Dichotomy between regulation of coral bacterial communities and calcification physiology under ocean acidification conditions.
Abstract Ocean acidification (OA) threatens the growth and function of coral reef ecosystems. A key component to coral health is the microbiome, but little is known about the impact of OA on coral microbiomes. A submarine CO2 vent at Maug Island in the Northern Marianas Islands provides a natural pH gradient to investigate coral responses to long-term OA conditions. Three coral species (Pocillopora eydouxi, Porites lobata, and Porites rus) were sampled from three sites where mean seawater pH is 8.04, 7.98, and 7.94. We characterized coral bacterial communities (using 16S rRNA gene sequencing) and determined pH of ...
Source: Applied and Environmental Microbiology - January 8, 2021 Category: Microbiology Authors: Shore A, Day RD, Stewart JA, Burge CA Tags: Appl Environ Microbiol Source Type: research

Generation of lactose and protease positive probiotic Lacticaseibacillus rhamnosus GG by conjugation with Lactococcus lactis NCDO 712.
In this study, we made L. rhamnosus GG lactose and protease positive by conjugation with the dairy Lactococcus lactis strain NCDO 712 carrying the lactose-protease plasmid pLP712. A lactose hydrolyzing transconjugant colony was obtained on agar containing lactose as the sole source of carbohydrates. By microscopic analysis and PCR with LGG- and pLP712-specific primers, the transconjugant was confirmed to be originated from LGG, and to carry the plasmid pLP712. The transconjugant was named L. rhamnosus LAB49. Isolation of plasmids revealed that not only pLP712, but also other plasmids had been transferred from L. lactis int...
Source: Applied and Environmental Microbiology - January 8, 2021 Category: Microbiology Authors: Hussain N, Li R, Takala TM, Tariq M, Zaidi AH, Saris PEJ Tags: Appl Environ Microbiol Source Type: research

Swimming Escherichia coli explore the environment by L évy walk.
Swimming Escherichia coli explore the environment by Lévy walk. Appl Environ Microbiol. 2021 Jan 08;: Authors: Huo H, He R, Zhang R, Yuan J Abstract E. coli cells swim in aqueous environment in a random walk of alternating runs and tumbles. The diffusion characteristics of this random walk remains unclear. Here, by tracking the swimming of wildtype cells in a 3d homogeneous environment, we found that their trajectories are super diffusive, consistent with Lévy walk behavior. For comparison, we tracked the swimming of mutant cells that lack the chemotaxis signaling noise (the steady-state...
Source: Applied and Environmental Microbiology - January 8, 2021 Category: Microbiology Authors: Huo H, He R, Zhang R, Yuan J Tags: Appl Environ Microbiol Source Type: research

Microbe-Mineral Interaction and Novel Proteins for Iron Oxide Mineral Reduction in the Hyperthermophilic Crenarchaeon Pyrodictium delaneyi.
In this study, the physiology of dissimilatory iron and nitrate reduction was examined in the hyperthermophilic crenarchaeon Pyrodictium delaneyi Su06T Iron barrier experiments showed that P. delaneyi required direct contact with the Fe(III) oxide mineral ferrihydrite for reduction. The separate addition of an exogenous electron shuttle (anthraquinone-2,6-disulfonate), a metal chelator (nitrilotriacetic acid), and 75% spent cell-free supernatant did not stimulate growth with or without the barrier. Protein electrophoresis showed that the c-type cytochrome and general protein compositions of P. delaneyi changed when grown o...
Source: Applied and Environmental Microbiology - January 8, 2021 Category: Microbiology Authors: Kashyap S, Holden JF Tags: Appl Environ Microbiol Source Type: research

Long-term survival of virulent tularemia pathogens outside a host in conditions that mimic natural aquatic environments.
elaus J Abstract Francisella tularensis, causative agent of the zoonotic disease tularemia, can cause seasonal outbreaks of acute febrile illness in humans with disease peaks in late summer to autumn. Interestingly, its mechanisms for environmental persistence between outbreaks are poorly understood. One hypothesis is that F. tularensis forms biofilm in aquatic environments. We utilized two fully virulent wild type strains: FSC200 (F. tularensis subsp. holarctica) and Schu S4 (F. tularensis subsp. tularensis); and three control strains: the attenuated Live Vaccine Strain (LVS; F. tularensis subsp. holarctica), a S...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Golovliov I, Bäckman S, Granberg M, Salomonsson E, Lundmark E, Näslund J, Busch JD, Birdsell D, Sahl JW, Wagner DM, Johansson A, Forsman M, Thelaus J Tags: Appl Environ Microbiol Source Type: research

Salmonella genomics and population analyses reveal high inter- and intra- serovar diversity in freshwater.
Abstract Freshwater can support the survival of the enteric pathogen Salmonella, though temporal Salmonella diversity in a large watershed has not been assessed. At 28 locations within the Susquehanna River basin, 10-liter samples were assessed in spring and summer over two years. Salmonella prevalence was 49%, and increased river discharge was the main driver of Salmonella presence. The amplicon-based sequencing tool, CRISPR-SeroSeq, was used to determine serovar population diversity and detected 25 different Salmonella serovars, including up to ten serovars from a single water sample. On average there were three...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Deaven AM, Ferreira CM, Reed EA, Chen See JR, Lee NA, Almaraz E, Rios PC, Marogi JG, Lamendella R, Zheng J, Bell RL, Shariat NW Tags: Appl Environ Microbiol Source Type: research

