Open AccessBiochemical characteristics of photosynthetic response to various external salanities in halotolerant and fresh water cyanobacteria
Author(s) -
Kumar Rai Ashwani
Publication year - 1990
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1990.tb04196.x
Subject(s) - halotolerance , rubisco , photosynthesis , carbon fixation , cyanobacteria , incubation , biology , chlorophyll , salinity , botany , total inorganic carbon , carbon dioxide , biochemistry , bacteria , ecology , genetics
The effect of various salinities on photosynthetic carbon fixation, activities of carboxylating enzymes, and contents of chlorophyll and protein, was examined in a halotolerant ( Aphanothece halophytica ) and fresh water ( Aphanothece stagnina ) cyanobacterium. These parameters were quantified immediately and after 48 h incubation in altered salinities. Photosynthetic carbon fixation was lower at altered salinities than in controls in both species. A. halophytica with 48 h incubation showed increased carbon fixation with increasing NaCl concentration, whereas A. stagnina did not. Chlorophyll content was drastically reduced for all salinities in A. stagnina but was unchanged in A. halophytica . d ‐ribulose‐1,5‐bisphosphate carboxylase (RuBisCO) activity from A. halophytica increased at higher external salinities but decreased in cells of A. stagnina . In vitro, the sensitivity of RuBisCO to NaCl from both the species was similar. It was noted that in A. stagnina NaCl affected chlorophyll content, carbon fixation, and RuBisCO activity in decreasing order.