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607700.9788Brytella acorum gen. nov., sp. nov., a novel acetic acid bacterium from sour beverages. Polyphasic taxonomic and comparative genomic analyses revealed that a series of lambic beer isolates including strain LMG 32668(T) and the kombucha isolate LMG 32879 represent a novel species among the acetic acid bacteria, with Acidomonas methanolica as the nearest phylogenomic neighbor with a valid name. Overall genomic relatedness indices and phylogenomic and physiological analyses revealed that this novel species was best classified in a novel genus for which we propose the name Brytella acorum gen. nov., sp. nov., with LMG 32668(T) (=CECT 30723(T)) as the type strain. The B. acorum genomes encode a complete but modified tricarboxylic acid cycle, and complete pentose phosphate, pyruvate oxidation and gluconeogenesis pathways. The absence of 6-phosphofructokinase which rendered the glycolysis pathway non-functional, and an energy metabolism that included both aerobic respiration and oxidative fermentation are typical metabolic characteristics of acetic acid bacteria. Neither genome encodes nitrogen fixation or nitrate reduction genes, but both genomes encode genes for the biosynthesis of a broad range of amino acids. Antibiotic resistance genes or virulence factors are absent.202337429096
607910.9782Genomic and metabonomic methods reveal the probiotic functions of swine-derived Ligilactobacillus salivarius. BACKGROUND: As substitutes for antibiotics, probiotic bacteria protect against digestive infections caused by pathogenic bacteria. Ligilactobacillus salivarius is a species of native lactobacillus found in both humans and animals. Herein, a swine-derived Ligilactobacillus salivarius was isolated and shown to colonize the ileal mucous membrane, thereby promoting nutritional digestion, absorption, and immunity. To evaluate its probiotic role, the entire genome was sequenced, the genetic information was annotated, and the metabolic information was analyzed. RESULTS: The phylogenetic relationship indicated that the bacteria was closer to L. salivarius MT573555.1 and MT585431.1. Functional genes included transporters, membrane proteins, enzymes, heavy metal resistance proteins, and putative proteins; metabolism-related genes were the most abundant. The six types of metabolic pathways secreted by L. salivarius were mainly composed of secretory transmembrane proteins and peptides. The secretory proteins of L. salivarius were digestive enzymes, functional proteins that regulate apoptosis, antibodies, and hormones. Non-targeted metabolomic analysis of L. salivarius metabolites suggested that ceramide, pyrrolidone- 5- carboxylic acid, N2-acetyl-L-ornithine, 2-ethyl-2-hydroxybutyric acid, N-lactoyl-phenylalanine, and 12 others were involved in antioxidation, repair of the cellular membrane, anticonvulsant, hypnosis, and appetite inhibition. Metabolites of clavaminic acid, antibiotic X14889C, and five other types of bacteriocins were identified, namely phenyllactic acid, janthitrem G, 13-demethyl tacrolimus, medinoside E, and tertonasin. The adherence and antioxidation of L. salivarius were also predicted. No virulence genes were found. CONCLUSION: The main probiotic properties of L. salivarius were identified using genomic, metabonomic, and biochemical assays, which are beneficial for porcine feeding. Our results provided deeper insights into the probiotic effects of L. salivarius.202337648978
613420.9780Complete genome and gene expression analyses of Asaia bogorensis reveal unique responses to culture with mammalian cells as a potential opportunistic human pathogen. Asaia bogorensis, a member of acetic acid bacteria (AAB), is an aerobic bacterium isolated from flowers and fruits, as well as an opportunistic pathogen that causes human peritonitis and bacteraemia. Here, we determined the complete genomic sequence of the As. bogorensis type strain NBRC 16594, and conducted comparative analyses of gene expression under different conditions of co-culture with mammalian cells and standard AAB culture. The genome of As. bogorensis contained 2,758 protein-coding genes within a circular chromosome of 3,198,265 bp. There were two complete operons encoding cytochrome bo3-type ubiquinol terminal oxidases: cyoABCD-1 and cyoABCD-2. The cyoABCD-1 operon was phylogenetically common to AAB genomes, whereas the cyoABCD-2 operon belonged to a lineage distinctive from the cyoABCD-1 operon. Interestingly, cyoABCD-1 was less expressed under co-culture conditions than under the AAB culture conditions, whereas the converse was true for cyoABCD-2. Asaia bogorensis shared pathogenesis-related genes with another pathogenic AAB, Granulibacter bethesdensis, including a gene coding pathogen-specific large bacterial adhesin and additional genes for the inhibition of oxidation and antibiotic resistance. Expression alteration of the respiratory chain and unique hypothetical genes may be key traits that enable the bacterium to survive under the co-culture conditions.201526358298
