Alkaline serine proteinase and lectin isolation from the culture fluid of Bacillus subtilis

Bacillus subtilis strain 316 M was found to produce extracellular alkaline serine proteinase and lectin. The characteristics of proteinase and lectin accumulation during the growth of the producer organism were found to be similar. The maxima of proteolytic and lectin activities were close and observed at 16 h and 14 h of B. subtilis 316 M batch cultivation, respectively. Alkaline serine proteinase was purified by ion exchange chromatography directly from the culture fluid. Proteinase (eluate) purified 40-fold possessed 60-90 units/ml of caseinolytic activity and 240-320 units/ml of elastolytic activity. Eluate obtained after enzyme sorption on the ion exchanger was used for lectin isolation followed by ammonium sulphate precipitation. Lectin purified 12.3-fold was shown to have a high carbohydrate specificity to N-glycolylneuraminic, N-acetylneuraminic, N-acetyl-muramic and D-galacturonic acids with minimal inhibiting concentrations of 2.5-7.5 mM.