Optimization Process Of Ethanol Production From Microalgae Chlamydomonas Sp. Icbb 9113, Icbb 9114 And Synechococcus Sp. Icbb 9111

Abstract

The production of crude oil in Indonesia is 860 thousand barrel per day. Total crude oil reserves in Indonesia today is 7,4 billion barrels, and it is estimated to be exhausted in 24 years. National energy policy targets the utilization of non-fossil energy by 5-20% in the year 2005-2020. The first generation of alternative energy materials used are crude palm oil, jatropha, cassava and corn. The potential feedstock other than terrestrial plants are aquatic organisms e.g microalgae. Components of microalgae such as lipids for biodiesel and carbohydrates to ethanol. Ethanol production from biomass of microalgae consist of two stages i.e. saccharification and fermentation. Problem often found in the saccarification process is low reducing sugar when using acid hydrolysis. Therefore, it is necessary to find an alternative approach to increase the sugar yield by using enzymes. The study consists of four stages. The first was regeneration three isolates in BG 11 medium. The second was cultivation in laboratory using N2P1, N2P2 and N3P3 medium. The commercial enzyme of α-amylase and amyloglucosidase was analyzed to determine the optimal temperature and pH of its activity. The last was evaluating ethanol production using α-amylase and amyloglucosidase. The results of hydrolysis then fermented for seven days using Saccharomyces cereviceae ICBB 8808 to produce ethanol. Microalgae Chlamydomonas sp. ICBB 9114 has the highest biomass yield of 0,44 g/L with a 14,16% starch content, whereas the biomass yield and the lowest starch content in Synechococcus sp. ICBB 9111. The results characterization of α-amylase, optimum at pH 7 and temperature of 90°C with enzyme activity of 63,69 U/mL, whereas the best characterization of amyloglucosidase obtained at pH 5,5 and temperature of 60°C with the enzyme activity of 148,59 U/mL. The hydrolysis of three types microalgae using α-amylase obtained the highest reducing sugars in the microalgae Chlamydomonas sp. ICBB 9114 (5,62 mg/mL). The lowest of reducing sugars obtained on microalgae Chlamydomonas sp. ICBB 9113 (4,39 mg/mL). The combination of the two types of enzymes α-amylase and amyloglucosidase the hydrolysis process increases the total reducing sugars (P<0,05) in all three types of microalgae. The highest reducing sugars produced in the microalgae Chlamydomonas sp. ICBB 9114 (41,83 mg / mL), whereas the lowest reducing sugar produced microalgae Synechococcus sp. ICBB 9111 (35,67 mg/mL). After fermentation for 96 hours on three types of microalgae to produce ethanol. Synechococcus sp. ICBB 9111 (920 ppm), Chlamydomonas sp. ICBB 9113 (980 ppm) and Chlamydomonas sp. ICBB 9114 (516 ppm) respectively.