ABSTRACT
To improve the efficiency of halophilic actinobacteria screening and carry out the rapid selection of targeted strains, we tested 34 strains of Streptomonospora by PCR-single strand conformation polymorphism analysis (PCR-SSCP) based on genus-specific primers for the PCR identification. This approach employs PCR with two pairs of primers located in the 16S rRNA sequence flanking two variable region, then build clustering tree according as SSCP data. Synchronously, we sequenced all the 16S rRNA partial sequences for these strains to verify them. The results showed that the PCR-SSCP analysis was an efficient, easy-to-handle and economic method for rapid selection of halophilic actinobacteria resources.
ABSTRACT
pH, affects of different alkaline materials KOH, K 2CO 3, NaOH, Na 2CO 3 on the growth, and NaCl, KCl tolerance of 29 isolates from the saline and alkaline soils in Xinjiang and Qinghai Provinces of China and 1 type strain were studied. Results showed that only a few alkaliphilic actinomycetes were Na +-obligately dependent, and K +-sensitive. Some alkaliphilic actinomycetes were CO 3 2- -sensitive, and NaCl, KCl could inhibit their growth. 4 kinds of alkaline materials had no affect on growth of alkaliphilic Nocardiopsis, and these strains showed high tolerance to NaCl, KCl. So it was presumed that only K + and CO 3 2- obligately dependent alkaliphilic Actinomycetes maybe exist in alkaline environments.
ABSTRACT
425 halophilic bacteria strains were isolated by using six different media from thirty salt-soil samples collected from Heijing ancient salt mine,Yunnan. By the growth on NaCl grandient concentration and other screening methods,79 strains of extremely halophilic microorganisms were chosen for further research. Based on colonies color,shape and size,15 stains were selected to be sequenced. The sequencing results revealed that 11 of them were haloarchaea. According to the phylogenetic analysis,they belong to four genera of the family Halobacteriaceae. The blast results showed that the similarities of six sequences were higher than 97 % with the validly described species of the following four genera: Halorubrum,Natronococcus,Natrialba,Halalkalicoccus. The similarities of other five sequences with any validly described species were less than 97 %,therefore,the taxonomic positions of the following five strains YIM-ARC 0032,YIM-ARC 0036,YIM-ARC 0037,and YIM-ARC 0050 could be determined according to further polyphasic taxonomy data.The results indicated that there was a considerable diversity of haloarcheaea in salt-mine environment of Heijing ancient salt mine,Yunnan and it was worth continuing to research on this area.