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Distribution of chloropigments in suspended particulate matter and benthic microbial mat of a meromictic lake, Lake Kaiike, Japan
Author(s) -
Nakajima Yoji,
Okada Hisatake,
Oguri Kazumasa,
Suga Hisami,
Kitazato Hiroshi,
Koizumi Yoshikazu,
Fukui Manabu,
Ohkouchi Naohiko
Publication year - 2003
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.2003.00517.x
Subject(s) - green sulfur bacteria , benthic zone , microbial mat , water column , chemocline , environmental chemistry , particulates , bacteriochlorophyll , sulfur , anoxic waters , biology , bacteria , cyanobacteria , photosynthesis , botany , chemistry , ecology , paleontology , organic chemistry
Summary We investigated the distribution of chloropigments in a small meromictic lake, Lake Kaiike, south‐west Japan. In the water‐column, concentrations of Chl a related to cyanobacteria, BChl a related to purple sulphur bacteria, and three types of BChl e homologues (BChls e 1 , e 2 and e 3 ) related to brown‐coloured green sulphur bacteria, were maximal at the redox boundary. Below the redox boundary, absolute concentrations of Chl a and BChl a gradually decreased with depth, whereas BChls e remained rather constant. Suspended particulate matter (SPM) at the deeper region of the anoxic water‐column was enriched in highly alkylated BChl e homologues compared with SPM at the redox boundary. The shift in the relative content of highly alkylated BChl e homologues beneath the boundary was associated with community related adaptation of brown‐coloured green sulphur bacteria to changes in light quality/quantity, resulting from the optical absorption and reflectance of SPMs in the overlying water‐column. Benthic microbial mats were characterized by high abundances of BChls e , in which highly alkylated homologues were substantially abundant. This suggests that the BChls e in the microbial mat may be derived from the low‐light adapted brown‐coloured green sulphur bacteria forming the bacterial mat.