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Environmental adaptability for quorum sensing: regulating iron uptake during biofilm formation in Paracoccus denitrificans.
This report elaborates the correlation among QS, iron uptake and biofilm formation, and thus contributes to understanding the ecological behavior of environmental bacteria. PMID: 29776923 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Zhang Y, Gao J, Wang L, Liu S, Bai Z, Zhuang X, Zhuang G Tags: Appl Environ Microbiol Source Type: research

Tools for rapid genetic engineering of Vibrio fischeri.
Abstract Vibrio fischeri is used as a model for number of processes, including symbiosis, quorum sensing, bioluminescence, and biofilm formation. Many of these studies depend on generating deletion mutants and complementing them. Engineering such strains, however, is a time-consuming, multi-step process that relies on cloning and subcloning. Here, we describe a set of tools that can be used to rapidly engineer deletions and insertions in the V. fischeri chromosome without cloning. We developed a uniform approach for generating deletions using PCR SOEing (Splicing by Overlap Extension) with antibiotic cassettes fla...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Visick KL, Hodge-Hanson KM, Tischler AH, Bennett AK, Mastrodomenico V Tags: Appl Environ Microbiol Source Type: research

Unravelling the reduction pathway as alternative metabolic route to hydroxycinnamate decarboxylation in Lactobacillus plantarum.
This study revealed that L. plantarum hydroxycinnamate reductase is a heterodimeric NADH-dependent coumarate reductase acting on a carbon-carbon double bond.IMPORTANCELactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables where hydroxycinnamic acids are present. The bacterial metabolism on these compounds during fermentation plays a fundamental role on the biological activity of hydroxycinnamates. L. plantarum strains exhibit an as yet unknown reducing activity, transforming hydroxycinnamates to substituted phenylpropionic acids, which possess higher antioxidant activity that thei...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Santamaría L, Reverón I, López de Felipe F, de Las Rivas B, Muñoz R Tags: Appl Environ Microbiol Source Type: research

Occurrence of traditional and alternative fecal indicators in tropical urban environments under different land use patterns.
This study evaluates the geospatial distribution of fecal indicator bacteria (FIB) (i.e., E. coli, Enterococcus spp.) and the alternative fecal indicator, pepper mild mottle virus (PMMoV), in tropical freshwater environments under different land use patterns. Results show that the occurrence and concentration of microbial fecal indicators was higher for urban-dominated areas than parkland-dominated, consistent with land use weightage. Significant positive correlations with traditional FIB indicate that PMMoV is a suitable indicator of fecal contamination in tropical catchments waters (0.549 ≤ rho ≤ 0.612, P
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Saeidi N, Gu X, Han TN, Goh SG, Kitajima M, Kushmaro A, Schmitz BW, Gin KY Tags: Appl Environ Microbiol Source Type: research

Ecological engineering helps maximize function in algal oil production.
Abstract Algal biofuels have the potential to curb emissions of greenhouse gases from fossil fuels, but current growing methods fail to produce fuels that meet the multiple standards necessary for economical industrial use. For example, algae grown as monocultures for biofuel production have not simultaneously and economically achieved high yields of the high-quality, lipid-rich biomass desired for the industrial-scale production of bio-oil. Decades of study in the field of ecology have demonstrated that simultaneous increases in multiple functions, such as the quantity and quality of biomass, can occur in natural...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Jackrel SL, Narwani A, Bentlage B, Levine RB, Hietala DC, Savage PE, Oakley TH, Denef VJ, Cardinale BJ Tags: Appl Environ Microbiol Source Type: research

Enrichment of clinically relevant organisms in spontaneous preterm delivered placenta and reagent contamination across all clinical groups in a large UK pregnancy cohort.
In this study differences in the placental microbiota of term and preterm deliveries from a large UK pregnancy cohort were studied using 16S targeted amplicon sequencing. The impact of contamination from DNA extraction, PCR reagents, as well as those from delivery itself were also examined. A total of 400 placental samples from 256 singleton pregnancies were analysed and differences investigated between spontaneous preterm, non-spontaneous preterm, and term delivered placenta. DNA from recently delivered placenta was extracted, and screening for bacterial DNA was carried out using targeted sequencing of the 16S rRNA gene o...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Leon LJ, Doyle R, Diez-Benavente E, Clark TG, Klein N, Stanier P, Moore GE Tags: Appl Environ Microbiol Source Type: research

Antibacterial effects of phage lysin LysGH15 on planktonic cells and biofilms of diverse staphylococci.
In this study, we observed the ability of the phage lysin LysGH15 to eliminate staphylococcal planktonic cells and biofilms formed by Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus hominis All these strains were sensitive to LysGH15, showing reductions in bacterial counts of approximately 4 log units within 30 min after treatment with 20 μg/mL LysGH15, and the minimum inhibitory concentrations (MICs) ranged from 8 μg/mL to 32 μg/mL. LysGH15 efficiently prevented biofilm formation by the four staphylococcal species at a dose of 50 μg/mL. At a higher dose (100 &m...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Zhang Y, Cheng M, Zhang H, Dai J, Guo Z, Li X, Ji Y, Cai R, Xi H, Wang X, Xue Y, Sun C, Feng X, Lei L, Han W, Gu J Tags: Appl Environ Microbiol Source Type: research

