Expression and activity analyses of industrially important extracellular enzymes produced by a bacilysin knock-out mutant of Bacillus Subtilis

Aytekin, Samet
Bacilysin, the smallest peptide antibiotic known to date, is produced non-ribosomally by Bacillus subtilis by the collective actions of seven proteins transcribed from bacABCDEF operon and bacG gene. Bacilysin is a two-amino acid peptide composed of L-alanine and a modified amino acid, L-anticapsin. Bacilysin biosynthesis was shown to be strongly regulated by quorum sensing through the actions of global regulator proteins including Spo0K, Spo0H, Spo0A, ComQ/ComX, ComP/ComA as well as several Phr proteins, OppA, CodY, SrfA and AbrB. Involvement of large numbers of regulatory proteins in bacilysin biosynthesis raises the question of whether the bacilysin itself affects physiological processes its own producer cells. Comparative secretome analysis between B. subtilis PY79 and its bac operon-silenced derivative OGU1, recently performed by our group, has identified more than 200 proteins differentially expressed in the mutant strain. Since B. subtilis is one of the most important cell-factories with a capacity to produce a wide range of extracellular enzymes, of biotechnological interest was a significant increment in levels of the industrially-important extracellular enzymes upon the disruption of bac operon. These enzymes included arabinanase, chitosanase, levanase, phytase, lipase, bacillopeptidase F, minor extracellular protease and endonuclease. This study aims to compare the expression profiles of the respective abn2, csn, sacC, phy, estA, bpr, vpr and YhcR genes as well as the enzymatic activities of their products between two strains. Both approaches showed a significant increase of these eight selected proteins in the OGU1 strain, suggesting a possible direct or indirect effect of the bacilysin on their biosynthesis.


Dynamic analysis of secretome alterations in a bacilysin-knock out mutant of bacillus subtilis
Tekin İşlerel, Elif; Özcengiz, Gülay; Department of Biology (2017)
The members of the genus Bacillus produce a wide variety of secondary metabolites with antimetabolic and pharmacological activities. Bacilysin, being produced and excreted by certain strains of B. subtilis, is a dipeptide antibiotic composed of L-alanine and L-anticapsin which is synthesized enzymatically. As shown earlier by our research group, the expression of bacilysin biosynthetic operon (bacA) is relatively constant during the exponential growth, but increases during the transition between exponential...
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Yılmaz, Tülay; Kocabıyık, Semra; Department of Biology (2013)
In this study differential expression of the two proteasome associated VAT genes (TVNO382 and TVN0947) of Thermoplasma volcanium GSS1 (Tpv) cells challenged by extracellular stresses, i.e., pH, heat-shock and hydrogen peroxide were investigated using quantitative RT-PCR and Western blotting/hybridization techniques. We also performed a comprehensive transcriptome analysis of the Tpv as response to environmental stresses by genome-wide expression arrays. Quantitative RT-PCR analyses revealed that VAT genes e...
Discovery of non-carbohydrate inhibitors of aminoglycoside-modifying enzymes
Welch, KT; Virga, KG; Whittemore, NA; Özen, Can; Wright, E; Brown, CL; Lee, RE; Serpersu, EH (2005-11-15)
Chemical modification and inactivation of aminoglycosides by many different enzymes expressed in pathogenic bacteria are the main mechanisms of bacterial resistance to these antibiotics. In this work, we designed inhibitors that contain the 1,3-diamine pharmacophore shared by all aminoglycoside antibiotics that contain the 2-deoxystreptamine ring. A discovery library of molecules was prepared by attaching different side chains to both sides of the 1,3-diamine motif. Several of these diamines showed inhibito...
Regulatory effects of alanine-group amino acids on serine alkaline protease production by recombinant Bacillus licheniformis
Çalık, Pınar; Ozdamar, TH (Wiley, 2003-04-01)
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Expression Analysis of TaNAC69-1 and TtNAMB-2, Wheat NAC Family Transcription Factor Genes Under Abiotic Stress Conditions in Durum Wheat (Triticum turgidum)
Baloglu, Mehmet Cengiz; Oz, Mehmet Tufan; Öktem, Hüseyin Avni; Yücel, Ayşe Meral (2012-10-01)
NAC-type plant-specific transcription factor genes encode proteins that play important roles in abiotic stress responses, as well as regulation of plant development. In the current study, expression profiles of wheat NAC-type transcription factor genes, TaNAC69-1 and TtNAMB-2, were examined under drought, salt, cold, and heat stress conditions in wheat. Based on reverse transcription quantitative PCR results, TaNAC69-1 was strongly expressed under drought, salinity, and high-temperature stress conditions. C...
Citation Formats
S. Aytekin, “Expression and activity analyses of industrially important extracellular enzymes produced by a bacilysin knock-out mutant of Bacillus Subtilis,” M.S. - Master of Science, Middle East Technical University, 2018.