Effect of Growth Promoting Bacteria on the Growth Rate and Lipid Content of Microalgae Chorella sp in Sludge Liquor of Anaerobic Digester of Dairy Manure

Abstract

Microalgae are microorganisms that have potential as biofuel feedstock since it has relatively high content of lipid. To be economically feasible, microalgae has to be cultivated in lower operational cost. Liquor of anaerobic sludge is one of the choices since it contents high concentration in nutrient. To boost its productivity, growth promoting bacteria (GPB) was added in the medium. The objective of this research is to observe the influence of GPB on the growth rate and oil content of the algae. The experiment used three treatment in respect to the dose of GPB added to the medium, and was done in triplicate. The three treatments are A3 (spiked with 3 ml of GPB inoculum), A6 (spiked with 6 ml of GPB inoculum) and A9 (spiked with 9 ml of GPB inoculum), and one more treatment as a control (A0). Result showed that the higher the dose of GPB added, the higher the lipid content of microalgae. For the growth rate of microalga, the highest growth rate was observed on A6 treatment, while the lowest one was observed on the control.