title: Bacterial proteases: production, isolation and utilization in animal nutrition.
abstract: Under conditions of submerged fermentation of Bacillus licheniformis strain L-3 in 15-L MBR-Schulzer bioreactor, the maximum production of proteolytic enzymes was achieved in the nutrient medium which contained 1% milk powder, 0.3% yeast autolysate, 0.5% corn starch and malt (20 ml per 100 ml of the medium). The preparation obtained of extracellular alkaline bacterial Ser-protease of the subtilisin type is characterized by optimum pH 9.8-10.2 good up to a temperature stability (65 degrees C) and has molecular weight cca of 26 kDa. The use of chemical mutagens (HNO2, 5-bromouracil) has enabled to select new strains (L-3N and L-3U) whose protease activity is 1.8-2.2 times higher as compared to the original Bacillus licheniformis strain L-3. The addition of these enzymes to the fodder has a positive effect on the retention of nitrogen substances.
authors.affiliation: Department of Biochemistry and Radiology, Faculty of Agronomy, Agricultural University, Nitra, Slovakia.
authors.forename: I
authors.initials: I
authors.lastname: Michalík
authors.forename: E
authors.initials: E
authors.lastname: Szabová
authors.forename: A
authors.initials: A
authors.lastname: Poláková
authors.forename: D
authors.initials: D
authors.lastname: Urminská
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001407:Bacillus / Q000201:enzymology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D010450:Endopeptidases / Q000096:biosynthesis* / Q000302:isolation & purification; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009153:Mutagens / Q000633:toxicity; D011480:Protease Inhibitors / Q000494:pharmacology; D013045:Species Specificity; D013552:Swine; D013696:Temperature
chemical_list: D003470:Culture Media; D009153:Mutagens; D011480:Protease Inhibitors; D010450:Endopeptidases