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Simple Summary: Corn-fermented protein, a co-product of ethanol production, can be utilized as a protein source for pet food. Currently, there are no studies that have evaluated the impact of this ingredient on the fecal microbiota of dogs, an indicator of animal health. The overall richness and diversity of the fecal microbiota were maintained when dogs were fed corn-fermented protein compared to traditional ingredients such as brewer's dried yeast and distiller's dried grains with solubles. Corn-fermented protein (CFP), a co-product from the ethanol industry, is produced using post-fermentation technology to split the protein and yeast from fiber prior to drying. The objective of this study was to determine the effect of CFP compared to traditional ingredients on the fecal microbiota of dogs. The four experimental diets included a control with no yeast and diets containing either 3.5% brewer's dried yeast, 2.5% brewer's dried yeast plus 17.5% distiller's dried grains with solubles, or 17.5% CFP. The experimental diets were fed to adult dogs (n = 12) in a 4 × 4 replicated Latin square design. Fresh fecal samples (n = 48) were analyzed by 16S metagenomic sequencing. Raw sequences were processed through mothur. Community diversity was evaluated in R. Relative abundance data were analyzed within the 50 most abundant operational taxonomic units using a mixed model of SAS. Alpha and beta diversity were similar for all treatments. Predominant phyla among all samples were Firmicutes (73%), Bacteroidetes (15%), Fusobacteria (8%), and Actinobacteria (4%). There were no quantifiable (p > 0.05) shifts in the predominant phyla among the treatments. However, nine genera resulted in differences in relative abundance among the treatments. These data indicate that compared to traditional ingredients, CFP did not alter the overall diversity of the fecal microbiota of healthy adult dogs over 14 days. [ABSTRACT FROM AUTHOR]

Corn-fermented protein (CFP), a co-product from the ethanol industry, is produced using post-fermentation technology to split the protein and yeast from fiber prior to drying. The objective of this study was to determine the effect of CFP compared to traditional ingredients on the fecal microbiota of dogs. The four experimental diets included a control with no yeast and diets containing either 3.5% brewer’s dried yeast, 2.5% brewer’s dried yeast plus 17.5% distiller’s dried grains with solubles, or 17.5% CFP. The experimental diets were fed to adult dogs (n = 12) in a 4 × 4 replicated Latin square design. Fresh fecal samples (n = 48) were analyzed by 16S metagenomic sequencing. Raw sequences were processed through mothur. Community diversity was evaluated in R. Relative abundance data were analyzed within the 50 most abundant operational taxonomic units using a mixed model of SAS. Alpha and beta diversity were similar for all treatments. Predominant phyla among all samples were Firmicutes (73%), Bacteroidetes (15%), Fusobacteria (8%), and Actinobacteria (4%). There were no quantifiable (p > 0.05) shifts in the predominant phyla among the treatments. However, nine genera resulted in differences in relative abundance among the treatments. These data indicate that compared to traditional ingredients, CFP did not alter the overall diversity of the fecal microbiota of healthy adult dogs over 14 days.

Declining coral reef health has triggered a multitude of studies focusing on the diversity and functional roles of reef-associated microbial communities. However, comparatively little is known about the microbial communities in deeper sediment assemblages (> 1 m) below the reef substrate. Here, we present the first characterisation of microbial community structure in sub-bottom sediment of up to 3.5 m beneath the reef substrate. Cores were retrieved from three reef sites in Singapore and profiled via 16S rRNA (V4 region) gene sequencing. Despite each core containing a large number of unique ASVs, cores from the same reef showed more similar taxonomic profiles compared to cores from other reefs. We detected limited differences in diversity between either cores or sediment facies. Our results provide novel insight into microbial communities in sub-bottom reef sediment and contribute to the growing research on reef–microbial interactions. [ABSTRACT FROM AUTHOR]

