Production Of Acid Protease Research Articles

Studies on pepsin inhibitor (S-PI) from Streptomyces naniwaensis. IV. Effect of a microbial acid protease inhibitor (S-PI) on the production of fungal acid protease.

Cladosporium sp. No. 45–2, an acid protease-producing microorganism, was cultured in medium containing a microbial acid protease inhibitor (S–PI). By the addition of S–PI, the amount of acid protease in the culture broth showed an increase of 50~80% over those of normal culture (S–PI-free). Acid protease was purified from the S–PI-added culture filtrate, and its enzymatic and physicochemical properties were compared with those of acid protease obtained from normal culture. It was determined that the acid protease obtained from S–PI-added culture was the same as that of normal culture, but that the productivity was increased by the addition of S–PI.The increase in acid protease productivity is assumed to be due to a change in metabolism by the addition of S–PI.

Acid protease production by fungi used in soybean food fermentation.

Growth conditions for maximum protease production by Rhizopus oligosporus, Mucor dispersus, and Actinomucor elegans, used in Oriental food fermentations, were investigated. Enzyme yields by all three fungi were higher in solid substrate fermentations than in submerged culture. The level of moisture in solid substrate must be at about 50 to 60%. Very little growth of these fungi was noted when the moisture of substrate was below 35%, whereas many fungi including most storage fungi generally grow well on solid substrate with that level of moisture. Among the three substrates tested-wheat bran, wheat, and soybeans-wheat bran was the most satisfactory one for enzyme production. The optimal conditions for maximum enzyme production of the three fungi grown on wheat bran were: R. oligosporus, 50% moisture at 25 C for 3 to 4 days; M. dispersus, 50 to 63% moisture at 25 C for 3 to 4 days; A. elegans, 50 to 63% moisture at 20 C for 3 days. Because these fungi are fast growing and require high moisture for growth and for enzyme synthesis, the danger of contamination by toxin-producing fungi would be minimal.

Acid Protease Production by Fungi Used in Soybean Food Fermentation

Growth conditions for maximum protease production by Rhizopus oligosporus, Mucor dispersus, and Actinomucor elegans, used in Oriental food fermentations, were investigated. Enzyme yields by all three fungi were higher in solid substrate fermentations than in submerged culture. The level of moisture in solid substrate must be at about 50 to 60%. Very little growth of these fungi was noted when the moisture of substrate was below 35%, whereas many fungi including most storage fungi generally grow well on solid substrate with that level of moisture. Among the three substrates tested-wheat bran, wheat, and soybeans-wheat bran was the most satisfactory one for enzyme production. The optimal conditions for maximum enzyme production of the three fungi grown on wheat bran were: R. oligosporus, 50% moisture at 25 C for 3 to 4 days; M. dispersus, 50 to 63% moisture at 25 C for 3 to 4 days; A. elegans, 50 to 63% moisture at 20 C for 3 days. Because these fungi are fast growing and require high moisture for growth and for enzyme synthesis, the danger of contamination by toxin-producing fungi would be minimal.

Production and purification of acid protease from the thermophilic fungus, Penicillium duponti K1014.

A thermophilic fungus, Penicillium duponti K1014, produced an acid protease in a submerged culture. Maximum enzyme production, in a 30-liter fermentor at a preselected optimum growth temperature of 50 C, occurred after 3 days. The productivity of the enzyme was associated with changes of viscosity and pH of culture broth during the growth. The acid protease was isolated from the culture filtrates and was purified ninefold by alcohol precipitation, column chromatography on O-(diethylaminoethyl)cellulose, batchwise treatment with O-(carboxymethyl)cellulose, and by gel filtration. The purified enzyme was homogeneous on disk electrophoresis and sedimentation analysis. The sedimentation constant s(20.w), calculated at a concentration of 0.64%, was 3.98S.

Production and Purification of Acid Protease from the Thermophilic Fungus, Penicillium duponti K1014

A thermophilic fungus, Penicillium duponti K1014, produced an acid protease in a submerged culture. Maximum enzyme production, in a 30-liter fermentor at a preselected optimum growth temperature of 50 C, occurred after 3 days. The productivity of the enzyme was associated with changes of viscosity and pH of culture broth during the growth. The acid protease was isolated from the culture filtrates and was purified ninefold by alcohol precipitation, column chromatography on O-(diethylaminoethyl)cellulose, batchwise treatment with O-(carboxymethyl)cellulose, and by gel filtration. The purified enzyme was homogeneous on disk electrophoresis and sedimentation analysis. The sedimentation constant s(20.w), calculated at a concentration of 0.64%, was 3.98S.

Production of Mucor pusillus Acid Protease in Reconstituted Whey

Protease production by Mucor pusillus in reconstituted whey (5%) was maximal after five to six days at 35C and the amount of enzyme synthesized was comparable to that formed in a wheat bran medium. Sodium chloride hastened the release of protease into the medium; greatest stimulation was observed at 0.5 m concentration. The protease produced by M.pusillus in reconstituted whey and in wheat bran medium had the same general characteristics.

Studies on the Proteolytic Enzymes of Black Aspergilli

The production of acid protease, as well as that of other enzymes, involves many variable factors, such as rate of aeration and agitation, temperature control during the operation, components of the media and type of antiform agents. The proper control of such factors can be achieved through effective utilization of a well-equipped pilot plant, designed specifically for the acid protease research and development. The fermentation unit described ranges in capacity from 500 ml shake-flask to 20-liter jar fermentor. Detailed studies on the various conditions for the production of acid protease by Aspergillus usamii, Aspergillus saitoi and other related species are described. It was found that high rates of agitation and aeration were required to obtain acid protease in maximum yield.

Studies on the Proteolytic Enzymes of Black Aspergilli

To examine the influence of different cultivation conditons on acid-protease production, black Aspergilli belonging to Kuro-Koji mold group which had been found to possess exceptional proteolytic activity in solid cultivation were grown under submerged condition. Furthermore, it was observed that the production of acid protease highly increased by forty to ninety per cent by adding a considerable amount of inorganic nitrogen compounds.

Studies on the Proteolytic Enzymes of Black Aspergilli

In order to investigate the production of acid protease, the cultivation conditons were studied with black Aspergilli belonging to Kuro-Koji mold group by solid cultivation (Koji-culture).It was observed that the production of acid-protease by A. saitoi R-3813 mut. UV-13 was markedly increased by adding an adequate amount of an inorganic nitrogen compound to the cultivation medium. Concerning the production of acid protease by adding an inorganic nitrogen compound, one hundred and eighty-four strains of Kuro-Koji mold group and eleven strains of other Aspergilli were tested.