scholarly journals 2,4-Dichlorophenoxyacetic acid degradation in methanogenic mixed cultures obtained from Brazilian Amazonian soil samples

2021 ◽  
Author(s):  
Gunther Brucha ◽  
Andrea Aldas-Vargas ◽  
Zacchariah Ross ◽  
Peng Peng ◽  
Siavash Atashgahi ◽  
...  

Abstract2,4-Dichlorophenoxyacetic acid (2,4-D) is the third most applied pesticide in Brazil to control broadleaf weeds in crop cultivation and pastures. Due to 2,4-D’s high mobility and long half-life under anoxic conditions, this herbicide has high probability for groundwater contamination. Bioremediation is an attractive solution for 2,4-D contaminated anoxic environments, but there is limited understanding of anaerobic 2,4-D biodegradation. In this study, methanogenic enrichment cultures were obtained from Amazonian top soil (0—40 cm) and deep soil (50 -80 cm below ground) that biotransform 2,4-D (5 µM) to 4-chlorophenol and phenol. When these cultures were transferred (10% v/v) to fresh medium containing 40 µM or 160 µM 2,4-D, the rate of 2,4-D degradation decreased, and biotransformation did not proceed beyond 4-chlorophenol and 2,4-dichlorophenol in the top and deep soil cultures, respectively. 16S rRNA gene sequencing and qPCR of a selection of microbes revealed no significant enrichment of known organohalide-respiring bacteria. Furthermore, a member of the genus Cryptanaerobacter was identified as possibly responsible for phenol conversion to benzoate in the top soil inoculated culture. Overall, these results demonstrate the effect of 2,4-D concentration on biodegradation and microbial community composition, which are both important factors when developing pesticide bioremediation technologies.

mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Andre Mu ◽  
Glen P. Carter ◽  
Lucy Li ◽  
Nicole S. Isles ◽  
Alison F. Vrbanac ◽  
...  

ABSTRACT Vancomycin-resistant Enterococcus faecium (VREfm) is an emerging antibiotic-resistant pathogen. Strain-level investigations are beginning to reveal the molecular mechanisms used by VREfm to colonize regions of the human bowel. However, the role of commensal bacteria during VREfm colonization, in particular following antibiotic treatment, remains largely unknown. We employed amplicon 16S rRNA gene sequencing and metabolomics in a murine model system to try and investigate functional roles of the gut microbiome during VREfm colonization. First-order taxonomic shifts between Bacteroidetes and Tenericutes within the gut microbial community composition were detected both in response to pretreatment using ceftriaxone and to subsequent VREfm challenge. Using neural networking approaches to find cooccurrence profiles of bacteria and metabolites, we detected key metabolome features associated with butyric acid during and after VREfm colonization. These metabolite features were associated with Bacteroides, indicative of a transition toward a preantibiotic naive microbiome. This study shows the impacts of antibiotics on the gut ecosystem and the progression of the microbiome in response to colonization with VREfm. Our results offer insights toward identifying potential nonantibiotic alternatives to eliminate VREfm through metabolic reengineering to preferentially select for Bacteroides. IMPORTANCE This study demonstrates the importance and power of linking bacterial composition profiling with metabolomics to find the interactions between commensal gut bacteria and a specific pathogen. Knowledge from this research will inform gut microbiome engineering strategies, with the aim of translating observations from animal models to human-relevant therapeutic applications.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benedicte Ella Zranseu Aka ◽  
Theodore N’dede Djeni ◽  
Simon Laurent Tiemele Amoikon ◽  
Jan Kannengiesser ◽  
Naaila Ouazzani ◽  
...  