Essential Roles of Two FRQ Proteins (Frq1/2) in Virulence, Infection Cycle and Calcofluor-Specific Signaling of Beauveria bassiana.
Abstract Two FRQ proteins (Frq1/2) distinct in molecular mass and structure coexist in Beauveria bassiana, an asexual insect-pathogenic fungus. Frq1 and Frq2 have been proven to have opposite nuclear rhythms that can persistently activate developmental activator genes, and hence orchestrate nonrhythmic conidiation in vitro under light or in darkness. Here, we report an essentiality of either FRQ, but greater importance of Frq2 than of Frq1, for the fungal virulence and infection cycle. The fungal virulence was attenuated significantly more in the absence of frq2 than of frq1 through either normal cuticle infection...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Tong SM, Gao BJ, Peng H, Feng MG Tags: Appl Environ Microbiol Source Type: research

Nature versus Nurture: Assessing the impact of strain diversity and pre-growth conditions on Salmonella enterica, Escherichia coli, and Listeria spp. growth and survival on selected produce items.
Abstract Inoculation studies are important when assessing microbial survival and growth in food products. These studies typically involve the pre-growth of multiple strains of a target pathogen under a single condition; this emphasizes strain diversity. To gain a better understanding of the impacts of strain diversity ("Nature") and pre-growth conditions ("Nurture") on subsequent bacterial growth in foods, we assessed the growth and survival of S. enterica (n=5), E. coli (n=6) and Listeria (n=5) inoculated onto tomatoes, pre-cut lettuce and cantaloupe rind, respectively. Pre-growth conditions i...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Harrand AS, Guariglia-Oropeza V, Skeens J, Kent D, Wiedmann M Tags: Appl Environ Microbiol Source Type: research

Insights into alginate degradation through the characterization of a thermophilic exolytic alginate lyase.
k VGH Abstract Enzymatic depolymerization of seaweed polysaccharides is gaining interest for the production of functional oligosaccharides and fermentable sugars. Herein, we describe a thermostable alginate lyase that belongs to Polysaccharide Lyase family 17 (PL17) and was derived from an Arctic Mid-Ocean Ridge (AMOR) metagenomics dataset. This enzyme, AMOR_PL17A, is a thermostable exolytic oligoalginate lyase (EC 4.2.2.26), which can degrade alginate, poly β-d-mannuronate and poly α-l-guluronate within a broad range of pH, temperature and salinity conditions. Site-directed mutagenesis showed that tyro...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Arntzen MØ, Pedersen B, Klau LJ, Stokke R, Oftebro M, Antonsen SG, Fredriksen L, Sletta H, Aarstad OA, Aachmann FL, Horn SJ, Eijsink VGH Tags: Appl Environ Microbiol Source Type: research

LysR Family regulator LttR Controls Conjugated Linoleic Acid Production by Directly Activating the cla Operon in Lactobacillus plantarum.
This study reveals a new regulatory mechanism in CLA biotransformation and provides a new potential metabolic engineering strategy to increase the yield of CLA.Importance Our work has identified a novel transcriptional regulator LTTR that regulates the production of CLA by activating the transcription of cla-dh and cla-dc, essential genes participating in the CLA synthesis in Lactobacillus plantarum This provides the insight into the regulatory mechanism of CLA synthesis and broadens our understanding about synthesis and regulatory mechanisms of biosynthesis of CLA. PMID: 33397697 [PubMed - as supplied by publisher] (...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Liu XX, Xiong ZQ, Wang GQ, Wang LF, Xia YJ, Song X, Ai LZ Tags: Appl Environ Microbiol Source Type: research

Additional role of nicotinic acid hydroxylase for the transformation of 3-succinoyl-pyridine by Pseudomonas sp. JY-Q.
Abstract Nicotine and nicotinic acid (NA) are both considered to be representatives of N-heterocyclic aromatic compounds, and their degradation pathways have been revealed in Pseudomonas species. However, the co-occurrence of these two pathways is only observed in Pseudomonas sp. JY-Q. Nicotine pyrrolidine catabolism pathway of strain JY-Q consists of function modules Nic1, Spm, and Nic2. The module enzyme, 3-succinoylpyridine monooxygenases (Spm), catalyzes transformation of 3-succinoyl-pyridine (SP) to 6-hydroxy-3-succinoyl-pyridine (HSP). There exist two homologous but not identical Spm (namely Spm1 and Spm2) i...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Li J, Li S, Xie L, Chen G, Shen M, Pan F, Shu M, Yang Y, Jiao Y, Zhang F, Linhardt RJ, Zhong W Tags: Appl Environ Microbiol Source Type: research

