1. Estimation on Biodegradability of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) and Numbers of Aerobic PHB/V Degrading Microorganisms in Different Natural Environments
- Author
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Shigeya Takeuchi, Cunjiang Song, Chao Yang, Mitsuyo Sano, Shufang Wang, Maeda Maki, Wataru Mizuno, and Bang-Hua Zhang
- Subjects
Environmental Engineering ,Materials science ,Polymers and Plastics ,Waste management ,Microorganism ,technology, industry, and agriculture ,macromolecular substances ,Biodegradation ,complex mixtures ,River water ,Activated sludge ,Poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate) ,Materials Chemistry ,Paddy field ,lipids (amino acids, peptides, and proteins) ,Food science - Abstract
To assess the capacity of the natural environment for degrading PHB/V, the film-MPN method proposed previously was modified to estimate the numbers of PHB/V degrading microorganisms (degraders) in various environments. The First-Order Reaction (FOR) model was used to determine the appropriate incubation period for the method. Numbers of aerobic PHB/V degraders were estimated in garden soil, paddy field soil, farm soil, river bank soil, infertile garden soil, river water, activated sludge, and seawater by the film-MPN method. Results were compared with those estimated by the clear-zone technique and showed that the film-MPN method was suitable for estimating the numbers of PHB/V degraders in the environments tested. On the other hand, biodegradability of injection molded PHB/V samples was investigated in several kinds of environments. The changes of weight were studied and results showed that biodegradability of PHB/V related to the numbers of PHB/V degraders in similar ecosystem in different regions. In different environments the biodegradability of PHB/V not only related to the number of PHB/V degraders, but also depended on whether there were conditions for the PHB/V degraders to grow and proliferate easily in the environment.
- Published
- 2005