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Study on degradation pattern and properties about in situ degradation mechanism of biodegradable polymer

生物可降解聚合物原位降解机理的降解模式及性能研究

基本信息

批准号：
10450307
负责人：
UNNO Hajime
金额：
$ 7.87万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

The contribution of fungi to the microbial degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)films in soil was studied. Various traces, cavities and grooves, observed on the dented surface of PHBV films demonstrated that the degradation was a concerted effect of a microbial consortium colonizing on the film surface including fungi, becteria and actinomycetes. The succession of microbial consortia in the soil around the PHBV films during the degradation showed a distinctive increase in the fungal population resulting in its dominance. Comparison of the degradation ability of microbial strains isolated from the soil, where PHBV films were degraded, revealed that fungi showed the highest contribution to the PHBV degradation in soil, where they grew very rapidly along the film surface with their high degradation ability and then expanded their hyphae in a three-dimensional manner.Fungal degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)film in soil was described mathematically in terms of the surface growth rate of fungal hyphae and the degradation ability of fungal depolymerase. the surface growth rate of fungi was derived from the notion of equivalent symmetric tree model and was expressed for the two different growth phases, i.e., exponential phase and deceleration phase. The proposed growth and degradation models represented well the experimental data obtained from fungal PHBV degradation in soil. Fungi degrade PHBV film with the formation of soil aggregate that gives the advantageous condition for fungal growth and PHBV degradation. Fungal degradation rate of PHBV film in soil depends on the population of colonized fungal biomass on PHBV film surface and their degradation ability

研究了真菌对土壤中聚3-羟基丁酸-co-3-羟戊酸（PHBV）薄膜微生物降解的贡献。在PHBV薄膜凹痕表面观察到的各种痕迹、空洞和凹槽表明，降解是真菌、细菌和放线菌等微生物群落在薄膜表面定殖的共同作用。降解过程中，PHBV膜周围土壤微生物群落的演替表明，真菌种群明显增加，导致其优势地位。比较从PHBV膜降解土壤中分离的微生物菌株的降解能力，发现真菌对PHBV在土壤中的降解贡献最大，真菌沿膜表面快速生长，具有较高的降解能力，然后以三维方式扩展菌丝。从真菌菌丝的表面生长速率和真菌解聚合酶的降解能力两方面对土壤中聚3-羟基丁酸-co-3-羟戊酸（PHBV）膜的真菌降解进行了数学描述。真菌的表面生长速率由等效对称树模型的概念推导而来，并表示为两个不同的生长阶段，即指数阶段和减速阶段。所建立的生长和降解模型较好地反映了真菌PHBV在土壤中的降解实验数据。真菌降解PHBV膜，形成土壤团聚体，为真菌生长和降解PHBV提供了有利条件。真菌对PHBV膜的降解速率取决于真菌在PHBV膜表面的定殖生物量及其降解能力