Reduced antibacterial drug resistance and bla CTX-M β-lactamase gene carriage in cattle-associated Escherichia coli at low temperatures, at sites dominated by older animals and on pastureland: implications for surveillance.
Reduced antibacterial drug resistance and bla CTX-M β-lactamase gene carriage in cattle-associated Escherichia coli at low temperatures, at sites dominated by older animals and on pastureland: implications for surveillance. Appl Environ Microbiol. 2021 Jan 04;: Authors: Schubert H, Morley K, Puddy EF, Arbon R, Findlay J, Mounsey O, Gould VC, Vass L, Evans M, Rees GM, Barrett DC, Turner KM, Cogan TA, Avison MB, Reyher KK Abstract Little is known about the drivers of critically important antibacterial resistance in species with zoonotic potential present on farms (e.g. CTX-M β-lactamase-positi...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Schubert H, Morley K, Puddy EF, Arbon R, Findlay J, Mounsey O, Gould VC, Vass L, Evans M, Rees GM, Barrett DC, Turner KM, Cogan TA, Avison MB, Reyher KK Tags: Appl Environ Microbiol Source Type: research

Control of competence in Vibrio fischeri.
Abstract Vibrio species, including the squid symbiont Vibrio fischeri, become competent to take up DNA under specific conditions. For example, V. fischeri becomes competent when grown in the presence of chitin oligosaccharides or upon overproduction of the competence regulatory factor TfoX. While little is known about the regulatory pathway(s) that control V. fischeri competence, this microbe encodes homologs of factors that control competence in the well-studied V. cholerae To further develop V. fischeri as a genetically-tractable organism, we evaluated the roles of some of these competence homologs. Using TfoX-o...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Cohen JJ, Eichinger SJ, Witte DA, Cook CJ, Fidopiastis PM, Tepavčević J, Visick KL Tags: Appl Environ Microbiol Source Type: research

Genomic insights into methicillin-resistant Staphylococcus aureus spa type t899 isolates belonging to different sequence types.
This study provides a genomic insight into the diversity of t899 isolates using cgMLST, SNP-based phylogeny and the description of selected antimicrobial resistance and virulence markers. The SNP-based phylogenic tree showed that isolates sharing the same spa type (t899) but different STs highly diverged in their core and accessory genomes, revealing discriminant antimicrobial-resistant (AMR) and virulence markers. Our results highlighted that, in a surveillance context where only spa typing is used, an additional multiplex PCR for the detection of the tet(M), sak and seg genes would valuably allow to distinguish ST9 from ...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Tegegne HA, Koláčková I, Florianová M, Wattiau P, Gelbíčová T, Boland C, Madec JY, Haenni M, Karpíšková R Tags: Appl Environ Microbiol Source Type: research

A Pseudoalteromonas clade with remarkable biosynthetic potential.
This study demonstrates that the Pseudoalteromonas strain, HM-SA03, isolated from the venomous blue-ringed octopus, Hapalochalaena sp., is a biosynthetically talented organism, capable of producing alterochromides and potentially six other specialized metabolites. We have identified a pseudoalterobactin biosynthesis gene cluster and proposed a pathway for the production of the associated siderophore. A novel siderophore biosynthesis gene cluster with unprecedented architecture was also identified in the HM-SA03 genome. Finally, we have demonstrated that HM-SA03 belongs to a phylogenetic clade of strains with extraordinary ...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Chau R, Pearson LA, Cain J, Kalaitzis JA, Neilan BA Tags: Appl Environ Microbiol Source Type: research

Hydrolytic dehalogenation operon of 4-chlorobenzoate is transcriptionally regulated by the TetR-type repressor FcbR and its ligand 4-chlorobenzoyl-CoA.
This study identified a transcriptional repressor and its ligand of the fcb operon, extending halogenated benzoyl-CoA as a member of known ligands of transcriptional regulators.Importance The bacterial hydrolytic dehalogenation of 4CBA is a special CoA-activation type catabolic pathway, which plays an important role in the biodegradation of polychlorinated biphenyls and many certain herbicides. With genetic and biochemical approaches, the present study identified the transcriptional repressor and its cognate effector of a 4CBA hydrolytic dehalogenation operon. This work extends halogenated benzoyl-CoA as a new member of Co...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Cheng M, Pei D, He X, Liu Y, Zhu P, Yan X Tags: Appl Environ Microbiol Source Type: research

Harnessing CRISPR-Cas9 for genome editing in Streptococcus pneumoniae D39V.
Abstract CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against viruses and plasmids by detection and cleavage of invading foreign DNA. Modified versions of this system can be exploited as a biotechnological tool for precise genome editing at a targeted locus. Here, we developed a replicative plasmid that carries the CRISPR-Cas9 system for RNA-programmable, genome editing by counterselection in the opportunistic human pathogen Streptococcus pneumoniae. Specifically, we demonstrate an approach for making targeted, marker-less gene knockouts and large genome deletions. After a precise double-...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Synefiaridou D, Veening JW Tags: Appl Environ Microbiol Source Type: research

Hidden Diversity within Common Protozoan Parasites Revealed by a Novel Genomotyping Scheme.
Abstract Giardia duodenalis (syn. G. lamblia, G. intestinalis) is the causative agent of giardiasis, one of the most common diarrheal infections in humans. Evolutionary relationships among G. duodenalis genotypes (or subtypes) of assemblage B, one of two genetic assemblages causing the majority of human infections, remain unclear due to poor phylogenetic resolution of current typing methods. Here, we devised a methodology to identify new markers for a streamlined multi-locus sequence typing (MLST) scheme based on comparisons of all core genes against the phylogeny of whole-genome sequences (WGS). Our analysis iden...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Seabolt MH, Konstantinidis KT, Roellig DM Tags: Appl Environ Microbiol Source Type: research