This study explored the microbial community and the energy requirement of an anaerobic packed bed reactor (APBR) treating a low-strength synthetic wastewater (200 mg COD/L). The APBR was run with different hydraulic retention times (HRTs) and temperatures. Results show that the COD removal decreased from 89 to 46% when the HRTs and the temperature were both gradually reduced to 1 h and 20°C. Meanwhile, the methane yield decreased from 0.386 to 0.232 g COD/g TCOD consumed with the decreasing temperature from 35 to 20°C at 1-h HRT. This low methane production was associated with a low relative abundance of 0.575–0.628% for the archaea group in genus level. Genus Methanosaeta with 0.307–0.388% relative abundance represented 53–62% of the archaea group whereas facultative Trichococcus with 7.3–11.3% relative abundance was dominant in the microbial consortia. Candidatus Moduliflexus found was the second largest microbial population with 4.2–6.1% relative abundance. This facultative environment was observed in the APBR, resulting in 18–37% COD unbalanced. The energy appraisement resolved that the total electrical energy required for the APBR was consistent at 4.192 × 10−3 kWh/m3 at 20–35°C to yield the net energy ratio of 5.97–15.29. The facultative-like APBR treated the low strength wastewater efficiently while the energy input was balanced by its self-produced methane energy. [Display omitted] [ABSTRACT FROM AUTHOR]

The methane production and the microbial community dynamics of thermophilic anaerobic co-digestion (AD) of corn stover, swine manure and effluent were conducted at total solid (TS) content of 5%, 10% and 15%, the carbon to nitrogen ratio (C/N) of 20, 30 and 40 and the effluent volumetric percentage (EVP) of 20%, 40% and 60%. For batches with 5% TS, the highest methane yield of 238.5–283.1 mL g−1 volatile solid (VS) and the specific methane productivity of 138.5–152.2 mL g−1 initial VS were obtained at the C/N ratios of 20 and 30. For the mixtures with 10% and 15% TS, the highest methane yield was 341.9 mL g−1 VS and 351.2 mL g−1 VS, respectively, when the C/N ratio of 20% and 60% EVP conditions were maintained. Co-digestion of swine manure with corn stover caused an obvious shift in microbial population, in which the archaeal population changed from 0.3% to 2.8% and the bacterial community changed from 97.2% to 99.7%. The experimental batches with the highest relative abundance of the archaeal population (2.00% of total microbial population for 5% TS, 1.74% for 10% TS and 2.76% for 15% TS) had the highest rate of methanogenesis subsequently enhancing methane production (283.08 mL g−1 VS for 5% TS, 341.91 mL g−1 VS for 10% TS and 351.23 mL g−1 VS for 15% TS). The results of microbiome analysis enabled understanding the key populations in biomethane generation. [ABSTRACT FROM AUTHOR]

Aim: A number of reports have implicated the role of the symbiotic bacterial communities associated with toxic dinoflagellates in the biosynthesis of saxitoxin during harmful algal blooms (HABs). However, the exact mechanisms by which the bacteria facilitate toxin production remain inconclusive. The toxic dinoflagellate, Pyrodinium bahamense var. compressum, is the causative organism responsible for paralytic shellfish poisoning in the coastal waters of Sabah, and it is caused by the consumption of filter-feeding shellfish contaminated with the neurotoxin, saxitoxin. The present study aimed at characterizing the species diversity of symbiotic bacteria occurring within a monoalgal culture of P. bahamense var. compressum. Methodology and results: The total bacterial DNA was amplified using paired-end 16S community sequencing on the Illumina platform, targeting the V3-V4 region of the 16S ribosomal RNA gene. Bacteria were classified into 20 classes, 43 orders, 60 families, and 105 genera. A total of 10 phyla were present, where the major phylum was Proteobacteria (69.5%). The major genera were Pseudoruegeria (32%), Roseibium (16%), Hyphomonas (16%), Phaeobacter (7%), Lutimaribacter (5%) and Methylophaga (5%). This study showed that the previous method of assessing microbial diversity occurring in P. bahamense var. compressum has underestimated the actual species diversity. Conclusion, significance and impact of study: The high-throughput sequencing of the 16S metagenomes revealed hitherto unreported bacterial taxa associated with P. bahamense var. compressum. The findings of the present work will pave the way for further studies aimed at isolating and characterizing symbiotic bacteria that are likely to be associated with the biosynthesis of toxins. [ABSTRACT FROM AUTHOR]