80330.9778Nucleotide sequences and genetic analysis of hydrogen oxidation (hox) genes in Azotobacter vinelandii. Azotobacter vinelandii contains a heterodimeric, membrane-bound [NiFe]hydrogenase capable of catalyzing the reversible oxidation of H2. The beta and alpha subunits of the enzyme are encoded by the structural genes hoxK and hoxG, respectively, which appear to form part of an operon that contains at least one further potential gene (open reading frame 3 [ORF3]). In this study, determination of the nucleotide sequence of a region of 2,344 bp downstream of ORF3 revealed four additional closely spaced or overlapping ORFs. These ORFs, ORF4 through ORF7, potentially encode polypeptides with predicted masses of 22.8, 11.4, 16.3, and 31 kDa, respectively. Mutagenesis of the chromosome of A. vinelandii in the area sequenced was carried out by introduction of antibiotic resistance gene cassettes. Disruption of hoxK and hoxG by a kanamycin resistance gene abolished whole-cell hydrogenase activity coupled to O2 and led to loss of the hydrogenase alpha subunit. Insertional mutagenesis of ORF3 through ORF7 with a promoterless lacZ-Kmr cassette established that the region is transcriptionally active and involved in H2 oxidation. We propose to call ORF3 through ORF7 hoxZ, hoxM, hoxL, hoxO, and hoxQ, respectively. The predicted hox gene products resemble those encoded by genes from hydrogenase-related operons in other bacteria, including Escherichia coli and Alcaligenes eutrophus.19921624446
14440.9776Genome analysis of Bacillus amyloliquefaciens Subsp. plantarum UCMB5113: a rhizobacterium that improves plant growth and stress management. The Bacillus amyloliquefaciens subsp. plantarum strain UCMB5113 is a Gram-positive rhizobacterium that can colonize plant roots and stimulate plant growth and defense based on unknown mechanisms. This reinforcement of plants may provide protection to various forms of biotic and abiotic stress. To determine the genetic traits involved in the mechanism of plant-bacteria association, the genome sequence of UCMB5113 was obtained by assembling paired-end Illumina reads. The assembled chromosome of 3,889,532 bp was predicted to encode 3,656 proteins. Genes that potentially contribute to plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, acetoin synthesis and siderophore production were identified. Moreover, annotation identified putative genes responsible for non-ribosomal synthesis of secondary metabolites and genes supporting environment fitness of UCMB5113 including drug and metal resistance. A large number of genes encoding a diverse set of secretory proteins, enzymes of primary and secondary metabolism and carbohydrate active enzymes were found which reflect a high capacity to degrade various rhizosphere macromolecules. Additionally, many predicted membrane transporters provides the bacterium with efficient uptake capabilities of several nutrients. Although, UCMB5113 has the possibility to produce antibiotics and biosurfactants, the protective effect of plants to pathogens seems to be indirect and due to priming of plant induced systemic resistance. The availability of the genome enables identification of genes and their function underpinning beneficial interactions of UCMB5113 with plants.201425119988
19150.9773Mariprofundus ferrooxydans PV-1 the first genome of a marine Fe(II) oxidizing Zetaproteobacterium. Mariprofundus ferrooxydans PV-1 has provided the first genome of the recently discovered Zetaproteobacteria subdivision. Genome analysis reveals a complete TCA cycle, the ability to fix CO(2), carbon-storage proteins and a sugar phosphotransferase system (PTS). The latter could facilitate the transport of carbohydrates across the cell membrane and possibly aid in stalk formation, a matrix composed of exopolymers and/or exopolysaccharides, which is used to store oxidized iron minerals outside the cell. Two-component signal transduction system genes, including histidine kinases, GGDEF domain genes, and response regulators containing CheY-like receivers, are abundant and widely distributed across the genome. Most of these are located in close proximity to genes required for cell division, phosphate uptake and transport, exopolymer and heavy metal secretion, flagellar biosynthesis and pilus assembly suggesting that these functions are highly regulated. Similar to many other motile, microaerophilic bacteria, genes encoding aerotaxis as well as antioxidant functionality (e.g., superoxide dismutases and peroxidases) are predicted to sense and respond to oxygen gradients, as would be required to maintain cellular redox balance in the specialized habitat where M. ferrooxydans resides. Comparative genomics with other Fe(II) oxidizing bacteria residing in freshwater and marine environments revealed similar content, synteny, and amino acid similarity of coding sequences potentially involved in Fe(II) oxidation, signal transduction and response regulation, oxygen sensation and detoxification, and heavy metal resistance. This study has provided novel insights into the molecular nature of Zetaproteobacteria.201121966516
