Pva Biodegradation Performance

In this paper, the selected mixed microbial was approved having the biodegradability of the three kind of PVA. Experiments carried out in the presence of the culture supernatant clearly demonstrated the presence of a PVA degrading enzymatic system in the solution. The dependence of PVA biodegradation on polymer molecular weight and degree of hydrolysis was investigated in the presence of a PVA-degrading microbial population and of the relevant extracellular enzyme. Enzymatic assays and ¹H NMR excluded the presence of extracellular esterases in the culture supernatant but confirmed the presence of oxidases. Respirometric tests of CO₂ carried out in the presence of the selected microbial population evidenced a limited but significant delay in the mineralization profile depending upon the degree of PVA hydrolysis, whereas no remarkable effect by molecular weight was detected. By the ¹H NMR chemical shifts of the different groups, it was discussed about the biodegradation mechanism of the PVA. Otherwise, there bacterial colonies were isolated from the PVA-degrading microbial population. After measuring the biodegradability of the selected microbes, it was found that the colony of the microbes which were composed of one kind of coccus and one kind of bacillus had relatively higher ability of degrading PVA. By the experiments of domestication and analysis the curve of biodegradation, it was proved that the domestication could improve the biodegradability of the microbes in a relatively short time. After that some researches were done about the influence of the organic compounds and pH value on the degree of biodegradation. By these experiments, it was discussed how to choose better conditions of biodegradation in order to put it into practical industrial use.