Discovery and functional analysis of a salicylic acid hydroxylase from Aspergillus niger.
In this study, we used transcriptome data of A. niger grown on salicylic acid to identify genes (shyA and crcA) involved in salicylic acid metabolism. Heterologous production in Escherichia coli followed by biochemical characterization confirmed the function of ShyA and CrcA. The combination of ShyA and CrcA demonstrated that cis,cis-muconic acid can be produced from salicylic acid. In addition, the in vivo roles of shyA, dhbA and crcA were studied by creating A. niger deletion mutants which revealed the role of these genes in the fungal metabolism of salicylic acid.Importance Nonrenewable petroleum sources are depleting a...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Lubbers RJM, Dilokpimol A, Visser J, Hildén KS, Mäkelä MR, de Vries RP Tags: Appl Environ Microbiol Source Type: research

A portable CRISPR-Cas9N system for flexible genome engineering in Lactobacillus acidophilus, Lactobacillus gasseri and Lactobacillus paracasei.
Abstract Diverse Lactobacillus strains are widely used as probiotic cultures in the dairy and dietary supplements industries, and specific strains such as Lactobacillus acidophilus NCFM have been engineered for the development of biotherapeutics. To expand the Lactobacillus manipulation toolbox with enhanced efficiency and ease, we present here a CRISPR-SpyCas9D10A nickase (Cas9N)-based system for programmable engineering of L. acidophilus NCFM, a model probiotic bacterium. Successful single-plasmid delivery system was achieved with the engineered pLbCas9N vector harboring cas9N under the regulation of a Lactobaci...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Goh YJ, Barrangou R Tags: Appl Environ Microbiol Source Type: research

Genomic characterization of Listeria spp. isolated from wild deer and boars' tonsils.
This study highlights the need for monitoring Lm environmental contamination and the importance of tonsils as a possible Lm intra-host reservoir.Importance: Listeria monocytogenes (Lm) is a foodborne bacterial pathogen responsible for listeriosis. Whole genome sequencing has been extensively used in public health and food industries to characterize circulating Listeria isolates, but genomic data on isolates occurring in natural environments and wild animals is still scarce. Here, we show that wild animals carry pathogenic Listeria and that the same genotypes can be found at different time points in different host species. ...
Source: Applied and Environmental Microbiology - January 4, 2021 Category: Microbiology Authors: Palacios-Gorba C, Moura A, Leclercq A, Gómez-Martín Á, Gomis J, Jiménez-Trigos E, Mocé ML, Lecuit M, Quereda JJ Tags: Appl Environ Microbiol Source Type: research

In vitro assessment of antimicrobial resistance dissemination dynamics during multidrug resistant bacteria invasion events using a continuous culture device.
Abstract Antimicrobial resistant pathogens display significant public health threats by causing difficulties in clinical treatment of bacterial infection. Antimicrobial resistance (AMR) is transmissible between bacteria, significantly increasing the appearance of antimicrobial resistant pathogens, aggravating the AMR problem. In this work, the dissemination dynamics of AMR from invading multidrug resistant (MDR) Escherichia coli to a community of pathogenic Salmonella enterica was investigated using a continuous culture device, and the behaviors of dissemination dynamics under different levels of antibiotic stress...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Li Z, Shi L, Wang B, Wei X, Zhang J, Guo T, Kong J, Wang M, Xu H Tags: Appl Environ Microbiol Source Type: research

A viability qPCR dilemma: Are longer amplicons better?
In this study, a wide range of incrementally increasing amplicon lengths (68-906 bp) was used on live and killed cells of nine bacterial species treated with viability dye (PMA). Increasing amplicon lengths up to approximately 200 bp resulted in increasing quantification cycle (Cq) differences between live and killed cells, while maintaining a good qPCR efficiency. Longer amplicon lengths, up to approximately 400 bp, further increased Cq difference, but at the cost of qPCR efficiency. Above 400 bp, no valuable increase in Cq differences was observed.ImportanceViability qPCR (v-qPCR) has evolved to a valuable, mainstream te...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Van Holm W, Ghesquière J, Boon N, Verspecht T, Bernaerts K, Zayed N, Chatzigiannidou I, Teughels W Tags: Appl Environ Microbiol Source Type: research

Formate dependent heterodisulfide reduction in a Methanomicrobiales archaeon.
Abstract Hydrogenotrophic methanogens produce CH4 using H2 as an electron donor to reduce CO2 In the absence of H2, many are able to use formate or alcohols as alternate electron donors. Methanogens from the order Methanomicrobiales are capable of growth with H2, but many lack genes encoding hydrogenases that are typically found in other hydrogenotrophic methanogens. In an effort to better understand electron flow in methanogens from the Methanomicrobiales, we undertook a genetic and biochemical study of heterodisulfide reductase (Hdr) in Methanoculleus thermophilus Hdr catalyzes an essential reaction by coupling ...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Abdul Halim MF, Day LA, Costa KC Tags: Appl Environ Microbiol Source Type: research

