Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Accumulation of Total Lipids and Triacylglycerides as Biodiesel Precursors upon Co-culturing a Phycospheric Bacterium with Indigenous Chlorella vulgaris   (#349)

Katherine L. Pintor 1 , Pierangeli G. Vital 1 , Metha Meetam 2
  1. Institute of Biology, University of the Philippines, Quezon City, Metro Manila, Philippines
  2. Faculty of Science, Mahidol University, Ratchathewi, Thailand

The cultivation of microalgae for the production of biomass and associated valuable compounds such as neutral lipids in the form of triacyglycerides (TAGs) has gained growing interest over the years. Currently, there has been a substantial attention given to Chlorellaspecies as source of feedstock for biodiesel production due to its ability to grow rapidly, and accumulate high amounts of TAGs stored in the cytosolic lipid bodies. However, when grown under favorable conditions, Chlorelladoes not accumulate neutral lipids. This has become the major bottleneck in meeting standard industrial requirements for biofuels. To address this drawback, the study utilized a new approach by engineering a microalgal-bacterial community in the phycosphere. Hence, themain objective of this project is to determine the influence of a previously isolated phycospheric bacterium Rhizobiumsp. to axenic and xenic freshwater C. vulgaris’total lipid content and TAG productivity determined by gravimetric quantification, TLC, and GC-MS. Results showed that xenic C. vulgarisinoculated with Rhizobium(CV+B) displayed more than two-fold increase on both total lipids (23.87 ± 1.23) and TAG productivity (8.21 ± 2.07)in comparison to the control and other variables. Meanwhile,the extracted TAGs from axenic C. vulgaris(CA)exhibited a variety in its FA composition (C16, C18, C18:1) amounting to 11.53%, 10.95% and 6.52%, respectively. Our study has demonstrated an efficient means of inducing microalgal biodiesel precursors by co-cultivation of algae and bacteria. To our knowledge, this is the first research undertaking in the Philippines that revealed its potential application for biofuel production.