Purification and characterization of a new neutral metalloprotease from marine Exiguobacterium sp. SWJS2. (7th August 2015)

• Record Type: Journal Article
• Authors: Lei, Fenfen; Cui, Chun; Zhao, Haifeng; Tang, Xuelu; Zhao, Mouming
• Is Part Of: Biotechnology and applied biochemistry. Volume 63:Number 2(2016:Mar./Apr.)
• Page Start: 238
• Page End: 248
• Publication Date: 2015-08-07
• Subjects: Exiguobacterium sp -- enzyme characteristics -- marine bacteria -- protease -- purification; Biotechnology -- Periodicals; Biochemical engineering -- Periodicals; Biochemistry -- Periodicals; Biochemistry -- Periodicals; Genetic Techniques -- Periodicals; Microbiological Techniques -- Periodicals; 660.6
• DOI: 10.1002/bab.1355
• Languages: English
• ISSNs: 0885-4513

Abstract

Abstract: Among the protease‐producing bacterial strains isolated from deep‐sea sediments, SWJS2 was finally selected and identified as genus Exiguobacterium . Plackett–Burman and orthogonal array designs were applied to optimize the fermentation conditions, and the results are as follows: Glucose 5g, yeast extract 15g, glycerin 2g and CaCl2 ⋅2H2 O 0.5 g dissolved in 1 L artificial seawater; temperature 25 °C, original pH 7, inoculum rate 2%, seed age 12 H, loading volume 25 mL (250‐mL Erlenmeyer flask), shaking speed 150 rpm, and fermentation time 44 H. The protease activity production was improved from about 80 to 660 U/mL under the optimized parameters. The protease was purified fourfold with specificity activity of 30, 654.1 U/mg protein and a total yield of 16.2%. The protease exhibited the maximum activity at 40–45 °C and pH 7. Moreover, the enzyme activity was found to be inhibited by Cu 2+, Ba 2+, Cd 2+, Hg 2+, and Al 3+ at 5 mM, whereas it can be increased by Mg 2+, Mn 2+, and Ca 2+ at 0.5–5 mM. The enzyme was totally inactivated by 1 or 5 mM ethylenediaminetetraacetic acid but not by phenylmethanesulfonyl fluoride, tyrpsin inhibitor from Glycine max (STI), benzamidine, 5, 5′‐dithio‐bis‐(2‐nitro benzoic acid), or pepstatin A, suggesting that it belonged to metalloprotease.