Geochemical and Microbiological Analysis of Sambe Hot Springs, Shimane Prefecture, Japan

Abstract

Microbiological contribution to the formation of the manganese deposits in Sambe hot springs, Shimane, was investigated in combination with water chemistry, characterization of sediments and microbial community structure. Analysis of bacterial and fungal community structure based on DNA extracted from a Mn-oxidizing enrichment culture indicated close matches with Pseudomonas putida, Phoma sp. and Plectosphaerella cucumerina, all Mn-oxidizing microorganisms. These sediments were poorly crystalline and formed at neutral pH values, which is characteristic of biogenic precipitates. The EPMA results demonstrated a positive correlation between Mn and Ba contents in well-crystalline Mn oxide grains. Substantial Ba contents were observed inside Mn oxide grains. These findings indicated that Ba contents in sediments are influenced by not only aqueous Ba 2+ concentrations but also crystallinity of biogenic birnessite. Barium would be incorporated in birnessite during biomineralization.

Diversity and Co-Occurrence Patterns of Fungal and Bacterial Communities from Alkaline Sediments and Water of Julong High-Altitude Hot Springs at Tianchi Volcano, Northeast China

“…This fungal species is known as Mn-oxidizing and, together with the dominant bacteria Pseudomonas spp. identified from water samples, was previously isolated from Mn oxide deposits of the Sambe hot springs in Japan [67,68]. Mn sediments in natural environments are closely related to microbial Mn-oxidizing activity [69].…”

Mn(II)-Oxidizing Activity of <i>Pseudomonas</i> sp. Strain MM1 is Involved in the Formation of Massive Mn Sediments around Sambe Hot Springs in Japan

“…as the only Mn(II)-oxidizing bacterial species. 20) In the present study, enrichment on selective solid media revealed only single type of black colored bacterial colonies, which turned out to be Pseudomonas sp. The results ).…”

“…The 16S rRNA gene sequence (135 bp) of Pseudomonas sp. previously detected from the site by DGGE 20) was not identical (94% homologous) to that of strain MM1, indicating that there is some phylogenetic diversity within the genus at the site. Consensus phylogenetic tree based on the 16S rRNA gene sequence shows the position of strain MM1 within the Pseudomonas branch and its relationship with other members of Mn(II) oxidizers (Fig.…”

“…18,19) One of the Mn-rich natural springs found in Honshu Island is located in the Sambe hot spring region of Shimane prefecture on the Sea of Japan, where precipitation of Mn oxides with a distinctive blackish color is distributed over an area of 60 m © 80 m. Two types of spring water streams are apparent in Sambe; (i) hot springs (HS) of 2540°C and pH ³7, where precipitates of orange-colored Fe oxides and black-colored Mn oxides are concomitantly deposited, and (ii) cold springs (CS) of 1025°C and pH ³6, where the deposit consists of black Mn oxide sediments of 20 cm thickness. 20) Microbial community structure analysis indicated the presence of Mn(II)-oxidizing bacterium Pseudomonas sp. and Mn(II)-oxidizing fungi Phoma sp.…”

“…and Plectosphaerella sp. 20) This study attempted to actually isolate the Mn(II)-oxidizing bacteria involved in formation of this massive Mn deposit at Sambe hot spring, and to characterize its Mn(II) oxidation efficiency as well as the resultant Mn-oxide product.…”