Spatial scale structure soil bacterial communities across an Arctic landscape.
This study identified a dispersal limitation (spatial autocorrelation) distance of approximately 60 m, required to obtain samples with fully independent bacterial communities, and therefore, should serve to inform future sampling strategies in the region and potentially elsewhere. The work also showed that strong taxa-environment statistical associations may not be reflected in the observed landscape distribution of the indicator taxa. PMID: 33361367 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Malard LA, Anwar MZ, Jacobsen CS, Pearce DA Tags: Appl Environ Microbiol Source Type: research

Acquired Resistance to Severe Ethanol Stress on Protein Quality Control in Saccharomyces cerevisiae.
Abstract Acute severe ethanol stress (10% v/v) damages proteins and causes the intracellular accumulation of insoluble proteins in Saccharomyces cerevisiae On the other hand, a pretreatment with mild stress increases tolerance to subsequent severe stress, which is called acquired stress resistance. It currently remains unclear whether the accumulation of insoluble proteins under severe ethanol stress may be mitigated by increasing protein quality control (PQC) activity in cells pretreated with mild stress. In the present study, we examined the induction of resistance to severe ethanol stress in PQC, and confirmed ...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Yoshida M, Kato S, Fukuda S, Izawa S Tags: Appl Environ Microbiol Source Type: research

Implementation of ATP and Microbial Indicator Testing for Hygiene Monitoring in a Tofu Production Facility Improves Product Quality and Hygienic Conditions of Food Contact Surfaces: A Case Study.
In this study, ATP testing and microbiological enumeration were implemented at a tofu production facility with the goal of improving cleaning practices and overall plant hygiene. Results from ATP monitoring were used to target areas of the production environment needing additional cleaning; ATP results were verified by microbiological enumeration of aerobic microorganisms, lactic acid bacteria, and yeasts and molds. Products from the production line were enumerated for the same microorganisms to determine if there was an impact on product quality. After the implementation of ATP monitoring and targeted cleaning, there was ...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Sogin JH, Lopez Velasco G, Yordem B, Lingle CK, David JM, Cobo M, Worobo RW Tags: Appl Environ Microbiol Source Type: research

A Large Tn7-like Transposon Confers Hyper-Resistance to Copper in Pseudomonas syringae pv. syringae.
ro JA Abstract Copper resistance mechanisms provide an important adaptive advantage to plant pathogenic bacteria under exposure to copper treatments. Copper resistance determinants have been described in Pseudomonas syringae pv. syringae (Pss) strains isolated from mango intimately associated with 62 kb plasmids belonging to the pPT23A family (PFP). It has been previously described that the indiscriminate use of copper-based compounds promotes the selection of copper resistant bacterial strains and constitutes a selective pressure in the evolution of copper resistance determinants. Hence, we have explored in this ...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Aprile F, Heredia-Ponce Z, Cazorla FM, de Vicente A, Gutiérrez-Barranquero JA Tags: Appl Environ Microbiol Source Type: research

Arsenate induced changes in bacterial metabolite and lipid pools during phosphate stress.
ner B Abstract Agrobacterium tumefaciens GW4 is a heterotrophic arsenite oxidizing bacterium with a high resistance to arsenic toxicity. It is now a model organism for studying the processes of arsenic detoxification and utilization. Previously, we demonstrated that under low phosphate conditions, arsenate (As(V)) could enhance bacterial growth and be incorporated into biomolecules including lipids. While the basic microbial As(V) resistance mechanisms have been characterized, global metabolic responses under low phosphate remain largely unknown. In the present work, the impact of As(V) and low phosphate on intrac...
Source: Applied and Environmental Microbiology - December 23, 2020 Category: Microbiology Authors: Zhuang W, Balasubramanian N, Wang L, Wang Q, McDermott TR, Copié V, Wang G, Bothner B Tags: Appl Environ Microbiol Source Type: research

A novel method for measuring phenotypic colistin resistance in Escherichia coli populations from chicken flocks.
Abstract Colistin is extensively used in animal production in many low- and middle-income countries. There is a need to develop methodologies to benchmark and monitor changes in resistance among mixed commensal bacterial populations in farms. We aimed to evaluate the performance of a broth microdilution method based on culturing a pooled Escherichia coli suspension (30-50 organisms) obtained from each sample. To confirm the biological basis and sensitivity of the method, we cultured 16 combinations of one colistin-susceptible and one mcr-1 encoded colistin-resistant E. coli in the presence of 2mg/L colistin. Optic...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Nguyen NT, Phuong Yen NT, Ky Thien NV, Van Cuong N, Kiet BT, Campbell J, Thwaites G, Baker S, Geskus RB, Carrique-Mas J Tags: Appl Environ Microbiol Source Type: research

The organosulfur compound dimethylsulfoniopropionate (DMSP) is utilized as an osmoprotectant by Vibrio species.
In this study, we showed that DMSP is used as an osmoprotectant by V. parahaemolyticus and several other Vibrio species including V. cholerae and V. vulnificus Using a V. parahaemolyticus proU double mutant, we demonstrated that these ABC transporters are not required for DMSP uptake. However, a bccT null mutant lacking all four BCCTs had a growth defect compared to wild type in high salinity media supplemented with DMSP. Using mutants possessing only one functional BCCT in growth pattern assays, we identified two BCCT-family transporters, BccT1 and BccT2, which are carriers of DMSP. The only V. parahaemolyticus BccT homol...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Gregory GJ, Boas KE, Boyd EF Tags: Appl Environ Microbiol Source Type: research

