Strain-level fitness in the gut microbiome is an emergent property of glycans and a single metabolite.

The human gut microbiota resides within a diverse chemical environment challenging our ability to understand the forces shaping this ecosystem. Here, we reveal that fitness of the Bacteroidales, the dominant order of bacteria in the human gut, is an emergent property of glycans and one specific metabolite, butyrate. Distinct sugars serve as strain-variable fitness switches activating context-dependent inhibitory functions of butyrate. Differential fitness effects of butyrate within the Bacteroides are mediated by species-level variation in Acyl-CoA thioesterase activity and nucleotide polymorphisms regulating an Acyl-CoA transferase. Using in vivo multi-omic profiles, we demonstrate Bacteroides fitness in the human gut is associated together, but not independently, with Acyl-CoA transferase expression and butyrate. Our data reveal that each strain of the Bacteroides exists within a unique fitness landscape based on the interaction of chemical components unpredictable by the effect of each part alone mediated by flexibility in the core genome.

Gut microbiota and BMI throughout childhood: the role of firmicutes, bacteroidetes, and short-chain fatty acid producers.

Childhood obesity is a risk factor for numerous health conditions. A critical factor in the etiology of obesity appears to be the gut microbiota, which is the microbial community that resides in the human gut. The ratio of the phyla Firmicutes and Bacteroidetes (F/B) and gut bacterial genera that produce short-chain fatty acids (SCFA) have been suggested to contribute to obesity. The current study investigated (1) whether differences in F/B ratio can be observed in infancy and childhood in relation to zBMI in healthy children, and (2) whether an innovative proxy measure adds evidence to a relationship between SCFA producers and the etiology of obesity. Stool samples were collected at five time points, and zBMI was assessed at eight time points throughout the first 12 years of life. Our confirmatory analyses with Bayesian multilevel models showed no relationship between the F/B ratio and zBMI. Also, a proxy measure constructed from known SCFA producers was unrelated to zBMI throughout the first 12 years of life. Exploratory analyses using multilevel and random forest models suggest that the relative abundances of Firmicutes and Bacteroidetes were independently negatively associated with zBMI from infancy through childhood, and the SCFA producing genera Subdoligranulum and Alistipes were negatively related to future BMI in childhood.

Living in a bottle: Bacteria from sediment-associated Mediterranean waste and potential growth on polyethylene terephthalate.

Ocean pollution is a worldwide environmental challenge that could be partially tackled through microbial applications. To shed light on the diversity and applications of the bacterial communities that inhabit the sediments trapped in artificial containers, we analyzed residues (polyethylene terephthalate [PET] bottles and aluminum cans) collected from the Mediterranean Sea by scanning electron microscopy and next generation sequencing. Moreover, we set a collection of culturable bacteria from the plastisphere that were screened for their ability to use PET as a carbon source. Our results reveal that Proteobacteria are the predominant phylum in all the samples and that Rhodobacteraceae, Woeseia, Actinomarinales, or Vibrio are also abundant in these residues. Moreover, we identified marine isolates with enhanced growth in the presence of PET: Aquimarina intermedia, Citricoccus spp., and Micrococcus spp. Our results suggest that the marine environment is a source of biotechnologically promising bacterial isolates that may use PET or PET additives as carbon sources.

Mobilization of vitamin B12 transporters alters competitive dynamics in a human gut microbe.

The functional and genomic diversity of the human gut microbiome is shaped by horizontal transfer of mobile genetic elements (MGEs). Characterized MGEs can encode genes beneficial for their host's self-defense (e.g., antibiotic resistance) or ability to compete for essential or limited resources (e.g., vitamins). Vitamin B12 and related compounds (corrinoids) are critical nutrients that enable colonization by members of the common gut microbe phylum, the Bacteroidetes. Herein, we identify a distinct class of MGEs in the Bacteroidetes responsible for the mobilization and exchange of the genes required for transport of corrinoids, a group of cyclic tetrapyrrole cofactors including vitamin B12 (btuGBFCD). This class includes two distinct groups of conjugative transposons (CTns) and one group of phage. Conjugative transfer and vitamin B12 transport activity of two of the CTns were confirmed in vitro and in vivo, demonstrating the important role MGEs play in distribution of corrinoid transporters in the Bacteroidetes.

Cross-feeding between intestinal pathobionts promotes their overgrowth during undernutrition.

