exopolysaccharide (EPS) of two benthic diatoms, Amphora sp. and Stauroneis sp., with different biofilm formation abilities were investigated. The ratio of suspension-cells/biofilm-cells was employed to indicate the diatom biofilm formation abilities. The soluble EPS from the supernatant of whole culture, tightly bound EPS from floating cells, loosely and tightly bound EPS from biofilm cells were fractionated as SL-EPS, F-TB-EPS, BF-LB-EPS and BF-TB-EPS, respectively. The analysis for productions and monosaccharide compositions indicated that EPS from two diatoms were different in terms of the productions, distributions, and monomer compositions. Amphora sp. produced more (1.5-fold) total exopolysaccharides, but less (<0.4-fold) BF-TB-EPS than Stauroneis sp. The monosaccharides of the EPS from Amphora sp. were more diverse than those of Stauroneis sp., with 13 and 10 monomers, respectively. Neutral sugars, Glc, Xyl and Man, were abundant in Stauroneis sp., while Gal, Glc and Xyl were rich in Amphora sp. Uronic acid and hexosamine were present in all fractions of two diatoms, especially Glc-A being the most abundant monomer in SL-EPS of Amphora sp. It was proposed that the high content of uronic acid (especially Glc-A) might be crucial for the strong biofilm formation abilities of Amphora sp.

Inflammatory Bowel Diseases and Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols: An Overview.

Inflammatory bowel diseases (IBDs) are mainly represented by ulcerative colitis and Crohn's disease, and the increase in the incidence tends to follow the rapid industrialization and lifestyle of modern societies. FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) consist of molecules that are poorly absorbed in the small intestine and are fermented by bacteria in the colon leading to symptoms such as bloating, flatulence, diarrhea, and abdominal pain. Reduction of the ingestion of FODMAP could reduce the symptoms and improve the quality of life. This review aimed to summarize some important aspects of IBD and evaluate the effects of this diet on this inflammatory condition. Studies including the term FODMAP (and similar terms) and IBD were selected for this review (MEDLINE database was used PubMed/PMC). A low FODMAP diet may be an effective tool to the management of the common abdominal symptoms in patients with functional gastrointestinal symptoms once these molecules trigger these symptoms. This diet may also reduce the expression of pro-inflammatory markers such as C-reactive protein and fecal calprotectin and may interfere with the microbiome and its metabolites. The use of a low FODMAP diet can bring benefits to the IBD patients, but may also modify their nutritional status. Thus it should be utilized in appropriated conditions, and dietary supplements should be necessary to avoid deficiencies that could be caused by a low FODMAP diet over long periods. We suggest that further investigations are required to elucidate when and how to apply the FODMAP diet in IBD patients.

The transcriptional regulator NtrC controls glucose-6-phosphate dehydrogenase expression and polyhydroxybutyrate synthesis through NADPH availability in Herbaspirillum seropedicae.

The NTR system is the major regulator of nitrogen metabolism in Bacteria. Despite its broad and well-known role in the assimilation, biosynthesis and recycling of nitrogenous molecules, little is known about its role in carbon metabolism. In this work, we present a new facet of the NTR system in the control of NADPH concentration and the biosynthesis of molecules dependent on reduced coenzyme in Herbaspirillum seropedicae SmR1. We demonstrated that a ntrC mutant strain accumulated high levels of polyhydroxybutyrate (PHB), reaching levels up to 2-fold higher than the parental strain. In the absence of NtrC, the activity of glucose-6-phosphate dehydrogenase (encoded by zwf) increased by 2.8-fold, consequently leading to a 2.1-fold increase in the NADPH/NADP+ ratio. A GFP fusion showed that expression of zwf is likewise controlled by NtrC. The increase in NADPH availability stimulated the production of polyhydroxybutyrate regardless the C/N ratio in the medium. The mutant ntrC was more resistant to H2O2 exposure and controlled the propagation of ROS when facing the oxidative condition, a phenotype associated with the increase in PHB content.

A physiologically-oriented transcriptomic analysis of the midgut of Tenebrio molitor.

Physiological data showed that T. molitor midgut is buffered at pH 5.6 at the two anterior thirds and at 7.9 at the posterior third. Furthermore, water is absorbed and secreted at the anterior and posterior midgut, respectively, driving a midgut counter flux of fluid. To look for the molecular mechanisms underlying these phenomena and nutrient absorption as well, a transcriptomic approach was used. For this, 11 types of transporters were chosen from the midgut transcriptome obtained by pyrosequencing (Roche 454). After annotation with the aid of databanks and manual curation, the sequences were validated by RT-PCR. The expression level of each gene at anterior, middle and posterior midgut and carcass (larva less midgut) was evaluated by RNA-seq taking into account reference sequences based on 454 contigs and reads obtained by Illumina sequencing. The data showed that sugar and amino acid uniporters and symporters are expressed along the whole midgut. In the anterior midgut are found transporters for NH3 and NH4+ that with a chloride channel may be responsible for acidifying the lumen. At the posterior midgut, bicarbonate-Cl- antiporter with bicarbonate supplied by carbonic anhydrase may alkalinize the lumen. Water absorption caused mainly by an anterior Na+-K+-2Cl- symporter and water secretion caused by a posterior K+-Cl- may drive the midgut counter flux. Transporters that complement the action of those described were also found.