Enhancement of nitrous oxide emissions in soil microbial consortia via copper competition between proteobacterial methanotrophs and denitrifiers.
Abstract Unique means of copper scavenging have been identified in proteobacterial methanotrophs, particularly the use of methanobactin, a novel ribosomally synthesized post-translationally modified polypeptide that binds copper with very high affinity. The possibility that copper sequestration strategies of methanotrophs may interfere with copper uptake of denitrifiers in situ and thereby enhance N2O emissions was examined using a suite of laboratory experiments performed with rice paddy microbial consortia. Addition of purified methanobactin from Methylosinus trichosporium OB3b to denitrifying rice paddy soil mi...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Chang J, Kim DD, Semrau JD, Lee J, Heo H, Gu W, Yoon S Tags: Appl Environ Microbiol Source Type: research

Staphylococcal enterotoxin gene cluster: prediction of enterotoxin (SEG and SEI) production and of the source of food poisoning based on vSa β typing.
In this study we show promising results that in vitro production of SEG and SEI can be predicted based on the whole genome sequencing data of a strain. In addition, this data could be used to find the source (human- or cattle-derived) of an outbreak strain, which is the key for a better understanding of the role SEG and SEI play in foodborne outbreaks caused by S. aureus. PMID: 33355100 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Schwendimann L, Merda D, Berger T, Denayer S, Feraudet Tarisse C, Kläui AJ, Messio S, Mistou MY, Nia Y, Hennekinne JA, Graber HU Tags: Appl Environ Microbiol Source Type: research

No endospore formation confirmed in members of the phylum Proteobacteria.
This study concludes that endospore formation is still unique to the phylum Firmicutes. PMID: 33355101 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Beskrovnaya P, Fakih D, Morneau I, Hashimi A, Bello DG, Xing S, Nanci A, Huan T, Tocheva EI Tags: Appl Environ Microbiol Source Type: research

Plant-Scale Validation of Physical Heat Treatment of Poultry Litter Composts Using Surrogate and Indicator Microorganisms for Salmonella.
This study selected and used indicator and surrogate microorganisms for Salmonella to validate the processes for physically heat-treated poultry litter compost in litter processing plants. Initially laboratory validation studies indicated that 1.2- to 2.7-log or more reductions of desiccation-adapted Enterococcus faecium NRRL B-2354 were equivalent to> 5-log reductions of desiccation-adapted Salmonella Senftenberg 775/W in poultry litter compost, depending on treatment conditions and compost types. Plant validation studies were performed in one turkey litter compost processor and one laying hen litter compost processor....
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Wang H, Chen Z, Dharmasena M, Greene AK, Gardener BM, Holden B, Jiang X Tags: Appl Environ Microbiol Source Type: research

Characterization of Aspergillus fumigatus cross-resistance between clinical and DMI azole drugs.
Abstract Drug resistance poses a serious threat to human health and agricultural production. Azole drugs are the largest group of 14-α sterol demethylation inhibitor fungicides that are used both in agriculture and in clinical practice. As plant pathogenic molds share their natural environment with fungi that cause opportunistic infections in humans, both are exposed to a strong and persistent pressure of demethylase inhibitor (DMI) fungicides, including imidazole and triazole drugs. As a result, a loss of efficacy has occurred for this drug class in several species. In the clinical setting, Aspergillus fumi...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Garcia-Rubio R, Gonzalez-Jimenez I, Lucio J, Mellado E Tags: Appl Environ Microbiol Source Type: research

Integrated RNA-seq and Proteomic Studies Reveal Resource Reallocation towards Energy Metabolism and Defense in Skeletonema marinoi in Response to CO2 Increase.
In this study, we found that the elevated pCO2 seems to repress photosynthesis and growth of S. marinoi, and through massive gene expression reconfiguration induce cells to increase investment in protein synthesis, energy metabolism and antioxidative stress defense, likely to maintain pH homeostasis and population survival. This survival strategy may deprive this usually dominant diatom in temperate coastal waters of its competitive advantages in acidified environments. PMID: 33355106 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Zhang M, Zhen Y, Mi T, Lin S Tags: Appl Environ Microbiol Source Type: research

The symbiotic 'all-rounders': Partnerships between marine animals and chemosynthetic nitrogen-fixing bacteria.
Abstract Nitrogen fixation is a widespread metabolic trait in certain types of microorganisms called diazotrophs. Bioavailable nitrogen is limited in various habitats on land and in the sea, and accordingly, a range of plant, animal, and single-celled eukaryotes have evolved symbioses with diverse diazotrophic bacteria, with enormous economic and ecological benefits. Until recently, all known nitrogen-fixing symbionts were heterotrophs such as nodulating rhizobia, or photoautotrophs such as cyanobacteria. In 2016, the first chemoautotrophic nitrogen-fixing symbionts were discovered in a common family of marine cla...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Petersen JM, Yuen B Tags: Appl Environ Microbiol Source Type: research