Child undernutrition is a global health issue associated with a high burden of infectious disease. Undernourished children display an overabundance of intestinal pathogens and pathobionts, and these bacteria induce enteric dysfunction in undernourished mice; however, the cause of their overgrowth remains poorly defined. Here, we show that disease-inducing human isolates of Enterobacteriaceae and Bacteroidales spp. are capable of multi-species symbiotic cross-feeding, resulting in synergistic growth of a mixed community in vitro. Growth synergy occurs uniquely under malnourished conditions limited in protein and iron: in this context, Bacteroidales spp. liberate diet- and mucin-derived sugars and Enterobacteriaceae spp. enhance the bioavailability of iron. Analysis of human microbiota datasets reveals that Bacteroidaceae and Enterobacteriaceae are strongly correlated in undernourished children, but not in adequately nourished children, consistent with a diet-dependent growth synergy in the human gut. Together these data suggest that dietary cross-feeding fuels the overgrowth of pathobionts in undernutrition.

Aryl Hydrocarbon Receptor (AhR) Activation by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) Dose-Dependently Shifts the Gut Microbiome Consistent with the Progression of Non-Alcoholic Fatty Liver Disease.

Gut dysbiosis with disrupted enterohepatic bile acid metabolism is commonly associated with non-alcoholic fatty liver disease (NAFLD) and recapitulated in a NAFLD-phenotype elicited by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. TCDD induces hepatic fat accumulation and increases levels of secondary bile acids, including taurolithocholic acid and deoxycholic acid (microbial modified bile acids involved in host bile acid regulation signaling pathways). To investigate the effects of TCDD on the gut microbiota, the cecum contents of male C57BL/6 mice orally gavaged with sesame oil vehicle or 0.3, 3, or 30 µg/kg TCDD were examined using shotgun metagenomic sequencing. Taxonomic analysis identified dose-dependent increases in Lactobacillus species (i.e., Lactobacillus reuteri). Increased species were also associated with dose-dependent increases in bile salt hydrolase sequences, responsible for deconjugation reactions in secondary bile acid metabolism. Increased L. reuteri levels were further associated with mevalonate-dependent isopentenyl diphosphate (IPP) biosynthesis and o-succinylbenzoate synthase, a menaquinone biosynthesis associated gene. Analysis of the gut microbiomes from cirrhosis patients identified an increased abundance of genes from the mevalonate-dependent IPP biosynthesis as well as several other menaquinone biosynthesis genes, including o-succinylbenzoate synthase. These results extend the association of lactobacilli with the AhR/intestinal axis in NAFLD progression and highlight the similarities between TCDD-elicited phenotypes in mice to human NAFLD.

Potential prebiotic properties of exopolysaccharides produced by a novel Lactobacillus strain, Lactobacillus pentosus YY-112.

Exopolysaccharides (EPSs) derived from Lactobacilli have important physiological effects and are commonly used as new prebiotics. We identified and studied a new Lactobacillus strain, YY-112, isolated from waxberry (Myrica rubra). This strain, identified as Lactobacillus pentosus, tolerates acids, bile salts, and artificial digestive fluids. The EPS derived from this strain weighed 5.9 × 104 Da and contained glucose, mannose, glucosamine, galactose, and rhamnose at 62.69 : 85.85 : 2.46 : 2.92 : 1.00 molar ratios. We found that the EPS from this strain increased the ratio of Bacteroidetes to Firmicutes and decreased the relative abundance of Proteobacteria, especially Escherichia-Shigella, when added to a simulated gastrointestinal system in vitro. After analysing the short-chain fatty acids, we found that this EPS promoted the production of acetic acid, propionic acid, and butyric acid, and reduced the ratio of acetic acid to propionic acid. We conclude that Lactobacillus pentosus YY-112 is a potential probiotic strain with EPS that is beneficial for the intestinal microbiota and short-chain fatty acid production.

COVID-19 Infection Alters the Microbiome: Elite Athletes and Sedentary Patients Have Similar Bacterial Flora.