843960.9770Comparative genomics analysis and virulence-related factors in novel Aliarcobacter faecis and Aliarcobacter lanthieri species identified as potential opportunistic pathogens. BACKGROUND: Emerging pathogenic bacteria are an increasing threat to public health. Two recently described species of the genus Aliarcobacter, A. faecis and A. lanthieri, isolated from human or livestock feces, are closely related to Aliarcobacter zoonotic pathogens (A. cryaerophilus, A. skirrowii, and A. butzleri). In this study, comparative genomics analysis was carried out to examine the virulence-related, including virulence, antibiotic, and toxin (VAT) factors in the reference strains of A. faecis and A. lanthieri that may enable them to become potentially opportunistic zoonotic pathogens. RESULTS: Our results showed that the genomes of the reference strains of both species have flagella genes (flaA, flaB, flgG, flhA, flhB, fliI, fliP, motA and cheY1) as motility and export apparatus, as well as genes encoding the Twin-arginine translocation (Tat) (tatA, tatB and tatC), type II (pulE and pulF) and III (fliF, fliN and ylqH) secretory pathways, allowing them to secrete proteins into the periplasm and host cells. Invasion and immune evasion genes (ciaB, iamA, mviN, pldA, irgA and fur2) are found in both species, while adherence genes (cadF and cj1349) are only found in A. lanthieri. Acid (clpB), heat (clpA and clpB), osmotic (mviN), and low-iron (irgA and fur2) stress resistance genes were observed in both species, although urease genes were not found in them. In addition, arcB, gyrA and gyrB were found in both species, mutations of which may mediate the resistance to quaternary ammonium compounds (QACs). Furthermore, 11 VAT genes including six virulence (cadF, ciaB, irgA, mviN, pldA, and tlyA), two antibiotic resistance [tet(O) and tet(W)] and three cytolethal distending toxin (cdtA, cdtB, and cdtC) genes were validated with the PCR assays. A. lanthieri tested positive for all 11 VAT genes. By contrast, A. faecis showed positive for ten genes except for cdtB because no PCR assay for this gene was available for this species. CONCLUSIONS: The identification of the virulence, antibiotic-resistance, and toxin genes in the genomes of A. faecis and A. lanthieri reference strains through comparative genomics analysis and PCR assays highlighted the potential zoonotic pathogenicity of these two species. However, it is necessary to extend this study to include more clinical and environmental strains to explore inter-species and strain-level genetic variations in virulence-related genes and assess their potential to be opportunistic pathogens for animals and humans.202235761183
867070.9767Complete Genome Analysis of Subtercola sp. PAMC28395: Genomic Insights into Its Potential Role for Cold Adaptation and Biotechnological Applications. This study reports the complete genome sequence of Subtercola sp. PAMC28395, a strain isolated from cryoconite in Uganda. This strain possesses several active carbohydrate-active enzyme (CAZyme) genes involved in glycogen and trehalose metabolism. Additionally, two specific genes associated with α-galactosidase (GH36) and bacterial alpha-1,2-mannosidase (GH92) were identified in this strain. The presence of these genes indicates the likelihood that they can be expressed, enabling the strain to break down specific polysaccharides derived from plants or the shells of nearby crabs. The authors performed a comparative analysis of CAZyme patterns and biosynthetic gene clusters (BGCs) in several Subtercola strains and provided annotations describing the unique characteristics of these strains. The comparative analysis of BGCs revealed that four strains, including PAMC28395, have oligosaccharide BGCs, and we confirmed that the pentose phosphate pathway was configured perfectly in the genome of PAMC28395, which may be associated with adaptation to low temperatures. Additionally, all strains contained antibiotic resistance genes, indicating a complex self-resistance system. These results suggest that PAMC28395 can adapt quickly to the cold environment and produce energy autonomously. This study provides valuable information on novel functional enzymes, particularly CAZymes, that operate at low temperatures and can be used for biotechnological applications and fundamental research purposes.202337374983
