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in fungal morphogenesis processes. Copyright © 2020 American Society for Microbiology.The Binary (Bin) toxin from Lysinibacillus sphaericus is effective to mosquito larvae but its utilization is threatened by the development of insect resistance. Bin toxin is composed by the BinB subunit required for binding to midgut receptors, and the BinA subunit that causes toxicity after cell internalization, mediated by BinB. Culex quinquefasciatus resistance to this toxin is caused by mutations that prevent expression of Bin toxin-receptors in the midgut. Previously, it was shown that the Cyt1Aa toxin, from Bacillus thuringiensis subsp. israelensis (Bti), restores Bin toxicity to Bin-resistant Cx. quinquefasciatus and to Aedes aegypti larvae, which is naturally devoid of functional Bin receptors. selleck chemicals Our goal was to elucidate the mechanism involved in Cyt1Aa synergism with Bin in such larvae. link2 In vivo assays showed that the mixture of Bin toxin, or its BinA subunit, with Cyt1Aa was effective to kill resistant larvae. However, no specific binding interaction between Cyt1Aa and the Bin toxin, or its subunits, alization of Bin or its BinA subunit into such cells but binding interaction between Bin and Cyt1Aa is not observed. Thus, this mechanism contrasts with that for the synergy between Cyt1Aa and the Bti Cry toxins where active Cyt1Aa is not necessary but a specific binding between Cry and Cyt1Aa is required. Our study established the initial molecular basis of the synergy between Bin-Cyt1Aa and these findings enlarge our knowledge of their mode of action that could help to develop improved strategies to cope with insect resistance. Copyright © 2020 American Society for Microbiology.During the course of evolution, dogs and cats have been subjected to extensive domestication becoming the principal companion animals for humans. For this reason, their health care, including their intestinal microbiota, is considered of considerable importance. However, the canine and feline gut microbiota is still a largely unexplored research area. In the current work, we profiled the microbiota of 23 feline fecal samples by 16S rRNA gene and bifidobacterial ITS approaches and compared this information with previously reported data from 138 canine fecal samples. The obtained data allowed the reconstruction of the core-gut microbiota of the abovementioned samples coupled with their classification into distinct Community State Types at both genus and species-levels, identifying Bacteroides, Fusobacterium and Prevotella 9 as the main bacterial components of the canine and feline gut microbiota. At species-level, the intestinal bifidobacterial gut community of dogs and cats differed from each other both in tere Types at either of the two investigated taxonomic levels. Furthermore, the reconstruction of core gut microbiota coupled with co-variance network analysis based on bifidobacterial ITS profiling revealed differences in the bifidobacterial composition of canine and feline gut microbiota, suggesting that particular bifidobacterial species have developed a selective ability to colonize a specific host. Copyright © 2020 American Society for Microbiology.The AdhR regulatory protein is an activator of σ54-dependent transcription of adhA1 and adhA2 genes, which are required for alcohol synthesis in C. beijerinckii Here, we identified the signal perceived by AdhR and determined the regulatory mechanism of AdhR activity. By assaying the activity of AdhR in N-terminally truncated forms, a negative control mechanism of AdhR activity was identified, in which the central AAA+ domain is subject to repression by the N-terminal GAF and PAS domains. Binding of Fe2+ to the GAF domain was found to relieve intramolecular repression and stimulate the ATPase activity of AdhR, allowing the AdhR to activate transcription. This control mechanism enables AdhR to regulate transcription of adhA1 and adhA2 in response to cellular redox status. The mutants deficient in AdhR or σ54 showed large shifts in intracellular redox state indicated by NADH/NAD+ ratio under conditions of increased electron availability or oxidative stress. We demonstrated the Fe2+-activated transcriptional regu Microbiology.Aspergillus fumigatus is a major cause of human disease. The survival of this fungus is dependent on cell wall organization and function of its components. The cell wall integrity pathway (CWIP) is the primary signaling cascade that controls de novo synthesis of the cell wall in fungi. Abundant conidiation is a hallmark in A. fumigatus and uptake of conidia by a susceptible host is usually the initial event in infection. The formation of conidia is mediated by the development of fungal-specific specialized structures, conidiophores, which are accompanied by cell wall remodeling. The molecular regulation of these changes in cell wall composition required for the rise of conidiophore from the solid surface and to disperse the conidia into the air are currently unknown. Here, we investigated the role of CWIP in conidiation. We show that mutants in the CWIP pkcA G579R, ΔmpkA and ΔrlmA displayed reduced conidiation during synchronized asexual differentiation. The transcription factor RlmA directly regulated the exres the remodeling of the cell wall so that the conidiophores can rise and withstand the chains of conidia. The events regulating cell wall remodeling during conidiation are currently unknown. Here, we show that the cell wall integrity pathway (CWIP) components RlmA and MpkA directly contribute to the activation of the conidiation cascade by enabling transcription or phosphorylation of critical proteins involved in