• Food Science and Biotechnology
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• v.17 no.5
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• pp.904-911
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• 2008

Covalent cross-links between a number of proteins and peptides explain why transglutaminase may be widely used by food processing industries. The objective of this work was optimization of the fermentation process to produce transglutaminase from a new microbial source, the Streptomyces sp. P20. The strategy adopted to modify the usual literature media was: (1) fractional factorial design (FFD) to elucidate the key medium ingredients, (2) central composite design (CCD) to optimise the concentration of the key components. Optimization of the medium resulted in not only an 86% increase in microbial transglutaminase activity as compared to the media cited in the literature, but also a reduction in the production cost. Optimal fermentation conditions - namely temperature and agitation rate - were also studied, using CCD methodology. Usual conditions of $30^{\circ}C$ and 100 rpm were within the optimal area. All other parameters for enzyme production were experimentally proven to be optimum fermentation conditions.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.193-198
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• 1999

The optimal culture condition of Bacillus sp. P16 was investigated for production of an extracellular endo-splitting chitosanase. The best carbon and nitrogen sources for the chitosanase production were chitosan and tryptone, respectively. The best condition for the maximum activity was at $37^{\circ}C$ in a medium containing 0.5% powdered chitosan, 1% tryptone, and 1% NaCl(at initial pH 7.0) in a rotary shaker(200 rpm). In a jar fermenter, the culture duration shortened to $6{\sim}12$ hr for maximum activity and the enzyme activity increased about 100% compared with that of flask culture.

• KSBB Journal
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• v.25 no.1
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• pp.79-84
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• 2010

In the present study, we isolated a new bacterial strain producing invertase (EC 3.2.1.26) and determined optimized culture condition in flask culture. The strain was identified as Bacilus flexus determined by the 16S rDNA sequencing method. The invertase was produced only in the sucrose medium as the sole carbon source. Potassium nitrate was an adequate nitrogen source for enzyme production, whereas meat peptone showed the highest bacterial growth. Enzyme production was increased about 2-fold when $MgSO_4\cdot7H_2O$ was supplemented to the growth media. The optimum temperature was found to be $30^{\circ}C$ for both enzyme production and bacterial growth. Invertase exhibited pH optima in the range 5.0-6.0 and have a temperature optimum at $40^{\circ}C$, similarly to other invertases found from different microbial sources. Several mineral ions (K and Fe) stimulated the invertase activity, whereas some bioelements (Ag, Mg, and Mn) inhibited enzyme activity. Under the optimized culture condition, the maximum enzyme production (over 250 units/mL) was achieved at 20 h. To the best of our knowledge, this is the first time to report on invertase production by Bacilus flexus.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.442-448
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• 2009

In this study Bacillus subtilis PTCC 1023 was used for the production of protopectinase using soybean based media. The use of isolated soybean protein (ISP) and soybean flour resulted in similar protopectinase production and growth rates. The effect of medium composition on protopectinase production was studied using central composite design (CCD) methodology. The change in the concentration of ISP (1-7%), glucose (0-10%), and phosphate (0.1-0.3 M) was found to affect the protopectinase activity (response variable) after 24 hr of cultivation. In the range studied, ISP and glucose had a negative effect on the response variable, whereas phosphate had a positive effect. A statistically significant interaction was identified between phosphate and ISP, suggesting that correct optimization of medium formulation in this case can only be obtained using factorial design of experiments. Protopectinase activity exceeding 215 U/mL was obtained in a medium containing 4% ISP, 0.3M phosphate, and no added sugar.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1531-1541
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• 2023

Lipase is a well-known and highly in-demand enzyme. During the last decade, several lipase optimization studies have been reported. However, production costs have always been a bottleneck for commercial-scale microbial enzyme production. This research aimed to optimize the conditions for lipase production by Limtongozyma siamensis DMKU-WBL1-3 via a One-Factor-At-a-Time (OFAT) approach combined with statistical methods while using a low-cost substrate. Results suggest that low-cost substrates can be substituted for all media components. An optimal medium was found, using response surface methodology (RSM) and central composite design (CCD), to consist of 0.50% (w/v) sweet whey, 0.40% (w/v) yeast extract (food grade), and 2.50% (v/v) palm oil with the medium pH adjusted to 4 under shaking flask cultivation. From an economic point of view, this work was successful in reducing production costs while increasing lipase productivity. The medium costs were reduced by 87.5% of the original cost while lipase activity was increased by nearly 6-fold. Moreover, lipase production was further studied in a 2-L stirred-tank fermentor. Its activity was 1,055.6 ± 0.0 U/ml when aeration and agitation rates were adjusted to 1 vvm and 170 rpm, respectively. Interestingly, under this optimal lipase production, the yeast showed accumulated lipids inside the cells. The primary fatty acid is a monounsaturated fatty acid (MUFA) that is typically linked to health benefits. This study hence reveals promising lipase production and lipid accumulation by L. siamensis DMKU-WBL1-3 that are worthy of further study.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1161-1168
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• 2009