Modifying the lantibiotic mutacin 1140 for increased yield, activity and stability.
Abstract Mutacin 1140 belongs to the epidermin family of type AI lantibiotics. This family has a broad spectrum of activity against Gram-positive bacteria. The binding of mutacin 1140 to lipid II leads to the inhibition of cell wall synthesis. Pharmacokinetic experiments on type AI lantibiotics are generally discouraging for clinical applications due to their short half-life. The unprotected dehydrated and protease susceptible residues outside of the lanthionine rings may play a role in their short half-life in physiological settings. Previous mutagenesis work on mutacin 1140 has been limited to the lanthionine-fo...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Geng M, Smith L Tags: Appl Environ Microbiol Source Type: research

Shuffling the neutral drift of unspecific peroxygenase in Saccharomyces cerevisiae.
In this study, we conducted a campaign of genetic drift with UPO in Saccharomyces cerevisiae so that neutral mutations were simply added and recombined in vivo With low mutational loading and an activity threshold of 45% of the parent's native function, mutant libraries enriched in folded and active UPO variants were generated. After only 8 rounds of genetic drift and DNA shuffling, we identified an ensemble of 25 neutrally evolved variants with modifications in peroxidative and peroxygenative activities, kinetic thermostability and enhanced tolerance to organic solvents. With an average 4.6 substitutions introduced per cl...
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Martin-Diaz J, Paret C, García-Ruiz E, Molina-Espeja P, Alcalde M Tags: Appl Environ Microbiol Source Type: research

CgMED3 affects cell size and budding index to coordinate Candida glabrata cell growth.
In conclusion, we report that CgMed3AB functions as a wheel responsible for driving cellular acetyl-CoA metabolism, indirectly inducing the transcription of Cgcln3 and coordinating cell growth (Fig. 1). We propose that mediator subunits may represent a vital regulatory target modulating cell growth in C. glabrata. PMID: 29776932 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - May 18, 2018 Category: Microbiology Authors: Liu H, Kong L, Qi Y, Chen X, Liu L Tags: Appl Environ Microbiol Source Type: research

Enhanced and complete removal of phenylurea herbicides by combinational transgenic plant-microbial remediation.
In this study, the synergistic relationship between transgenic Arabidopsis expressing the bacterial N-demethylase PdmAB in the chloroplast and the inoculated intermediate-mineralizing bacterium Sphingobium sp. strain 1017-1 in the rhizosphere is used to develop an intriguing bioremediation method. The combinational transgenic plant-microbe remediation system shows a more efficient and complete removal of phenylurea herbicides from contaminated-sites, and can overcome the constraints of individual phytoremediation or bioaugmentation methods. PMID: 29752264 [PubMed - as supplied by publisher] (Source: Applied and Enviro...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Yan X, Huang JW, Xu XH, Chen D, Xie XT, Tao Q, He J, Jiang JD Tags: Appl Environ Microbiol Source Type: research

An iterative synthetic approach to engineer a high-performing PhoB-specific reporter.
bb EV Abstract Transcriptional reporters are common tools for analyzing either the transcription of a gene of interest or the activity of a specific transcriptional regulator. Unfortunately, the latter application has the shortcoming that native promoters did not evolve as optimal readouts for the activity of a particular regulator. We sought to synthesize an optimized transcriptional reporter for assessing PhoB activity, aiming for maximal "on" expression when PhoB is active, minimal background in the "off" state, and no control elements for other regulators. We designed specific sequences for...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Stoudenmire JL, Essock-Burns T, Weathers EN, Solaimanpour S, Mrázek J, Stabb EV Tags: Appl Environ Microbiol Source Type: research

Biofilm formation by Helicobacter pylori is differentially affected by common culture conditions and protein plays a central role in the biofilm matrix.
Abstract The concept of Helicobacter pylori biofilm formation is relatively new. To help provide a foundation for future biofilm studies, we characterized the biofilm formation ability of a common H. pylori lab strain, G27. The goal of this study was to evaluate biofilm formation by G27 in response to common culture conditions and to explore the biofilm matrix. Our results indicate that while growth in varies types of media did not dramatically effect biofilm formation, surface selection had a significant effect on final biofilm mass. Furthermore, enzymatic assays and confocal microscopy revealed that proteins app...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Windham IH, Servetas SL, Whitmire JM, Pletzer D, Hancock REW, Merrell DS Tags: Appl Environ Microbiol Source Type: research

