Protoplast fusion and genetic recombination between Ochromonas danica (Chrysophyta) and Haematococcus pluvialis (Chlorophyta)

Abstract:

We carried out interphylum protoplast fusion between Ochromonas danica and Haematococcus pluvialis using polyethylene glycol. Different enzyme mixtures were evaluated to prepare the protoplast of H. pluvialis; however, in the absence of a cell wall, O. danica was not treated with lytic enzymes. Maximum lytic activity of 57% was observed using proteinase K for 90 min. The heterofusants were easily identified by pigmentation of the hybrid colonies on BG11 medium. Fatty acid analysis in putative hybrids of O. danica and H. pluvialis confirmed the hybrid origin of these cells. Accordingly, the characteristic fatty acids of O. danica (C16:2 and C24:0) and H. pluvialis (C16:0 and C18:3n-6) were detected in the hybrid algae. These results indicated successful genetic recombination between the two microalgal phyla.

Key Words::

• Haematococcus pluvialis
• Lytic enzymes
• Ochromonas danica
• Protoplast fusion

ACKNOWLEDGEMENTS

We thank Elke Wölken and Sigrid Mörke (Department of Cell Biology and Phycology, University of Hamburg, Germany) for their technical assistance. We are grateful to Mr Mohammed Eid (Plant Pathology Department, University of Kentucky, Lexington, Kentucky, USA) for his contribution in writing the manuscript. This work was supported by joint grants from Egyptian Ministry of Higher Education & Scientific Research (MHESR) and German Academic Exchange Service (DAAD).