Abstract
Research on proteases and secondary metabolites from endophytes is an area that requires
attention from researchers. In this study, proteases from Bacillus sp. strain MHSD16 and Bacillus
sp. strain MHSD17 endophytes were characterised, and their potential biotechnological applications
were investigated. Optimum protease production was achieved when isolates were grown
in media containing (g/L): glucose 10g, casein 5g, yeast extract 5g, KH2PO4 2g, Na2CO3 10g at pH
9. The crude protease extracts were active in alkaline environments, thus referred to as alkaline
proteases with optimal pH of 10. Additionally, Bacillus sp. strain MHSD 16 and Bacillus sp. strain
MHSD17 proteases were active at high temperatures, with optimum enzyme activity at 50 ◦C.
Thermostability profiles of these proteases showed that the enzymes were highly stable between
(40–60 ◦C), maintaining over 85 % stability after 120 min incubation at 60 ◦C. Furthermore, the
enzymes were stable and compatible with various household and laundry detergents. In the
presence of commercial laundry detergent, OMO® 68 % and 72 % activity was retained for
Bacillus sp. strain MHSD16 and Bacillus sp. strain MHSD17, respectively, while 67 % and 68 %
activity were retained in the presence of Sunlight®. The potential application for use in detergents
was investigated through the removal of blood stains with the crude alkaline extracts
displaying efficient stain removal abilities. Feather degradation was also investigated and Bacillus
sp. MHSD17 exhibited feather keratin degrading properties more effectively than Bacillus sp.
MHSD16.