In this study we examined diversity and activities of some actinomycetes isolated from mangroves in Giao Thuy, Nam Dinh Province. The distribution of actinomycetes in soil is strongly affected by external factors. Extra-cellular enzyme producing ability of mangrove actinomycetes is very high, particularly the ability of producing cellulase degrading filter paper (122/128 strains), CMC (110/128 strains), protease (83/128 strains) and amylase (78/128 strains). | JOURNAL OF SCIENCE OF HNUE Natural Sci. 2011 Vol. 56 No. 7 pp. 109-116 STUDY ON SOME ACTINOMYCETES ISOLATED FROM MANGROVE SOIL IN GIAO THUY NAM DINH PROVINCE Duong Minh Lam and Nguyen Thanh Dat Hanoi National University of Education Email Abstract. In this study we examined diversity and activities of some acti- nomycetes isolated from mangroves in Giao Thuy Nam Dinh Province. The distribution of actinomycetes in soil is strongly affected by external factors. Extra-cellular enzyme producing ability of mangrove actinomycetes is very high particularly the ability of producing cellulase degrading filter paper 122 128 strains CMC 110 128 strains protease 83 128 strains and amylase 78 128 strains . Mangrove actinomycetes often produce antibiotics of narrow activity range few strains are able to produce broad ranged antibi- otics. The ability of producing antibiotics inhibiting test micro-organisms worked best on Fusarium oxysporium 34 strains or 34 or at worst on Pseudomonas aeruginosa 2 strains or 2 . All the studied strains grew well in NaCl free environment or at low NaCl concentrations and grew slower at 20 o NaCl grew poorly or no growth at 50 o NaCl. The studied actino- mycetes are halotolerant not halophilic. The selected actinomycetes were all able to assimilate different N and C sources. They were able to produce quite strong degrading enzymes for filter paper. Keywords Mangrove actinomycetes microbial ecology. 1. Introduction At present there are about hectares of mangroves worldwide Vietnam has mangroves of approximately 200 000 hectares. Besides their main functions such as coast protection wind and wave shielding and silt trapping mangroves are able to recreate and supply many resources to coastal people helping conserve biodiversity and regulate the climate 3 . In the mangroves there is not only flora and fauna but also an abundant and diverse microbiota among which actinomycetes plays a very significant role. Micro- .