Characterization of a galactosyl-binding protein module from a Cellvibrio japonicus endo-xyloglucanase defines a new family of Carbohydrate Binding Modules.
This study reveals Carbohydrate Binding Module Family 88 (CBM88) as a new family of galactose-binding protein modules, which are found in series with diverse microbial glycoside hydrolases, polysaccharide lyases, and carbohydrate esterases. The definition of CBM88 in the Carbohydrate-Active Enzymes classification (http://www.cazy.org/CBM88.html) will significantly enable future microbial (meta)genome analysis and functional studies. PMID: 33355108 [PubMed - as supplied by publisher] (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Attia MA, Brumer H Tags: Appl Environ Microbiol Source Type: research

L-arabinose induces the formation of viable non-proliferating spheroplasts in Vibrio cholerae.
lli E Abstract Vibrio cholerae, the agent of the deadly human disease cholera, propagates as a curved rod-shaped bacterium in warm waters. It is sensitive to cold, but persists in cold waters under the form of viable but non-dividing coccoidal shaped cells. Additionally, V. cholerae is able to form non-proliferating spherical cells in response to cell wall damage. It was recently reported that L-arabinose, a component of the hemicellulose and pectin of terrestrial plants, stops the growth of V. cholerae. Here, we show that L-arabinose induces the formation of spheroplasts that lose the ability to divide and stop g...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Espinosa E, Daniel S, Hernández SB, Goudin A, Cava F, Barre FX, Galli E Tags: Appl Environ Microbiol Source Type: research

Influence of single nitrogen compounds on growth and fermentation performance of Starmerella bacillaris and Saccharomyces cerevisiae during alcoholic fermentation.
Abstract Nitrogen is among the essential nutriments that govern interactions between yeast species in the wine environment. A thorough knowledge of how these yeasts assimilate the nitrogen compounds of grape juice is an important prerequisite for a successful co- or sequential fermentation. In the present study, we investigated the efficiency of 18 nitrogen sources for sustaining the growth and fermentation of two Starm. bacillaris strains displaying metabolic properties, compared to the reference yeast S. cerevisiae The analysis of growth and fermentation parameters provided a comprehensive picture of Starm. baci...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Englezos V, Cocolin L, Rantsiou K, Ortiz-Julien A, Bloem A, Seguinot P, Camarasa C Tags: Appl Environ Microbiol Source Type: research

Hindgut microbiota reflects different digestive strategies in dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae).
In this study, we characterised the hindgut bacterial communities found in 21 species of dung beetles across two lineages using 16S rRNA sequencing. We found that gut microbial diversity was more dependent on host phylogeny and gut morphology than specific dietary preferences or environment. In particular, gut microbial diversity was highest in the endemic, flightless genus Cephalodesmius that feeds on a broad range of composted organic matter. The hindgut of Cephalodesmius harbours a highly conserved core set of bacteria suggesting that the bacteria are symbiotic. Symbiosis is supported by the persistence of the core micr...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Ebert KM, Arnold WG, Ebert PR, Merritt DJ Tags: Appl Environ Microbiol Source Type: research

Modulating the gut microbiota of humans by dietary intervention with plant glycans.
Abstract The human colon contains a community of microbial species, mostly bacteria, which is often referred to as the gut microbiota. The community is considered essential to human well-being by conferring additional energy harvesting capacity, niche exclusion of pathogens, and molecular signaling activities that are integrated into human physiological processes. Plant polysaccharides (glycans, dietary fiber) are an important source of carbon and energy that supports the maintenance and functioning of the gut microbiota. Therefore, the daily quantity and quality of plant glycans consumed by the human host has the...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Tannock GW Tags: Appl Environ Microbiol Source Type: research

Recovery in methanotrophic activity does not reflect on the methane-driven interaction network after peat mining.
Abstract Aerobic methanotrophs are crucial in ombrotrophic peatlands, driving the methane and nitrogen cycles. Peat mining adversely affects the methanotrophs, but activity and community composition/abundances may recover after restoration. Considering that the methanotrophic activity and growth are significantly stimulated in the presence of other microorganisms, the methane-driven interaction network, encompassing methanotrophs and non-methanotrophs (i.e., methanotrophic interactome), may also be relevant in conferring community resilience. Yet, little is known of the response and recovery of the methanotrophic ...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Kaupper T, Mendes LW, Harnisz M, Krause SMB, Horn MA, Ho A Tags: Appl Environ Microbiol Source Type: research

Analysis and modeling of Blastomyces dermatitidis environmental prevalence in Minnesota using soil collected to compare basal and outbreak levels.
In this study, we used a culture-independent, PCR-based method to identify B. dermatitidis DNA in environmental samples using the BAD1 promoter region. We tested 250 environmental samples collected in Minnesota, either associated with blastomycosis outbreaks or environmental samples collected from high- and low-endemic regions to determine basal prevalence of B. dermatitidis in the environment. We identified a fifth BAD1 promoter haplotype of B. dermatitidis prevalent in Minnesota. Ecological niche analysis identified latitude, longitude, elevation, and site classification as environmental parameters associated with the pr...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Jackson KM, Pelletier KC, Scheftel J, Kerkaert JD, Robinson SL, McDonald T, Bender JB, Knight JF, Ireland M, Nielsen K Tags: Appl Environ Microbiol Source Type: research