AbstractPalm Oil Mill Effluents (POME) are complex fermentative substrates which habour diverse native microbial contaminants. However, knowledge on the microbiota community shift caused by the anthropogenic effects of POME in the environment is up to date still to be extensively documented. In this study, the bacterial and archaeal communities of POME from two palm oil processing systems (artisanal and industrial) were investigated by Illumina MiSeq Platform. Despite the common characteristics of these wastewaters, we found that their microbial communities were significantly different with regard to their diversity and relative abundance of their different Amplicon Sequence Variants (ASV). Indeed, POME from industrial plants harboured as dominant phyla Firmicutes (46.24%), Bacteroidetes (34.19%), Proteobacteria (15.11%), with the particular presence of Spirochaetes, verrucomicrobia and Synergistetes, while those from artisanal production were colonized by Firmicutes (92.06%), Proteobacteria (4.21%) and Actinobacteria (2.09%). Furthermore, 43 AVSs of archaea were detected only in POME from industrial plants and assigned to Crenarchaeota, Diapherotrites, Euryarchaeota and Nanoarchaeaeota phyla, populated mainly by many methane-forming archaea. Definitively, the microbial community composition of POME from both type of processing was markedly different, showing that the history of these ecosystems and various processing conditions have a great impact on each microbial community structure and diversity. By improving knowledge about this microbiome, the results also provide insight into the potential microbial contaminants of soils and rivers receiving these wastewaters.


2020 ◽  
Author(s):  
Xiaoying Yang ◽  
Yuchen Yao ◽  
Xueying Zhang ◽  
Jiahui Zhong ◽  
Fuli Gao ◽  
...  

Abstract Background: Seasonal breeding is a normal phenomenon that animals adapt to natural selection and reproduce only in specific seasons. With the gradual popularization of Next-generation sequencing (NGS), large studies have shown that seasonal breeding has been affected by gut microbiota. Consequently, the purpose of this study is to explore the effect of seasonal breeding on the gut microbiota of wild ground squirrel (Spermophilus dauricus). We used 16S rRNA gene sequencing technology to sequence the gut microbiota of the wild ground squirrel in the breeding season and non-breeding season. We also predicted the function of gut microbiota by bioinformatic software.Results: The results showed that the main components of gut microbiota in all samples consisted of Firmicutes (61.8%), Bacteroidetes (32.4%), and Proteobacteria (3.7%). Microbial community composition analyses revealed significant differences between these two groups. At the genus level, Alistipes, Mycoplasma, Anaerotruncus, and Odoribacter were up-regulated in the non-breeding season, while Blautia and Streptococcus spp. were up-regulated in the breeding season. The result of function prediction suggested that the relative abundance of functional categories related to lipid metabolism, carbohydrate metabolism, and nucleotide metabolism was higher in the breeding season. The expression of transcription, energy metabolism, and signal transduction was enriched in the non-breeding season. Conclusions: Overall, the results of this study emphasized the significant effects of seasonal breeding on gut microbiota community composition of the wild ground squirrel and laid a foundation for further study of gut microbiota on seasonal breeding in the future.


2021 ◽  
Author(s):  
Jialiang Li ◽  
Xueyan Li ◽  
Sina Zhang ◽  
Chen Jin ◽  
Zixia Lin ◽  
...  

Abstract BACKGROUNDThe liver-microbiome axis is implicated in the pathogenesis of hepatobiliary cancer, and the role of the gut microbiota in cholangiocarcinoma (CCA) remains unclear.METHODWe conducted a case-control study on the intestinal flora of 33 CCA patients and 47 cholelithiasis individuals. We performed 16S rRNA gene sequencing to identify disease-related gut microbiota and assess the potential of the intestinal microbiome as a non-invasive biomarker for CCA.RESULTWe found that gut microbiome of CCA patients had a significantly higher alpha diversity (Shannon and Observed species indices, p = 0.006 and p = 0.02, respectively) and an overall different microbial community composition (p = 0.032). The genus Muribaculaceae_unclassified was most strongly associated with CCA (p < 0.001). We put forward a disease predictive model including twelve intestinal microbiome genera distinguished CCA patients from CF patients with an area under curve (AUC) of approximately 0.93 (95%CI, 0.85–0.987). The forecasting performance of this model was better than CA19-9. Moreover, genera Ezakiella and Garciella were only observed among intrahepatic cholangiocarcinoma patients. Further, we assessed predicted functional modules alternations CCA patients and uncovered a microbiota pattern specific to CCA.CONCLUSIONOur findings provide evidence of the intestinal microbiome as a non-invasive biomarker for CCA.


