Bioprocess Parameters and Oxygen Transfer Characteristics in β-Lactamase Production by Bacillus Species

Department of Chemical Engineering, Industrial Biotechnology Laboratory, Middle East Technical University, 06531 Ankara, Turkey.
Biotechnology Progress (Impact Factor: 2.15). 03/2004; 20(2):491-9. DOI: 10.1021/bp0342351
Source: PubMed


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) beta-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., (NH(4))(2)HPO(4), NH(4)Cl, yeast extract, casamino acids and peptone, pH, and temperature on beta-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) (NH(4))(2)HPO(4), 8.0 kg m(-)(3) yeast extract, and the salt solution at 32 degrees 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 Damköhler 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 >1) 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 m(S) = 3.02 kg kg(-)(1) h(-)(1).

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    • ") were determined by measuring the hydrolysis of cephalexin according to Çelik and Çalik (2004). Samples of the treated sewage effluents were harvested by centrifugation at 13,500 (rpm) for 10 min. "
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    ABSTRACT: The aim of this study was to investigate the potentials for enzymatic biodegradation of pharmaceutical active compounds (β-lactam antibiotics) in treated sewage effluents as a function of β-lactamase produced Bacillus subtilis 1556WTNC. Four β-lactams antibiotics were selected: two of them belong to penicillin’s (amoxicillin and ampicillin) and two belong to cephalosporins (cephalexin and cefuroxime); ciprofloxacin (belongs to quinolones) was used as a negative control. The enzymatic biodegradation process was conducted under the optimal conditions for β-lactams production (5.9 log10 CFU mL−1; pH 6.5; temperature 35 °C for 12 days) as determined in this research. The maximum biodegradation was 25.03 % at 1 mg mL−1 for amoxicillin, 15.59 % at 0.8 mg mL−1 of ampicillin, 22.59 % at 1 mg mL−1 of cephalexin, 10.62 % at 1 mg mL−1 of cefuroxime, while it was 2.45 % at 0.6 mg mL−1 of ciprofloxacin. B. subtilis 1556WTNC exhibited the potential to produce β-lactamase and biodegrade β-lactam antibiotic genetically and inducibly B. subtilis 1556WTNC could grow and biodegrade β-lactam antibiotics in conditions similar to the characteristics of treated sewage effluents such as pH, temperature, and during short time (12 days), because it was already acclimatized to those conditions. For this reason, treated sewage effluents were used as source to isolate this strain. It can be concluded that B. subtilis 1556WTNC is suitable to remove pharmaceutical residues from the treated sewage effluents and produce effluents at higher quality than that achieved by secondary treatment process.
    12/2014; 1(4). DOI:10.1007/s40710-014-0034-6
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    • "Experimental designs to produce natural colorants It is known that metabolite production by microorganisms is largely influenced by the medium compounds, such as carbon and nitrogen sources, physicochemical factors , such as pH, temperature, inoculum size, stirring intensity and incubation time (Oh et al., 2000; Celik and Calik, 2004; Mapari et al., 2005). In previous work (Santos- Ebinuma et al., 2013b) different carbon (glucose, fructose, sucrose, maltose and starch) and nitrogen (malt extract, ammonium sulfate, peptone, yeast extract and tryptone) sources was evaluated in order to produce natural colorants by submerged culture of P. purpurogenum and sucrose and yeast extract were the more suitable sources. "
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    ABSTRACT: Safety issues related to the employment of synthetic colorants in different industrial segments have increased the interest in the production of colorants from natural sources, such as microorganisms. Improved cultivation technologies have allowed the use of microorganisms as an alternative source of natural colorants. The objective of this work was to evaluate the influence of some factors on natural colorants production by a recently isolated from Amazon Forest, Penicillium purpurogenum DPUA 1275 employing statistical tools. To this purpose the following variables: orbital stirring speed, pH, temperature, sucrose and yeast extract concentrations and incubation time were studied through two fractional factorial, one full factorial and a central composite factorial designs. The regression analysis pointed out that sucrose and yeast extract concentrations were the variables that influenced more in colorants production. Under the best conditions (yeast extract concentration around 10 g/L and sucrose concentration of 50 g/L) an increase of 10, 33 and 23% respectively to yellow, orange and red colorants absorbance was achieved. These results show that P. purpurogenum is an alternative colorants producer and the production of these biocompounds can be improved employing statistical tool.
    Brazilian Journal of Microbiology 08/2014; 45(2):731-42. DOI:10.1590/S1517-83822014000200049 · 0.59 Impact Factor
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    • "Furthermore, some studies had shown that B. thuringiensis bioinsecticides production is achieved by significant levels of enzymes in the growth media (Zouari and Jaoua, 1999; Chen et al., 2004). The production and secretion of enzymes by microorganisms is induced by medium ingredients and other physical factors such as inoculum size and available oxygen (Celik and Calik, 2004; Singh et al., 2004). Proteolytic activities are essential to assimilate proteins as nitrogen source, but they are involved in the stability of proteins produced by the bacterium as metabolites. "
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    ABSTRACT: A multiple linear regression analyses were performed to screen for the significant factors simultaneously influencing production of deltaendotoxin, proteolytic activities and spore formation by a Bacillus thuringiensis kurstaki strain. Investigated factors included: pH of the medium, available oxygen and inoculum size. It was observed that oxygen availability was the most influencing setting on both deltaendotoxins production and spores counts, followed by initial pH of the medium and inoculum size. On other hand, pH of medium was found to be the most significant parameter for proteolytic activity, followed by inoculum size and dissolved oxygen. Our results suggested that the first order with two-factor interaction model seemed to be more satisfactory than simple first order model for optimization of delta-endotoxin overproduction. The coefficients of determination (R') indicated a better adequacy of the second order models to justify the obtained data. Based on results, relationships between delta-endotoxins production, proteolytic activities and spores counts were established. Our results can help to balance delta-endotoxins production and its stability.
    Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists 01/2013; 62(3):287-93. · 0.70 Impact Factor
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