Production and Characterization of an Extracellular Acid Protease from Thermophilic Brevibacillus sp. OA30 Isolated from an Algerian Hot Spring

Abstract

Proteases have numerous biotechnological applications and the bioprospection for newly-thermostable proteases from the great biodiversity of thermophilic microorganisms inhabiting hot environments, such as geothermal sources, aims to discover more effective enzymes for processes at higher temperatures. We report in this paper the production and the characterization of a purified acid protease from strain OA30, a moderate thermophilic bacterium isolated from an Algerian hot spring. Phenotypic and genotypic study of strain OA30 was followed by the production of the extracellular protease in a physiologically-optimized medium. Strain OA30 showed multiple extracellular proteolytic enzymes and protease 32-F38 was purified by chromatographic methods and its biochemical characteristics were studied. Strain OA30 was affiliated with Brevibacillus thermoruber species. Protease 32-F38 had an estimated molecular weight of 64.6 kDa and was optimally active at 50 °C. It showed a great thermostability after 240 min and its optimum pH was 6.0. Protease 32-F38 was highly stable in the presence of different detergents and solvents and was inhibited by metalloprotease inhibitors. The results of this work suggest that protease 32-F38 might have interesting biotechnological applications.

Test for the production and assay of the enzymatic activity of bacterial and Archean halophilic proteolytic strains isolated from Algerian hypersaline environments

“…The culture was incubated in aerobic conditions at 37°C during 24h for bacteria and 4_h for archaea. The optical density at 660 nm was mesured with a Synergy H1 hybrid multi-mode microplate reader [10].…”

“…After centrifugation at 15,000 g for 10 min, the absorbance of the supernatant was measured at OD366nm. One unit of protease activity was defined as the amount required to produce enough acid-soluble material from azocasein to yield an absorbance of 0.01 at 366 nm, following 1 h of incubation [13,10].…”

“…The enzymatic assay was first performed for the 45 proteolytic selected strains with azocasein using PBS buffer [13,10], after production on casein and gelatin media. Results presented on figures 2 and 3 allowed us to select 5 bacteria and 5 archaea that shown interesting enzymatic activity: 1, 4, 11, 13 and 17 for bacteria ; B, F, H, L and N for archaea.…”

Identification of Protease-Producing Bacteria Isolated from Banyuwedang, Bali, and Characterization of its Protease

“…Brevibacillus thermoruber OA30 produced protease 32-F38 which showed a great thermostability after 240 min. It also showed a highly stable activity in the presence of different detergents and solvents (Gomri et al, 2018). An anaerobic thermophic bacteria had been isolated from a hydrothermal hot spring in Algeria, Caldicoprobacter algeriensis strain TH7C1, which showed capability of producing protease with high keratinolitic activity.…”

Editorial for the Special Issue: Thermophiles and Thermozymes

“…strain isolated from a gold mine, its comparison (favorable) with commercial counterparts for lignocellulosic biomass hydrolysis, and the use of the strain in co-culture for ethanol fermentation of the biomass. Gomri et al [6] depict the characterization of a new acid protease produced extracellularly by a thermophilic bacterium that was isolated from an Algerian hot spring and affiliated with Brevibacillus thermoruber species. The purified 32-F38 protease resulted to be thermostable and highly stable in the presence of different detergents and solvents, suggesting potential biotechnological applications.…”