A novel lysozyme namedβ-1, 4-N, 6-O-diacetylmuramidase R2 was purified and characterized from Streptomyces griseus. The molecular weight of the enzyme was determined by MALDI-TOF-MS as 23.5 kDa. The N-terminal amino acid sequence was DTSGVQGIDVS-HWQG.Chemical modification ofβ-1, 4-N, 6-O-diacetylmuramidase R2 indicated that sulfhydry1 group and carbamidine of arginine residues are not essential for the activity of the enzyme, but lysine residues and imidazole of histidine residues are essential for the activity. The number of essential tryptophan and carboxyl groups was found that only one tryptophan residue and three carboxyl groups in the active site.

The optimal fermentation medium by Serratia marcesens L15-2 produceing chitinase highly,was composed of 1% chitin,0.3% K_2HPO_4,0.3% KH_2PO_4,0.05% MgSO_4,0.05% CaCl_2,0.001% FeSO_4.After fermentation for 4 days at 37 ℃ and purification,the obtained chitinase was purified and tested by SDS-PAGE.The optimal temperature was 50 ℃ and pH was 6.6 for catalysis by the obtained enzyme.The enzyme was stable below 60 ℃ and under pH 4～10.The enzyme activity was effected on by different metal ions.Its actiaity was enhanced by Ba~(2+),Mn~(2+) and Ca~(2+) and inhibited by Fe~(2+) and Zn~(2+).The chitinase also has an obvious effect on restraining the growth of epiphyte.

A Penicillium sp.which can produce phytase with high-activity has been screened and mutated by UV.The best phytase-producing medium is: 3% soluble starch,0.5% peptone,0.5% NH 4NO 3,0.05% MgSO 4·7H 2O,0.05% FeSO 4·7H 2O,0.001% MnSO 4·4H 2O.Primary pH of medium at 6.5,inoculum size at 4%(V/V),fermentation for 72 hours are beneficial to the yield of phytase.The adding of a small quantity of phytate can stimulative the produce of phytase,while excessive phytate will inhibit the reaction.

海洋微生物多样性(marine microorganisms diversity)是指所有海洋微生物种类、种内遗传变异和它们的生存环境的总称.本文介绍了海洋微生物多样性方面的研究和利用进展,包括研究微生物多样性方法的改进,有价值的海洋微生物功能性产品的开发;关于海洋微生物抗肿瘤、抗病毒药物的研究等.

Several strains were isolated from sea mud in the sea area ofQingdao,Shandong and screened four strains A-21,4-2,5-23 and 7-11producing biology activity substances.More studies have been done and according to bergey’s Manunal of Determinative Bacteriology,8thed,they are identified to be Erwinia sp.,Aeromonas sp.,Micrococuus sp.and Pseudomonas sp..