19280.9767N-Succinyltransferase Encoded by a Cryptic Siderophore Biosynthesis Gene Cluster in Streptomyces Modifies Structurally Distinct Antibiotics. The antibiotic desertomycin A and its previously undescribed inactive N-succinylated analogue, desertomycin X, were isolated from Streptomyces sp. strain YIM 121038. Genome sequencing and analysis readily identified the desertomycin biosynthetic gene cluster (BGC), which lacked genes encoding acyltransferases that would account for desertomycin X formation. Scouting the genome for putative N-acyltransferase genes led to the identification of a candidate within a cryptic siderophore BGC (csb) encoding a putative homologue of the N6'-hydroxylysine acetyltransferase IucB. Expression of the codon-optimized gene designated csbC in Escherichia coli yielded the recombinant protein that was able to N-succinylate desertomycin A as well as several other structurally distinct antibiotics harboring amino groups. Some antibiotics were rendered antibiotically inactive due to the CsbC-catalyzed succinylation in vitro. Unlike many known N-acyltransferases involved in antibiotic resistance, CsbC could not efficiently acetylate the same antibiotics. When expressed in E. coli, CsbC provided low-level resistance to kanamycin and ampicillin, suggesting that it may play a role in antibiotic resistance in natural habitats, where the concentration of antibiotics is usually low. IMPORTANCE In their natural habitats, bacteria encounter a plethora of organic compounds, some of which may be represented by antibiotics produced by certain members of the microbial community. A number of antibiotic resistance mechanisms have been described, including those specified by distinct genes encoding proteins that degrade, modify, or expel antibiotics. In this study, we report identification and characterization of an enzyme apparently involved in the biosynthesis of a siderophore, but also having the ability of modify and thereby inactivate a wide variety of structurally diverse antibiotics. This discovery sheds light on additional capabilities of bacteria to withstand antibiotic treatment and suggests that enzymes involved in secondary metabolism may have an additional function in the natural environment.202236040031
836490.9764Trimeric autotransporter adhesins in members of the Burkholderia cepacia complex: a multifunctional family of proteins implicated in virulence. Trimeric autotransporter adhesins (TAAs) are multimeric surface proteins exclusively found in bacteria. They are involved in various biological traits of pathogenic Gram-negative bacteria including adherence, biofilm formation, invasion, survival within eukaryotic cells, serum resistance, and cytotoxicity. TAAs have a modular architecture composed by a conserved membrane-anchored C-terminal domain and a variable number of stalk and head domains. In this study, a bioinformatic approach has been used to analyze the distribution and architecture of TAAs among Burkholderia cepacia complex (Bcc) genomes. Fifteen genomes were probed revealing a total of 74 encoding sequences. Compared with other bacterial species, the Bcc genomes contain a large number of TAAs (two genes to up to eight genes, such as in B. cenocepacia). Phylogenetic analysis showed that the TAAs grouped into at least eight distinct clusters. TAAs with serine-rich repeats are clearly well separated from others, thereby representing a different evolutionary lineage. Comparative gene mapping across Bcc genomes reveals that TAA genes are inserted within conserved synteny blocks. We further focused our analysis on the epidemic strain B. cenocepacia J2315 in which seven TAAs were annotated. Among these, three TAA-encoding genes (BCAM019, BCAM0223, and BCAM0224) are organized into a cluster and are candidates for multifunctional virulence factors. Here we review the current insights into the functional role of BCAM0224 as a model locus.201122919579