A Novel Maltogenic Amylase CoMA from Corallococcus sp. EGB Catalyzes the Conversion of Maltooligosaccharides and Soluble Starch to Maltose.
Abstract Here, a novel amylolytic enzyme gene designated coMA was cloned from Corallococcus sp. EGB. The deduced amino acid sequence contained a predicted lipoprotein signal peptide (residues 1-18) and conserved glycoside hydrolase family 13 (GH13) module. The amino acid sequence of CoMA exhibits low sequence identity (10-19%) with cyclodextrin-hydrolyzing enzymes (GH13_20) and is assigned to GH13_36. The most outstanding feature of CoMA is its ability to catalyze the conversion of maltooligosaccharides (≥ G3) and soluble starch to maltose as the sole hydrolysate. Moreover, it can hydrolyze γ-cyclodextrin...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Zhou J, Li Z, Zhang H, Wu J, Ye X, Dong W, Jiang M, Huang Y, Cui Z Tags: Appl Environ Microbiol Source Type: research

Preferred hexoses influence long-term memory and induction of lactose catabolism by Streptococcus mutans.
Abstract Bacteria prioritize sugar metabolism via carbohydrate catabolite repression, which regulates global gene expression to optimize the catabolism of preferred substrates. Here, we report an unusual long-term memory effect in certain Streptococcus mutans strains that alters adaptation to growth on lactose after prior exposure to glucose or fructose. In strain GS-5, cells that were first cultured on fructose then transferred to lactose displayed an exceptionally long lag (>11 h) and slower growth, compared to cells first cultured on glucose or cellobiose, which displayed a reduction in lag phase by as much ...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Zeng L, Chen L, Burne RA Tags: Appl Environ Microbiol Source Type: research

Thioredoxin and glutaredoxin systems required for oxidative stress resistance, fungicide sensitivity and virulence of Alternaria alternata.
This study determines the function of thioredoxin and glutaredoxin systems in the phytopathogenic fungus Alternaria alternata via analyzing mutants from the targeted deletion of genes encoding thioredoxin peroxidase (Tsa1), thioredoxin reductase (Trr1) and glutathione reductase (Glr1). Trr1, Glr1 but not Tsa1 are required for growth and conidiation. Reduced growth and conidiation seen in the Trr1 or Glr1 deletion mutant can be restored by glutathione. Deletion mutants showing growth inhibition by oxidants are defective for H2O2 detoxification and induce smaller lesions on citrus leaves. Trr1, Glr1 but not Tsa1 also contrib...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Ma H, Wang M, Gai Y, Fu H, Zhang B, Ruan R, Chung KR, Li H Tags: Appl Environ Microbiol Source Type: research

The discovery of two native Baeyer-Villiger monooxygenases for asymmetric synthesis of bulky chiral sulfoxides.
Abstract Two Baeyer-Villiger monooxygenases (BVMOs) designated BoBVMO and AmBVMO were discovered from Bradyrhizobium oligotrophicum and Aeromicrobium marinum, respectively. Both monooxygenases displayed novel features for catalyzing the asymmetric sulfoxidation of bulky and pharmaceutically relevant thioethers. Evolutionary relationship and sequence analysis revealed that the two BVMOs belong to the family of typical type I BVMO and the subtype ethionamide monooxygenase. Both BVMOs are active toward medium- and long-chain aliphatic ketones as well as various thioether substrates, but ineffective toward cyclohexano...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Zhang Y, Liu F, Xu N, Wu YQ, Zheng YC, Zhao Q, Lin G, Yu HL, Xu JH Tags: Appl Environ Microbiol Source Type: research

Microbial mineral illization of montmorillonite in low-permeability oil reservoirs for microbial enhanced oil recovery.
This study aimed to reveal the interaction mechanism between Fe (III)-reducing bacterial strains and Ca-montmorillonite under anaerobic atmosphere, and to investigate the extent and rates of Fe (III) reduction and phase changes with their activities. Application of Fe (III)-reducing bacteria will provide a new way to inhibit clay swelling, to elevate reservoir permeability, and to reduce pore throat resistance after water flooding for enhanced oil recovery in low-permeability reservoirs. PMID: 29752271 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Cui K, Sun S, Xiao M, Liu T, Xu Q, Dong H, Wang D, Gong Y, Sha T, Hou J, Zhang Z, Fu P Tags: Appl Environ Microbiol Source Type: research

Functional profiling and crystal structures of isothiocyanate hydrolases found in gut-associated and plant pathogenic bacteria.
This study explores a newly discovered protein in the beta-lactamase superfamily: SaxA, or isothiocyanate hydrolase. Isothiocyanates are defensive compounds found in many cabbage-related crop plants, and are currently being investigated for their antimicrobial and anticarcinogenic properties. We show that isothiocyanate hydrolases are responsible for the breakdown of several of these plant defensive chemicals in vitro and suggest their potential for mitigating the beneficial effects of isothiocyanates in crop protection and cancer prevention. PMID: 29752272 [PubMed - as supplied by publisher] (Source: Applied and Envi...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: van den Bosch TJM, Tan K, Joachimiak A, Welte CU Tags: Appl Environ Microbiol Source Type: research

