Presence of PMSF (15mM) in the reaction mixture
severely decreased the hydrolytic activity of B. coagulans
lipase (Fig. 6). After 20min, almost a complete loss of lipase
activity was noticed.
Substrate aYnity and speciWcity of lipase of B. coagulans
MTCC-6375
The speciWcity as well as aYnity of the B. coagulans
lipase towards various p-nitrophenyl esters was studied by
determining Vmax and Km values for each of the selected
substrate (Table 4). The PL of B. coagulans MTCC-6375
exhibited highest aYnity towards pNPC followed by pNPP
as observed from measured Vmax and Km of 0.7mmolmg¡1
proteinmin¡1 and 32mM, and 0.44 and 28mmolmg¡1
proteinmin¡1, respectively. Although, the lipase was highly
speciWc towards pNPC but showed variable speciWcities
towards other esters. The hydrolytic activity of B. coagulans
for hydrolysis of pNPP was approximately 14% lower than
pNPC.