Generation and characterization of pigment mutants of Chlamydomonas reinhardtii CC-124

Abstract

The induced mutagenesis method for deriving pigment mutants of a green microalga, Chlamydomonas reinhardtii CC-124 and their pigment composition as well as ability to assess mutability of contaminated aquatic ecosystems were studied. In the present study, 14086 mutants (colonies) were obtained by exposure of the wild strain, C. reinhardtii CC-124, to 1, 2, 3, 5 min of ultraviolet (UV) irradiation. After screening, these mutants (colonies) revealed four pigmented mutants (124y-1, 124p-1, 124y-2 and 124p- 2). Compared to the wild CC-124, these mutants are characterized by a decrease in chlorophyll a & b content and an increase in carotenoids. The lowest decrease in chlorophyll a was three to four folds, while the highest increase in carotenoids was two to four folds. The result of bio-test, using the resulting pigment mutant of C. reinhardtii 124y-1 showed that mutagenic activity was observed significantly in both Tekeli River and Pavlodar Oil Refinery in Kazakhstan; the waste water of the Pavlodar Oil Refinery had high-toxicity while the water of the Tekeli River had medium-toxicity.

Keywords: Ultraviolet (UV) mutagenesis, Chlamydomonas reinhardtii, biotesting.