Document Type



Master of Science (MS)


Environmental Studies

First Advisor's Name

Kateel G. Shetty

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Miroslav Gantar

Second Advisor's Committee Title

Co-Committee chair

Third Advisor's Name

Krishnaswamy Jayachandran

Third Advisor's Committee Title

committee member


Algae, Biofuels, Co-culture, productivity, cyanobacteria, fungus, yeast, heterotrophic bacteria, mixed culture

Date of Defense



This thesis investigates the effects of co-culturing microorganisms including 37 yeast, 38 bacteria, nine diazotrophic cyanobacteria, and three fungi on biomass and lipid production in fresh- and saltwater algae. Algal lipid content was measured using Nile Red method and gravimetric techniques. Among the algal strains tested, freshwater Coelastrum sp. 46-4, and saltwater Cricosphaera sp. 146-2-9, showed enhanced biomass yield and lipid content in response to co-culture with bacteria, cyanobacteria, and fungi. While co-culture with yeast caused inhibition of algal productivity, no difference in algal productivity was observed between nitrogen-free diazotrophic cyanobacterial co-culture and nitrogen-replete monoalgal culture. Results indicated that extracellular compounds from the freshwater bacteria Pseudomonas stutzeri and marine fungus Fusarium sp. significantly account for stimulation of lipid accumulation within algal cells, while co-cultivation with live microorganism cells stimulated biomass production in algae.





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