Differential production of Psl in planktonic cells leads to two distinctive attaching phenotypes in Pseudomonas aeruginosa.
Abstract Exponentially growing bacteria in a well-mixed planktonic culture are generally assumed to be physiologically and phenotypically uniform, and distinct from their genetically identical counterparts living in biofilms. Using a combination of high spatiotemporal microscopy and a bacterial tracking algorithm, in this study, we showed that the planktonic cells of Pseudomonas aeruginosa differently attach to surfaces even when they remained in the exponential phase. We consistently observed that fast- and slow-attaching phenotypes coexist in planktonic cells, regardless of their growth phase. Furthermore, we fo...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Yang S, Cheng X, Jin Z, Xia A, Ni L, Zhang R, Jin F Tags: Appl Environ Microbiol Source Type: research

Molecular epidemiology of Shiga toxin-producing Escherichia coli (STEC) on New Zealand dairy farms: application of a culture-independent assay and whole genome sequencing.
This study provides evidence that would be useful for designing on-farm interventions to reduce direct and indirect human exposure to STEC.ImportanceCattle are asymptomatic carriers of Shiga toxin-producing E. coli (STEC) that can cause bloody diarrhea and kidney failure in humans if ingested. New Zealand has relatively high numbers of STEC cases, and contact with cattle feces and living near cattle are risk factors for human infection. This study assessed the national prevalence of STEC in young dairy cattle by randomly selecting 102 farms all over New Zealand. The study used a molecular laboratory method that has relativ...
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Browne AS, Midwinter AC, Withers H, Cookson AL, Biggs PJ, Marshall JC, Benschop J, Hathaway S, Haack NA, Akhter RN, French NP Tags: Appl Environ Microbiol Source Type: research

Whole genomic analysis of Bacillus thuringiensis revealing partial genes as a source of novel Cry toxins.
This study provides insight of a potential source for novel Cry toxins. PMID: 29752275 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - May 11, 2018 Category: Microbiology Authors: Sajid M, Geng C, Li M, Wang Y, Liu H, Zheng J, Peng D, Sun M Tags: Appl Environ Microbiol Source Type: research

Mutant variants of the substrate-binding protein DppA from Escherichia coli enhance growth on non-standard γ-glutamyl amide-containing peptides.
Mutant variants of the substrate-binding protein DppA from Escherichia coli enhance growth on non-standard γ-glutamyl amide-containing peptides. Appl Environ Microbiol. 2018 May 04;: Authors: Kuenzl T, Li-Blatter X, Srivastava P, Herdewijn P, Sharpe T, Panke S Abstract The import of non-natural molecules is a recurring problem in fundamental as well as applied aspects of microbiology. Escherichia coli's dipeptide permease (Dpp) is an ABC-type multicomponent transporter system located in the cytoplasmic membrane, which is capable of transporting a wide range of di- and tripeptides with structural...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Kuenzl T, Li-Blatter X, Srivastava P, Herdewijn P, Sharpe T, Panke S Tags: Appl Environ Microbiol Source Type: research

Susceptibility of Methicillin-Resistant and -Susceptible Staphylococcus aureus-Isolates of Various Clonal Lineages from Germany to Eight Biocides.
Abstract Few studies have been conducted on the susceptibility of bacteria to biocides. A total of 182 methicillin-resistant and -susceptible Staphylococcus aureus isolates collected from healthy or diseased humans and animals in Germany were included in the present study. Sixty-three isolates of animal origin and 119 human isolates were tested for their MICs to eight biocides or heavy metals by the broth microdilution method. The MIC50 and MIC90 values of human and animal isolates were equal or differed by not more than one dilution step and statistical analysis revealed that differences between MICs of human and...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Kernberger-Fischer IA, Krischek C, Strommenger B, Fiegen U, Beyerbach M, Kreienbrock L, Klein G, Kehrenberg C Tags: Appl Environ Microbiol Source Type: research

Effects of Ceftiofur and Chlortetracycline on the Resistome of Feedlot Cattle.
Abstract Treatment of food producing animals with antimicrobial drugs (AMD) is controversial because of concerns regarding promotion of antimicrobial resistance (AMR). To investigate this concern, resistance genes in metagenomic bovine fecal samples during a clinical trial were analyzed to assess the impacts of treatment on beef feedlot cattle resistomes. Four groups of cattle were exposed, using a 2x2 factorial design, to different regimens of antimicrobial treatment. Injections of ceftiofur crystalline free acid (a third generation cephalosporin) were used to treat all cattle in treated pens vs. only a single an...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Weinroth MD, Scott HM, Norby B, Loneragan GH, Noyes NR, Rovira P, Doster E, Yang X, Woerner DR, Morley PS, Belk KE Tags: Appl Environ Microbiol Source Type: research

