Bacterial proteases: production, isolation and utilization in animal nutrition.

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.

Corynebacterium pseudotuberculosis infection in goats in the Czech Republic.

Prevalence of caseous lymphadenitis was studied in goats from six herds in the Czech Republic. Corynebacterium pseudotuberculosis exhibiting typical properties was isolated from clinically affected animals only. Antibodies to C. pseudotuberculosis were identified by means of agar immunodiffusion and the neutralization test using a toxin--phospholipase D (PLD)--as antigen. No clinical manifestations of caseous lymphadenitis or antibodies to C. pseudotuberculosis were found in four herds. In one herd without any history of clinical caseous lymphadenitis, serological positivity was reported in two out of 148 examinations. In a herd with clinical manifestations of caseous lymphadenitis, antibodies were ascertained to a various degree in subsequent samplings (100%, 87% and 64%, respectively). The importance of serologic examination of caseous lymphadenitis in goat herds is discussed.