Idiopathic chronic enterocolitis (ICE) is one of the most commonly encountered and difficult to manage diseases of captive rhesus macaques (Macaca mulatta). The etiology is not well understood, but perturbations in gut microbial communities have been implicated. Here we evaluated the effects of a 14-day course of vancomycin, neomycin, and fluconazole on animals affected with ICE, comparing treated, untreated, and healthy animals. We performed microbiome analysis on duodenal and colonic mucosal samples and feces in order to probe bacterial and/or fungal taxa potentially associated with ICE. All treated animals showed a significant and long-lasting improvement in stool consistency over time when compared to untreated and healthy controls. Microbiome analysis revealed trends associating bacterial community composition with ICE, particularly lineages of the Lactobacillaceae family. Sequencing of DNA from macaque food biscuits revealed that fungal sequences recovered from stool were dominated by yeast-derived food additives; in contrast, bacteria in stool appeared to be authentic gut residents. In conclusion, while validation in larger cohorts is needed, the treatment described here was associated with significantly improved clinical signs; results suggested possible correlates of microbiome structure with disease, though no strong associations were detected between single microbes and ICE.

Idiopathic chronic enterocolitis (ICE) is one of the most commonly encountered and difficult to manage diseases of captive rhesus macaques (Macaca mulatta). The etiology is not well understood, but perturbations in gut microbial communities have been implicated. Here we evaluated the effects of a 14-day course of vancomycin, neomycin, and fluconazole on animals affected with ICE, comparing treated, untreated, and healthy animals. We performed microbiome analysis on duodenal and colonic mucosal samples and feces in order to probe bacterial and/or fungal taxa potentially associated with ICE. All treated animals showed a significant and long-lasting improvement in stool consistency over time when compared to untreated and healthy controls. Microbiome analysis revealed trends associating bacterial community composition with ICE, particularly lineages of the Lactobacillaceae family. Sequencing of DNA from macaque food biscuits revealed that fungal sequences recovered from stool were dominated by yeast-derived food additives; in contrast, bacteria in stool appeared to be authentic gut residents. In conclusion, while validation in larger cohorts is needed, the treatment described here was associated with significantly improved clinical signs; results suggested possible correlates of microbiome structure with disease, though no strong associations were detected between single microbes and ICE. [ABSTRACT FROM AUTHOR]

Broad-spectrum antibiotics such as ceftiofur and ampicillin are recommended for the treatment of metritis in dairy cows. Nonetheless, little is known about the impacts of antibiotics on the uterine microbiota. Here, we evaluated the shift in uterine microbiota after treating metritic cows with ceftiofur or ampicillin, and also gained insight into the uterine microbiota associated with cure of metritis. Uterine swabs from ceftiofur-treated, ampicillin-treated, and untreated metritic Holstein cows were collected on the day of metritis diagnosis (D1) and on D6 and then used for genomic DNA extraction and sequencing of the V4 hypervariable region of the 16S rRNA gene on the Illumina MiSeq platform. The uterine microbiota consolidated over time by decreasing species richness and increasing evenness; therefore, becoming more homogeneous. The uterine microbial community showed distinct clustering patterns on D6 according to antibiotic treatment, which could be attributed to more dynamic changes in the microbial structure from D1 to D6 in ceftiofur-treated cows. Ceftiofur led to significant changes at the community level, phylum level, and genus level, whereas the changes in ampicillin and untreated cows, although following the same pattern, were mostly non-significant. Bacteroidetes was significantly increased in ceftiofur-treated cows but was not changed after ampicillin and no treatment. Different responses to antibiotics were observed in Porphyromonas , which increased in relative abundance with ceftiofur and decreased with ampicillin. Regardless of treatment group, failure to cure metritis was associated with a decrease in diversity of uterine microbiota and an increase in the relative abundance of Bacteroides , Porphyromonas , and Fusobacterium . [ABSTRACT FROM AUTHOR]

