Bioprocess parameters and oxygen transfer characteristics in beta-lactamase production by Bacillus species

Celik, E
Çalık, Pınar
After screening potential beta-lactamase producers in a medium containing penicillin G, an inducible (Bacillus subtilis NRS 1125) and a constitutive (Bacillus licheniformis 749/C ATCC 25972) P-lactamase producer were selected. As the highest enzyme activity was obtained with B. licheniformis 749/C, the effects of the concentration of carbon sources, i.e., glucose, fructose, sucrose, citric acid, and glycerol, and nitrogen sources, i.e., (NH4)(2)HPO4, NH4Cl, yeast extract, casamino acids and peptone, pH, and temperature on P-lactamase production were investigated with B. licheniformis 749/C in laboratory scale bioreactors. Among the investigated media, the highest volumetric activity was obtained as 270 U cm(-3) in the medium containing 10.0 kg m(-3) glucose, 1.18 kg m(-3) (NH4)(2)HPO4, 8.0 kg m(-3) yeast extract, and the salt solution at 32 'C and pH(0) = 6.0. By using the designed medium, fermentation and oxygen transfer characteristics of the bioprocess were investigated at V = 3.0 dm(3) bioreactor systems with a V-R = 1.65 dm(3) working volume at Q(O)/V-R = 0.5 vvm and N = 500 min(-1). At the beginning of the process the Damkohler number was < 1, indicating that the process was at biochemical reaction limited condition; at t = 2-5 h both mass-transfer and biochemical reaction resistances were effective; and at t = 6-10 h (Da much greater than1) the bioprocess was at mass transfer limited condition. Overall oxygen transfer coefficients (K(L)a) varied between 0.01 and 0.03 s(-1), enhancement factor (K(L)a/K(L)a(O)) varied between 1.2 and 2.3, and volumetric oxygen uptake rate varied between 0.001 and 0.003 mol m(-3) s(-1) throughout the bioprocess. The specific oxygen uptake and the specific substrate consumption rates were the highest at t = 2 h and then decreased with the cultivation. The maximum yield of cells on substrate and the maximum yield of cells on oxygen values were obtained, respectively, as Y-X/S = 0.34 and Y-X/O = 1.40, at t = 5 h, whereas the highest yield of substrate on oxygen was obtained as Y-S/O = 6.94 at t = 3.5 h. The rate of oxygen consumption for maintenance and the rate of substrate consumption for maintenance values were found, respectively, as m(O) = 0.13 kg kg(-1) h(-1) and ms = 3.02 kg kg(-1) h(-1).


Comparison of benzaldehyde lyase production capacity in recombinant Escherichia coli and recombinant Bacillus species
Kaya, Hande; Çalık, Pınar; Department of Chemical Engineering (2006)
In this study, the benzaldehyde lyase (BAL, EC production in E. coli BL21 (DE3) pLySs as intracellular and in Bacillus species as extracellular were investigated, and comparison of the production capacity of the enzyme in the developed recombinant microorganisms were compared. For this purpose, firstly, PCR amplified bal gene was cloned into pRSETA vector which is under the control of strong T7 promoter and expressed in E. coli BL21 (DE3) pLysS strain. With developed recombinant E. coli BL21 (DE3)...
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Sevinç, Pelin; Gündüz, Ufuk; Department of Biotechnology (2010)
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Exponential feeding strategy development for benzaldehyde lyase production by recombinant "Escherichia coli"
Taşpınar, Hatice; Çalık, Pınar; Özdamar, Tunçer H.; Department of Biotechnology (2010)
In this study, the aim was to investigate the effects of exponential feeding strategy on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21. For this purpose, the effects of medium components were investigated to optimize the initial medium composition of the fed-batch fermentations. For the batch bioreactor operations, the highest cell concentration and BAL activity were achieved in a media containing 30 g L-1 pretreated molasses, and 5 g L-1 (NH4)2HPO4 as 5.07 g L-1, and 1611 U ml-1 ...
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...
Citation Formats
E. Celik and P. Çalık, “Bioprocess parameters and oxygen transfer characteristics in beta-lactamase production by Bacillus species,” BIOTECHNOLOGY PROGRESS, pp. 491–499, 2004, Accessed: 00, 2020. [Online]. Available: