Optimization of Nutrients and Culture Conditions for Alkaline Protease Production Using Two Endophytic Micrococci: Micrococcus aloeverae and Micrococcus yunnanensis.

An endophytic species of Micrococcus was isolated from Aloe vera leaf (syn. Aloe barbadensis) and screened for protease production with five other species of Micrococcus. Data indicated that endophytic Micrococcus aloeverae AE-6 MCC 2184T and Micrococcus yunnanensis DSM 21948T showed efficient protease production potential and secreted active protease at high salt (10%), temperature (40 °C) and in wide range of pH 8-10. Unlike M. yunnanensis DSM 21948T, protease production by M. aloeverae AE-6 MCC 2184T was stringently controlled by pH. Protease induction study using different group of peptides, peptide carbohydrates and peptide macronutrient combinations showed variable response with both the organisms. Result indicated that the amount of protease was not directly related to cell biomass but it depends on nature of inducible peptides. In this study we also developed a modified agar-well assay for semi-quantitative data from large number of replicates.