FtsEX-CwlO regulates biofilm formation by a plant-beneficial rhizobacterium Bacillus velezensis SQR9
This study revealed that FtsEX-CwlO plays a previously undiscovered regulatory role in biofilm formation by SQR9 that may enhance root colonization and plant-beneficial functions of SQR9 and other beneficial rhizobacteria as well. (Source: Research in Microbiology)
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
The sharp phase of respiratory inhibition during amino acid starvation in Escherichia coli is RelA-dependent and associated with regulation of ATP synthase activity
Publication date: April 2018Source: Research in Microbiology, Volume 169, Issue 3Author(s): Galina V. Smirnova, Aleksey V. Tyulenev, Nadezda G. Muzyka, Oleg N. OktyabrskyAbstractAmino acid starvation causes an RelA-dependent increase in the regulatory nucleotide (p)ppGpp that leads to pleiotropic changes in Escherichia coli metabolism, but the role of (p)ppGpp in regulation of respiration remains unclear. Here we demonstrate that amino acid starvation is accompanied by sharp RelA-dependent inhibition of respiration. The sharp phase of inhibition is absent in relA mutants, and can be prevented by translation inhibitors chlo...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Adaptation of Escherichia coli to long-term batch culture in various rich media
Publication date: April 2018Source: Research in Microbiology, Volume 169, Issue 3Author(s): Lacey L. Westphal, Jasmine Lau, Zuly Negro, Ivan J. Moreno, Wazim Ismail Mohammed, Heewook Lee, Haixu Tang, Steven E. Finkel, Karin E. KramAbstractExperimental evolution studies have characterized the genetic strategies microbes utilize to adapt to their environments, mainly focusing on how microbes adapt to constant and/or defined environments. Using a system that incubates Escherichia coli in different complex media in long-term batch culture, we have focused on how heterogeneity and environment affects adaptive landscapes. In thi...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Editorial board
Publication date: April 2018Source: Research in Microbiology, Volume 169, Issue 3Author(s): (Source: Research in Microbiology)
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Regulator DegU is required for multicellular behavior in Lysinibacillus sphaericus
In this study, it was found that deletion of degU or degS-degU inhibited the swarming motility, biofilm formation, sporulation and binary toxin production through regulating the related genes, and phosphorylation was necessary for the functions of DegU. Based on the findings, a regulation network mediated by DegU was delineated. Both DegU-pi and Spo0A-pi positively regulates genes which are linked with the transition from stage Ⅱ to the end of the sporulation process and also influences the production of binary toxins via regulation on sigE. Both DegU-pi and Spo0A-pi negatively regulate abrB/sinR and influence the biofil...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Positive autoregulation of the flhDC operon in Proteus mirabilis
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): Kristen E. Howery, Emrah Şimşek, Minsu Kim, Philip N. RatherAbstractUsing a variety of techniques, we demonstrate the Class I regulator of the flagellar cascade, FlhD4C2, can activate its own expression in Proteus mirabilis. This activation was direct, as the FlhD4C2 protein specifically bound to its promoter region. The expression of bacterial genes under a positive feedback control can exhibit varying levels between cells due to stochastic fluctuations that activate the feedback loop and result in some cells in an “O...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
C-di-GMP turnover influences motility and biofilm formation in Bacillus amyloliquefaciens PG12
In this study, we characterized the core regulators of c-di-GMP turnover in B. amyloliquefaciens PG12. Using bioinformatic analysis, heterologous expression and biochemical characterization of knockout and overexpression derivatives, we identified and characterized two active diguanylate cyclases (which catalyze c-di-GMP biosynthesis), YhcK and YtrP and one active c-di-GMP phosphodiesterase (which degrades c-di-GMP), YuxH. Furthermore, we showed that elevating c-di-GMP levels up to a certain threshold inhibited the swimming motility of B. amyloliquefaciens PG12. Although yhcK, ytrP and yuxH knockout mutants did not display...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
The transcriptional regulator VarN contributes to Salmonella Typhimurium growth in macrophages and virulence in mice
In this study, we investigated the biological function of the S. Typhimurium STM4320 gene (named varN), which encodes a putative MerR family transcriptional regulator. We found that varN is upregulated 2.6- to 6.8-fold after S. Typhimurium enters murine macrophages. A varN mutant reduced S. Typhimurium growth in murine macrophages and attenuated virulence in mice. Moreover, we showed that deletion of varN decreased the transcription of Salmonella pathogenicity island-2 (SPI-2) genes, which are required for S. Typhimurium growth in macrophages, indicative of the positive regulation of SPI-2 by VarN. We confirmed that the vi...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Prevalence and dynamics of Lactobacillus sp. in the lower respiratory tract of patients with cystic fibrosis
