scholarly journals Expression of degQ gene and its effect on lipopeptide production as well as the formation of secretory proteases in Bacillus subtilis strains

2021 ◽  
Author(s):  
Lars Lilge ◽  
Maliheh Vahidinasab ◽  
Mareen Hoffmann ◽  
Chantal Treinen ◽  
Chanthiya Kuppusamy Nesamani ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Protease Activity ◽  
Response Regulator ◽  
Fold Increase ◽  
Extracellular Protease ◽  
Negative Effect ◽  
Reporter Strains ◽  
Extracellular Protease Activity ◽  
Surfactin Production ◽  
The Impact

Bacillus subtilis is described as a promising production strain for lipopeptides. In the case of B. subtilis strains JABs24 and DSM10T, surfactin, and plipastatin are produced. Lipopeptide formation is controlled, among others, by the DegU response regulator. The activating phospho-transfer by the DegS sensor kinase is stimulated by the pleiotropic regulator DegQ, resulting in enhanced DegU activation. In B. subtilis 168, a point mutation in the degQ promoter region leads to a reduction in gene expression. Corresponding reporter strains showed a 14-fold reduced expression. This effect on degQ expression and the associated impact on lipopeptide formation was examined for B. subtilis JABs24, a lipopeptide-producing derivative of strain 168, and B. subtilis wild-type strain DSM10T, which has a native degQ expression. Based on the stimulatory effects of the DegU regulator on secretory protease formation, the impact of degQ expression on extracellular protease activity was additionally investigated. To follow the impact of degQ, a deletion mutant was constructed for DSM10T, while a natively expressed degQ version was integrated into strain JABs24. This allowed strain-specific quantification of the stimulatory effect of degQ expression on plipastatin and the negative effect on surfactin production in strains JABs24 and DSM10T. While an unaffected degQ expression reduced surfactin production in JABs24 by about 25%, a 6-fold increase in plipastatin was observed. In contrast, degQ deletion in DSM10T increased surfactin titer by 3-fold but decreased plipastatin production by 5-fold. In addition, although significant differences in extracellular protease activity were detected, no decrease in plipastatin and surfactin produced during cultivation was observed.

scholarly journals The Virulence Function and Regulation of the Metalloprotease Gene prtA in the Plant-Pathogenic Bacterium Burkholderia glumae

2019 ◽  
Vol 32 (7) ◽  
pp. 841-852 ◽  
Author(s):  
Tiago Lelis ◽  
Jingyu Peng ◽  
Inderjit Barphagha ◽  
Ruoxi Chen ◽  
Jong Hyun Ham
Keyword(s):  
Protease Activity ◽  
Virulent Strain ◽  
Regulatory Gene ◽  
Extracellular Protease ◽  
Bacterial Disease ◽  
Rna Seq ◽  
Burkholderia Glumae ◽  
Responsible Gene ◽  
Extracellular Protease Activity ◽  
Serine Metalloprotease

Bacterial panicle blight caused by Burkholderia glumae is a major bacterial disease of rice. Our preliminary RNA-seq study showed that a serine metalloprotease gene, prtA, is regulated in a similar manner to the genes for the biosynthesis and transport of toxoflavin, which is a known major virulence factor of B. glumae. prtA null mutants of the virulent strain B. glumae 336gr-1 did not show a detectable extracellular protease activity, indicating that prtA is the solely responsible gene for the extracellular protease activity detected from this bacterium. In addition, inoculation of rice panicles with the prtA mutants resulted in a significant reduction of disease severity compared with the wild-type parent strain, suggesting the requirement of prtA for the full virulence of B. glumae. A double mutant deficient in both serine metalloprotease and toxoflavin (ΔtoxA/prtA−) exhibited a further numeric but not statistically significant decrease of disease development compared with the ΔtoxA strain. Both the prtA-driven extracellular protease activity and the toxoflavin production were dependent on both the tofI/tofR quorum-sensing and the global regulatory gene qsmR, indicating the important roles of the two global regulatory factors for the bacterial pathogenesis by this pathogen.