asexual development. This study points to an essential role for the CWIP during conidiation and provides further insights into the complex regulation of asexual development in filamentous fungi. Copyright © 2020 American Society for Microbiology.Sophoricoside glycosylated derivatives, especially long chain glycosylated sophoricosides (LCGS) have greatly improved water solubility compared with sophoricoside. Here cyclodextrin glycosyltransferase from Paenibacillus macerans (PmCGTase) was employed for sophoricoside glycosylation. Saturation mutagenesis of alanine 156, alanine 166, glycine 173, and leucine 174 were performed due to their non-conservative properties among (α-, β-, and γ-) CGTases with different product specificities. Variants L174P, A156V/L174P, and A156V/L174P/A166Y greatly improved the product specificity for LCGS. pH significantly affected the extent of glycosylation catalyzed by the variants. Further investigations revealed that the pH-regulatory mechanism for LCGS synthesis mainly depends on a disproportionation route at a lower pH (pH 4) and a cyclization-coupling route at a higher pH (pH 8), and equivalent effects of cyclization-coupling and disproportionation routes at pH 5. Whereas SCGS are primarily produced via disproportionat significantly affected by pH. Our results reveal the pH-regulatory mechanism on the glycosylated product specificity of CGTase. This work adds to our understanding of the synthesis of long chain glycosylated sophoricosides and provides guidance for exploring related product specificity of CGTase based on pH regulation. Copyright © 2020 American Society for Microbiology.Klebsiella pneumoniae (Kp) is of growing public health concern due to the emergence of strains that are multidrug-resistant, virulent, or both. Taxonomically, Kp includes seven phylogroups, with Kp1 (K. pneumoniae sensu stricto) being medically prominent. Kp can be present in environmental sources such as soils and vegetation, which could act as reservoirs of animal and human infections. However, the current lack of screening methods to detect Kp in complex matrices limits research on Kp ecology. Here we analysed 1,001 genome sequences and found that existing molecular detection targets lack specificity for Kp. A novel real-time PCR method, the ZKIR assay, was developed and used to detect Kp in 96 environmental samples. link3 Results were compared to a culture-based method using Simmons citrate agar with 1% inositol (SCAI) medium coupled to MALDI-TOF mass spectrometry identification. Whole-genome sequencing of environmental Kp was performed.The ZKIR assay was positive for the 48 tested Kp reference strains, whereasgens are diverse and classified into seven phylogroups, which may differ in their reservoirs and epidemiology. Proper management of this public health hazard requires a better understanding of Kp ecology and routes of transmission to humans. So far, detection of these microorganisms in complex matrices such as food or the environment has been difficult due to a lack of accurate and sensitive methods. Here, we describe a novel method based on real-time PCR, which enables detection of all Kp phylogroups with high sensitivity and specificity. We used this method to detect Kp isolates from environmental samples, and show based on genomic sequencing that they differ in antimicrobial resistance and virulence gene content, from human clinical Kp isolates. The ZKIR PCR assay will enable rapid screening of multiple samples for Kp presence and will thereby facilitate tracking the dispersal patterns of these pathogenic strains across environmental, food, animal and human sources. Copyright © 2020 Barbier et al.In Saccharomyces cerevisiae, Y family DNA polymerase Rev1 is involved in the repair of DNA damage by translesion DNA synthesis (TLS). In the current study, to elucidate the role of Rev1 in oxidative stress-induced DNA damage in S. cerevisiae, REV1 was deleted and overexpressed; transcriptome analysis of these mutants along with the wild-type strain was performed to screen potential genes that could be associated with REV1 during response to DNA damage. Under 2 mM H2O2 treatment, the deletion of REV1 resulted in a 1.5- and 2.8-fold decrease in the survival rate and mutation frequency, respectively, whereas overexpression of REV1 increased the survival rate and mutation frequency by 1.1- and 2.9-fold, respectively, as compared to the survival rate and mutation frequency of the wild-type strain. Transcriptome and phenotypic analyses identified that Sml1 aggravated oxidative stress in the yeast cells by inhibiting the activity of Rev1. This inhibition was due to the physical interaction between the BRCT domain of Rev1 and the amino acid residues 36-70 of Sml1, the cell survival rate and mutation frequency increased by 1.8 and 3.1-fold, respectively, upon blocking this interaction. We also found that Sml1 inhibited Rev1 phosphorylation under oxidative stress, deletion of SML1 increased the phosphorylation of Rev1 by 46 %, whereas overexpression of SML1 reduced phosphorylation of Rev1. Overall, these findings demonstrate that Sml1 could be a novel regulator that mediates Rev1 dephosphorylation to inhibit its activity during oxidative stress.IMPORTANCE Rev1 was critical for cell growth in S. cerevisiae, and the deletion of REV1 caused a severe growth defect under exposure to oxidative stress with 2 mM H2O2 Furthermore, we found that Sml1 physically interacted with Rev1 and inhibited Rev1 phosphorylation, thereby inhibited Rev1 DNA antioxidant activity. These findings indicate that Sml1 could be a novel regulator for Rev1 in response to DNA damage by oxidative stress. Copyright © 2020 American Society for Microbiology.