International Journal of Current Microbiology and Applied Sciences

ISSN: 2319-7706 Volume 2 Number 7 (2013) pp. 233-239

Nutrient feeding strategy determines the fate of Microalgal growth and carbon metabolizing enzyme system - A study with Desmodesmus commuis LUCC 002

Swaminathan Palanisami1, Keesoo Lee1* and Paul Ki-souk Nam2

1Center for Bioenergy, Cooperative Research, Lincoln University in Missouri, Jefferson City, MO 65101, United States. 2Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409, United States. *Corresponding author e-mail: keesoo@lincolnu.edu

A B S T R A C T

The increasing applications of microalgae have led researchers worldwide to investigate a reliable, cost effective, and fast means of biomass production. In this study commercial, agricultural fertilizer was used for algal nutrients as an approach for reducing the production cost of biomass. To optimize biomass production, two different strategies of nutrient feeding were tested: [#1] supplying all of the nutrients required for the entire growth phase in one initial feeding; [#2] feeding the optimal quantity of nutrients at a regular interval as it was consumed by the algae. Between the two tested strategies the second method was found to be ideal in achieving maximum biomass while also enhancing the activity of the carbon metabolizing enzyme carbonic anhydrase (CA). Both of the systems, fed with different strategies, received equal amounts of nutrients. The results clearly show that the feeding strategy is the only responsible factor for inducing the carbon metabolizing system. Esterase isozyme profiling was studied to understand the stress response exerted by the organism while growing in the different conditions created by the feeding strategies. It was clear that the first feeding method stressed the Desmodesmus commuis LUCC 002, this was evident from the stunted growth comparing to the second method.

Keywords

Carbonic anhydrase; Microalgal growth; Desmodesmu s commuis; Biomass; Zinc; Copper.