Terminal olefin profiles and phylogenetic analyses of olefin synthases in diversified cyanobacterial species.
In this study, investigations of the domains, modular architectures and phylogenies of Ols in 28 cyanobacterial strains suggested distinctive pathway evolution. Structural feature analyses revealed 1-alkenes with three carbon chain lengths (C15, C17 and C19). In addition, the total cellular fatty acid profile revealed the diversity of the carbon chain lengths, while the fatty acid feeding assay indicated substrate carbon chain length specificity of cyanobacterial Ols enzymes. Finally, in silico analyses suggested that the N-terminus of the modular Ols enzyme exhibited typical characteristics of a fatty acyl-adenylate ligas...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Zhu T, Scalvenzi T, Sassoon N, Lu X, Gugger M Tags: Appl Environ Microbiol Source Type: research

Crown-of-thorns sea star, Acanthaster cf. solaris, have tissue-characteristic microbiomes with potential roles in health and reproduction.
This study shows that CoTS have tissue-characteristic bacterial communities and identifies taxa that could play a role in reproduction and host health.IMPORTANCECoral-eating crown of thorns sea stars (CoTS; Acanthaster spp. complex) are native to the Indo-Pacific, but during periodic population outbreaks they can reach extreme densities (>1000 starfish per hectare) and function like a pest species. On the Great Barrier Reef, Australia, CoTS have long been considered one of the major contributors to coral loss. There has been significant investment in a targeted control program using lethal injection, and there is intere...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Høj L, Levy N, Baillie BK, Clode PL, Strohmaier RC, Siboni N, Webster NS, Uthicke S, Bourne DG Tags: Appl Environ Microbiol Source Type: research

Phylotype-level profiling of lactobacilli in highly complex environments by means of an ITS-based metagenomic approach.
Abstract The genus Lactobacillus is a widespread taxon, members of which are highly relevant to functional and fermented foods, while they are also commonly present in host-associated gut and vaginal microbiota. Substantial efforts have been undertaken to disclose the genetic repertoire of all members of the genus Lactobacillus, yet their species-level profiling in complex matrices is still undeveloped due to the poor phylotype resolution of profiling approaches based on the 16S rRNA gene. To overcome this limitation, an ITS-based profiling method was developed to accurately profile lactobacilli at species-level. ...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Milani C, Duranti S, Mangifesta M, Lugli GA, Turroni F, Mancabelli L, Viappiani A, Anzalone R, Alessandri G, Ossiprandi MC, van Sinderen D, Ventura M Tags: Appl Environ Microbiol Source Type: research

A Fungal P450 from Thanatephorus cucumeris with Novel Steroid Hydroxylation Capabilities.
In this study, we identified a P450 enzyme (STH10) and an oxidoreductase (POR) from Thanatephorus cucumeris NBRC 6298 by a combination of transcriptome sequencing and heterologous expression in Pichia pastoris The biotransformation of 11-deoxycortisol was performed by using the Pichia pastoris whole cells co-expressing sth10 and por, and the product analysis indicated that the STH10 enzyme possessed steroidal 19- and 11β-hydroxylase activities. This is a novel fungal P450 enzyme with 19-hydroxylase activity, which is different from the known steroidal aromatase CYP19 and CYP11B families of enzymes.IMPORTANCE Hydroxyla...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Lu W, Chen X, Feng J, Bao YJ, Wang Y, Wu Q, Zhu D Tags: Appl Environ Microbiol Source Type: research

Characterization and engineering of 3-ketosteroid 9 α-hydroxylases in Mycobacterium neoaurum ATCC 25795 for the development of androst-1,4-diene-3,17-dione and 9α-hydroxy-androst-4-ene-3,17-dione--producing strains.
In this study, two KshA homologues, KshA1N and KshA2N, were characterized and further engineered in a sterol-digesting strain, Mycobacterium neoaurum ATCC 25795 to construct androstenone-producing strains. Thereinto, kshA1N is a member of the gene cluster encoding sterol catabolism enzymes, and its transcription exhibited a 4.7-fold increase under cholesterol induction. Furthermore, null mutation of kshA1N led to the stable accumulation of androst-4-ene-3,17-dione (AD) and androst-1,4-diene-3,17-dione (ADD). We determined kshA2N to be a redundant form of kshA1N Through a combined modification of kshA1N , kshA2N , and other...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Liu HH, Xu LQ, Yao K, Xiong LB, Tao XY, Liu M, Wang FQ, Wei DZ Tags: Appl Environ Microbiol Source Type: research

Effects of PslG on the surface movement of Pseudomonas aeruginosa.
Abstract PslG attracted a lot of attention recently due to its great potential abilities in inhibiting biofilms of Pseudomonas aeruginosa However, how PslG affects biofilm development still remains largely unexplored. Here, we focused on the surface motility of bacterial cells, which is critical for biofilm development. We studied the effect of PslG on bacterial surface movement in early biofilm development at a single-cell resolution by using a high-throughput bacterial tracking technique. The results showed that compared with no exogenous PslG addition, when PslG was added to the medium, bacterial surface moveme...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Zhang J, He J, Zhai C, Ma LZ, Gu L, Zhao K Tags: Appl Environ Microbiol Source Type: research