This study utilized innovative analyses to develop multiple lines of evidence for natural attenuation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in groundwater at the U.S. Department of Energy's Pantex Plant. RDX, as well as the degradation product 4-nitro-2,4-diazabutanal (NDAB; produced by aerobic biodegradation or alkaline hydrolysis) were detected in a large portion of the plume, with lower concentrations of the nitroso-containing metabolites produced during anaerobic biodegradation. 16S metagenomic sequencing detected the presence of bacteria known to aerobically degrade RDX (e.g., Gordonia , Rhodococcus) and NDAB (Methylobacterium), as well as the known anoxic RDX degrader Pseudomonas fluorescens I–C. Proteomic analysis detected both the aerobic RDX degradative enzyme XplA, and the anoxic RDX degradative enzyme XenB. Groundwater enrichment cultures supplied with low concentrations of labile carbon confirmed the potential of the extant groundwater community to aerobically degrade RDX and produce NDAB. Compound-specific isotope analysis (CSIA) of RDX collected at the site showed fractionation of nitrogen isotopes with δ15N values ranging from approximately −5‰ to +9‰, providing additional evidence of RDX degradation. Taken together, these results provide evidence of in situ RDX degradation in the Pantex Plant groundwater. Furthermore, they demonstrate the benefit of multiple lines of evidence in supporting natural attenuation assessments, especially with the application of innovative isotopic and –omic technologies. • The RDX breakdown product NDAB was widely detected. • 16S metagenomic sequencing and proteomics indicated the presence of active RDX degraders. • Aerobic RDX degradation potential was confirmed by groundwater enrichments. • CSIA of RDX nitrogen indicated evidence of degradation. [ABSTRACT FROM AUTHOR]

Research on gut microbiota of phytophagous insects has shown to be important for the physiological functions of insect hosts; however, little is known about the changes in gut microbiota when they are suffering from environmental stress or pathogen infections. During rearing of Phasmotaenia lanyuhensis (Phasmatodea: Phasmatidae), sluggish locomotion was usually followed by the death of the insect with a symptom of melanization in the front part of the abdomen. Therefore, the abnormal individuals were initially classified into moribund, light- and serious-symptom based on the level of abnormal physiological circumstances and melanization. The gut microbiota of these samples were further investigated by 16S metagenomic sequencing and the differences in bacterial abundance and structure of bacterial community were analyzed. A decrease in microbiota diversity was observed in the diseased P. lanyuhensis, with the abundance of phyla Proteobacteria and Firmicute relatively higher compared to those without symptom. Interestingly, principal component analysis based on the bacterial richness was correlated to the level of melanization symptom in the diseased P. lanyuhensis, suggested the change in bacterial microbiota involved in this abnormal circumstance. However, the factor that caused the initial alternation of microbiota remains to be identified. Additionally, the lack of bacterial diversity (i.e., absence of Meiothermus and Nubsella spp.) in P. lanyuhensis might reduce the fitness for surviving. This report provided the comprehensive microbiota analysis for P. lanyuhensis and concluded that either the relative abundance or the bacterial diversity of microbiota in the insect digestive system may influence the physiological functions of phytophagous insects., (© 2020 Wiley Periodicals LLC.)

The prevalence of obesity and diabetes, and their complicating mental disorders, severely affect public health. This study aimed to investigate the long-term effects of an Akkermansia muciniphila subtype (A. muciniphila sub ) on high-fat diet-induced obesity and diabetes, and to evaluate whether this subtype can alleviate their complicated mental disorders. Whole genome sequencing and short chain fatty acid production analysis in supernatant of pure culture were performed. Female adult C57BL/6 mice were fed a high-fat diet or a normal chow diet and were gavaged with A. muciniphila sub or phosphate-buffered saline daily for 10 months. Body weight, food consumption and blood glucose were measured. At the end of the treatment period, all mice were subjected to the Y-maze test, sucrose preference test, analyses of serum, fecal microbiota analysis and histological examination. This A. muciniphila sub had 278 unique genes compared to the type strain (A. muciniphila ATCC BAA-835) and produced short chain fatty acids both. A. muciniphila sub administration significantly reduced body weight gain and improved the spatial memory of high-fat diet-fed mice. A. muciniphila sub increased Nissl bodies in neurons of the hippocampus, and restored the high-fat diet-inhibited tryptophan metabolism. The high-fat diet led to decreased serum 5-hydroxytryptamine and induced depression, which were not alleviated by A. muciniphila sub . A. muciniphila sub increased the relative fecal abundance of Bifidobacterium , and was negatively correlated with the fecal abundance of Bacteroides. The present study demonstrated the beneficial effects of this A. muciniphila sub on body weight, blood glucose control and the alleviation of the memory decay caused by a high-fat diet in mice. • A. muciniphila sub has 278 unique genes when compared to the type strain. • A. muciniphila sub alleviated high-fat diet-induced metabolic disorders and memory decay in mice. • A. muciniphila sub restored the tryptophan metabolism and normal gut microbiota inhibited by a high-fat diet. [ABSTRACT FROM AUTHOR]