190100.9763The Two TpsB-Like Proteins in Anabaena sp. Strain PCC 7120 Are Involved in Secretion of Selected Substrates. The outer membrane of Gram-negative bacteria acts as an initial diffusion barrier that shields the cell from the environment. It contains many membrane-embedded proteins required for functionality of this system. These proteins serve as solute and lipid transporters or as machines for membrane insertion or secretion of proteins. The genome of Anabaena sp. strain PCC 7120 codes for two outer membrane transporters termed TpsB1 and TpsB2. They belong to the family of the two-partner secretion system proteins which are characteristic of pathogenic bacteria. Because pathogenicity of Anabaena sp. strain PCC 7120 has not been reported, the function of these two cyanobacterial TpsB proteins was analyzed. TpsB1 is encoded by alr1659, while TpsB2 is encoded by all5116 The latter is part of a genomic region containing 11 genes encoding TpsA-like proteins. However, tpsB2 is transcribed independently of a tpsA gene cluster. Bioinformatics analysis revealed the presence of at least 22 genes in Anabaena sp. strain PCC 7120 putatively coding for substrates of the TpsB system, suggesting a rather global function of the two TpsB proteins. Insertion of a plasmid into each of the two genes resulted in altered outer membrane integrity and antibiotic resistance. In addition, the expression of genes coding for the Clp and Deg proteases is dysregulated in these mutants. Moreover, for two of the putative substrates, a dependence of the secretion on functional TpsB proteins could be confirmed. We confirm the existence of a two-partner secretion system in Anabaena sp. strain PCC 7120 and predict a large pool of putative substrates.IMPORTANCE Cyanobacteria are important organisms for the ecosystem, considering their contribution to carbon fixation and oxygen production, while at the same time some species produce compounds that are toxic to their environment. As a consequence, cyanobacterial overpopulation might negatively impact the diversity of natural communities. Thus, a detailed understanding of cyanobacterial interaction with the environment, including other organisms, is required to define their impact on ecosystems. While two-partner secretion systems in pathogenic bacteria are well known, we provide a first description of the cyanobacterial two-partner secretion system.202133257527
8729110.9763Protein S-Acyl Transferase GhPAT27 Was Associated with Verticillium wilt Resistance in Cotton. Protein palmitoylation is an ability of the frame of the cell marker protein is one of the most notable reversible changes after translation. However, studies on protein palmitoylation in cotton have not yet been performed. In our current research, the PAT gene family was systematically identified and bioinformatically analyzed in G. arboreum, G. raimondii, G. barbadense and G. hirsutum, and 211 PAT genes were authenticated and classified into six subfamilies. Sixty-nine PAT genes were identified in upland cotton, mainly at the ends of its the 26 chromosomes of upland cotton. The majority of these genes are located in the nucleus of the plant. Gene structure analysis revealed that each member encodes a protein that which contains at least one DHHC structural domain. Cis-acting element analysis indicated that GhPATs genes are mainly involved in hormone production, light response and stress response. Gene expression pattern analysis indicated that most GhPATs genes were differentially expressed upon induction by pathogenic bacteria, drought, salt, hot and cold stresses, and some GhPATs could be induced by multiple abiotic stresses simultaneously. GhPATs genes showed different expression patterns in tissue-specific assays and were found to be preferentially expressed in roots, followed by expression in stems and leaves. Virus-induced gene silencing (VIGS) experiments showed that cotton was significantly less resistant to Verticillium dahliae when GhPAT27 was silenced. We conclude that the GhPAT27 gene, which mediates S-palmitoylation acetylation, may be involved in the regulation of upland cotton resistance to Verticillium wilt (VW). Overall, this work has provided a fundamental framework for understanding the latent capabilities of GhPATs and a solid foundation for molecular breeding and plant pathogen resistance in cotton.202236297782
8481120.9761Universal stress proteins contribute Edwardsiella piscicida adversity resistance and pathogenicity and promote blocking host immune response. Universal stress proteins (Usps) exist ubiquitously in bacteria and other organisms. Usps play an important role in adaptation of bacteria to a variety of environmental stresses. There is increasing evidence that Usps facilitate pathogens to adapt host environment and are involved in pathogenicity. Edwardsiella piscicida (formerly included in E. tarda) is a severe fish pathogen and infects various important economic fish including tilapia (Oreochromis niloticus). In E. piscicida, a number of systems and factors that are involved in stress resistance and pathogenesis were identified. However, the function of Usps in E. piscicida is totally unknown. In this study, we examined the expressions of 13 usp