Thai Indigenous Mixed Microbial Culture for Degrading Polyvinyl Alcohol and the Study of its Degradation Potential

Abstract

The NS3 mixed microbial culture, which is isolated from landfill soil by enrichment culture, had strengthened its ability to degrade PVA. An 0.5 % (w/v) PVA concentration of starting culture was suitable for maintaining the degradation rate. PVA degradation for the mixed microbial culture was enhanced by continuous shaking at 30 °C. It degraded PVA at the initial concentration in the range 1-5 g.L -1 completely over 5-20 days of incubation. Urea and glucose added to the medium inhibited PVA degradation by increasing the pH to a strongly alkaline level, which would cause cell viability and enzyme stability. The FT-IR spectra and SEM imaging revealed the mechanisms and the physical degradation of PVA films, respectively. PVA uptake in bacterial cells produced a dent on the cell surface, which represents the consumption of PVA by bacterial cell.