Author(s):  
Chin-Hee Song ◽  
Nayoung Kim ◽  
Ryoung Hee Nam ◽  
Soo In Choi ◽  
Jeong Eun Yu ◽  
...  

The frequency of azoxymethane/dextran sulfate sodium (AOM/DSS)-induced carcinogenesis in male mice is higher than that in female mice. Previous studies have reported that 17β-estradiol inhibits tumorigenesis in males by modulating nuclear factor-erythroid 2-related factor 2 (Nrf2). This study aimed to investigate the changes in mouse gut microbiome composition based on sex, AOM/DSS-induced colorectal cancer (CRC), and Nrf2 genotype. The gut microbiome composition was determined by 16S rRNA gene sequencing fecal samples obtained at week 16 post-AOM administration. In terms of sex differences, our results showed that the wild-type (WT) male control mice had higher alpha diversity (i.e. Chao1, Shannon, and Simpson) than the WT female control mice. The linear discriminant analysis effect size (LEfSe) results revealed that the abundances of Akkermansia muciniphila and Lactobacillus murinus were higher in WT male control mice than in WT female controls. In terms of colon tumorigenesis, the alpha diversity of the male CRC group was lower than that of the male controls in both WT and Nrf2 KO, but did not show such changes in females. Furthermore, the abundance of A. muciniphila was higher in male CRC groups than in male controls in both WT and Nrf2 KO. The abundance of Bacteroides vulgatus was higher in WT CRC groups than in WT controls in both males and females. However, the abundance of L. murinus was lower in WT female CRC and Nrf2 KO male CRC groups than in its controls. The abundance of A. muciniphila was not altered by Nrf2 KO. In contrast, the abundances of L. murinus and B. vulgatus were changed differently by Nrf2 KO depending on sex and CRC. Interestingly, L. murinus showed negative correlation with tumor numbers in the whole colon. In addition, B. vulgatus showed positive correlation with inflammatory markers (i.e. myeloperoxidase and IL-1β levels), tumor numbers, and high-grade adenoma, especially, developed mucosal and submucosal invasive adenocarcinoma at the distal part of the colon. In conclusion, Nrf2 differentially alters the gut microbiota composition depending on sex and CRC induction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongde Yang ◽  
Xuan Yu ◽  
Xuebing Liu ◽  
Guangya Liu ◽  
Kuan Zeng ◽  
...  

AbstractAs a severe public health problem, methamphetamine (METH) abuse places a heavy burden on families and society. A growing amount of evidence has indicated communication between gut microbiota and the CNS in drug addiction, with associations to neural, endocrine and immune pathways. Thus, we searched for alterations in the gut microbiota and their potential effects in METH users through 16S rRNA gene sequencing. A decreased Shannon index indicated lower bacterial diversity in the METH users than in the age-matched control group. The gut microbial community composition in the METH users was also altered, including reductions in Deltaproteobacteria and Bacteroidaceae abundances and increases in Sphingomonadales, Xanthomonadales, Romboutsia and Lachnospiraceae abundances. Moreover, the Fusobacteria abundance was correlated with the duration of METH use. Enterobacteriaceae, Ruminococcaceae, Bacteroides, and Faecalibacterium had statistically significant correlations with items related to the positive and negative symptoms of schizophrenia and to general psychopathology in the METH users, and all have previously been reported to be altered in individuals with psychotic syndromes, especially depression. Abstraction, one of the items of the cognitive assessment, was positively related to Blautia. These findings revealed alterations in the gut microbiota of METH users, and these alterations may play a role in psychotic syndrome and cognitive impairment. Although the mechanisms behind the links between these disorders and METH abuse are unknown, the relationships may indicate similarities in the pathogenesis of psychosis induced by METH abuse and other causes, providing a new paradigm for addiction and METH use disorder treatment.


