Study On The Isolation,taxonomy And Application Of Halophilic Microorganisms

Seventy-three halophilic and halotolerant strains were isolated from eighty samples in salt pool at Bohai seacoast and in salt lakes of Qinghai, which included twenty bacteria, fifty-one actinomycetes and two fungi. In this study, the halotolerance and alkalitolerance ranges, morphological, chemical analysis of these new isolates were determined; Phylogenetic analysis was carried out on some moderately halophilic actinomycetes mainly depended on the 16S rDNAIRNA sequencing ; In addition, the bioactive microbiol products and desalt effect were tested on these new isolates.Most of the new isolates were moderately halophilies. They grew best in 5æ¡° 0% NaCJ condition, some even could grow in saturate solutions. Most of the newisolated moderately halophilic actinomycetes could tear high alkalitcondition andcould grow well at pHil .0. In them, strain D101 1 and G2013 were alkalihalophilicactinomycetes. They did not grow when NaCI lower than 2% and pH lower than8.0.Morphological studies were carried out on actinomycetes and fungi. Except strains of genus Streptomycete, It is hard to determine most strains?taxonomy structure only by morphological characteristics. Classification based primarily on cytochemistry and morphology is no longer tenable.16S rDNA/RINA sequencing analysis was carried out on five strains, D1013, D3115, D3116, D3414, D3615. The results showed that D1013, D3115, D3414 were belonging to Norcardiopsis, Dl 013 was related taxons of N. antarctica, D3 115 and D34 14 were similar to N. dassonvillei. D3 116 was belonging to Streptomyces and was similar to S. griseus subsp. griseus.Almost completed sequences of 165 rDNA of strain D36 15 was obtained and phylogenetic analysis was carried out of the genus Nocardiopsis. The resalts showed that strain D361 5 should clustered into the genus Nocardiopsis and formed an independent branch. Physiological and biochemical characteristics of strain D3 615 were obviously different from other strains of the genus. Nocardiopsis. Therefor, strain D361 5 was probably a new taxon of genus Nocardiopsis.in this study, the bioactive microbial products of two actinomycetes were tested. Both of this two strains had obvious restrain effect on gram-positive coccus. Theycould also restrain some spieces of fungi but could not restrain gram-negative bacteria. Finally, the desalt efficiency of these new isolates were tested. Almost all halophilc strains had certain desalt effect. There was some relationship between desalt efficiency and halotolerance but it was not obvious. Maybe desalt efficiency were closely contacted with the characteristics of test stains. A few strains were found their desalt efficiency were above 20%. After a series of treatment such as domestication, gene transfer etc., they should be able to do some work on high salts concentration wastewater treatment and even on seawater desaltation.