Role of casein on induction and enhancement of production of a bacterial milk clotting protease from an indigenously isolated Bacillus subtilis.
OBJECTIVE
To isolate and enhance the yield of a bacterial milk clotting protease (MCP) through process optimization and scale up.


RESULTS
Bacillus subtilis was isolated as MCP producer with good milk clotting activity (MCA) per proteolytic activity (PA) index. The enzyme production was inducible with casein and enhanced with fructose and ammonium nitrate resulting in 571.43 U ml(-1) of enzyme.


CONCLUSIONS
Medium containing 4% fructose, 0.75% casein, 0.3% NH(4)NO(3) and 10 mmol l(-1) CaCl(2), pH 6.0, inoculated with 4% (v/v) inoculum, incubated at 37 degrees C, 200 rev min(-1) for 72 h gave maximum production. A 6.67-fold increase in MCP yield with very high MCA per PA index was observed after final optimization indicating similarity to rennets.


CONCLUSIONS
Mostly fungal MCPs have been reported. The MCA and MCA per PA index of this bacterium is comparable to that of many fungal reports and better than quite a few bacterial MCPs. Thus, this enzyme by B. subtilis has good probability of successful use in cheese production.
Dutt
K
K
Department of Microbiology, University of Delhi South Campus, New Delhi, India.
Meghwanshi
G K
GK
Gupta
P
P
Saxena
R K
RK
D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000096:biosynthesis; D019149:Bioreactors; D002364:Caseins / Q000378:metabolism*; D002417:Cattle; D004790:Enzyme Induction; D005285:Fermentation; D005632:Fructose / Q000378:metabolism; D007218:Industrial Microbiology; D008892:Milk / Q000201:enzymology* / Q000382:microbiology; D010447:Peptide Hydrolases / Q000096:biosynthesis*
D001426:Bacterial Proteins; D002364:Caseins; D005632:Fructose; D010447:Peptide Hydrolases