The diversity of thermotolerant bacteria in coastal seawaters of Taiwan
Date Issued
2008
Date
2008
Author(s)
Chang, Hsiao-Yun
Abstract
Taiwan is surrounded by sea, the marine biological resources nearby still has development potentials. Past researches focused on the isolation of thermotolerant bacteria from the high temperature environments, but this study aims to isolate thermotolerant bacteria from coastal seawater with normal temperature. This study selected thermotoletant bacteria which can grow at 45 oC from Taiwan coastal seawater and is divided into 88 isolates. According to RFLP genotypes (DdeI、HhaI、RsaI) of 16S rDNA fragments, Gram test, growth temperature range and growth salinity range, divided these 88 bacteria into 12 groups. These isolates are mostly Gram negative bacteria, and they can grow in PY broth that contains 0.5-12.5 % NaCl with a temperature range from 4-50 oC. According to the comparison between 16S rDNA sequence with known bacteria, these 12 groups of bacteria can be defined as Alcanivorax、Bacillus、Exiguobacterium、Idiomarina、Marinobacter、Marinomonas、Mesorhizobium、Nitratireducter、Pseudidiomarina、Salinivibrio、Vibrio. This result indicates that there are abundant thermotolerant bacteria in the coastal seawater of Taiwan and the γ- Proteobacteria is the major group. One of these isolates, E8, its 16S rDNA sequence is similar to Idiomarina fontislapidosi、Pseudidiomarina tainanensis with similarity of 92.5 % and 94.0 %. Isolate E8 is a Gram negative rod bacterium with monotrichous flagellum, it can grow at 4-45 oC, pH 7-9, 0.5-10 % NaCl in PY broth, and with optimal growth temperature at 37 oC. E8 contains urease, lipase, gletinase, protease activity. The DNA G+C content of E8 is 51.5 mol%. At 37 oC, the cellular fatty acid contents of E8 larger than 5 % are iso-C15:0 (24.83 %)、iso-C17:0 (23.85 %)、iso-C17:1 ω9c (16.32 %)、C16:0 (9.95 %)、iso-C11:0 3-OH (5.35%). According to cell morphology, physiology, biochemistry and genetic characters, isolate E8 should be a new bacterium of Idiomarinaceae.
Subjects
thermotolerant bacteria
diversity
seawater
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-97-R93241201-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):bc4fcdaa5dc724d776a031890a629a62