Novel human-associated Lachnospiraceae genetic markers improve detection of fecal pollution sources in urban waters.
Abstract The human microbiome contains many organisms that could potentially be used as indicators of human fecal pollution. Here we report the development of two novel human-associated genetic marker assays that target organisms within the family Lachnospiraceae Next-generation sequencing of the V6 region of the 16S rRNA gene from sewage and animal stool samples identified 40 human-associated marker candidates with a robust signal in sewage and low or no occurrence in nonhuman hosts. Two were chosen for quantitative PCR (qPCR) assay development using longer sequences (V2 to V9 regions) generated from clone librar...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Feng S, Bootsma M, McLellan SL Tags: Appl Environ Microbiol Source Type: research

An Escherichia coli nitrogen starvation response is important for mutualistic coexistence with Rhodopseudomonas palustris.
Abstract Microbial mutualistic cross-feeding interactions are ubiquitous and can drive important community functions. Engaging in cross-feeding undoubtedly affects the physiology and metabolism of individual species involved. However, the nature in which an individual's physiology is influenced by cross-feeding and the importance of those physiological changes for the mutualism have received little attention. We previously developed a genetically tractable coculture to study bacterial mutualisms. The coculture consists of fermentative Escherichia coli and phototrophic Rhodopseudomonas palustris In this coculture, ...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: McCully AL, Behringer MG, Gliessman JR, Pilipenko EV, Mazny JL, Lynch M, Drummond DA, McKinlay JB Tags: Appl Environ Microbiol Source Type: research

Fecal microbiota transplantation in experimental ulcerative colitis reveals associated gut microbial and host metabolic reprogramming.
This study combined clinical symptoms measurement, 16S rRNA gene microbial profiling and metabolomics to comprehensively investigate the gut bacterial and host metabolic association and reprogramming in FMT treated experimental UC. These data can advance our understanding of the effect of FMT on UC and the involvement of gut microbial dysbiosis in the development of UC. PMID: 29728388 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Yan Z, Gao XJ, Li T, Wei B, Wang P, Yang Y, Yan R Tags: Appl Environ Microbiol Source Type: research

Insight into Energy Conservation via Alternative Carbon Monoxide Metabolism in Carboxydothermus pertinax Revealed by Comparative Genome Analysis.
In this study, we used comparative genome analysis of the genus Carboxydothermus to show variations in the CO dehydrogenase/energy-converting hydrogenase gene cluster, which is responsible for CO metabolism with H2 production (hydrogenogenic CO metabolism). Indeed, ability or inability to produce H2 with CO oxidation is explained by the presence or absence of this gene cluster in C. hydrogenoformans, C. islandicus, and C. ferrireducens Interestingly, despite its hydrogenogenic CO metabolism, C. pertinax lacks the Ni-CO dehydrogenase catalytic subunit (CooS-I) and its transcriptional regulator encoding genes in this gene cl...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Fukuyama Y, Omae K, Yoneda Y, Yoshida T, Sako Y Tags: Appl Environ Microbiol Source Type: research

Unprotonated Short Chain Alkylamines Inhibit Staphylolytic Activity of Lysostaphin in a Wall Teichoic Acid-Dependent Manner.
This study offers new insight into the impact of short-chain alkylamines on both Lst and WTA structure and function, and provides guidance to the application of Lst in harsh environments.Importance Lysostaphin (Lst) effectively and selectively kills Staphylococcus aureus, the bacterial culprit of many hospital- and community-acquired skin and respiratory infections, and food poisoning. Lst has been investigated in animal models and clinical trials, in industrial formulations and environmental settings. Herein, we studied the mechanistic basis of the inhibitory effect of alkylamines, such as monoethanolamine (MEA), a widely...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Wu X, Kwon SJ, Kim D, Zha J, Mora-Pale M, Dordick JS Tags: Appl Environ Microbiol Source Type: research

Proteins encoded by the gerP operon are localised to the inner coat in Bacilluscereus spores and are dependent on GerPA and SafA for assembly.
Abstract Germination of Bacillus spores is triggered by certain amino acids and sugar molecules, which permeate through the outermost layers of the spore to interact with receptor complexes that reside in the inner membrane. Previous studies have shown that mutations in the hexacistronic gerP locus reduce the rate of spore germination, with experimental evidence indicating that the defect stems from reduced permeability of the spore coat to germinant molecules. Here we use the ellipsoid localisation microscopy technique to reveal that all six Bacillus cereus GerP proteins share proximity with cortex lytic enzymes ...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Ghosh A, Manton JD, Mustafa AR, Gupta M, Ayuso-Garcia A, Rees EJ, Christie G Tags: Appl Environ Microbiol Source Type: research

