Comparative analysis of product and by-product distributions in defined and complex media in serine alkaline protease production by recombinant Basillus subtilis

Oktar, Ceren
In this study, firstly the effects of aspartic acid group amino acids -which were reported to be the potential bottleneck in serine alkaline protease (SAP) synthesis- on SAP production were investigated by substituting at a concentration range of 0-15 mM by using recombinant Bacillus subtilis carrying pHV1434::subC gene. All aspartic acid group amino acids except threonine inhibited SAP activity when CAA= 2.5 mM. The highest SAP activities with asparagine, aspartic acid, lysine, threonine, isoleucine and methionine werefound to be 1.89-, 1.87-, 1.61-, 1.48-, 1.4-, and 1.4-fold higher than the reference medium activity, respectively, when the concentration of each amino acid was CAA=0.25 mM. The product and by-product distributions in defined and complex media in SAP production were also analyzed and compared in order to obtain a depth in-sight on functioning of the metabolic reaction network. The highest SAP activity in complex medium was found to be 3اfold higher than defined medium activity, while, specific SAP production rate was 1.2- fold higher. The highest cell concentration in complex medium (CX= 14.3 g/dm-3) was 8.1-fold higher than that obtained in defined medium (CX= 1.75 g/dm-3). In both media, oxaloacetic acid was observed extracellularly and intracellularly. In complex medium there was also succinic acid in the extracellular medium indicating that the operation of TCA cycle was insufficient. In both media serine, valine and glycine were observed neither in the extracellular nor in the intracellular media indicating that the synthesis of these amino acids can be a secondary rate limiting step. In defined medium asparagine was present neither in the cell nor in fermentation broth whereas, methionine was observed in the cell in high amounts, probably due to the lower flux values towards asparagine. Thus, in defined medium the synthesis of asparagine can also


Proteome-wide analysis of the role of expression of bacilysin operon on idiophase physiology of B. Subtilis
Demir, Mustafa; Özcengiz, Gülay; Department of Biology (2013)
The members of the genus Bacillus produce a wide variety of secondary metabolites with antimetabolic and pharmacological activities. These metabolites are mostly small peptides and have unusual components and chemical bonds. These metabolites are synthesized nonribosomally by multifunctional enzyme complexes called peptide synthetases. One of those small peptides, bacilysin, is a dipeptide antibiotic composed of L-alanine and L-anticapsin which is produced and excreted by certain strains of Bacillus subtili...
Molecular cloning, characterization, and homologous expression of an endochitinase gene from Bacillus thuringiensis serovar morrisoni
Okay, Sezer; Özcengiz, Gülay (2011-01-01)
The endochitinase gene (chi3023) of Bacillus thuringiensis (Bt) serovar morrisoni strain 3023 was amplified via polymerase chain reaction (PCR) and cloned in Escherichia coli. The ORF of chi3023 (GenBank Accession Number: DQ993175) consists of 2031 nucleotides encoding a 676-residue protein with a calculated molecular mass of 74.5 kDa and a pI value of 6.0. The amino acid sequence of Chi3023 was compared with previously sequenced Bt chitinases and the phylogenetic relationships among them were determined. T...
A QSAR study of the biological activities of some benzimidazoles and imidazopyridines against Bacillus subtilis
Ertepınar, Hamide; Gök, Yaşar; Geban, Ömer; Özden, Seçkin (1995-04-01)
A set of benzimidazole (I) and imidazopyridine (II) derivatives that have previously been tested for their antibacterial activities against Bacillus subtilis were analyzed using the quantitative structure-activity relationship (QSAR) method. The activity contributions for structural and substituent effects were determined from the correlation equations, which were derived using all possible combination and stepwise regression techniques. The best equation was chosen among the other equations by considering ...
Protease secretion capacity and perforce analysis of recombinant Bacillus species
Çalık, Pınar; Ozdamar, TH (2000-10-08)
Recombinant Bacillus species carrying subC gene encoding serine alkaline protease (SAP) enzyme were developed in order to increase the yield and selectivity in the bioprocess for SAP production. subC gene was amplified from the chromosomal DNA of the wild-type Bacillus licheniformis by using PCR technology; thereafter, subC gene was first cloned into the pRS316 E. coli yeast shuttle plasmid, then sub-cloned into the pHV1431 E. coli-Bacillus shuttle vector, and transferred to the host Bacillus species, i.e. ...
Biological network modelling based on differentially expressed proteins in a bacilysin-deficient strain of bacillus subtilis
Kutnu, Meltem; Özcengiz, Gülay; Department of Molecular Biology and Genetics (2019)
Bacillus subtilis is a non-pathogenic, Gram-positive organism which is known for producing a broad range of secondary metabolites with pharmacological and antimicrobial activities. The dipeptide bacilysin is one of the many antibiotics synthesized by certain strains of B. subtilis, and it is composed of L-alanine and the non-proteinogenic amino acid L-anticapsin. Earlier silencing studies by our group have suggested that bacilysin acts as a pleiotropic molecule on its host. Therefore, the absence or lack of...
Citation Formats
C. Oktar, “Comparative analysis of product and by-product distributions in defined and complex media in serine alkaline protease production by recombinant Basillus subtilis,” M.S. - Master of Science, Middle East Technical University, 2003.