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F J Babel

Publications and source records attributed to F J Babel.

9 recordsLinked to original sources
PubMed1969

Lipase of Mucor pusillus.

Lipase of Mucor pusillus NRRL 2543 was recovered with ammonium sulfate precipitation, gel filtration on Sephadex G-75, and anion-exchange chromatography on diethylaminoethyl-Sephadex A-50. Maximal glycerol ester hydrolase (lipase) activity was observed at pH 5.0 to 5.5 and 50 C when trioctanoin and olive oil were used as substrates. The enzyme also showed esterase activity; it hydrolyzed, with the exception of methyl butyrate, all methyl esters tested. A minimum chain length of six carbons appeared to be a requirement for esterase activity, which was maximal at about pH 5.5 with methyl dodecanoate (C(12)) as the substrate. Neither the glycerol ester hydrolase (lipase) nor the esterase activity of the enzyme appeared to be affected by thiol group inhibitors, chelating agents, and reducing compounds. On the other hand, hydrolysis of triolein and methyl dodecanoate was arrested to the same extent in the presence of diisopropyl fluorophosphate, which suggested the involvement of serine in the active center of the enzyme. The enzyme remained stable during a 30-day storage at - 10 C.

Chemical Precipitation↗
PubMed1969

Cellulolysis by Mucor pusillus.

Culture filtrates of Mucor pusillus NRRL 2543 contained hydrolytic enzymes that attacked native cellulose, acid-swollen cellulose, carboxymethylcellulose, and cellobiose. The distribution profiles of cellulolytic and beta-glucosidase activities after gel filtration on Sephadex G-75 showed the presence of several active peaks. Glucose was the only product of hydrolysis when native cellulose was used as the substrate. Acid-swollen cellulose, when treated with cellulase free of beta-glucosidase activity, gave rise to glucose, cellobiose, and at least two higher molecular weight components which were also hydrolyzed in turn to cellobiose and glucose. The presence of a multiple cellulolytic enzyme system was indicated, the components of which may have specific roles in the degradation of cellulose.

Cellulose↗
PubMed1968

Lipase activity of Mucor pusillus.

Two strains of Mucor pusillus were examined for their ability to synthesize lipase in a complex medium used in the production of milk-clotting protease. Lipase activity of both strains reached maximal after 6 days of incubation under submerged conditions at 35 C. Lipase secreted into the medium hydrolyzed butterfat and vegetable lipids, as well as selected synthetic triglycerides. About 50% of lipase activity was destroyed after a 45-min heat treatment at 58 C.

Culture Media↗
PubMed1968

Purification and properties of Mucor pusillus acid protease.

The protease produced by Mucor pusillus was recovered from a wheat bran medium by treatment with ammonium sulfate, ethyl alcohol, gel filtration and ion-exchange chromatography. The yield of the enzyme was 55%. The overall increase in the specific activity of the protease was 34-fold. The purified protease was most active at pH 3.8 and 5.6 against hemoglobin and casein, respectively. Optimal hydrolysis of casein was observed at 55 C. The enzyme was stable from pH 3.0 to 6.0. Enzyme inactivated by metal ions was reactivated by ethylenediaminetetraacetate and o-phenanthroline. Reducing agents and thiol poisons had no effect on the protease, suggesting that free sulfhydryl groups were not required for enzyme activity. Diisopropyl fluorophosphate did not inhibit the protease, indicating the probable absence of serine in the active center. The Michaelis-Menten constant for casein was 0.357%. Electrophoretic analysis of active protein recovered by ion-exchange chromatography showed that the protease preparation was homogeneous.

Caseins↗
PubMed1968

Acid protease synthesis by Mucor pusillus in chemically defined media.

The acid protease synthetized by Mucor pusillus in chemically defined medium displayed a gel filtration pattern and optimal pH similar to that shown by protease isolated from complex medium. Protease synthesis was influenced by the concentration of sulfur in the medium. At sulfur concentrations greater than 10(-4)m, protease synthesis was suppressed, indicating a controlling role of sulfur compounds in the synthesis of extracellular protein. Inorganic phosphate was found to be without negative effect on enzyme synthesis. Growth studies showed that M. pusillus had the capacity to utilize ammonium N, nitrate N, amino N, and urea.

Amino Acids↗
PubMed1967

Conditions influencing the synthesis of acid protease by Mucor pusillus Lindt.

Protease synthesis by Mucor pusillus Lindt, in a wheat bran medium under submerged conditions, was influenced by substrate concentration, initial pH of the medium, and temperature of incubation. A 4% wheat bran (dry weight) concentration was satisfactory for enzyme production. The initial pH of the medium had a substantial effect on enzyme synthesis; adjustment of the enzyme production medium to pH 5.0 prior to sterilization was desirable. Incubation at 35 C resulted in the best enzyme yields. Under optimal conditions of enzyme production, maximal activity was detected after 5 days of incubation. The enrichment of the medium with glucose increased the yield of mycelia but lowered the amount of enzyme produced.

Caseins↗