Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)

The effect of fed-batch operation (FBO) strategy was investigated using pretreated-beet molasses, containing galactose that induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l(-1) pretreated-beet molasses consisting of 7.5 g l(-1) glucose and 7.5 g l(-1) fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In FBO1 when air-flow rate decreased considerably, feed was given to the system in pulses in such a way that pretreated-beet molasses concentration increased by 10 kg m(-3) (containing 2.5 g l(-1) glucose+2.5 g l(-1) fructose); however, decrease in air-flow rate demonstrated only the absence of glucose but not fructose. Thus, in FBO2 when fructose and glucose were completely utilized, pretreated-beet molasses was pulse-fed and its concentration increased by 10 g l(-1). In FBO3 with the decreased amount of pretreated-beet molasses (6 g l(-1)), shift response time from glucose to fructose consumption was avoided, and glucose and fructose consumptions were well correlated with air-flow rate, and the highest C (X) (8.04 g l(-1)) and BAL (2,315 U ml(-1)) production were obtained (t = 24 h) with the highest substrate yield on cell and product formation.


Influence of controlled-pH and uncontrolled-pH operations on recombinant benzaldehyde lyase production by Escherichia coli
Çalık, Pınar; Demir, AS (Elsevier BV, 2006-03-02)
To select the host microorganism having the highest benzaldehyde lyase (BAL) production capacity, pUC 18::bal gene was transferred into four Escherichia coli strains. As the highest enzyme activity was obtained with E. coli K12 (ATCC 10798) carrying pUC18::bal gene, BAL production medium was designed for K 12. Using the designed medium containing 8.0 kg m(-3) glucose, 5.0 kg m(-3) (NH4)(2)HPO4 and the salt solution, the effects of uncontrolled-pH and controlled-pH operations were investigated at uncontrolle...
Determination and metabolic engineering of rate limiting reactions in aromatic amino acid pathway in Bacillus subtilis for L-phenylaianine production
Guzide, Calik; Yasemin, Demirci; Pinar, Calik; Ozdamar, Tuncer H. (2007-09-01)
Rate limiting reactions in the aromatic-group amino acid pathway (AAAP) in Bacillus subtilis for l-phenylalanine (Phe) production were determined as reported elsewhere (Özçelik-Şenver et al., 2004). The biochemical reactions in the AAAP start with the reaction using phosphoenolpyruvate (PEP) and erythrose 4-phosphate (E4P) synthesised in the glycolysis pathway and the PPP, respectively, leading to the formation of Phe via chorismate by branching at prephenate. The branch-point metabolites E4P supplied in vi...
Influence of oxygen transfer on benzaldehyde lyase production by recombinant Escherichia coli BL21(DE3) pLySs
Angardi, Vahideh; Çalık, Pınar; Department of Chemical Engineering (2007)
In this study, the effects of oxygen transfer conditions on the synthesis of the enzyme benzaldehyde lyase as intracellular in recombinant E. coli BL21 (DE3) pLysS was investigated sistematically and a comprehensive model was developed to determine benzaldehyde lyase activity. For this purpose, the research program was carried out in mainly two parts. In the first part of study, the effects of oxygen transfer together with the mass transfer coefficient (KLa), enhancement factor E (=KLa/KLao), volumetric oxy...
Effects of pH strategy on endo- and exo-metabolome profiles and sodium potassium hydrogen ports of beta-lactamase-producing Bacillus licheniformis
Ileri, N; Çalık, Pınar (Wiley, 2006-03-01)
The effects of pH strategy on endo- and exo-metabolome profiling of beta-lactamase-producing Bacillus licheniformis were investigated at controlled-pH (pH(C) = 6.5, 6.75, 7.0, 7.25, 7.5) and uncontrolled-pH (pH(UC) = 7.5) values using a glucose-based defined medium. The cell concentration profiles were not affected by the pH considerably within the investigated range. The highest enzyme activities were obtained as A = 54 U cm(-3) at pHc = 6.75 among the controlled-pH operations and as A = 57 U cm(-3) at the...
Role of the cmcH-ccaR intergenic region and ccaR overexpression in cephamycin C biosynthesis in Streptomyces clavuligerus
Kurt, Aslihan; Alvarez-Alvarez, Ruben; Liras, Paloma; Özcengiz, Gülay (Springer Science and Business Media LLC, 2013-07-01)
The effect of the CcaR regulatory protein on expression of the cephamycin C gene cluster is studied. Quantitative reverse transcription PCR (qRT-PCR) expression analysis of the cephamycin biosynthesis genes in the ccaR-disrupted strain, S. clavuligerus ccaR::aph, revealed that in the absence of CcaR, the lat and cmcI genes expression was reduced 2,200-and 1,087-fold compared with the wild type. Expression of pcbAB-pcbC-cefD-cefE-cmcJ-cmcH and blp was 225- to 359-fold lower, while expression of pcbR-pbpA-bla...
Citation Formats
P. Çalık, “Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3),” APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, pp. 65–73, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37394.