Screening and characterization of the alkaline protease isolated from PLI-1, a strain of Brevibacillus sp. collected from Indonesia’s hot springs |
| |
| Authors: | Shuai Wang Xuezheng Lin Xiaohang Huang Li Zheng Dewi Seswita Zilda |
| |
| Institution: | 1) The Key Laboratory of Marine Bioactive Substances, The First Institute of Oceanography, SOA, Qingdao 266061, P. R. China 2) Research Center for Marine and Fishery Product Processing and Biotechnology, Jakarta, Indonesia |
| |
| Abstract: | A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia’s hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability. |
| |
| Keywords: | hot spring thermophilic bacterium thermophilic protease identification |
| 本文献已被 CNKI SpringerLink 等数据库收录！ |
|
