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.
ABSTRACT
A two-layer plate was developed for in situ detection of siderophore from halophilic archaea. Halophilic archaea could grow on the upper nutrient layer without addition of iron and excrete siderophore under iron-limited stress.The lower layer was the detection agar,which contained universal blue-coloured ferric-CAS complex.The presence of the siderophore was indicated by the decolorization of the blue complex, resulting in a yellow-orange halo around colonies growing on the upper nutrient layer,when the excreted siderophore penetrated from the upper nutrient layer into the lower detection agar.The results showed that the two-layer plate method was applicable to the detection of siderophore from halophilic archaea, which was more convenient and definite than former approach for halophilic archaea siderophore detection.