Streptomyces canus NRC-718 sub sp as a source of glucose isomerase

Twenty-four of Streptomyces isolated from Egyptian soil samples were tested for the production of glucose isomerase. Streptomyces NRC-718 was closely related to Streptomyces canus according to the morphology, cultural and physiological properties was the highest producer of glucose isomerase among other tested strains. The enzyme was extracted from cells suspension ultrasonically. D-xylose served as substrate for the enzyme and the value of specific activity was 2.35 units/mg protein

Studies on beta-galactosidase I- Screening and extraction

Fifteen yeast strains belonging to different genera and species were screened for their ability to utilize lactose as a sole-carbon source. NRRL Y-1205 and Kluyveromyces fragilis CAIM-29 were capable to produce beta-galactosidase. The highest level of enzyme production [10.5 units-ml] was detected in Candida pseudotropicalis. Three treatments of extraction were used to release the enzyme from yeast cells [solvent extraction-freezing and thawing and ultrasonic treatment]. Solvent treatment with benzene at concentration 1: 5 [w-w] cells to solvent was the most favorable solvent for beta-galactosidase release

Partial acid and enzymatic hydrolysis of cellulose prior to B-glucosidase production by debaryomyces spp

Avicel, pure microcrystalline cellulose, was treated with superconcentrated acid [conc. HCl followed by gaseous HC1] for one and three hours. The resulting solid was then hydrolyzed with Trichoderma reesel cellulasc at 45°C for 3,6,24 and 48 hours. The presence of glucose and cellobiose liberated during enzymatic hydrolysis were detected. The highest reducing sugar yields were obtained during enzymatic hydrolysis of pretreated materials as compared to hydrolysis of the untreated avicel. It is suggested that the increased sugar yields achieved after this pretreatment are due to reduced degree of polymerization and change in the crystallinity. In an attempt to use the sugar syrup for the production of beta-glucosidase, two yeast strains Debaryomyces vanriji and Debaryomyces hansenii were examined. D. hansenii gave the highest yield [163 Unit/ml] when it grew on the hydrolyzate obtained from avicel treated for one hour and hydrolyzed by enzyme for 6 hours. While, D.vanriji produced the greatest quantity [105 Unit/ml], when 24 hours enzyme hydrolyzate of avicel treated with acid for 3 hr was used

Carbon sources influencing the production of cellulases and proteases by different cellulolytic microorganisms

Treated corn cobs cellulose [2%] was used as the only carbon source for the growth and production of extracellular cellulases and proteases by four cellulolytic microbes: Penicillium funiculosum, Phanerochaete chrysosporium, Micromonospora calcea and Trichoderma virideTViride and Pfuniculosum showed a great ability for the production of carboxy-methyl cellulase [CMCase], filter paper-ase [FPA], neutral and acid proteasesMaximum neutral protease activity was obtained with MCalcea and TvirideOptimum activities in relation to the incubation periods varied according to the enzyme studied and the organism testedThe effect of different carbon sources on cellulases and proteases production indicates that cellulose and lactose were good inducers for CMCase production by Pfuniculosum and PhChrysosporium respectivelyThe latter inducers were also the best for the production of neutral proteases by Tviride and Mcalcea respectively, while cellobiose and lactose were the best inducers for acid protease production by PFuniculosum and Phchrysosporium, respectively