Towards genetic improvement of commercially important microalga Haematococcus pluvialis for biotech applications

Haematococcus pluvialis is a unicellular green
alga which produces a ketocarotenoid, astaxanthin which
has pharmaceutical and nutraceutical applications owing to
its high antioxidant activity. Biotechnological approaches
such as genetic transformation methods (Agrobacteriummediated)
and cloning strategies, are essential to improve/
regulate this ketocarotenoid in Haematococcus. For this
studies are necessary to improve Haematococcus through
biotechnological means. In this connection, a suitable
cocultivation medium for Haematococcus and Agrobacterium
tumefaciens was standardized and different antibiotics
were screened. Among the cocultivation media viz Z8,
Bold’s Basal Medium, Tris Acetate Phosphate Z8 with
0.5% mannitol and BBM and Z8 with half strength LB TAP
medium was found suitable for growth of both the alga
Haematococcus and Agrobacterium. For the different antibiotics
screened to identify the sensitivity of algae,
hygromycin at more than 2 mg L−1 showed lethal effect
which can be used as a selectable marker gene in genetic
transformation, whereas cefotaxime and augmentin showed
no effect up to 2,000 mg L−1. The growth of algae was
higher in solid selection medium when compared to the
liquid selection medium.