Starch producing in microalga biomass as a raw material for bioethanol

A preliminary research in the field of environmental biotechnology to the production of biofuel from the tropical microalga consortium consisting of Chlorella vulgaris and Closterium sp have been done. Microalga cultivation in batch culture are controlled at temperature of 25 degrees C, PH 6, aeration of 1 ml/sec, and lights of 4000 lux. Nutrient sources utilize artificial Provasoli Heamatococcus Media which consist of micro and macro nutrients. Analysis of bioethanol from microalga start with finding the maximum starch production from wet weight of biomass, dried weight of biomass, and at hydrolysis. Hydrolysis is proceeded by adding HCL 1 Molar as much as 0.04 grams of dried weight of biomass. The analysis of starch is proceeded by nelson samogy method by adding alkali and pre reaction arsenomolibdat. Absorbent is measured through the wave length 540 nm by spectrofotometre. The average of dried weight biomass is 0,8 grams/liter. Research reveal that the highest starch production is occured in microalga consortium at hydrolysis process and produces starch of 88.31% (v/v). The two types of tropical microalgae have a potential as solid compound of bioethanol.