Altering growth rates and nutritional qualities of microalgal feedstock with symbiotic bacteria

Abstract

The cultivation of microalgae has many commercial purposes; it is integral in the farming of marine animals such as finfish, shrimp, and bivalves through its use as feedstock, and it has potential for use in renewable energy sources as a biofuel. Pink pigmented facultatively methylotrophic bacteria (PPFM) are known to live symbiotically on plants, feeding off of metabolic wastes and producing growth regulators and nutrients vital for plant development. These bacteria have also been isolated from algae and water samples. One strain of vitamin B12 over-producing PPFM has been previously isolated by our lab, and past research has indicated that co-culturing microalgae with PPFM can increase algal growth rates. Our research investigated the possibility of altering the growth rates and nutritional qualities of microalgae through the use of PPFM by conducting algae growth experiments and nutritional analysis. Microalgal species commonly used as feedstock for industrial bivalve aquaculture were supplemented with vitamin B12 over-producing PPFM. A significant difference in growth between PPFM supplemented and non-supplemented algal cultures was not seen consistently, while preliminary nutritional quality testing showed an increase in amino acid and lipid content for PPFM supplemented algal cultures over non-supplemented cultures.