Regular exercise can upgrade the efficiency of the immune system and beneficially alter the composition of the gastro-intestinal microbiome. We tested the hypothesis that active athletes have a more diverse microbiome than sedentary subjects, which could provide better protection against COVID-19 during infection. Twenty active competing athletes (CA) (16 male and 4 females of the national first and second leagues), aged 24.15 ± 4.7 years, and 20 sedentary subjects (SED) (15 male and 5 females), aged 27.75 ± 7.5 years, who had been diagnosed as positive for COVID-19 by a PCR test, served as subjects for the study. Fecal samples collected five to eight days after diagnosis and three weeks after a negative COVID-19 PCR test were used for microbiome analysis. Except for two individuals, all subjects reported very mild and/or mild symptoms of COVID-19 and stayed at home under quarantine. Significant differences were not found in the bacterial flora of trained and untrained subjects. On the other hand, during COVID-19 infection, at the phylum level, the relative abundance of Bacteroidetes was elevated during COVID-19 compared to the level measured three weeks after a negative PCR test (p < 0.05) when all subjects were included in the statistical analysis. Since it is known that Bacteroidetes can suppress toll-like receptor 4 and ACE2-dependent signaling, thus enhancing resistance against pro-inflammatory cytokines, it is suggested that Bacteroidetes provide protection against severe COVID-19 infection. There is no difference in the microbiome bacterial flora of trained and untrained subjects during and after a mild level of COVID-19 infection.

Marine biofilms on different fouling control coating types reveal differences in microbial community composition and abundance.

Marine biofouling imposes serious environmental and economic impacts on marine applications, especially in the shipping industry. To combat biofouling, protective coatings are applied on vessel hulls which are divided into two major groups: biocidal and non-toxic fouling release. The current study aimed to explore the effect of coating type on microbial biofilm community profiles to better understand the differences between the communities developed on fouling control biocidal antifouling and biocidal-free coatings. Biocidal (Intersmooth® 7460HS SPC), fouling release (Intersleek® 900), and inert surfaces were deployed in the marine environment for 4 months, and the biofilms that developed on these surfaces were investigated using Illumina NGS sequencing, targeting the prokaryotic 16S rRNA gene. The results confirmed differences in the community profiles between coating types. The biocidal coating supported communities dominated by Alphaproteobacteria (Loktanella, Sphingorhabdus, Erythrobacter) and Bacteroidetes (Gilvibacter), while other taxa, such as Portibacter and Sva0996 marine group, proliferated on the fouling-release surface. Knowledge of these marine biofilm components on fouling control coatings will serve as a guide for future investigations of marine microfouling as well as informing the coatings industry of potential microbial targets for robust coating formulations.

Nitrite as a causal factor for nitrate-dependent anaerobic corrosion of metallic iron induced by Prolixibacter strains.

Microbially influenced corrosion (MIC) may contribute significantly to overall corrosion risks, especially in the gas and petroleum industries. In this study, we isolated four Prolixibacter strains, which belong to the phylum Bacteroidetes, and examined their nitrate respiration- and Fe0 -corroding activities, together with two previously isolated Prolixibacter strains. Four of the six Prolixibacter strains reduced nitrate under anaerobic conditions, while the other two strains did not. The anaerobic growth of the four nitrate-reducing strains was enhanced by nitrate, which was not observed in the two strains unable to reduce nitrate. When the nitrate-reducing strains were grown anaerobically in the presence of Fe0 or carbon steel, the corrosion of the materials was enhanced by more than 20-fold compared to that in aseptic controls. This enhancement was not observed in cultures of the strains unable to reduce nitrate. The oxidation of Fe0 in the anaerobic cultures of nitrate-reducing strains occurred concomitantly with the formation of nitrite. Since nitrite chemically oxidized Fe0 under anaerobic and aseptic conditions, the corrosion of Fe0 - and carbon steel by the nitrate-reducing Prolixibacter strains was deduced to be mainly enhanced via the biological reduction of nitrate to nitrite, followed by the chemical oxidation of Fe0 to Fe2+ and Fe3+ coupled to the reduction of nitrite.

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review.

Irritable bowel syndrome is not a life-threatening disease, yet it significantly affects the quality of life and contributes to economic loss. It is estimated that even up to 45% of the world's population can suffer from the disease. The first attempts to diagnose irritable bowel syndrome were made at the end of the 19th century; however, establishing appropriate diagnostic criteria and treatment methods is still ongoing. To date, little is known about the etiology of irritable bowel syndrome; however, growing attention is drawn to the intestinal microbiota as a factor in the disease development. For this reason, researchers have conducted many studies on therapies that modulate the microbiota, among which probiotics, prebiotics, and synbiotics are widely studied. To date, most studies have examined probiotics; however, there are also several studies demonstrating the efficacy of prebiotics and synbiotics. The aim of this review was to summarize findings on the usefulness of probiotics, prebiotics, and synbiotics in the treatment of irritable bowel syndrome.

