Bio-CH4 yield of swine manure and food waste optimized by co-substrate proportions diluted in domestic sewage and pH interactions using the response surface approach.

This research aimed at evaluating optimal conditions to obtain value-added metabolites, such as bio-CH4, by co-digesting swine manure and food waste diluted in domestic sewage. The assays were carried out in batches using the statistical methods of Rotational Central Composite Design (RCCD) and Surface Response to evaluate the ranges of food waste (1.30-9.70 gTS.L-1), pH (6.16-7.84) and granular Upflow Anaerobic Sludge Blanket sludge as inoculum (2.32-5.68 gTS.L-1), besides about 250 mL of swine manure in 500 mL Duran flasks. According to the RCCD matrix, bio-CH4 yields among 600.6 ± 60.1 and 2790.0 ± 112.0 mL CH4 gTS.L-1 were observed, besides the maximum CH4 production rate between 0.4 ± 0.5 and 49.7 ± 2.0 mL CH4 h-1 and λ between ≤0.0 and 299.3 ± 4.5 h. In the validation assay, the optimal conditions of 9.98 gTS.L-1 of food waste, pH adjusted to 8.0 and 2.20 gTS.L-1 of inoculum were considered, and the bio-CH4 yield obtained (5640.79 ± 242.98 mL CH4 gTS.L-1 or also 5201.83 ± 224.07 mL CH4 gTVS.L-1) was 11.3 times higher than in assays before optimization (499.3 ± 16.0 mL CH4 gTS.L-1) with 5 gTS.L-1 of food waste, 3 gTS.L-1 of inoculum and pH 7.0. Besides, the results observed about the energetic balance of the control and validation assays highlight the importance of process optimization, as this condition was the only one with energy supply higher than the energy required for its operation, exceeding max consumption sevenfold. Based on the most dominant microorganisms (Methanosaeta, 31.06%) and the metabolic inference of the validation assay, it could be inferred that the acetoclastic methanogenesis was the predominant pathway to CH4 production.

Effect of probiotic, prebiotic, and synbiotic on the gut microbiota of autistic children using an in vitro gut microbiome model.

Imbalances in gut microbiota composition occur in individuals with autism spectrum disorder (ASD). The administration of probiotics, prebiotics, and synbiotics is emerging as a potential and promising strategy for regulating the gut microbiota and improving ASD-related symptoms. We first investigated the survival of the probiotics Limosilactobacillus (L.) reuteri and Bifidobacterium (B.) longum alone, mixed and combined with a galacto-oligosaccharide (GOS) under simulated gastrointestinal conditions. Next, we evaluated the impact of probiotics (L. reuteri + B. longum), prebiotic (GOS), and synbiotic (L. reuteri + B. longum + GOS) on gut microbiota composition and metabolism of children with ASD using an in vitro fermentation model (SHIME®). The combination of L. reuteri, B. longum, and GOS showed elevated gastrointestinal resistance. The probiotic, prebiotic, and synbiotic treatments resulted in a positive modulation of the gut microbiota and metabolic activity of children with ASD. More specifically, the probiotic treatment increased the relative abundance of Lactobacillus, while the prebiotic treatment increased the relative abundance of Bifidobacterium and decreased the relative abundance of Lachnoclostridium. Changes in microbial metabolism were associated with increased short-chain fatty acid concentrations and reduced ammonium levels, particularly in the prebiotic and synbiotic treatments.

Human microbiota modulation via QseC sensor kinase mediated in the Escherichia coli O104:H4 outbreak strain infection in microbiome model.

BACKGROUND: The intestinal microbiota plays a crucial role in human health, adjusting its composition and the microbial metabolites protects the gut against invading microorganisms. Enteroaggregative E. coli (EAEC) is an important diarrheagenic pathogen, which may cause acute or persistent diarrhea (≥14 days). The outbreak strain has the potent Shiga toxin, forms a dense biofilm and communicate via QseBC two-component system regulating the expression of many important virulence factors. RESULTS: Herein, we investigated the QseC histidine sensor kinase role in the microbiota shift during O104:H4 C227-11 infection in the colonic model SHIME® (Simulator of the Human Intestinal Microbial Ecosystem) and in vivo mice model. The microbiota imbalance caused by C227-11 infection affected ỿ-Proteobacteria and Lactobacillus spp. predominance, with direct alteration in intestinal metabolites driven by microbiota change, such as Short-chain fatty acids (SCFA). However, in the absence of QseC sensor kinase, the microbiota recovery was delayed on day 3 p.i., with change in the intestinal production of SCFA, like an increase in acetate production. The higher predominance of Lactobacillus spp. in the microbiota and significant augmented qseC gene expression levels were also observed during C227-11 mice infection upon intestinal depletion. Novel insights during pathogenic bacteria infection with the intestinal microbiota were observed. The QseC kinase sensor seems to have a role in the microbiota shift during the infectious process by Shiga toxin-producing EAEC C227-11. CONCLUSIONS: The QseC role in C227-11 infection helps to unravel the intestine microbiota modulation and its metabolites during SHIME® and in vivo models, besides they contribute to elucidate bacterial intestinal pathogenesis and the microbiota relationships.

