In:
Environmental Microbiology, Wiley, Vol. 7, No. 7 ( 2005-07), p. 1009-1016
Abstract:
Stable carbon and nitrogen isotopic compositions were determined for individual photosynthetic pigments isolated and purified from the saline meromictic Lake Kaiike, Japan, to investigate species‐independent biogeochemical processes of photoautotrophs in the natural environment. In the anoxic monimolimnion and benthic microbial mats, the carbon isotopic compositions of BChls e and isorenieratene related to brown‐coloured strains of green sulfur bacteria are substantially (∼10‰) depleted in 13 C relative to those found in the chemocline. In conjunction with 16S rDNA evidence reported previously, it strongly suggests that Pelodyctyon luteolum inhabited and photosynthesized in the anoxic monimolimnion and benthic microbial mats by using 13 C‐depleted regenerated CO 2 . By contrast, both Chl a and BChl a in the monimolimnion and microbial mats have similar isotopic compositions as they do in the chemocline, implying that the source organisms live only in the chemocline. In the chemocline, the nitrogen isotopic compositions of BChl e homologues ranges from −7.7 to − 6.5‰, whereas that of BChl a is −2.1‰. These isotopic compositions suggest that green sulfur bacteria Chlorobium phaeovibrioides would conduct nitrogen fixation in the chemocline, whereas purple sulfur bacteria Halochromatium sp. and cyanobacteria Synechococcus sp. may assimilate nitrite.
Type of Medium:
Online Resource
ISSN:
1462-2912
,
1462-2920
DOI:
10.1111/emi.2005.7.issue-7
DOI:
10.1111/j.1462-2920.2005.00772.x
Language:
English
Publisher:
Wiley
Publication Date:
2005
detail.hit.zdb_id:
2020213-1
SSG:
12
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