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s found between the microbial communities present on the two different types of sheet piling. However, there were clear differences in the microbial communities in the corrosion layers of tubercles, which were also different to the microbes present in adjacent seawater. The overall results suggest that the presence of orange tubercles, a single measurement of water quality, or the detection of certain general types of microbes (e.g. sulfate reducing bacteria) should not be taken alone as definitive indications of accelerated corrosion. Copyright © 2020 American Society for Microbiology.Microbial interactions abound in natural ecosystems and shape community structure and function. Substantial attention has been given to cataloging mechanisms by which microbes interact, but there is a limited understanding of the genetic landscapes that promote or hinder microbial interactions. We previously developed a mutualistic coculture pairing Escherichia coli and Rhodopseudomonas palustris, wherein E. coli provides carbon to R. palustris in the form of glucose fermentation products and R. palustris fixes N2 gas and provides nitrogen to E. coli in the form of NH4 + The stable coexistence and reproducible trends exhibited by this coculture make it ideal for interrogating the genetic underpinnings of a cross-feeding mutualism. Here, we used random barcode transposon sequencing (RB-TnSeq) to conduct a genome-wide search for E. coli genes that influence fitness during cooperative growth with R. palustris RB-TnSeq revealed hundreds of genes that increased or decreased E. coli fitness in a mutualism-dependenthnology. Here, we identified genes that influenced Escherichia coli fitness during cooperative growth with a mutualistic partner, Rhodopseudomonas palustris Although this mutualism centers on the bidirectional exchange of essential carbon and nitrogen, E. coli fitness was positively and negatively affected by genes involved in diverse cellular processes. click here Furthermore, we discovered an unexpected purine cross-feeding interaction. These results contribute knowledge on the genetic foundation of a microbial cross-feeding interaction and highlight that unanticipated interactions can occur even within engineered microbial communities. Copyright © 2020 American Society for Microbiology.Microorganisms in nature are commonly exposed to various stresses in parallel. The isiA gene encodes an iron stress-induced chlorophyll-binding protein which is significantly induced under iron starvation and oxidative stress. Acclimation of oxidative stress and iron deficiency was investigated using a regulatory mutant of the Synechocystis sp. PCC 6803. In this study, the ΔisiA mutant grew more slowly in oxidative stress and iron depletion conditions compared to the wild type (WT) counterpart under the same conditions. Thus, we performed RNA-seq analysis of WT and ΔisiA under double stress conditions to obtain a comprehensive view of isiA-regulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed significant differences between WT and ΔisiA, mainly related to photosynthesis and the iron-sulfur cluster. The deletion of isiA affects the expression of various genes that are involved in cellular processes and structures, such as photosynthesis, phycobilisomen which the blue module was correlated with oxidative stress. We further demonstrated that the isi operon contained the following five genes isiA, isiB, isiC, ssl0461, and dfp by co-transcriptional PCR. Three sRNAs were identified that were related to oxidative stress. This study enhances our knowledge of IsiA regulatory mechanisms under iron deficiency and oxidative stress. Copyright © 2020 American Society for Microbiology.Microbiota plays a vital role in maintaining gut health and influence the overall performance of chickens. link2 Most of the gut microbiota related studies have been performed in broilers, which have different microbial communities compared to layers. The normal gut microbiota of laying chickens is dominated by Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria at the phylum level. The composition of the gut microbiota changes with chicken age, genotype and production system. The metabolites of gut microbiota, such as short-chain fatty acids, indole, tryptamine, vitamins and bacteriocins are involved in host-microbiota cross talk, maintenance of barrier function and immune homeostasis. Resident gut microbiota members also limit and control the colonisation of foodborne pathogens. In-feed supplementations of prebiotics and probiotics strengthen the gut microbiota for improved host performance and colonisation resistance to gut pathogens, such as Salmonella and Campylobacter The mechanisms of action of prebiotics and probiotics come through the production of organic acids, activation of the host immune system and production of antimicrobial agents. Probiotic candidates including Lactobacillus, Bifidobacterium, Bacillus, Saccharomyces and Faecalibacterium isolates have shown promising results towards enhancing food safety and gut health. Additionally, a range of complex carbohydrates including mannose-oligosaccharides, fructo-oligosaccharides and galacto-oligosaccharides and inulin are promising candidates for improving gut health. Here, we review the potential roles of prebiotics and probiotics in the reshaping of the gut microbiota of layer chickens to enhance intestinal health and food safety. © Crown copyright 2020.Immunoglobulin A (IgA) is essential for defense of the intestinal mucosa against harmful pathogens. Previous studies have shown that Bacteroidetes, the