Structural characteristics of Gracilaria lemaneiformis oligosaccharides and their alleviation of dextran sulphate sodium-induced colitis by modulating the gut microbiota and intestinal metabolites in mice.

Ulcerative colitis (UC) is a chronic lifetime disorder with a high incidence worldwide. A functional food-based method to prevent UC would be a good option for disease control. G. lemaneiformis oligosaccharides (GLOs) should have potent benefits for the gastrointestinal tract, based on in vitro fermentation assessed in our previous study. This study evaluated the therapeutic potential of GLOs in UC, as well as their possible mechanisms of action. The administration of GLOs was able to reduce the severity of dextran sulphate sodium-induced colitis by protecting mice from weight loss, reductions in colon length, inflammatory infiltration, and colon damage. Gut microbiota composition analysis showed that at the phylum level, GLOs could restore the composition of Bacteroidetes and decrease the level of Firmicutes. Consistently, it increased the contents of beneficial microbial metabolites and short-chain fatty acids in the mouse colitis model. In conclusion, GLOs could comprise a promising functional food strategy to alleviate UC symptoms.

Gut microbiome heritability is nearly universal but environmentally contingent.

Relatives have more similar gut microbiomes than nonrelatives, but the degree to which this similarity results from shared genotypes versus shared environments has been controversial. Here, we leveraged 16,234 gut microbiome profiles, collected over 14 years from 585 wild baboons, to reveal that host genetic effects on the gut microbiome are nearly universal. Controlling for diet, age, and socioecological variation, 97% of microbiome phenotypes were significantly heritable, including several reported as heritable in humans. Heritability was typically low (mean = 0.068) but was systematically greater in the dry season, with low diet diversity, and in older hosts. We show that longitudinal profiles and large sample sizes are crucial to quantifying microbiome heritability, and indicate scope for selection on microbiome characteristics as a host phenotype.

Ginseng ameliorates exercise-induced fatigue potentially by regulating the gut microbiota.

The therapeutic effects of water extract of ginseng (WEG) on exercise-induced fatigue (EF) have been reported in several previous studies, but the molecular mechanisms involved remain unexplored. In this study, the anti-EF effects of WEG were studied, and the potential mechanisms were discussed. We characterized the chemical components of WEG by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) and high performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD), and then examined the anti-EF effects of WEG on a rat model of weight-loaded swimming with a focus on endogenous metabolism and gut microbiota. WEG contains abundant (90.15%, w/w) saccharides and ginsenosides with structurally diverse glycosyls. WEG taken orally showed strong anti-EF effects by ameliorating energy metabolism abnormality, oxidative stress, lipid peroxidation, inflammatory response, disorders in the metabolism of bile acid, amino acid, fatty acid and lipid, as well as the gut microbiota dysbiosis. Given that gut microbiota is significantly associated with energy expenditure, systemic inflammation and host metabolism, these findings suggest a potential central role of the gut microbiota in mediating the anti-EF effect of WEG. That is, the saccharides and ginsenosides in WEG serve as energy substrates for specific intestinal bacteria, thereby beneficially regulating the gut microbiota, and the reshaped gut microbial ecosystem then triggers several molecular and cellular signaling pathways (e.g. butyrate or TGR5 signals) to achieve the therapeutic effects on EF. The outcomes highlighted here enable deeper insight into how WEG overcomes EF.

Effect of Trilobatin from Lithocarpus polystachyus Rehd on Gut Microbiota of Obese Rats Induced by a High-Fat Diet.

