earticle

영어

The absence of lignin and the low content of cellulose in algae make them a simpler material for bio-conversion than land plants[1]. Brown algae Laminaria Japonica, was used in anaerobic fermentation for methane production. The changes in microbial populations, associated with volatile fatty acids profiles and methane gas productions, were investigated in anaerobic batch reactor during 42 days. The concentration of acetic and propionic acid accounted for 90.4% of overall VFAs production and total amounts of accumulated methane gas was 1.34 L/L. The microbial population dynamics was monitored using 16S rRNA gene targeted real-time PCR. At time 0, Methanobacteriales(MBT), Methanomicrobiales(MMB) and Methanosarcinales(MSL) groups in order of the 16S rRNA gene abundance, were detected and quantified. However, the MSL 16S rRNA gene concentration increased rapidly at day 16, which coincided with the decrease in acetic acid.
Methane started to from at 10 days and was continuously produced. This indicated the possible growth of aceticlastic methanogens actively utilizing the acetate produced in this period. After the day 16, the population of MSL was decreased. Only order MBT, hydrogenotrophic methanogens, kept increasing and accounted for 73% of total methanogenic population. Thus, MBT was the primary methanogenic group responsible for methane production from the latter half of overall period.