Insights into the effects of glycosylation and the monosaccharide-binding activity of the plant lectin CrataBL.

CrataBL is a glycoprotein isolated from Crataeva tapia bark, containing two N-glycosylation sites. It has been identified to present lectin activity with some specificity for binding glucose over galactose. However, to date, no information on the effects of glycosylation or CrataBL monosaccharide-binding sites and monosaccharide specificity has been obtained. Thus, molecular docking and molecular dynamics simulations were employed to characterize the glycosylated CrataBL conformation and dynamics in aqueous solutions, as well as the molecular basis for its binding specificity. The obtained results indicate both local and distant conformational stabilization effects of N-linked glycans over CrataBL protein moiety. Regarding its lectin activity, molecular docking calculations were performed in two possible binding sites, identified through sequence-based, structure-based and evolutionary information, using α- and ß-anomeric states of the monosaccharides. The obtained poses were further refined through molecular dynamics simulations, suggesting that positively-charged amino acids dictate the binding preference for glucose over galactose in both sites. In addition, a possible preference for ß-monosaccharides was proposed. Such data are expected to contribute to a better comprehension of the lectins monosaccharide-binding activities and carbohydrate-binding site structures.

Synthesis and purification of galacto-oligosaccharides: state of the art.

Lactose-derived non-digestible oligosaccharides are prominent components of functional foods. Among them, galacto-oligosaccharides (GOS) outstand for being prebiotics whose health-promoting effects are supported on strong scientific evidences, having unique properties as substitutes of human milk oligosaccharides in formulas for newborns and infants. GOS are currently produced enzymatically in a kinetically-controlled reaction of lactose transgalactosylation catalyzed by ß-galactosidases from different microbial strains. The enzymatic synthesis of GOS, although being an established technology, still offers many technological challenges and opportunities for further development that has to be considered within the framework of functional foods which is the most rapidly expanding market within the food sector. This paper presents the current technological status of GOS production, its main achievements and challenges. Most of the problems yet to be solved refer to the rather low GOS yields attainable that rarely exceed 40 %, corresponding to lactose conversions around 60 %. This means that the product or reaction (raw GOS) contains significant amounts of residual lactose and monosaccharides (glucose and galactose). Efforts to increase such yields have been for the most part unsuccessful, even though improvements by genetic and protein engineering strategies are to be expected in the near future. Low yields impose a burden on downstream processing to obtain a GOS product of the required purity. Different strategies for raw GOS purification are reviewed and their technological significance is appraised.

Non-severe thermochemical hydrolysis of stover from white corn and sequential enzymatic saccharification and fermentation to ethanol.

A parametric study, with an initial load of 15%w/w of dry stover from white corn, was conducted to evaluate the sequential thermochemical hydrolysis (TH), enzymatic saccharification (ES) and fermentation of the whole slurry with ethanologenic Escherichia coli. The TH was designed to release the maximum amount of xylose with a concomitant formation of minimal amounts of furans. It was found that 29.0% or 93.2% of the xylan was recovered as free xylose at 130°C after 8 min in the presence of 1% or 2%w/w H2SO4 and produced only 0.06 or 0.44 g/L of total furans, respectively. After 24h of ES, 76.14-77.18 g/L of monosaccharides (pentoses and hexoses) were obtained. These slurries, which contained 0.03-0.26 g/L of total furans and 5.14-5.91 g/L of acetate, were fermented with 3.7 g/L of ethanologenic E. coli to produce 24.5-23.5 g/L of ethanol.

Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass.

BACKGROUND: Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G) bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses), must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant. RESULTS: Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and ß-glucan (that compose the most external part of the cell wall in sugarcane) are likely the first to be released and assimilated by both species of fungi. At all time points tested, A. niger produced more enzymes (quantitatively and qualitatively) than T. reesei. However, the most important enzymes related to biomass degradation, including cellobiohydrolases, endoglucanases, ß-glucosidases, ß-xylosidases, endoxylanases, xyloglucanases, and α-arabinofuranosidases, were identified in both secretomes. We also noticed that the both fungi produce more enzymes when grown in culm as a single carbon source. CONCLUSION: Our work provides a detailed qualitative and semi-quantitative secretome analysis of A. niger and T. reesei grown on sugarcane biomass. Our data indicate that a combination of enzymes from both fungi is an interesting option to increase saccharification efficiency. In other words, these two fungal species might be combined for their usage in industrial processes.

