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Proteases are important industrial enzymes used in different areas of industry, mainly detergent, food and leather industries. In this study, novel alkaline protease-producing bacterium was isolated from Geinarje hot spring and examined for maximum protease activity to be utilized in washing-powder. The isolated bacterium was cultured in mineral salt medium including 2% Skim Milk. Proteolytic activity of supernatant was measured by caseinolytic method. The effects of pH, temperature, SDS, Tween 80 and EDTA on protease stability and activity were investigated. The detergent compatibility of protease was assayed. On the basis of phylogenetic analysis and morphological as well as biochemical tests, the isolate was identified as a new strain of Brevibacillus borstelensis capable of generating extracellular alkaline protease. The generated protease was determined as alkaline metallo-protease having high activity at 60 ^oC and pH 9. Moreover, the alkaline protease was stable in the presence of SDS, Tween 80 and H₂O₂. It is compatible with commercial detergents. Finding proteases capable of degrading proteins in extreme environment (i.e. alkaline pH, high temperature and presence of surfactants) is valuable in biotechnological and industrial practices. Therefore, it can be utilized in detergent formulation in the future.

 

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Nowadays plant endophytic bacteria have found diverse and useful applications in biotechnology; therefore, much attention has been paid to the isolation, identification, and evaluation of these microorganisms. Since the sterilizing plant tissue surfaces from epiphytic bacteria is difficulty, the efficacy of three different screening methods for endophytic bacteria including 1- HClO sterilization, 2- Periodic sterilization (modified tyndallization) and 3- Triton X100 and HClO sterilization, was evaluated in this study. The modified Tyndallization is an innovative method used in this study to appropriately remove the internal spores of epiphytic bacteria, considered to be an obstacle to the isolation of endophytes. Most of the endophytic bacteria were isolated from dicotyledons and leaves. Endophytic bacteria were also studied for the production of different hydrolase enzymes, whereas the protease enzyme was produced in a wide range of endophytic bacteria in greater quantities than other enzymes. The EndoA strain was molecularly identified and found to be 100% similar to Bacillus halotolerans.