Optimization of cold-active protease production by the psychrophilic bacterium Colwellia sp. NJ341 with response surface methodology

Wang, Quanfu; Hou, Yanhua; Xu, Zhenbo; Miao, Jun; Guang-you, LI

doi:10.1016/j.biortech.2007.03.028

Cited by 71 publications

(45 citation statements)

References 15 publications

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“…Assay of protease activity Protease activity was determined by the method of Wang et al (2008). Briefly, 200 μl of the crude extract was added to the reaction mixture, containing 2% (w/v) casein (Sigma) in 200 μl of 50 mM TrisHCl (pH 8).…”

Section: Methodsmentioning

confidence: 99%

Production of Sufu, a Traditional Chinese Fermented Soybean Food, by Fermentation with Mucor flavus at Low Temperature

Cheng

Li-te

et al. 2009

FSTR

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This study evaluated biochemical changes, especially those related to protein degradation, occurring in sufu fermentation with Mucor flavus at low temperature. The effects of incubation temperature on M. flavus growth, biomass accumulation and protease production were described. Results indicated that M. flavus could grow well on the surface of soybean curd and produce considerable protease to degrade soybean proteins during sufu fermentation at lower temperature such as 15℃. Almost no subunits of protein could be observed after maturation for 8 weeks in M. flavus-type sufu. Post-fermentation was the main stage responsible for the hydrolysis of protein together with the increase in the content of amino-type nitrogen and free amino acid. Our results demonstrated that M. flavus had possible application as an alternative strain for sufu manufacturing at low temperature.Keywords: sufu, Mucor flavus, fermentation, protein degradation *To whom correspondence should be addressed. E-mail: yinljmail@yahoo.com.cn IntroductionIn Asian countries, soybean is consumed in many forms, including soymilk, soybean curd products, and fermented soybean food such as miso, soy sauce, tempeh, natto and sufu. Sufu is a traditional fermented soybean curd originating in China (Steinkraus, 1996). It is a soft cheese-like product with a spreadable creamy consistency, and it has been consumed widely as an appetizer for centuries in China (Zhang and Shi, 1993;Han, et al., 2001;Han, et al., 2003a). There is a similar product called tofuyo in Okinawa, Japan (Yasuda, 2000(Yasuda, , 2001. Several types of sufu can be distinguished, according to different local processes or colour and flavour in China. Mould-fermented sufu is the most popular type due to its attractive colour and strong flavour (Han, et al., 2001).Sufu is produced by means of solid-state fermentation of soybean curd after inoculation with pure culture moulds. In commercial practice, Actinomucor spp., Mucor spp. and Rhizopus spp. are used for sufu preparation. Among fungal genera, Actinomucor elegans and Actinomucor taiwanensis seemed to be the most frequently used for commercial sufu production in China. However, these two mould species generally grow well at temperatures ranging from 25℃ to 30℃, hence making it difficult to produce sufu when the indoor temperature of the factory exceeds 35℃ during hot summer or below 20℃ during cold winter. Recently, the screening of alternative strains for the commonly used starter cultures in sufu production is receiving much attention. (Han, et al., 2003b;Hu, 2006;Hu, et al., 2008;Hu and Zhao, 1998a;Hu and Zhao, 1998b).Fermentation temperature greatly affects the growth of fungus and the variations in the enzyme activities produced by microorganisms, which are thought to have a close relation to sufu quality. Protein degradation is one of the important biochemical events during sufu fermentation. It had been reported that most of the soybean proteins were degraded into peptides and amino acids in well-qualified sufu. With the exception of the ...

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Section: Methodsmentioning

confidence: 99%

Production of Sufu, a Traditional Chinese Fermented Soybean Food, by Fermentation with Mucor flavus at Low Temperature

Cheng

Li-te

et al. 2009

FSTR

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“…21,22) This method is most frequently used in biotechnology operations to obtain maximum cell density, and high yields of the desired metabolic product and enzyme levels in microbial 23) and plant systems, 24) but these single-variable optimization methods have weaknesses, such as being time-consuming 24) and expensive when a large number of variables are considered. 6) Furthermore, misinterpretation of results may occur if the interaction effects between different variables are overlooked.…”

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confidence: 99%

Optimization of Protease Extraction from Horse Mango (Mangifera foetidaLour) Kernels by a Response Surface Methodology

Ahmad

Liew

Yarmo

et al. 2012

Bioscience, Biotechnology, and Biochemistry

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“…However, the p-value of the coefficients of the linear effects of soy flour and the interactive effect of soy flour and skimmed milk may have been significant to some extent. According to this result, skimmed milk, which is a source of casein, appeared to have the greatest effect on enzyme production (p-values of β 1 , β 11 < 0.001), since the casein provided the intact peptides necessary for the induction process of the enzyme 28 . Thus, the response of silk degumming protease production (Y ) by B. subtilis C4 can be expressed in terms of the regression equation: + 513.32…”

Section: Optimization By Response Surface Methodologymentioning

confidence: 91%

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Romsomsa¹,

Chim-anagae²,

Jangchud³

2010

ScienceAsia

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Bacillus subtilis C4 was isolated from waste water of a Thai-silk dyeing factory, and identified as a potent strain for producing silk-degumming protease. To optimize the protease production of this bacterial strain, seven fermentation variables were screened using a Plackett-Burman design, and were then further optimized via response surface methodology based on a central composite design. Three significant variables, i.e., soy flour, skimmed milk, and shaker speed, were selected. The optimal values were 2.0% soy flour, 0.1% skimmed milk, and a shaker speed of 280 rpm. The experimental result (1537 units/ml) in a medium optimized for protease production was in good agreement with the predicted value of a quadratic model (1576 units/ml), thus confirming its validity. In addition, the adequacy of the model was supported by a coefficient of determination (R 2 ) of 0.912. Protease production in the optimized medium (1537 units/ml) increased 2.2-fold over that of the non-optimized medium (729 units/ml) in the shaken flask culture. When the experiment was scaled up in a stirred tank reactor, 1891 units/ml protease activity was achieved at 27 h of cultivation, which was an overall 2.6-fold increase over the basal medium.

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Optimization of cold-active protease production by the psychrophilic bacterium Colwellia sp. NJ341 with response surface methodology

Cited by 71 publications

References 15 publications

Production of Sufu, a Traditional Chinese Fermented Soybean Food, by Fermentation with Mucor flavus at Low Temperature

Production of Sufu, a Traditional Chinese Fermented Soybean Food, by Fermentation with Mucor flavus at Low Temperature

Optimization of Protease Extraction from Horse Mango (Mangifera foetidaLour) Kernels by a Response Surface Methodology

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