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Some properties of an extracellular lipase produced by Lactobacillus delbrueckii subsp. bulgaricus were studied. Maximum enzyme activity was found against olive and butter oil as enzyme substrates. Addition of 9% acacia gum, 0.1% Na-deoxycholate and 0.01 M CaCl2 to the enzyme reaction mixture increased-lipase activity from 5.3 to 14.5 (FFA/mg protein/minute) at pH 6.0 and at 40 degrees C. Maximum lipase production was reached in the presence of glucose as a sole source of carbon, wheat bran as nitrogen source, olive oil as a sole lipid source and butyric acid as fatty acid supporting the growth medium. An initial pH value of the culture medium of 6.0 and a temperature of 35 degrees C gave the highest lipolytic activity.

Seven fungal isolates characterized by high chitinolytic activity were isolated from soil a n d identified. Aspergillus carneus in a 7-day-old shaken culture was the most p r o m i s i n g chitinase producer. The use of chitin as a c a r b o n source favoured p r o d u c t i o n of extracellular chitinase enzymes. M a x i m u m chitinase activity was reached at 10 g chitin/1. A n initial p H value of the culture m e d i u m of 5.0 gave the highest chitinolytic activity. Some properties of the crude enzyme p r o d u c e d by A. carneus were studied. M a x i m a l enzyme activitywas reached at p H 4.5 a n d 4 0°C after 30 min. T h e r m a l treatments at 7 0°C a n d p H 4.5 had the most adverse effect o n enzyme activity.

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Several bacterial isolates were isolated from Dakahlia and Damitta Governorates. The isolates were purified, identified and tested for PHB production. The tested isolates were 17 isolates of Azotobacter chroococcum, 8 isolates of Azospirillum lipoferum, 22 isolates of Alcaligenes eutrophus, 3 isolates of A. latus, 3 isolates of Bacillus subtilis, 2 isolates of B. cereus, 5 isolates of B. megaterium, 2 isolates of B. coagulans, 3 isolates of B. polymexa, 4 isolates of B. thuringiensis, 2 isolates of Pseudomonas fluorescens, 2 isolates of P. putida, 2 isolates of P. alcaligenes, 2 isolates of P. aeruginosa, 4 isolates of Rhizobium leguminosarim, 2 isolates of R. meliloti, one isolate of R. japonicum and 12 isolates of Streptomyces albus. Also, the occurrence of alginate in different isolates of Azotobacter and Pseudomonas were investigated.All isolated strains proved to be PHB producers. The amount of PHB produced by Bacillus isolates varied from 0.02 to 0.16 g/l, while by Azospirillum isolates the PHB amounts ranged from 0.12 to 0.58 g/l. Using Rhizobium isolates, the highest amount of PHB (0.36 g/l) was produced by R. leguminasarim No 3 , while the lowest amount (0.06 g/l) was obtained by R. leguminosarim No 2. Usig two media, Alcaligenus eutrophus No. 20, seemed to be the most active PHB producer among all Alcaligenes isolates (0.52 g/l). By Pseudomonas isolates, Pseudomonas fluorescens No. 2 produced 0.30 g/L of PHB while P. aeruginosa No. 2 produced 0.10 g/L. Generally the isolate of Azotobacter chroococcum No. 16 showed the highest values. The cell dry weight, PHB concentration and the yield of PHB were 2.28 g/l, 0.78 g/l, 34.21%, respectively. And the highest amount of alginate concentration (g/l) was 0.44 by Azotobacter chroococcum No. 14.