Detection of extracellular protease activity in different species and genera of ectomycorrhizal fungi

Mycorrhiza ◽  
2007 ◽  
Vol 17 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Cajsa M. R. Nygren ◽  
Johan Edqvist ◽  
Malin Elfstrand ◽  
Gregory Heller ◽  
Andy F. S. Taylor
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Protease Activity ◽  
Extracellular Protease ◽  
Extracellular Protease Activity

scholarly journals Cilia protein IFT88 regulates extracellular protease activity by optimizing LRP‐1–mediated endocytosis

2018 ◽  
Vol 32 (12) ◽  
pp. 6771-6782 ◽  
Author(s):  
Clarissa R. Coveney ◽  
Isabella Collins ◽  
Megan Mc Fie ◽  
Anastasios Chanalaris ◽  
Kazuhiro Yamamoto ◽  
...  
Keyword(s):  
Protease Activity ◽  
Extracellular Protease ◽  
Extracellular Protease Activity

scholarly journals The RapP-PhrP Quorum-Sensing System of Bacillus subtilis Strain NCIB3610 Affects Biofilm Formation through Multiple Targets, Due to an Atypical Signal-Insensitive Allele of RapP

2014 ◽  
Vol 197 (3) ◽  
pp. 592-602 ◽  
Author(s):  
Shira Omer Bendori ◽  
Shaul Pollak ◽  
Dorit Hizi ◽  
Avigdor Eldar
Keyword(s):  
Bacillus Subtilis ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Response Regulator ◽  
Subtilis Strain ◽  
Transcriptional Level ◽  
Response Regulators ◽  
Multiple Targets ◽  
Content Type ◽  
Negative Effect

The genome ofBacillus subtilis168 encodes eightrap-phrquorum-sensing pairs. Rap proteins of all characterized Rap-Phr pairs inhibit the function of one or several important response regulators: ComA, Spo0F, or DegU. This inhibition is relieved upon binding of the peptide encoded by the cognatephrgene.Bacillus subtilisstrain NCIB3610, the biofilm-proficient ancestor of strain 168, encodes, in addition, therapP-phrPpair on the plasmid pBS32. RapP was shown to dephosphorylate Spo0F and to regulate biofilm formation, but unlike other Rap-Phr pairs, RapP does not interact with PhrP. In this work we extend the analysis of the RapP pathway by reexamining its transcriptional regulation, its effect on downstream targets, and its interaction with PhrP. At the transcriptional level, we show thatrapPandphrPregulation is similar to that of otherrap-phrpairs. We further find that RapP has an Spo0F-independent negative effect on biofilm-related genes, which is mediated by the response regulator ComA. Finally, we find that the insensitivity of RapP to PhrP is due to a substitution of a highly conserved residue in the peptide binding domain of therapPallele of strain NCIB3610. Reversing this substitution to the consensus amino acid restores the PhrP dependence of RapP activity and eliminates the effects of therapP-phrPlocus on ComA activity and biofilm formation. Taken together, our results suggest that RapP strongly represses biofilm formation through multiple targets and that PhrP does not counteract RapP due to a rare mutation inrapP.

scholarly journals Extracellular protease-producing actinomycetes and other bacteria in cultivated soil

1986 ◽  
Vol 58 (1) ◽  
pp. 9-17
Author(s):  
Raina Niskanen ◽  
Eva Eklund
Keyword(s):  
Protease Activity ◽  
Mineral Soil ◽  
Soil Samples ◽  
Extracellular Protease ◽  
The Other ◽  
Bacterial Strains ◽  
Pasture Soil ◽  
Cultivated Soil ◽  
Proteolytic Bacteria ◽  
Extracellular Protease Activity

The occurrence and properties of extracellular protease-producing actinomycetes and other bacteria in cultivated soil were studied. Experimental soils consisted of three mineral soil samples and one Sphagnum peat sample from a greenhouse. The mineral soil samples represented arable, pasture and uncultivated soils. From experimental soils, 240 bacterial strains were isolated, 68 strains there of were proteolytic. A greater number of proteolytic strains originated from pasture soil than from the other soils. Actinomycetes accounted for 70 % of the proteolytic strains isolated from pasture soil. Several proteolytic bacteria were isolated also from peat, but only few of them were typical actinomycetes. Many strains with high extracellular protease activity proved to be fermentative bacilli. Production of oxidase enzymes, significant in the humification processes, occurred frequently among strains isolated from pasture soil and peat. The ability to produce dark melanoid pigments was a frequently noted characteristic of the proteolytic actinomycetes.

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