The effect of temperature variation on the growth of Leptolyngbya (cyanobacteria) HS-16 and HS-36 to biomass weight in BG-11 medium

Leptolyngbya is known to be used for human purposes, including for biofuel production. Therefore, it is important to study the physiology of these microorganisms. This study is expected to provide information on the temperature of growth ability of Leptolyngbya HS-16 and Leptolyngbya HS-36, so that storage conditions of culture space in subsequent research can be arranged to prevent these strains from dying or not growing well. In the utilization of cyanobacteria, a clear physiological characterization of the cyanobacteria is required. Temperature is one of the major factors affecting the growth of cyanobacteria. The growth differences between cyanobacteria strains Leptolyngbya HS-16 and Leptolyngbya HS-36 which were incubated in 20 degrees C, 35 degrees C, and 50 degrees C had been studied. Those strains were isolated from Gunung Pancar (Leptolyngbya HS-16) and Maribaya (Leptolyngbya HS-36) hot springs which located in West Java, Indonesia. The water temperature of habitat was 69 degrees C (Gunung Pancar) and 42 degrees C (Maribaya). Those strains were grown in batch culture methods for 21 days in BG-11 medium. This research aims to determine the best growth temperature of Leptolyngbya HS-16 and Leptolyngbya HS-36 based on the biomass weight of chlorophyll content. The result showed that the biomass weight and chlorophyll content in 35 degrees C of Leptolyngbya HS-16 and Leptolyngbya HS-36 were the highest. Both Leptolyngbya were likely thermotolerant cyanobacteria and had optimum cultured temperature 35 degrees C. There was no correlation between biomass weight and chlorophyll of Leptolyngbya HS-16 and Leptolyngbya HS-36. Further research should be focus on utilizing Leptolyngbya on various photobioreactor systems and biofuel development due their ability to growth optimally in that temperature.