genes in E. piscicida and found that most of these usp genes were up-regulated expression under high temperature, oxidative stress, acid stress, and host serum stress. Particularly, among these usp genes, usp13, exhibited dramatically high expression level upon several stress conditions. To investigate the biological role of usp13, a markerless usp13 in-frame mutant strain, TX01Δusp13, was constructed. Compared to the wild type TX01, TX01Δusp13 exhibited markedly compromised tolerance to high temperature, hydrogen peroxide, and low pH. Deletion of usp13 significantly retarded bacterial biofilm growth and decreased resistance against serum killing. Pathogenicity analysis showed that the inactivation of usp13 significantly impaired the ability of E. piscicida to invade into host cell and infect host tissue. Introduction of a trans-expressed usp13 gene restored the lost virulence of TX01Δusp13. In support of these results, host immune response induced by TX01 and TX01Δusp13 was examined, and the results showed reactive oxygen species (ROS) levels in TX01Δusp13-infected macrophages were significantly higher than those in TX01-infected cells. The expression level of several cytokines (IL-6, IL-8, IL-10, TNF-α, and CC2) in TX01Δusp13-infected fish was significantly higher than that in TX01-infected fish. These results suggested that the deletion of usp13 attenuated the ability of bacteria to overcome the host immune response to pathogen infection. Taken together, our study indicated Usp13 of E. piscicida was not only important participant in adversity resistance, but also was essential for E. piscicida pathogenicity and contributed to block host immune response to pathogen infection.201931654767
6349130.9760High-level chromate resistance in Arthrobacter sp. strain FB24 requires previously uncharacterized accessory genes. BACKGROUND: The genome of Arthrobacter sp. strain FB24 contains a chromate resistance determinant (CRD), consisting of a cluster of 8 genes located on a 10.6 kb fragment of a 96 kb plasmid. The CRD includes chrA, which encodes a putative chromate efflux protein, and three genes with amino acid similarities to the amino and carboxy termini of ChrB, a putative regulatory protein. There are also three novel genes that have not been previously associated with chromate resistance in other bacteria; they encode an oxidoreductase (most similar to malate:quinone oxidoreductase), a functionally unknown protein with a WD40 repeat domain and a lipoprotein. To delineate the contribution of the CRD genes to the FB24 chromate [Cr(VI)] response, we evaluated the growth of mutant strains bearing regions of the CRD and transcript expression levels in response to Cr(VI) challenge. RESULTS: A chromate-sensitive mutant (strain D11) was generated by curing FB24 of its 96-kb plasmid. Elemental analysis indicated that chromate-exposed cells of strain D11 accumulated three times more chromium than strain FB24. Introduction of the CRD into strain D11 conferred chromate resistance comparable to wild-type levels, whereas deletion of specific regions of the CRD led to decreased resistance. Using real-time reverse transcriptase PCR, we show that expression of each gene within the CRD is specifically induced in response to chromate but not by lead, hydrogen peroxide or arsenate. Higher levels of chrA expression were achieved when the chrB orthologs and the WD40 repeat domain genes were present, suggesting their possible regulatory roles. CONCLUSION: Our findings indicate that chromate resistance in Arthrobacter sp. strain FB24 is due to chromate efflux through the ChrA transport protein. More importantly, new genes have been identified as having significant roles in chromate resistance. Collectively, the functional predictions of these additional genes suggest the involvement of a signal transduction system in the regulation of chromate efflux and warrants further study.200919758450
8193140.9760Sinorhizobium meliloti Functions Required for Resistance to Antimicrobial NCR Peptides and Bacteroid Differentiation. Legumes of the Medicago genus have a symbiotic relationship with the bacterium Sinorhizobium meliloti and develop root nodules housing large numbers of intracellular symbionts. Members of the nodule-specific cysteine-rich peptide (NCR) family induce the endosymbionts into a terminal differentiated state. Individual cationic NCRs are antimicrobial peptides that have the capacity to kill the symbiont, but the nodule cell environment prevents killing. Moreover, the bacterial broad-specificity peptide uptake transporter BacA and exopolysaccharides contribute to protect the endosymbionts against the toxic activity of NCRs. Here, we show that other S. meliloti functions participate in the protection