Human microbiota modulation via QseC sensor kinase mediated in the Escherichia coli O104:H4 outbreak strain infection in microbiome model

Background: The intestinal microbiota plays a crucial role in human health, adjusting its composition and the microbial metabolites protects the gut against invading microorganisms. Enteroaggregative E. coli (EAEC) is an important diarrheagenic pathogen, which may cause acute or persistent diarrhea (≥14 days). The outbreak strain has the potent Shiga toxin, forms a dense biofilm and communicate via QseBC two-component system regulating the expression of many important virulence factors. Results: Here in, we investigated the QseC histidine sensor kinase role in the microbiota shift during O104:H4 C227–11 infection in the colonic model SHIME® (Simulator of the Human Intestinal Microbial Ecosystem) and in vivo mice model. The microbiota imbalance caused by C227–11 infection affected ỿ-Proteobacteria and Lactobacillus spp. predominance, with direct alteration in intestinal metabolites driven by microbiota change, such as Short-chain fatty acids (SCFA). However, in the absence of QseC sensor kinase, the microbiota recovery was delayed on day 3 p.i., with change in the intestinal production of SCFA, like an increase in acetate production. The higher predominance of Lactobacillus spp. in the microbiota and significant augmented qseC gene expression levels were also observed during C227–11 mice infection upon intestinal depletion. Novel insights during pathogenic bacteria infection with the intestinal microbiota were observed. The QseC kinase sensor seems to have a role in the microbiota shift during the infectious process by Shiga toxin-producing EAEC C227–11. Conclusions: The QseC role in C227–11 infection helps to unravel the intestine microbiota modulation and its metabolites during SHIME® and in vivo models, besides they contribute to elucidate bacterial intestinal pathogenesis and the microbiota relationships.

Effect of Daily Consumption of Orange Juice on the Levels of Blood Glucose, Lipids, and Gut Microbiota Metabolites: Controlled Clinical Trials.

Ingestion of bioactive compounds, such as hesperidin and naringin, found in citrus fruits and orange juice, can improve the homeostasis of gut microbiota. A controlled clinical study with temporal series intergroup design with 10 apparently healthy women (28.5 ± 8.4 years, 24.1 ± 3.3 kg/m2) were evaluated after continuous consumption of commercial pasteurized orange juice for 2 months. Samples of blood serum and stool were collected at basal time and periodically during the experiment for biochemical and microbiology assays. Intestinal microbiota was evaluated for total anaerobic bacteria, Lactobacillus spp., Bifidobacterium spp., and Clostridium spp. An independent culture evaluation was performed using Denaturing Gradient Gel Electrophoresis (DGGE). The pH, ammonium (NH4+), and short-chain fatty acids (SCFAs) were evaluated for microbial metabolism. The results showed that daily intake of orange juice did not change women's body composition, but improved blood biochemical parameters, such as low-density lipoprotein-cholesterol, glucose, and insulin sensitivity. Orange juice positively modulated the composition and metabolic activity of microbiota, increasing the population of fecal Bifidobacterium spp. and lactobacillus spp. Polymerase chain reaction-DGGE of microbiota showed similar composition of total bacteria, and microbial metabolism showed a reduction of ammonia and an increase of the production of SCFAs. These results suggested that a daily consumption of orange had a positive effect on the intestinal microbiota and metabolic biomarkers of young women, which may be an effective alternative for a healthy drink.

Impact of combining acerola by-product with a probiotic strain on a gut microbiome model.

In this study, we first investigated the survival of three probiotic strains, individually and combined with acerola by-product during simulated gastrointestinal conditions. Next, we investigated the effects of acerola by-product combined with Bifidobacterium longum BB-46 on a gut microbiota model (SHIME®). Chemical composition, total phenolic compounds, antioxidant activity of the acerola by-product and microbial counts, denaturing gradient gel electrophoresis (DGGE), ammonium ions ( NH4+ ) and short-chain fatty acids (SCFAs) analysis of the SHIME® samples were performed. Acerola by-product revealed high protein and fibre, reduced lipid contents, and showed to be an excellent source of total phenolic compounds with high in vitro antioxidant activity. A decreased amount of NH4+ in the ascending colon and an increase (p < .05) in SCFAs were observed in the three regions of colon during treatment with BB-46 and acerola by-product. BB-46 combined with acerola by-product showed positive effects on the gut microbiota metabolism in SHIME® model.

