Oxygen-transfer strategy and its regulation effects in serine alkaline protease production byBacillus licheniformis

Çalı́k, Pınar; Çalık, Güzide; Özdamar, Tunçer H.

doi:10.1002/1097-0290(20000805)69:3<301::aid-bit8>3.0.co;2-4

Cited by 71 publications

(37 citation statements)

References 17 publications

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“…A kind of Damköhler number, Da, defined as maximum possible oxygen utilization rate per maximum mass transfer rate (6,8), and effectiveness factor, η, defined as the oxygen uptake rate per maximum possible oxygen utilization rate values (6,8), can be seen in Table 5.…”

Section: Oxygen Transfer Characteristics and Ratelimiting-mentioning

confidence: 99%

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

Çelik

Çalı́k

2004

Biotechnology Progress

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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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Section: Oxygen Transfer Characteristics and Ratelimiting-mentioning

confidence: 99%

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

Çelik

Çalı́k

2004

Biotechnology Progress

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“…Semibatch reactors operate at unsteady‐state conditions and are described as flexible but more difficult to analyse than other reactor types; further, they offer good control of reaction rate as the reaction proceeds by means of the addition or removal of at least one fermentation medium component. These systems have more applications in the fields of bio‐industries and conventionally are called fed‐batch bioreactors; synthesis of a biomolecule occurs through pathways of the intracellular reaction network within the cell which acts as a semibatch micro‐bioreactor . Yamane and Shimizu described fed‐batch bioreactor operation as superior to batch operation especially when changing concentrations of nutrient(s) affect the yield or productivity.…”

Section: Introductionmentioning

confidence: 99%

“…The starting point for the design of fed‐batch bioreactor operation is the development of batch bioreactor operation conditions, i.e. medium composition design followed by investigation of pH and oxygen transfer conditions. For rhGH production using recombinant B. subtilis under batch bioreactor operation conditions on a glucose based defined medium, pH and oxygen transfer characteristics have already been investigated and produced 81 mg dm −3 rhGH .…”

Section: Introductionmentioning

confidence: 99%

Parametric continuous feed stream design to fine-tune fed-batch bioreactor performance: recombinant human growth hormone production inBacillus subtilis

Çalık

Kocabaş

Afşar

et al. 2016

J. Chem. Technol. Biotechnol.

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BACKGROUND Design principles of a fed‐batch bioreactor system to fine‐tune bioreactor performance by increasing production and productivity are investigated. To enhance the production and productivity in fed‐batch fermentation of recombinant human growth hormone (rhGH) by Bacillus subtilis, this work develops a continuous feed stream (CFS) design method with the parameters, cultivation time to switch batch‐ to fed‐batch operation, so called transition time, tT, and specific growth rate, μ. RESULTS Based on batch‐bioreactor data for rhGH production by recombinant B. subtilis (scoC−) carrying pMK4::pre(subC)::hGH, three components of the defined medium were determined for continuous feeding. Theoretical analysis and modelling of the fed‐batch reactor lead to CFS design, to be applied starting at tT, which is a function of specific growth rate, μ. Transition time tT was optimised experimentally using the batch operation μ value, 0.100 h−1; and the highest rhGH concentration was obtained at tT=4 h. rhGH concentration increased further to 127 mg dm−3, when the CFS flow rate applied was calculated using μ = 0.125 h−1. CONCLUSION The performance of the fermentation process was enhanced by 36% and 8 h shortened cultivation time of t = 16 h, increased the rhGH productivity 2.4‐fold compared with batch‐fermentation. © 2015 Society of Chemical Industry

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“…Oxygen transfer into bacterial cells in aerobic fermentation process strongly affects growth and enzyme production by affecting the metabolic pathways and fluxes [23]. Several other researchers also reported maximum protease production at an agitation speed of 200 rpm [22].…”

Section: Resultsmentioning

confidence: 99%

Comparative one-factor-at-a-time, response surface (statistical) and bench-scale bioreactor level optimization of thermoalkaline protease production from a psychrotrophic Pseudomonas putida SKG-1 isolate

Singh

Tripathi

et al. 2011

Microb Cell Fact

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BackgroundProduction of alkaline protease from various bacterial strains using statistical methods is customary now-a-days. The present work is first attempt for the production optimization of a solvent stable thermoalkaline protease by a psychrotrophic Pseudomonas putida isolate using conventional, response surface methods, and fermentor level optimization.ResultsThe pre-screening medium amended with optimized (w/v) 1.0% glucose, 2.0% gelatin and 0.5% yeast extract, produced 278 U protease ml-1 at 72 h incubation. Enzyme production increased to 431 Uml-1 when Mg2+ (0.01%, w/v) was supplemented. Optimization of physical factors further enhanced protease to 514 Uml-1 at pH 9.0, 25°C and 200 rpm within 60 h. The combined effect of conventionally optimized variables (glucose, yeast extract, MgSO4 and pH), thereafter predicted by response surface methodology yielded 617 U protease ml-1 at glucose 1.25% (w/v), yeast extract 0.5% (w/v), MgSO4 0.01% (w/v) and pH 8.8. Bench-scale bioreactor level optimization resulted in enhanced production of 882 U protease ml-1 at 0.8 vvm aeration and 150 rpm agitation during only 48 h incubation.ConclusionsThe optimization of fermentation variables using conventional, statistical approaches and aeration/agitation at fermentor level resulted in ~13.5 folds increase (882 Uml-1) in protease production compared to un-optimized conditions (65 Uml-1). This is the highest level of thermoalkaline protease reported so far by any psychrotrophic bacterium.

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Oxygen-transfer strategy and its regulation effects in serine alkaline protease production byBacillus licheniformis

Cited by 71 publications

References 17 publications

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

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

Parametric continuous feed stream design to fine-tune fed-batch bioreactor performance: recombinant human growth hormone production inBacillus subtilis

Comparative one-factor-at-a-time, response surface (statistical) and bench-scale bioreactor level optimization of thermoalkaline protease production from a psychrotrophic Pseudomonas putida SKG-1 isolate

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