major phylum of gut microbiota together with Firmicutes, impact IgA production. However, relative abundance of species of Bacteroidetes responsible for IgA production were not well understood. In the present study, we identified some specific Bacteroidetes species that were associated with gut IgA induction by Hps60-based profiling of species distribution among Bacteroidetes The levels of IgA and the expression of the gene encoding activation-induced cytidine deaminase (AID) in the large intestine lamina propria, which is crucial for class switch recombination from IgM to IgA, were increased in soluble high fiber diet (sHFD)-fed mice. We found that Bacteroides acidifaciens (B. acidifaciens) was the most abundant Bacteroidetes species in both sHFD- and normal diet-fed mice. In addition, the gut IgA levels were associated with the relative abundance of Bacteroidd mice. We show here that the levels of IgA in the gut and the expression of activation-induced cytidine deaminase (AID) in the large intestine lamina propria, which is crucial for class switch recombination from IgM to IgA were correlated with the abundance of Bacteroides fragilis group such as Bacteroides faecis, Bacteroides caccae and Bacteroides acidifaciens (B. acidifaciens). B. acidifaciens monoassociated mice increased gut IgA production and AID expression. Soluble dietary fiber may improve gut immune function, thereby protecting against bowel pathogens and reducing inflammatory bowel diseases. Copyright © 2020 American Society for Microbiology.Cerato-platanins (CPs) form a family of fungal small-secreted cysteine-rich proteins (SSCPs) and are of particular interest not only because of their surface activity but also their abundant secretion by fungi. We performed an evolutionary analysis for 283 CPs from 157 fungal genomes with the focus on the opportunistic plant-beneficial and mycoparasitic fungus Trichoderma Our results revealed the long evolutionary history of CPs in Dikarya fungi that have undergone several events of lateral gene transfer and gene duplication. Three genes were maintained in the core genome of Trichoderma, while some species have up to four CP-encoding genes. All Trichoderma CPs evolve under stabilizing natural selection pressure. The functional analysis of CPs in T. guizhouense and T. harzianum revealed that only EPL1 is active at all stages of the development but plays a minor role in interactions with other fungi and bacteria. The deletion of this gene results in increased colonization of tomato roots by Trichoderma spp. Sim long evolutionary history of CPs with multiple cases of gene duplication and events of inter-fungal lateral gene transfers. In the mycoparasitic Trichoderma spp., CPs evolve under stabilizing natural selection and hamper the colonization of roots. We propose that the ability to modify the hydrophobicity of fungal hyphosphere is a key to unlock the evolutionary and functional paradox of these proteins. Copyright © 2020 American Society for Microbiology.Endophytes are microorganisms that live inside plants and are often beneficial for the host. Kosakonia is a novel bacterial genus that includes several species that are diazotrophic and plant-associated. link3 This study reports two quorum sensing related LuxR solos, designated as LoxR and PsrR, in the plant endophyte Kosakonia sp. KO348. LoxR modeling and biochemical studies demonstrated that LoxR binds N-acyl homoserine lactones (AHLs) in a promiscuous way. PsrR on the other hand belongs to the plant-associated-bacteria (PAB) LuxR solos that respond to plant compounds. Target promoter studies as well as modeling and phylogenetic comparisons suggest that PAB LuxR solos are likely to respond to different plant compounds. Finally, LoxR is involved in the regulation of T6SS and PsrR plays a role in root endosphere colonization.Significance of the study Cell-cell signaling in bacteria allows a synchronized and coordinated behavior of a microbial community. LuxR solos represent a sub-family of proteins in proteobacteria which most commonly detect and respond to signals produced exogenously by other microbes or eukaryotic hosts. In this study we report that a plant beneficial bacterial endophyte belonging to the novel genus of Kosakonia possesses two LuxR solos; one is involved in the detection of exogenous N-acyl homoserine lactone quorum sensing signals and the other in detecting compound(s) produced by the host plant. These two Kosakonia LuxR solos are therefore most likely involved in interspecies and interkingodm signaling. Copyright © 2020 Mosquito et al.The Moore swab is a classic environmental surveillance tool whereby a gauze pad tied with string is suspended in flowing water or wastewater contaminated with human feces and harboring enteric pathogens that pose a human health threat. In contrast to single volume “grab” samples, Moore swabs act as continuous filters to “trap” microorganisms, which are subsequently isolated and confirmed using appropriate laboratory methods. Continuous filtration is valuable for isolation of transiently present pathogens such as human-restricted Salmonella enterica serovars Typhi and Paratyphi A and B. The technique was first proposed (1948) to trace Salmonella Paratyphi B systematically through sewers to pinpoint the residence of a chronic carrier responsible for sporadic outbreaks of paratyphoid fever. From 1948-1986, Moore swabs proved instrumental to identify long-term human reservoirs (chronic carriers) and long-cycle environmental transmission pathways of S. Typhi and Paratyphi, for example to decipher endemic transmission in Santiago, Chile during the 1980s.