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): Marie-Sarah Fangous, Ismaïl Lazzouni, Youenn Alexandre, Stéphanie Gouriou, Sylvie Boisramé, Sophie Vallet, Jean Le Bihan, Sophie Ramel, Geneviève Héry-Arnaud, Rozenn Le BerreAbstractNo prevalence or dynamics analysis of Lactobacilli in the lung of cystic fibrosis (CF) patients has yet been conducted. In order to use them as probiotics in the treatment of Pseudomonas aeruginosa infection, we describe their lung epidemiology.Over a period of 8 months, we analyzed 279 sputum samples from 124 CF patients classified accord...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Expression and deletion analyses of cspE encoding cold-shock protein E in Acinetobacter oleivorans DR1
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): Jisun Kim, Sunhee Ha, Woojun ParkAbstractSix genes encoding cold-shock-like proteins, including cspE, are contained within the genome of Acinetobacter oleivorans DR1. All six genes are similar in size as well as amino acid identity, but appear to be differentially regulated under stressful conditions. Four of these genes (cspA, cspB, cspC and cspE) were functionally important during cold shock because of their gradual upregulation during a temperature decrease under our assay conditions. cspE also showed higher expression ...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
New cblA gene participates in regulation of cobalt-dependent transcription of nitrile hydratase genes in Rhodococcus rhodochrous
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): Konstantin V. Lavrov, Anna O. Shemyakina, Elena G. Grechishnikova, Andrey D. Novikov, Denis D. Derbikov, Tatyana I. Kalinina, Alexander S. YanenkoAbstractRhodococcus strains are important biocatalysts used for biotechnological production of acrylamide catalysed by a nitrile hydratase (NHase) containing cobalt. This metalloenzyme is present at high intracellular concentrations representing up to 50% of the soluble proteins in Rhodococcus rhodochrous M8 strain. Cobalt ions were formerly reported to be essential for the synth...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Keeping it together: absence of genetic variation and DNA incorporation by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus during predation
In this study, we examined the genetic makeup of several lab isolates of the predators Bdellovibriobacteriovorus and Micavibrioaeruginosavorus that were cultured repeatedly and stored over a course of 13 years. We also conducted controlled experiments in which the predators were sequentially co-cultured on Klebsiella pneumoniae followed by genetic analysis of the predator. In both cases, we saw little genetic variation and no evidence of horizontally transferred chromosomal DNA from the prey during predator–prey interaction. Culturing the predators repeatedly did not cause any change in predation efficacy. (Source: Research in Microbiology)
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Evaluating the use of diversity indices to distinguish between microbial communities with different traits
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): Sergey Feranchuk, Natalia Belkova, Ulyana Potapova, Dmitry Kuzmin, Sergei BelikovAbstractSeveral measures of biodiversity are commonly used to describe microbial communities, analyzed using 16S gene sequencing. A wide range of available experiments on 16S gene sequencing allows us to present a framework for a comparison of various diversity indices. The criterion for the comparison is the statistical significance of the difference in index values for microbial communities with different traits, within the same experiment.T...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Editorial board
Publication date: May–June 2018Source: Research in Microbiology, Volume 169, Issues 4–5Author(s): (Source: Research in Microbiology)
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
Mechanistic and phenotypic studies of bicarinalin, BP100 and colistin action on Acinetobacter baumannii
Publication date: Available online 8 May 2018Source: Research in MicrobiologyAuthor(s): Marcus G. Eales, Enrico Ferrari, Alan D. Goddard, Lorna Lancaster, Peter Sanderson, Clare MillerAbstractAcinetobacter baumannii has been identified by the WHO as a high priority pathogen. It can be resistant to multiple antibiotics and colistin sulphate is often used as a last-resort treatment. However, the potentially severe side-effects of colistin are well documented and this study compared the bactericidal and anti-biofilm activity of two synthetic nature-inspired antimicrobial peptides, bicarinalin and BP100, with colistin. The min...
Source: Research in Microbiology - July 10, 2018 Category: Microbiology Source Type: research