Trilobatin was identified as the primary bioactive component in the Lithocarpus polystachyus Rehd (LPR) leaves. This study explored the antiobesity effect of trilobatin from LPR leaves and its influence on gut microbiota in obese rats. Results showed that trilobatin could significantly reduce body and liver weight gain induced by a high-fat diet, and the accumulation of perirenal fat, epididymal fat, and brown fat of SD (Male Sprague-Dawley) obese rats in a dose-independent manner. Short-chain fatty acids (SCFAs) concentrations increased, especially the concentration of butyrate. Trilobatin supplementation could significantly increase the relative abundance of Lactobacillus, Prevotella, CF231, Bacteroides, and Oscillospira, and decrease greatly the abundance of Blautia, Allobaculum, Phascolarctobacterium, and Coprococcus, resulting in an increase of the ratio of Bacteroidetes to Firmicutes (except the genera of Lactobacillus and Oscillospira). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway predicted by the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) indicated the different relative metabolic pathways after trilobatin supplementation. This study may reveal the contribution of gut microbiota to the antiobesity effect of trilobatin from LPR leaves and predict the potential regulatory mechanism for obesity induced by a high-fat diet.

Heat-inactivated Lactobacillus plantarum nF1 promotes intestinal health in Loperamide-induced constipation rats.

Constipation is a common condition that affects individuals of all ages, and prolonged constipation needs to be prevented to avoid potential complications and reduce the additional stress on individuals with pre-medical conditions. This study aimed to evaluate the effects of heat-inactivated Lactobacillus plantarum (HLp-nF1) on loperamide-induced constipation in rats. Constipation-induced male rats were treated orally with low to high doses of HLp-nF1 and an anti-constipation medication Dulcolax for five weeks. Study has 8 groups, control group; loperamide-treated group; Dulcolax-treated group; treatment with 3.2 × 1010, 8 × 1010 and 1.6 × 1011, cells/mL HLp-nF1; Loperamide + Dulcolax treated group. HLp-nF1 treated rats showed improvements in fecal pellet number, weight, water content, intestinal transit length, and contractility compared to the constipation-induced rats. Also, an increase in the intestine mucosal layer thickness and the number of mucin-producing crypt epithelial cells were observed in HLp-nF1-treated groups. Further, the levels of inflammatory cytokines levels were significantly downregulated by treatment with HLp-nF1 and Dulcolax. Notably, the metagenomics sequencing analysis demonstrated a similar genus pattern to the pre-preparation group and control with HLp-nF1 treatment. In conclusion, the administration of >3.2 × 1010 cells/mL HLp-nF1 has a positive impact on the constipated rats overall health.

One dog's waste is another dog's wealth: A pilot study of fecal microbiota transplantation in dogs with acute hemorrhagic diarrhea syndrome.

Canine acute hemorrhagic diarrhea syndrome (AHDS) has been associated in some studies with Clostridioides perfringens overgrowth and toxin-mediated necrosis of the intestinal mucosa. We aimed to determine the effect of a single fecal microbiota transplantation (FMT) on clinical scores and fecal microbiomes of 1 and 7 dogs with AHDS from New Zealand and South Africa. We hypothesized that FMT would improve AHDS clinical scores and increase microbiota alpha-diversity and short-chain fatty acid (SCFA)-producing microbial communities' abundances in dogs with AHDS after FMT. We sequenced the V3-V4 region of the 16S-rRNA gene in the feces of AHDS FMT-recipients and sham-treated control dogs, and their healthy donors at admission, discharge, and 30 days post-discharge. There were no significant differences in median AHDS clinical scores between FMT-recipients and sham-treated controls at admission or discharge (P = 0.22, P = 0.41). At admission, the Shannon diversity index (SDI) was lower in AHDS dogs than healthy donors (P = 0.002). The SDI did not change from admission to 30 days in sham-treated dogs yet increased in FMT-recipients from admission to discharge (P = 0.04) to levels not different than donors (P = 0.33) but significantly higher than sham-treated controls (P = 0.002). At 30 days, the SDI did not differ between FMT recipients, sham-treated controls, and donors (P = 0.88). Principal coordinate analysis of the Bray-Curtis index separated post-FMT and donor dogs from pre-FMT and sham-treated dogs (P = 0.009) because of increased SCFA-producing genera's abundances after FMT. A single co-abundance subnetwork contained many of the same OTUs found to be differentially abundant in FMT-recipients, and the abundance of this module was increased in FMT-recipients at discharge and 30 days, compared to sham-treated controls. We conclude in this small pilot study FMT did not have any clinical benefit. A single FMT procedure has the potential to increase bacterial communities of SCFA-producing genera important for intestinal health up to 30 days post-FMT.

Millet-based supplement restored gut microbial diversity of acute malnourished pigs.