Ethanol production by the simultaneous saccharification and fermentation (SSF) of low-value rice wine cake (RWC) without cooking was investigated. RWC is the filtered solid waste of fermented rice wine mash and contains 53% raw starch. For the SSF, the RWC slurry was mixed with the raw-starch-digesting enzyme of Rhizopus sp. and yeast, where the yeast strain was selected from 300 strains and identified as Saccharomyces cerevisiae KV25. The highest efficiency (94%) of ethanol production was achieved when the uncooked RWC slurry contained 23.03% starch. The optimal SSF conditions were determined as 1.125 units of the raw-starch-digesting enzyme per gram of RWC, a fermentation temperature of $30^{\circ}C$, slurry pH of 4.5, 36-h-old seeding culture, initial yeast cell number of $2{\times}10^7$ per ml of slurry, 17 mM of urea as the nitrogen additive, 0.25 mM of $Cu^{2+}$ as the metal ion additive, and a fermentation time of 90 h. Under these optimal conditions, the ethanol production resulting from the SSF of the uncooked RWC slurry was improved to 16.8% (v/v) from 15.1% (v/v) of pre-optimization.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.43-51
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• 2002

The cloning and expression of $\beta-glucosidase$ II, encoded by the gene ${\beta}glu2$, from thermotolerant yeast Pichia etchellsii into Escherichia coli is described. Cloning of the 7.3 kb BamHI/SalI yeast insert containing ${\beta}glu2$ in pUC18, which allowed for reverse orientation of the insert, resulted in better enzyme expression. Transformation of this plasmid into E. coli JM109 resulted in accumulation of the enzyme in periplasmic space. At $50^{\circ}C$, the highest hydrolytic activity of 1686 IU/g protein was obtained on sophorose. Batch and fed-batch techniques were employed for enzyme production in a 14 L bioreactor. Exponential feeding rates were determined from mass balance equations and these were employed to control specific growth rate and in turn maximize cell growth and enzyme production. Media optimization coupled with this strategy resulted in increased enzyme units of 1.2 kU/L at a stabilized growth rate of $0.14\;h^{-l}$. Increased enzyme production in bioreactor was accompanied by formation of inclusion bodies.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.2
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• pp.33-37
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• 2023

Purpose: Since 2013, marine dumping of wastewater has been banned, and research on eco-friendly and efficient land treatment has emerged. This study compared and tested changes in biogas production and anaerobic process efficiency depending on whether or not enzyme pretreatment was performed during anaerobic digestion from single-phase and two-phase to medium-temperature. Research design, data and methodology: The total sugar, direct sugar, pH, and acidity before and after fermentation were analyzed by G/C by anaerobic fermentation of the liquor wastewater, food wastewater 1, and food wastewater 2 at 30℃ for 67 hours, and the amount of methane gas generated was analyzed by balloon volume. Results: It was found that stable organic acid concentration and pH were found in the enzyme-treated food wastewater 2, and the amount of methane gas generated was also increased. Conclusions: When anaerobic digestion of the liquor wastewater and the food wastewater together, the performance of enzyme pretreatment resulted in increased digestive efficiency. It will be the basic data that can contribute to carbon neutrality and greenhouse gas reduction by increasing the production of biogas.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.176-185
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• 2016

Yeonsan Ogae has been known as supporting health and high efficacy of treatment. In recent days, as the efficacy of functional peptides has known, the optimization of oligo peptides production and its characteristics from Ogae legs has been performed. Response surface method was used to perform the optimizaion of enzyme hydrolysis. The range of processes was temperature ( 40, 50 and $60^{\circ}C$), pH( pH 6.0, 7.0 and 8.0 ), and enzyme( 1, 2 and 3% ). The degree of hydrolysis, amino acids, molecular weight of products were analyzed. The optimum process of enzyme hydrolysis were determined as temperature $58^{\circ}C$, pH 7.5, and enzyme concentration 3%. At optimum conditions, the degree of hydrolysis after 2 h reaction was 75-80%. The amino acid and were 168.131 mg/100 g, respectively. The molecular weight of products by using MALDI-TOF was ranged from 300 to 1,000 Da.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.182-191
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• 2016

The purpose of this research was the optimization of protein hydrolysate production using a commercial enzyme bromelain 1200 derived from the leg of Yeonsan Ogae by response surface methodology. Yeonsan Ogae has long been known as supporting health and high efficacy treatment. In recent days, as the efficacy of functional peptides becomes more known, optimization of oligopeptide production and its characteristics from Ogae leg meat has been performed. Response surface methodology was performed for optimization of enzyme hydrolysis. The process was varied in pressure (30 to 100 MPa), time (1 to 3 h), and substrate concentration (10 to 30%). The degree of hydrolysis, amino acids, and molecular weight of products were analyzed. The optimum conditions were determined to be a pressure of 100 Mpa, time of 3 h, and substrate concentration of 20%. Under optimized conditions, degree of hydrolysis was 34.10%. The average molecular weight of protein hydrolysates was less than 1,000 Da. Major amino acids were leucine, lysine, alanine, glutamic acid, and phenylalanine.