2019 ◽  
Author(s):  
Andre Mu ◽  
Glen P. Carter ◽  
Lucy Li ◽  
Nicole S. Isles ◽  
Alison F. Vrbanac ◽  
...  

AbstractVancomycin resistant Enterococcus faecium (VREfm) is an emerging antibiotic resistant pathogen. Strain-level investigations are beginning to reveal the molecular mechanisms used by VREfm to colonize regions of the human bowel. However, the role of commensal bacteria during VREfm colonization, in particular following antibiotic treatment, remains largely unknown. We employed amplicon 16S rRNA gene sequencing and metabolomics in a murine model system to try and investigate functional roles of the gut microbiome during VREfm colonization. First-order taxonomic shifts between Bacteroidetes and Tenerricutes within the gut microbial community composition were detected both in response to pretreatment using ceftriaxone, and to subsequent VREfm challenge. Using neural networking approaches to find co-occurrence profiles of bacteria and metabolites, we detected key metabolome features associated with butyric acid during and after VREfm colonization. These metabolite features were associated with Bacteroides, indicative of a transition towards a pre-antibiotic naïve microbiome. This study shows the impacts of antibiotics on the gut ecosystem, and the progression of the microbiome in response to colonisation with VREfm. Our results offer insights towards identifying potential non-antibiotic alternatives to eliminate VREfm through metabolic re-engineering to preferentially select for Bacteroides.ImportanceThis study demonstrates the importance and power of linking bacterial composition profiling with metabolomics to find the interactions between commensal gut bacteria and a specific pathogen. Knowledge from this research will inform gut microbiome engineering strategies, with the aim of translating observations from animal models to human-relevant therapeutic applications.


2020 ◽  
Author(s):  
Matthew P. Highton ◽  
Lars R. Bakken ◽  
Peter Dörsch ◽  
Steve Wakelin ◽  
Cecile A. M. de Klein ◽  
...  

AbstractSoil denitrification produces the potent greenhouse gas nitrous oxide (N2O) and by further reduction of N2O, the harmless inert gas N2. N2O emission is determined by rate and timing of the N2O producing and reducing steps which are sensitive to a series of proximal and distal regulators such as pH and microbial community composition. Microbial community associations to N2O emission potential (N2O/(N2O+N2)) are commonly entangled with pH leaving the true role of community composition unclear. Here, we leverage a set of soil microbiomes strongly linked to rainfall above pH to test the hypothesis that microbiome vs. N2O emission potential (N2O/(N2O+N2)) correlations will be maintained across alternative distal drivers. N2O emission potential (N2O/(N2O+N2)) and denitrification gas (NO, N2O, N2) kinetics were assessed by automated gas chromatography while community composition was assessed by 16S rRNA gene sequencing and qPCR of nosZI and II genes. Analyses revealed a sustained correlation between microbiome and N2O emission potential (N2O/(N2O+N2)) in the absence of a pH effect. Further, a continuum of gas accumulation phenotypes linked to NO accumulation and sensitive to carbon addition are identified. Separate phenotypes carried out N2O production and reduction steps more concurrently or sequentially and thus determined N2O accumulation and emission potential (N2O/(N2O+N2)). Concurrent N2O producing/reducing soils typically contained NO accumulation to a low steady state, while carbon addition manipulations which increased NO accumulation also increased sequentiality of N2O production/reduction and thus emission potential (N2O/(N2O+N2)). These features may indicate a conserved NO inhibitory mechanism across multiple effectors (rainfall, community composition, carbon availability).HighlightsN2O emission potential is linked to microbiome changes associated with rainfall, but not to pH.Sequential vs. concurrent denitrification phenotypes differing in NO and N2O accumulation are identified.High N2O accumulation is associated with increased NO accumulation.Sequentiality of N2O production/reduction determines soil N2O emission potential.Sequentiality of N2O reduction was susceptible to manipulation via carbon addition.


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