of the endosymbionts; these include an additional broad-specificity peptide uptake transporter encoded by the yejABEF genes and lipopolysaccharide modifications mediated by lpsB and lpxXL, as well as rpoH1, encoding a stress sigma factor. Strains with mutations in these genes show a strain-specific increased sensitivity profile against a panel of NCRs and form nodules in which bacteroid differentiation is affected. The lpsB mutant nodule bacteria do not differentiate, the lpxXL and rpoH1 mutants form some seemingly fully differentiated bacteroids, although most of the nodule bacteria are undifferentiated, while the yejABEF mutants form hypertrophied but nitrogen-fixing bacteroids. The nodule bacteria of all the mutants have a strongly enhanced membrane permeability, which is dependent on the transport of NCRs to the endosymbionts. Our results suggest that S. meliloti relies on a suite of functions, including peptide transporters, the bacterial envelope structures, and stress response regulators, to resist the aggressive assault of NCR peptides in the nodule cells. IMPORTANCE The nitrogen-fixing symbiosis of legumes with rhizobium bacteria has a predominant ecological role in the nitrogen cycle and has the potential to provide the nitrogen required for plant growth in agriculture. The host plants allow the rhizobia to colonize specific symbiotic organs, the nodules, in large numbers in order to produce sufficient reduced nitrogen for the plants' needs. Some legumes, including Medicago spp., produce massively antimicrobial peptides to keep this large bacterial population in check. These peptides, known as NCRs, have the potential to kill the rhizobia, but in nodules, they rather inhibit the division of the bacteria, which maintain a high nitrogen-fixing activity. In this study, we show that the tempering of the antimicrobial activity of the NCR peptides in the Medicago symbiont Sinorhizobium meliloti is multifactorial and requires the YejABEF peptide transporter, the lipopolysaccharide outer membrane, and the stress response regulator RpoH1.202134311575
5145150.9759Genome sequence and comparative analysis of a putative entomopathogenic Serratia isolated from Caenorhabditis briggsae. BACKGROUND: Entomopathogenic associations between nematodes in the genera Steinernema and Heterorhabdus with their cognate bacteria from the bacterial genera Xenorhabdus and Photorhabdus, respectively, are extensively studied for their potential as biological control agents against invasive insect species. These two highly coevolved associations were results of convergent evolution. Given the natural abundance of bacteria, nematodes and insects, it is surprising that only these two associations with no intermediate forms are widely studied in the entomopathogenic context. Discovering analogous systems involving novel bacterial and nematode species would shed light on the evolutionary processes involved in the transition from free living organisms to obligatory partners in entomopathogenicity. RESULTS: We report the complete genome sequence of a new member of the enterobacterial genus Serratia that forms a putative entomopathogenic complex with Caenorhabditis briggsae. Analysis of the 5.04 MB chromosomal genome predicts 4599 protein coding genes, seven sets of ribosomal RNA genes, 84 tRNA genes and a 64.8 KB plasmid encoding 74 genes. Comparative genomic analysis with three of the previously sequenced Serratia species, S. marcescens DB11 and S. proteamaculans 568, and Serratia sp. AS12, revealed that these four representatives of the genus share a core set of ~3100 genes and extensive structural conservation. The newly identified species shares a more recent common ancestor with S. marcescens with 99% sequence identity in rDNA sequence and orthology across 85.6% of predicted genes. Of the 39 genes/operons implicated in the virulence, symbiosis, recolonization, immune evasion and bioconversion, 21 (53.8%) were present in Serratia while 33 (84.6%) and 35 (89%) were present in Xenorhabdus and Photorhabdus EPN bacteria respectively. CONCLUSION: The majority of unique sequences in Serratia sp. SCBI (South African Caenorhabditis briggsae Isolate) are found in ~29 genomic islands of 5 to 65 genes and are enriched in putative functions that are biologically relevant to an entomopathogenic lifestyle, including non-ribosomal peptide synthetases, bacteriocins, fimbrial biogenesis, ushering proteins, toxins, secondary metabolite secretion and multiple drug resistance/efflux systems. By revealing the early stages of adaptation to this lifestyle, the Serratia sp. SCBI genome underscores the fact that in EPN formation the composite end result - killing, bioconversion, cadaver protection and recolonization- can be achieved by dissimilar mechanisms. This genome sequence will enable further study of the evolution of entomopathogenic nematode-bacteria complexes.201526187596