Thermopressurized diluted phosphoric acid pretreatment of ligno(hemi)cellulose to make free sugars and nutraceutical oligosaccharides.

Ligno(hemi)cellulosics (L(h)Cs) as sugarcane bagasse and loblolly pine sawdust are currently being used to produce biofuels such as bioethanol and biobutanol through fermentation of free sugars that are often obtained enzymatically. However, this bioconversion requires a pretreatment to solubilize the hemicellulose fractions, thus facilitating the action of the cellulolytic enzymes. Instead of the main free monosaccharides used in these current models, the modulation of thermopressurized orthophosphoric acid as a pretreatment, in the ranges of 3-12 atm and pH 1.5-2.5, can produce nondigestible oligosaccharides (NDOS) such as xylo-oligosaccharides (XOS) because heteroxylan is present in both types of hardwood and softwood hemicelluloses. A comparative thin-layer chromatographic analysis of the hydrolytic products showed the best conditions for NDOS production to be 7 atm/water, pH 2.25 and 2.50, and 8.5 atm/water for both sources. Particular hydrolysates from 7 atm (171 °C) at pHs 2.25 and 2.50 both for cane bagasse and pine sawdust, with respective oligosaccharide contents of 57 and 59 %, once mixed in a proportion of 1:1 for each plant source, were used in vitro as carbon sources for Bifidobacterium or Lactobacillus. Once both bacteria attained the stationary phase of growth, an unforeseen feature emerged: the preference of B. animalis for bagasse hydrolysates and, conversely, the preference of L. casei for pine hydrolysates. Considering the fact that nutraceutical oligosaccharides from both hemicelluloses correspond to higher value-added byproducts, the technology using a much diluted thermopressurized orthophosphoric acid pretreatment becomes an attractive choice for L(h)Cs.

Assessment of different carbohydrates as exogenous carbon source in cultivation of cyanobacteria.

Glucose is the substrate most widely used as exogenous carbon source for heterotrophic cultivation of cyanobacteria. Due to limited information about the use of different carbohydrates as carbon sources to support cyanobacterial heterotrophic metabolism, the objective of this work was to evaluate different monosaccharides (arabinose, fructose, galactose, glucose, mannose and xylose), disaccharides (lactose, maltose, sucrose and trehalose) and polysaccharides (carboxymethylcellulose, cassava starch, Hi-maize(®), maltodextrin Corn Globe 1805(®) and xylan) as exogenous carbon source for heterotrophic culture of cyanobacterium Phormidium sp. The batch cultivation using fructose as organic carbon source resulted in the highest (p < 0.05) cell biomass (5,540 mg/L) in parallel with the highest (p < 0.05) substrate yield coefficient (0.67 mg(biomass)/mg(fructose)). Mannose was the carbon source with the highest (p < 0.05) substrate consumption rate (3,185.7 mg/L/day) and maltodextrin was the carbohydrate with major potential to produce biomass (1,072.8 mg(biomass)/L/day) and lipids (160.8 mg(lipids)/L/day). Qualitatively, the fatty acid profiles of the lipid extract from Phormidium sp. showed predominance of saturated chains for the cultures grown with most of the carbon sources, with the exception of the ones grown with xylose and maltodextrin.

Acidobacteria from oligotrophic soil from the Cerrado can grow in a wide range of carbon source concentrations.

Soils from the Brazilian Cerrado are nutrient-poor, acidic, and aluminum-rich. A previous study revealed that members of the phylum Acidobacteria were predominant in these oligotrophic soils. Five acidobacteria from Cerrado soil were isolated on VL-55 medium containing 0.05% of xylan as carbon source. All isolates belong to the Acidobacteria subdivision 1, and their 16S rRNA showed similarities of 94.2%-96% with Acidobacterium capsulatum or 98.6% with Edaphobacter aggregans. All isolates were able to sustain growth in a wide range of carbon source concentrations. Growth occurred in all concentrations of arabinose, dextrose, and xylose; only one isolate did not grow on fructose. Isolates grew poorly on N-acetyl-D-glucosamine at all concentrations tested. In general, increasing concentrations of these monosaccharides did not inhibit growth rates. Isolates exhibited growth on solid medium containing xylan, carboxymethyl cellulose, and colloidal chitin; however, growth was observed on solid medium that did not contain these polysaccharides. These isolates may be able to use the solidifying agents tested (gellan gum or agar) as carbon source. This interpretation is supported by the absence of growth in liquid media containing chitin or carboxymethyl cellulose at 0.05% as sole carbon source, whereas growth in the same conditions using xylan was confirmed.