Small, low, but potent: the complex regulatory role of the small RNA SolB on solventogenesis in Clostridium acetobutylicum.
Abstract The recently revived Clostridium acetobutylicum based Acetone-Butanol-Ethanol (ABE) fermentation is widely celebrated and studied for its impact on industrial biotechnology. C. acetobutylicum has been extensively studied and engineered, yet critical areas of the molecular basis of how solvent formation is regulated remain unresolved. The core solventogenic genes (adhE1/aad, ctfA, ctfB, adc) are coded on the sol locus of the pSOL1 megaplasmid, whose loss leads to asporogenous, "degenerate" cells. The sol locus includes a noncoding sRNA, SolB, whose role is presumed as critical for solventogenesis...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Jones AJ, Fast AG, Clupper M, Papoutsakis ET Tags: Appl Environ Microbiol Source Type: research

Maximizing Growth Yield and Dispersal via Quorum Sensing Promotes Cooperation in Vibrio Bacteria.
In this study, we demonstrate in multiple conditions that QS-mediated cooperation can increase in populations of Vibrios when cells experience narrow population bottlenecks or disperse from defectors. This occurred for both conditional cooperation mediated by QS and unconditional cooperation, although conditional cooperators were better able to stabilize cooperation over a much wider range of conditions. Thus, we observed that population structuring allowed for assortment of competing genotypes and promoted cooperation via kin selection in microbes in a QS-dependent manner. PMID: 29728393 [PubMed - as supplied by publ...
Source: Applied and Environmental Microbiology - May 4, 2018 Category: Microbiology Authors: Bruger EL, Waters CM Tags: Appl Environ Microbiol Source Type: research

Regulation of the Synthesis and Secretion of the Iron Chelator Cyclodipeptide Pulcherriminic Acid in Bacillus licheniformis.
This study provides insights into the regulation network and explained the decision mechanism of pulcherriminic acid biosynthesis. The synthetic gene cluster yvmC-cypX was directly negatively regulated by three regulators, AbrB, YvnA and YvmB. Inside the regulation network, YvnA expression was not only repressed by AbrB but also repressed by iron-limiting environments, while YvmB expression was repressed by YvnA. The transporter gene yvmA is repressed by YvmB and required for pulcherriminic acid secretion. The biosynthesis window was determined by the combined concentration of the three regulators in iron rich environment....
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Wang D, Zhan Y, Cai D, Li X, Wang Q, Chen S Tags: Appl Environ Microbiol Source Type: research

Glycine betaine monooxygenase, an unusual Rieske-type oxygenase system, catalyzes the oxidative N-demethylation of glycine betaine in Chromohalobacter salexigens DSM 3043.
Abstract Although some bacteria, including Chromohalobacer salexigens DSM 3043, can use glycine betaine (hereafter referred to as GB) as the sole carbon and energy source, little information is available about the genes and their encoded proteins involved in the initial step of GB degradation pathway. In the present study, the results of conserved domain analysis, construction of in-frame deletion mutants, and in vivo functional complementation assay suggested that the open reading frames Csal_1004 and Csal_1005, designated bmoA and bmoB, may act as the terminal oxygenase and the ferredoxin reductase in a novel Ri...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Shao YH, Guo LZ, Zhang YQ, Yu H, Zhao BS, Pang HQ, Lu WD Tags: Appl Environ Microbiol Source Type: research

An ATP-dependent ligase with substrate flexibility involved in assembly of the peptidyl nucleoside antibiotic polyoxin.
Abstract Polyoxin (POL) is an unusual peptidyl nucleoside antibiotic, in which peptidyl moiety and nucleoside skeleton are linked by an amide bond. However, their biosynthesis remains poorly understood. Here, we report the deciphering of PolG as an ATP-dependent ligase responsible for the assembly of POL. A polG mutant is capable of accumulating multiple intermediates, including the peptidyl moiety (carbamoylpolyoxamic acid, CPOAA) and the nucleosides skeletons (POL-C and the previously overlooked thymine POL-C). We further demonstrated that PolG employs an ATP-dependent mechanism for amide bond formation, and tha...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Gong R, Qi J, Wu P, Cai YS, Ma H, Liu Y, Duan H, Wang M, Deng Z, Price NPJ, Chen W Tags: Appl Environ Microbiol Source Type: research

The catabolite repressor/activator, Cra, bridges a connection between carbon metabolism and host colonization in the plant drought resistance-promoting bacterium Pantoea alhagi LTYR-11Z.
This study elucidates the regulatory role of Cra in bacterial attachment and colonization of plants, which raises the possibility to extend our studies to other bacteria associated with plant and human health. PMID: 29703735 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Zhang L, Li M, Li Q, Chen C, Qu M, Li M, Wang Y, Shen X Tags: Appl Environ Microbiol Source Type: research

Distribution and diversity of rhodopsin-producing microbes in the Chesapeake Bay.
Abstract Although sunlight is an abundant source of energy in surface environments, less than 0.5% of the available photons are captured by (bacterio)chlorophyll dependent photosynthesis in plants and bacteria. Metagenomic data indicate that 30-60% of the bacterial genomes in some environments encode rhodopsins, retinal-based photosystems found in heterotrophs, suggesting that sunlight may provide energy for more life than previously suspected. However, quantitative data on the number of cells that produce rhodopsins in environmental systems is limited. Here, we use total internal reflection fluorescence microscop...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Maresca JA, Miller KJ, Keffer JL, Sabanayagam CR, Campbell BJ Tags: Appl Environ Microbiol Source Type: research

