Influence of pH conditions on metabolic regulations in serine alkaline protease production by Bacillus licheniformis

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

doi:10.1016/s0141-0229(02)00162-x

Cited by 44 publications

(25 citation statements)

References 15 publications

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“…The increase of the pH after glucose depletion is due to the induction of genes that enable the consumption of the previously secreted organic acids (Voigt et al, ). It was further reported that under uncontrolled pH batch operation, the pH increases due to H + transport into the cells (Çalık, Bilir, Çalık, & Özdamar, ). Since B. licheniformis maintains a constant intracellular (cytoplasmic) pH of about 7.5, cells react on variations of the extracellular pH by pumping H + ions in or out through the membrane (Çalık et al, ).…”

Section: Resultsmentioning

confidence: 99%

“…It was further reported that under uncontrolled pH batch operation, the pH increases due to H + transport into the cells (Çalık, Bilir, Çalık, & Özdamar, ). Since B. licheniformis maintains a constant intracellular (cytoplasmic) pH of about 7.5, cells react on variations of the extracellular pH by pumping H + ions in or out through the membrane (Çalık et al, ). The accumulated overflow metabolite concentrations are rather low, with the highest concentration of 0.6 g/L for acetate and 0.35 g/L for 2,3‐butanediol (Figure b).…”

Section: Resultsmentioning

confidence: 99%

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Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Habicher

John

Scholl

et al. 2019

Biotech & Bioengineering

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To overcome catabolite repression, industrial fermentation processes are usually operated in substrate-limited fed-batch mode. Therefore, the implementation of such an operating mode at small scale is crucial to maintain comparable process conditions. In this study, Bacillus licheniformis, a well-known producer of proteases, was cultivated with carbon (glucose)-and nitrogen (ammonium)-limited fed-batch conditions using the previously introduced membrane-based fed-batch shake flasks. A repression of protease production by glucose and ammonium was thus avoided and yields increased 1.5-and 2.1-fold relative to batch, respectively. An elevated feeding rate of glucose caused depletion of ammonium, which was recognizable within the oxygen transfer rate (OTR)signal measured with the Respiration Activity MOnitoring System (RAMOS). Ammonium limitation was prevented by feeding ammonium simultaneously with glucose. The OTR signal clearly indicated the initiation of the fed-batch phase and gave direct feedback on the nutrient release kinetics. Increased feeding rates of glucose and ammonium led to an elevated protease activity without affecting the protease yield (Y P/Glu ). In addition to Y P/Glu , protease yields were determined based on the metabolized amount of oxygenThe results showed that the protease production correlated with the amount of consumed glucose as well as with the amount of consumed oxygen. The membranebased fed-batch shake flask in combination with the RAMOS device is a powerful combination to investigate the effect of substrate-limited fed-batch conditions. K E Y W O R D SBacillus licheniformis, catabolite repression, fed-batch, membrane-based fed-batch shake flask, proteases

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Habicher

John

Scholl

et al. 2019

Biotech & Bioengineering

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“…Catabolic pathways of imported carbon sources are pH dependent in many microbes [24][25][26]. As shown in Supplementary Table S1, growth of A. pullulans and EPS formation are significantly affected by the initial pH.…”

Section: Resultsmentioning

confidence: 99%

Optimization of culture medium for enhanced production of exopolysaccharide from Aureobasidium pullulans

Yoon

Hong

Kim

et al. 2011

Bioprocess Biosyst Eng

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Polysaccharides produced by microorganisms are utilized for a variety of purposes, including the use in cosmetics and as food additives. More recently, polysaccharides have been exploited by the medical and pharmaceutical industries, and those originated from many species of mushrooms have been especially useful in industrial applications; however, the production and synthesis of these compounds is costly and time consuming. In this study, we developed a method for low-cost production of exopolysaccharide (EPS) that effectively screens components and optimizes medium composition using statistical methods (Plackett-Burman and Box-Behnken design). As a result, we obtained the following optimized medium: sucrose 165.73 g/L, sodium nitrate 3.08 g/L, dipotassium phosphate 1.00 g/L, potassium chloride 0.50 g/L, magnesium sulfate 0.50 g/L, ferrous sulfate 0.01 g/L, and 0.71 g/L of Ashbya gossypii extract. The maximum production of about 29 g/L EPS was achieved in the optimized medium during 84 h batch fermentation.

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“…The reaction was stopped by adding 500 ll of 10 % (w/v) trichloroacetic acid solution (Merck) and the mixture was centrifuged at 150009g for 15 min at 4°C, and absorbance of the supernatant was measured at 275 gm with a UV-VIS spectrophotometer (Shimadzu UV-1601 PC). One unit protease (U/ml) activity was defined as the activity that liberates 1 lg of tyrosine per minute (lg Tyr 9 ml -1 min -1 ) under described conditions (Ç alik et al 2002;Kumar 2002).…”

Section: Protease Assaymentioning

confidence: 99%

Alkaline protease from Bacillus sp. isolated from coffee bean grown on cheese whey

Dias

Vilela

Silvestre

et al. 2008

World J Microbiol Biotechnol

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Two strains of Bacillus, one from a culture collection (B. subtilis ATCC 6633) and a wild type (Bacillus sp. UFLA 817CF) isolated during coffee fermentation in the south of Minas Gerais, Brazil, were evaluated in relation to secretion of alkaline proteases. The strains were grown on nutrient broth, nutrient broth with sodium caseinate and nutrient broth with three different concentrations of cheese whey powder for 72 h. Samples were collected at 24-h intervals to evaluate the proteolytic activity, protein content and cell population. Maximum protease activity was observed after 24-h growth for both the microorganisms, a period that coincided with the end of the exponential phase. The specific activity values were, respectively, 839.8 U/mg for B. subtilis ATCC 6633 and 975.9 U/mg for Bacillus sp. UFLA 817CF. The 60% saturation presented the best results for specific protease activity in all the growth culture media tested with B. sp. UFLA 817CF. Bacillus sp. UFLA 817CF showed highest enzymatic activity at pH 9.0 and 40°C in the three culture media tested. The protease obtained from culture of the wild Bacillus strain presented stability at pH 7.0 and considerable heat stability at 40°C and 50°C, and could be an alternative for the industry to utilize cheese whey to produce proteolytic enzymes.

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Influence of pH conditions on metabolic regulations in serine alkaline protease production by Bacillus licheniformis

Cited by 44 publications

References 15 publications

Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Optimization of culture medium for enhanced production of exopolysaccharide from Aureobasidium pullulans

Alkaline protease from Bacillus sp. isolated from coffee bean grown on cheese whey

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