TY - JOUR AU - ACHMAD, DWI ISYANA AU - IHSANAWATI, AU - HERTADI, RUKMAN PY - 2021/07/17 Y2 - 2024/03/29 TI - ISOLATION AND CHARACTERIZATION OF A SURFACTANT-STABLE PROTEASE FROM HALOPHILIC BACTERIA Chromohalobacter Japonicus BK-AB18 JF - Malaysian Applied Biology JA - MAB VL - 49 IS - 2 SE - Research Articles DO - 10.55230/mabjournal.v49i2.1520 UR - https://jms.mabjournal.com/index.php/mab/article/view/1520 SP - 37-42 AB - <p>The protease from <em>Chromohalobacter japonicus </em>BK-AB18 was produced by growing bacteria in a LB medium containing 5% casein and 5% NaCl. The crude protease was partially purified by three levels of ammonium sulfate concentration (ranges of 0–70%, 70–75% and 75–80%) and the highest specific activity was exhibited in the range of 75–80%. The enzyme has a relative molecular weight of 65 kDa. The protease in this fraction had the highest activity in the following optimum conditions: 7.5% NaCl, a pH of 9.0 and a temperature of 45°C. The activity of the enzyme at the optimum pH and temperature was enhanced by the addition of a Ca2+ ion, but its activity was significantly inhibited by EDTA, hence this enzyme is included as metalloenzyme. Interestingly, the protease activity increased when exposed to a concentration of 0.01% and 0.05% SDS, and was relatively stable in this solution up to a concentration of 10%. It is thus demonstrated that <em>C. japonicus </em>BK-AB18 is a potential source to produce extracellular protease that can be applied in the surfactant/detergent industry.</p> ER -