Quantitative survival of Leptospira interrogans in soil and water microcosms.
In this study, we aimed to quantitatively characterize the survival of Leptospira interrogans serovar Copenhageni in environmental matrices. We constructed laboratory microcosms to simulate natural conditions and determined the persistence of DNA markers in soil, mud, spring water and sewage using a qPCR and a PMA-qPCR assay. We found that L. interrogans does not survive at high concentrations in the tested matrices. No net growth was detected in any of the experimental conditions and in all cases the concentration of the DNA markers targeted decreased from the beginning of the experiment following an exponential decay wit...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Casanovas-Massana A, Pedra GG, Wunder EA, Diggle PJ, Begon M, Ko AI Tags: Appl Environ Microbiol Source Type: research

Yeast cell wall chitin reduces wine haze formation.
In this study, Chardonnay grape must fermented by various yeast strains resulted in wines with different protein haze levels indicating differences in haze protective capacities of the strains. The cell wall chitin levels of these strains were determined, and a strong correlation between cell wall chitin levels and haze protection capability was observed. To further evaluate the mechanism of haze protection, Escherichia coli-produced GFP-tagged grape chitinase was shown to bind efficiently to yeast cell walls in a cell wall chitin concentration-dependent manner, while commercial chitinase was removed from synthetic wine in...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Ndlovu T, Divol B, Bauer FF Tags: Appl Environ Microbiol Source Type: research

Tuf gene sequence variation in Bifidobacterium longum subspecies infantis detected in the fecal microbiota of Chinese infants.
Abstract Members of the bacterial genus Bifidobacterium generally dominate the faecal microbiota of infants. The species B. longum is prevalent, but the subspecies longum and infantis that are known to colonize the infant bowel are not usually differentiated in microbiota investigations. These subspecies differ in their capacity to metabolize Human Milk Oligosaccharides (HMO) and may have differing ecological and symbiotic roles in humans. Quantitative PCR provides a quick analytical method by which to accurately ascertain the abundances of target species in microbiotas and microcosms. However, amplification targe...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Lawley B, Centanni M, Watanabe J, Sims I, Carnachan S, Broadbent R, Lee PS, Wong KH, Tannock GW Tags: Appl Environ Microbiol Source Type: research

Free chlorine disinfection as a selection pressure on norovirus.
This study aimed to prove the strain-dependent susceptibility of norovirus to free chlorine. A population originated from murine norovirus S7-PP3, a surrogate for human noroviruses in environmental testing, was exposed to free chlorine and then propagated in a host cell. This cycle of free chlorine exposure followed by propagation in cells was repeated ten times, and populations with lower susceptibility to free chlorine were obtained from two independent trials of chlorine exposure cycles. Open reading frames (ORFs) 2 and 3 of murine norovirus genome were analyzed by next-generation sequencing, and a unique nonsynonymous ...
Source: Applied and Environmental Microbiology - April 27, 2018 Category: Microbiology Authors: Rachmadi AT, Kitajima M, Watanabe K, Yaegashi S, Serrana J, Nakamura A, Nakagomi T, Nakagomi O, Katayama K, Okabe S, Sano D Tags: Appl Environ Microbiol Source Type: research

Serotype diversity and antimicrobial resistance among Salmonella enterica isolated from patients at an equine referral hospital.
In this study, we identify temporal trends in the distribution of Salmonella serotypes and their mechanisms of antimicrobial resistance; further, we are able to determine the likely origin of several temporal clusters of infection by using whole genome sequencing. These data can be used to focus strategies to better contain the dissemination and enhance the mitigation of Salmonella infections, and to provide evidence-based policies and guidelines to steward antimicrobial use in veterinary medicine. PMID: 29678910 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - April 20, 2018 Category: Microbiology Authors: Leon IM, Lawhon SD, Norman KN, Threadgill DS, Ohta N, Vinasco J, Scott HM Tags: Appl Environ Microbiol Source Type: research

Food-spoilage-associated Leuconostoc, Lactococcus, and Lactobacillus species display different survival strategies in response to competition.
This study gives an insight into the system-level interactions and the different competition-induced survival strategies related to enhanced uptake and catabolism of carbon sources, overexpression of adhesins and putative bacteriocins, and to the induction of exchange of genetic material. Even though this experiment dealt only with three LAB strains in vitro, these findings agreed well with the relative abundance patterns typically reported for these species in natural food microbial communities. PMID: 29678911 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - April 20, 2018 Category: Microbiology Authors: Andreevskaya M, Jääskeläinen E, Johansson P, Ylinen A, Paulin L, Björkroth J, Auvinen P Tags: Appl Environ Microbiol Source Type: research