Protease activity of bacterial isolates TP5K1 and TP6K5 in tofu solid waste substrate and identification of isolates based on 16S rDNA

摘要

In Indonesia the utilization of tofu solid waste is limited, only used as animal feed and traditional food although tofu solid waste contains 23.7 % protein. This study focused on using tofu solid waste as substrate for protease production of bacteria isolates TP5K1 and TP6K5. The aim of this research were to observe the highest protease spesific activity from isolates TP5K1 and TP6K5 and to identify the isolates using 16S rDNA. Identification of those isolates was carried out using universal primer 27F and 1495R and amplif ication of 16S rDNA. Ten percent (w/v ) of t ofu solid waste broth medium was used as gr o wt h medi u m for isolates TP5K1 and TP6K5, wh e reas tofu solid waste 0.5 % and 1 % (w/v ) was used as substrate for crude protease activity measurement compared to control 1 % (w/v ) casein . The result showed that the highest specific activity of isolate TP5K1 wa s 663.4 U /mg occured at 18 hours, whereas isolate TP6K5 was 324.5 U/mg occurred at 24 hours. The h ighest protease specific activity of isolates TP5K1 occurred in 0.5 % (w/v ) tofu solid waste substrate reached 11o.06 U /mg and TP6K5 occurred i n 1 % (w/v ) tofu solid waste substrate reached 10.10 U/mg. Based on 16S rDNA, isolate TP5K1 was identified as Exiguobacterium indicum PCWCW1 and isolate TP6K5 was identified as Exiguobacterium sp. TDWCW9.