Publication Date:
2022-05-26
Description:
Author Posting. © American Society for Microbiology, 2003. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Applied and Environmental Microbiology 69 (2003): 390-398, doi:10.1128/AEM.69.1.390-398.2003.
Description:
Filamentous, gliding, sulfide-oxidizing bacteria of the genus Thioploca were found on sediments in profundal areas of Lake Biwa, a Japanese freshwater mesotrophic lake, and were characterized morphologically and phylogenetically. The Lake Biwa Thioploca resembled morphologically Thioploca ingrica, a brackish water species from a Danish fjord. The diameters of individual trichomes were 3 to 5.6 µm; the diameters of complete Thioploca filaments ranged from 18 to 75 µm. The cell lengths ranged from 1.2 to 3.8 µm. In transmission electron microscope specimens stained with uranyl acetate, dense intracellular particles were found, which did not show any positive signals for phosphorus and sulfur in an X-ray analysis. The 16S rRNA gene of the Thioploca from Lake Biwa was amplified by using newly designed Thioploca-specific primers (706-Thioploca, Biwa160F, and Biwa829R) in combination with general bacterial primers in order to avoid nonspecific amplification of contaminating bacterial DNA. Denaturing gradient gel electrophoresis (DGGE) analysis of the three overlapping PCR products resulted in single DGGE bands, indicating that a single 16S rRNA gene had been amplified. With the same method, the Thioploca from Lake Constance was examined. The 16S rRNA sequence was verified by performing fluorescence in situ hybridization targeted at specific motifs of the Lake Biwa Thioploca. Positive signals were obtained with the bacterial probe EUB-338, the {gamma}-proteobacterial probe GAM42a, and probe Biwa829 targeting the Lake Biwa Thioploca. Based on the nearly complete 16S rRNA sequence and on morphological similarities, the Thioploca from Lake Biwa and the Thioploca from Lake Constance are closely related to T. ingrica and to each other.
Description:
This work was supported by grant 12440219 from the Ministry of
Education, Culture, Sports, Science and Technology, Japan, to
Manabu Fukui. Andreas Teske was supported by an Independent
Studies Award from the Mellon Foundation.
Keywords:
Thioploca
;
Sulfide-oxidizing bacteria
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
3483321 bytes
Format:
application/pdf
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