Isolation of halophilic and halotolerant bacteria from a Japanese salt field and comparison of the partial 16S rRNA gene sequence of an extremely halophilic isolate with those of other extreme halophiles

✍ Scribed by Tomonori Takashina; Kiyotaka Otozati; Tetsuo Hamamoto; Koki Horikoshi

• Publisher: Springer
• Year: 1994
• Tongue: English
• Weight: 577 KB
• Volume: 3
• Category: Article
• ISSN: 0960-3115
• DOI: 10.1007/bf00114206

✦ Synopsis

Halophilic and halotolerant bacteria were isolated from soil samples of a Japanese salt field, an environment where salt concentrations vary annually. From 1 g of each of the five samples collected, over 1 × 103 bacterial colonies (colony forming units (cfu)g-l) grew on agar medium containing 2M Na 4 . In contrast, 0-4 bacterial colonies (cfu g-l) were observed on agar medium containing 4M Na ÷. Two of the five samples contained numerous bacteria (102-103 cfu g-l) capable of growth on a 2M Na ÷ alkaline (pH = 9.5) medium, while few bacterial colonies were observed from the other three samples. Only one of the five samples was shown to contain bacteria capable of growth on a 4M Na ÷ alkaline medium. Most of the bacteria isolated on 4M Na ÷ agar were eubacteria, but one extreme halophile (TR-1, already described as Haloarcula japonica JCM7785) was also isolated. The 16S rRNA sequence of TR-I was determined and shows high homology (94.4-98.5%) to Ha. marismortui and Ha. sinaiiensis. These results suggested that: 1) environments with seasonally varying salinity can harbour halotolerants as well as halophiles and, 2) closely related halophiles can be isolated from geographically distant habitats.