Author(s)

Y. Y. Wu, P. P. Li, B. L. Wang & C. Q. Liu

Abstract

The relationship between carbonic anhydrase activity, net photosynthetic O2 evolution rate and calcium precipitation in Chlamydomonas reinhardtii was studied. By adding bovine carbonic anhydrase and inhibitor of carbonic anhydrase-acetazolamide to SE medium to alter the activity of external carbonic anhydrase, the variation of net photosynthetic O2 evolution rate and calcium precipitation in Chlamydomonas reinhardtii was determined. Calcium precipitation of Chlamydomonas reinhardtii was determined by the difference of algal calcium content during the culture period. The result shows that net photosynthetic O2 evolution rate and calcium precipitation in Chlamydomonas reinhardtii were enhanced when bovine carbonic anhydrase was added to medium. Acetazolamide can inhibit calcium precipitation and photosynthetic O2 evolution. Carbonic anhydrase may be an important factor to accelerate algal calcium precipitation. Moreover, the geological significance of carbonic anhydrase in algal calcium precipitations and the relationship between algal calcium precipitation and biomineralization of carbonate precipitation are discussed. Keywords: calcium precipitation, carbonic anhydrase, Chlamydomonas reinhardtii, net photosynthetic O2 evolution rate. 1 Introduction The biogeochemical cycle, which regulates all the biochemical reactions, is the important \“driving force” of the geo-environment. The carbon cycle is one of the

Keywords

calcium precipitation, carbonic anhydrase, Chlamydomonas reinhardtii, net photosynthetic O2 evolution rate.