Modulation of gut microbiota from obese individuals by in vitro fermentation of citrus pectin in combination with Bifidobacterium longum BB-46.

This study aimed to evaluate the effects of three treatments, i.e., Bifidobacterium longum BB-46 (T1), B. longum BB-46 combined with the pectin (T2), and harsh extracted pectin from lemon (T3) on obesity-related microbiota using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). The effects of the treatments were assessed by the analysis of the intestinal microbial composition (using 16S rRNA gene amplicon sequencing) and the levels of short-chain fatty acids (SCFAs) and ammonium ions (NH4+). Treatments T2 and T3 stimulated members of the Ruminococcaceae and Succinivibrionaceae families, which were positively correlated with an increase in butyric and acetic acids. Proteolytic bacteria were reduced by the two treatments, concurrently with a decrease in NH4+. Treatment T1 stimulated the production of butyric acid in the simulated transverse and descending colon, reduction of NH4+ as well as the growth of genera Lactobacillus, Megamonas, and members of Lachnospiracea. The results indicate that both B. longum BB-46 and pectin can modulate the obesity-related microbiota; however, when the pectin is combined with B. longum BB-46, the predominant effect of the pectin can be observed. This study showed that the citric pectin is able to stimulate butyrate-producing bacteria as well as genera related with anti-inflammatory effects. However, prospective clinical studies are necessary to evaluate the anti/pro-obesogenic and inflammatory effects of this pectin for future prevention of obesity.

Impact of multi-functional fermented goat milk beverage on gut microbiota in a dynamic colon model.

The aim of this research was to evaluate the effect of grape probiotic fermented beverages made of goat milk, with or without added grape pomace on gut microbiota in a Simulator of Human Intestinal Microbial Ecosystem (SHIME®). SHIME® model was used to investigate to assess changes in microbial composition and fermentation metabolites (short- and branched-chain fatty acids and ammonium), as well as under the antioxidant capacity. The results demonstrated that the beverages formulated, with or without grape pomace extract, exhibited high dietary fiber, oleic acid, phenolic compounds content and antioxidant activity. Both beverages also kept L. rhamnosus and S. thermophilus viable during their passage through the intestinal tract and had a positive effect on gut microbiota metabolism, increasing the antioxidant capacity and the production of short-chain fatty acids, and decreasing the ammonium concentration. Therefore, the multifunctional beverages formulated in this study can offer a new perspective for the production of foods with positive potential effects on human health.

Beneficial effects of fermented vegetal beverages on human gastrointestinal microbial ecosystem in a simulator.

The aim of this study was to evaluate the effects of four beverage formulations (prebiotic - fructooligosaccharide, probiotic - Lactobacillus casei Lc-01, synbiotic - fructooligosaccharide and L. casei Lc-01 and placebo) based on aqueous extracts of soy and quinoa, towards the human intestinal microbiota using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®), a dynamic model of the human gut. To monitor the effects on microbial community composition, plate counts on specific growth media and a PCR-DGGE analysis were performed on samples from all colon compartments - ascending, transverse and descending. To verify the effects on microbial metabolism, we analyzed the ammonium and short chain fatty acids (SCFAs) concentrations. The synbiotic beverage showed the best microbiological results in the ascending colon compartment, stimulating the growth of Lactobacillus spp. and Bifidobacterium spp., and reducing Clostridium spp., Bacteroides spp., enterobacteria and Enterococcus spp. populations in this compartment. A larger reduction (p<0.05) of ammonia ions in the ascending colon was observed during the synbiotic beverage treatment. No statistical difference was observed in SCFA production among the treatments and the basal period. Plate count and DGGE analysis showed the survival of L. casei Lc-01 in the colon. DGGE analysis also showed higher richness and diversity of the Lactobacillus spp. community during the treatment with synbiotic beverage, with higher accentuation in the ascending colon.

Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB) catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN) method were 9.0x10(7) cells/mL at the beginning of the assay and 8.0x10(5) cells/mL after 738 hours of operation.

Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production.

This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30°C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8h. The reactor R1 operating with a HRT of 2h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2)mol(-1) glucose with 1.3mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter.