This study aimed to isolate and identify a new local bacterial strain, able to completely degrade keratin-rich wastes into soluble and useful materials which can be used in many proposes. Bacterial keratinases are of particular interest because of their action on insoluble keratin substrates and generally on a broad range of protein substrates. These enzymes have been studied for de-hairing processes in the leather industry and hydrolysis of feather and keratin. Samples from poultry industry wastes, soil, water, fodder and feather were collected from different places in Jeddah, Saudi Arabia. Each sample was plated on feather meal agar plates containing 5 g LG feather as the sole carbon and nitrogen source and 1 the obtained colonies were selected, purified and their growth were detected on skimmed milk agar and feather meal broth media. The well grown isolates on feather meal agar which producing the largest clearing zone on skimmed milk plate were selected for keratinase assays. Out of 23 bacterial isolates, 7 isolates were selected. The best keratinase producing bacterium kera MS21 was selected and identified based on morphological, physiological and some biochemical characteristics. It was recorded as a species belonging to the genus Pseudomonas and identified as Pseudomonas sp. The results of identification were confirmed by 16S rDNA studies. Precipitation and purification of the keratinase enzyme in addition to factors affecting enzyme activity were studied. The enzyme molecular weight was determined to be of 30 KDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The optimum temperature and pH were determined to be 37°C and pH 8.0, respectively. The effect of some proteases inhibitors and activators were also studied.

Lipases (triacyl glycerol acyl hydrolase) catalyze hydrolysis and syntheses of ester formed from glycerol and long-chain fatty acids. They have many industrial applications, especially in food and detergent industries. Out of 33 bacterial isolates, a group of 20 bacterial isolates produced lipase enzyme on tributyrin agar and Tween 80 agar media. In liquid medium, the lipase activity was ranged from 1.5 to 6.9 IU/ml. Among the evaluated bacteria, the isolate LP10 that was isolated from soil collected from fuel station. It was the most active isolate in lipase production (6.9 IU/ml). Using morphological, physiological and biochemical studies, it was identified as an isolate belonging to the genus Streptomyces and identified as Streptomyces exfoliates LP10. Identification was confirmed using 16S rDNA analysis. Growth of the selected bacterium in medium containing tributyrin and Tween 60 at initial pH 6 in addition to incubation at 37°C for three days yielded the maximum lipase production. The molecular weight of the purified enzyme was 60 kDa, determined using gel electrophoresis. Improvement of lipase production was carried out between Streptomyces exfoliates LP10 and Streptomyces niveus using protoplast fusion. Five fusants were obtained. Fusant LP3 was the best lipase producer (3 times higher) compared to its parents.

Abstract:The present investigation was designed to study intensively, the fungi associated with stone-fruits (apricots, cherries, peaches and plums)