[Production and properties of a beta-galactosidase preparation from Alternaria tenuis]. / Poluchenie i svoistva preparata beta-galaktozidazy iz Alternaria tenuis

Different methods of the preparation of fungal beta-galactosidase from the 72-hour culture of Alternaria tenuis were tested: lyophilization of the culture liquid, precipitation with ethanol, acetone, ammonium sulphate. Optimal results were obtained with precipitation by 1.5 acetone volume. Studies of the properties of fungal beta-galactosidase demonstrated that the preparation retained its activity during 22 month storage at 5 degrees C. The fungal preparation had pH optimum at a more acidic zone (4.2 versus 6.9), was active in a wider pH range 2.8-5.7 and 6.2-7.5), had a much higher temperature optimum (65 degrees and 30 degrees) and better thermostability as compared with the yeast preparation. Data on other properties of the preparation are presented.

[Separation and characteristics of the proteolytic enzymes of Bacillus subtilis]. / Razdelenie i kharakteristika proteoliticheskikh fermentov Bacillus subtilis

The composition of two protosubtilins -- proteolytic enzymes of the enzymes isolated from submerged cultures of two Bacillus subtilis strains was investigated. Each of the preparations contained two proteinases that differed in their pH optimum. Conditions of chromatographic separation of two proteinases on CM-52 cellulose were tested. With the use of specific inhibitors and specific substrates it has been shown that one of the proteinases belongs to metal enzymes and is inhibited by ethylene diamine tetracetate (EDTA). Another proteinase, which is probably serine proteinase, is inhibited by diazopropine fluorophosphate (DFP). The isoelectric point of neutral proteinase is 8.15-8.20.