6118160.9757Integrated genomics and transcriptomics reveal the extreme heavy metal tolerance and adsorption potentiality of Staphylococcus equorum. In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.202336592848
8469170.9757Probiogenomic analysis of Lactiplantibacillus plantarum SPS109: A potential GABA-producing and cholesterol-lowering probiotic strain. Lactiplantibacillus plantarum SPS109, an isolated strain of lactic acid bacteria (LAB) from fermented foods, showed remarkable potential as a probiotic with dual capabilities in γ-aminobutyric acid (GABA) production and cholesterol reduction. This study employs genomic and comparative analyses to search into the strain's genetic profile, safety features, and probiotic attributes. The safety assessment reveals the absence of virulence factors and antimicrobial resistance genes, while the genome uncovers bacteriocin-related elements, including sactipeptides and a cluster for putative plantaricins, strengthening its ability to combat diverse pathogens. Pangenome analysis revealed unique bacteriocin-related genes, specifically lcnD and bcrA, distinguishing SPS109 from four other L. plantarum strains producing GABA. In addition, genomic study emphasizes SPS109 strain distinctive features, two GABA-related genes responsible for GABA production and a bile tolerance gene (cbh) crucial for cholesterol reduction. Additionally, the analysis highlights several genes of potential probiotic properties, including stress tolerance, vitamin production, and antioxidant activity. In summary, L. plantarum SPS109 emerges as a promising probiotic candidate with versatile applications in the food and beverage industries, supported by its unique genomic features and safety profile.202439044985
6090180.9757Draft genome sequence of Mesorhizobium alhagi CCNWXJ12-2T, a novel salt-resistant species isolated from the desert of northwestern China. Mesorhizobium alhagi strain CCNWXJ12-2(T) is a novel species of soil-dwelling, nitrogen-fixing bacteria that can form symbiotic root nodules with Alhagi sparsifolia. Moreover, the strain has high resistance to salt and alkali. Here we report the draft genome sequence of Mesorhizobium alhagi strain CCNWXJ12-2(T). A large number of osmotic regulation-related genes have been identified.201222328758
8372190.9757A Plasmid-Encoded Putative Glycosyltransferase Is Involved in Hop Tolerance and Beer Spoilage in Lactobacillus brevis. Lactobacillus brevis beer-spoiling strains harbor plasmids that contain genes such as horA, horC, and hitA which are known to confer hop tolerance. The L. brevis beer-spoiling strain UCCLBBS124, which possesses four plasmids, was treated with novobiocin, resulting in the isolation of UCCLBBS124 derivatives exhibiting hop sensitivity and an inability to grow in beer. One selected derivative was shown to have lost a single plasmid, here designated UCCLBBS124_D, which harbors the UCCLBBS124_pD0015 gene, predicted to encode a glycosyltransferase. Hop tolerance and growth in beer were restored when UCCLBBS124_pD0015 was introduced in one of these hop-sensitive derivatives on a plasmid. We hypothesize that this gene modifies the surface composition of the polysaccharide cell wall, conferring protection against hop compounds. Furthermore, the introduction of this gene in trans in L. brevis UCCLB521, a strain that cannot grow in and spoil beer, was shown to furnish the resulting strain with the ability to grow in beer, while its expression also conferred phage resistance. This study underscores how the acquisition of certain mobile genetic elements plays a role in hop tolerance and beer spoilage for strains of this bacterial species.IMPORTANCELactobacillus brevis is a member of the lactic acid bacteria and is often reported as the causative agent of food or beverage spoilage, in particular, that of beer. Bacterial spoilage of beer may result in product withdrawal or recall, with concomitant economic losses for the brewing industry. A very limited number of genes involved in beer spoilage have been identified and primarily include those involved in hop resistance, such as horA, hitA, and horC However, since none of these genes are universal, it is clear that there are likely (many) other molecular players involved in beer spoilage. Here, we report on the importance of a plasmid-encoded glycosyltransferase associated with beer spoilage by L. brevis that is involved in hop tolerance. The study highlights the complexity of the genetic requirements to facilitate beer spoilage and the role of multiple key players in this process.202031757821