Evolution of diverse effective N2-fixing microsymbionts of Cicer arietinum following horizontal transfer of the Mesorhizobium ciceri CC1192 symbiosis integrative and conjugative element.
Abstract Rhizobia are soil bacteria capable of forming N2-fixing symbioses with legumes, with highly effective strains often selected in agriculture as inoculants to maximize symbiotic N2 fixation. When rhizobia in the genus Mesorhizobium have been introduced with exotic legumes into farming systems, horizontal transfer of symbiosis Integrative and Conjugative Elements (ICEs) from the inoculant strain to soil bacteria has resulted in the evolution of ineffective N2-fixing rhizobia that are competitive for nodulation with the target legume. In Australia, Cicer arietinum (chickpea) has been inoculated since the 1970...
Source: Applied and Environmental Microbiology - December 18, 2020 Category: Microbiology Authors: Hill Y, Colombi E, Bonello E, Haskett T, Ramsay J, O'Hara G, Terpolilli J Tags: Appl Environ Microbiol Source Type: research

Cry75Aa (Mpp75Aa) Insecticidal Proteins for Controlling the Western Corn Rootworm, Diabrotica virgifera virgifera, (Coleoptera: Chrysomelidae), Isolated from the Insect Pathogenic Bacteria Brevibacillus laterosporus.
This study describes three closely related proteins, cloned from Brevibacillus laterosporus strains, that are lethal upon feeding to Diabrotica virgifera virgifera LeConte, the western corn rootworm (WCR). Mpp75Aa1, Mpp75Aa2 and Mpp75Aa3 were toxic to WCR larvae when fed purified protein. Transgenic plants expressing each mMpp75Aa protein were protected from feeding damage and showed significant reduction in adult emergence from infested plants by both susceptible and Cry3Bb1 and Cry34Ab1/Cry35Ab1-resistant WCR. These results demonstrate that proteins from B. laterosporus are as efficacious as the well-known Bacillus thuri...
Source: Applied and Environmental Microbiology - December 11, 2020 Category: Microbiology Authors: Bowen D, Yin Y, Flasinski S, Chay C, Bean G, Milligan J, Moar W, Pan A, Werner B, Buckman K, Howe A, Ciche T, Turner K, Pleau M, Zhang J, Kouadio JL, Hibbard BE, Price P, Roberts J Tags: Appl Environ Microbiol Source Type: research

Environmental conditions modulate the protein content and immunomodulatory activity of extracellular vesicles produced by the probiotic Propionibacterium freudenreichii.
Abstract Propionibacterium freudenreichii is a probiotic Gram-positive bacterium with promising immunomodulatory properties. It modulates regulatory cytokines, mitigates the inflammatory response in vitro and in vivo These properties were initially attributed to specific bacterial surface proteins. Recently, we showed that extracellular vesicles (EVs) produced by P. freudenreichii CIRM-BIA129 mimic the immunomodulatory features of parent cells in vitro (i.e. modulating NF-κB transcription factor activity and IL-8 release) which underlies the role of EVs as mediators of the probiotic effects of the bacterium....
Source: Applied and Environmental Microbiology - December 11, 2020 Category: Microbiology Authors: de Rezende Rodovalho V, da Luz BSR, Nicolas A, do Carmo FLR, Jardin J, Briard-Bion V, Jan G, Le Loir Y, de Carvalho Azevedo VA, Guedon E Tags: Appl Environ Microbiol Source Type: research

The Effects of Soil Depth on the Structure of Microbial Communities in Agricultural Soils in Iowa, USA.
This study investigated the differences in microbial community abundance, composition and diversity throughout the depth profiles in soils collected from corn and soybean fields in lowa, USA using 16S rRNA amplicon sequencing. The results revealed decreased richness and diversity in microbial communities at increasing soil depth. Soil microbial community composition differed due to crop type only in the top 60 cm and due to location only in the top 90 cm. While the relative abundance of most phyla decreased in deep soils, the relative abundance of the phylum Proteobacteria increased and dominated agricultural...
Source: Applied and Environmental Microbiology - December 11, 2020 Category: Microbiology Authors: Hao J, Chai YN, Lopes LD, Ordóñez RA, Wright EE, Archontoulis S, Schachtman DP Tags: Appl Environ Microbiol Source Type: research

YbeY controls the type III and type VI secretion systems and biofilm formation through RetS in Pseudomonas aeruginosa.
In this study, we demonstrate that mutation of the ybeY gene results in upregulation of the type III secretion system (T3SS) genes as well as downregulation of the type VI secretion system (T6SS) genes and reduction of biofilm formation. By examining the expression of the known sRNAs in P. aeruginosa, we found that mutation of the ybeY gene leads to downregulation of the small RNAs RsmY/Z that control the T3SS, the T6SS and biofilm formation. Further studies revealed that the reduced levels of RsmY/Z are due to upregulation of retS Taken together, our results reveal the pleiotropic functions of YbeY and provide detailed me...
Source: Applied and Environmental Microbiology - December 11, 2020 Category: Microbiology Authors: Xia Y, Xu C, Wang D, Weng Y, Jin Y, Bai F, Cheng Z, Kuipers OP, Wu W Tags: Appl Environ Microbiol Source Type: research