Anaerobic biodegradation of poly-3-hydroxybutyrate (PHB) by sulfate reducing bacterium Desulfotomaculum sp
Gazi Faculty of Education, Department of Primary School Teaching, Science Teaching Programme, Gazi University, Ankara, Turkey.
Poly-3-hydroxybutyrate (PHB) film pieces were degraded by sulfate reducing Desulfotomaculum sp. incubated under anaerobic laboratory conditions. Degradation started with adherence of the microbial cells and followed by formation of black colonies on the film surface. Scanning electron microscopic (SEM) observations revealed the presence of bacteria and formation of small holes on the film. After 60 days of incubation at 30°C, 10 % weight loss in polymer and 13 % sulfate reduction in the medium was observed. According to gel permeation chromatography (GPC) analysis, the molecular weight of the PHB decreased after 30 days and did not decrease further at a more extended incubation period. Loss of weight of PHB does not seem to be correlated with molecular weight decrease.
Keywords:Anaerobic biodegradation, Desulfotomaculum, poly-3-hydroxybutyrate, PHB, sulfate reducing bacteria, SRB.