The tight association between malnutrition and gut microbiota (GM) dysbiosis enables microbiota-targeting intervention to be a promising strategy. Thus, we used a malnourished pig model to investigate the host response and GM alterations under different diet supplementation strategies. Pigs at age of 4 weeks were fed with pure maize diet to induce malnutrition symptoms, and followed by continuous feeding with maize (Maize, n = 8) or re-feeding using either corn-soy-blend (CSB+, n = 10) or millet-soy-blend based (MSB+, n = 10) supplementary food for 3 weeks. Meanwhile, 8 pigs were fed on a standard formulated ration as control (Ref). The effect of nutritional supplementation was assessed by the growth status, blood chemistry, gastrointestinal pathology, mucosal microbiota composition and colon production of short-chain fatty acids. Compared with purely maize-fed pigs, both CSB+ and MSB+ elevated the concentrations of total protein and globulin in blood. These pigs still showed most malnutrition symptoms after the food intervention period. MSB+ had superior influence on the GM development, exhibiting better performance in both structural and functional aspects. MSB+ pigs were colonized by less Proteobacteria but more Bacteroidetes, Firmicutes and Lachnospira spp. Pearson's correlation analysis indicated a strong correlation between the abundance of mucosal e.g., Faecalibacterium and Lachnospira spp. and body weight, crown-rump length and total serum protein. In conclusion, the malnutrition symptoms were accompanied by an aberrant GM, and millet-based nutritional supplementation showed promising potentials to restore the reduced GM diversity implicated in pig malnutrition.

Fusobacterium nucleatum impedes remission of colitis in a mouse model.

The role of Fusobacterium nucleatum, often associated with intestinal diseases, in the remission of dextran sulfate sodium (DSS)-induced colitis was investigated. Female mice were divided into groups DC (DSS control) and DF (DSS + F. nucleatum). F. nucleatum (1.0 × 1010 cfu/mouse/day) in phosphate-buffered saline (PBS) was orally given to DF, while DC had PBS only. All mice had DSS in drinking water. In Experiment 1, mice underwent 2 inflammation phases, an in-between recovery phase and had their disease activity indices (DAI) calculated. Experiment 2 was similarly conducted, except that mice were dissected 3 days postrecovery, and had blood and colonic mucosal samples collected. In Experiment 1, DF had significantly (P < .05) higher DAI than DC, during the recovery and 2nd inflammation phases. In Experiment 2, genus Bacteroides was significantly (P < .05) higher and family Lachnospiraceae significantly lower in cecal mucosa-associated microbiota of DF than in that of DC. We concluded that F. nucleatum can impede colitis remission.

Bagasse minority pathway expression: Real time study of GH2 ß-mannosidases from bacteroidetes.

After being isolated from a sugarcane pile, the bacterium Chitinophaga sp. CB10 demonstrated to be a rich source of carbohydrases, with 350 predicted CAZyme domains. CB10 was able to grow on carbohydrates of different structural complexities: glucose, carboxymethylcellulose, corn starch, galactomannan, Aloe vera gum and sugarcane bagasse. The sugarcane bagasse is a rich source of complex polymers, and the diversity of metabolites released by its enzymatic hydrolysis has an important role for green chemistry, including minority pathways such as the degradation of mannan conjugates. In this sense, CB10 demonstrated considerable levels of gene expression for mannanases, and was stable for a period of 96-144 hours in the presence of sugarcane bagasse as sole carbon source. The bacterium showed respectively 4.8x and 5.6x expression levels for two genes predicted for GH2 ß-mannosidase: one located within a gene cluster identified as "polysaccharide utilization loci" (PUL), and another a classic ß-mannosidase. These enzymes shared less than 45% of identity with enzymes characterized from the genus Chitinophaga belonging to the phylum Bacteroidetes. The degree of novelty-as demonstrated by the low identity with previously characterized enzymes; the remarkable capability to grow in different substrates; mannanase activity, evidenced by the release of residual oligosaccharides in the cultivation with galactomannan (HPLC-RID, 12.3 mMol); associated to the ability of mannanases expression in a low concentration of inductor conditions (sugarcane bagasse, 0.2%) indicate the high potential for the application of CB10 as a source of enzymes in the production of oligosaccharides from biomass. This capacity might prove to be very valuable for the biorefinery process of pre-biotic precursors and other functional oligosaccharides focused on the food and pharmaceutical industries.