聚丁二酸丁二醇酯高效降解菌的筛选及降解特性

Fungi screening and degradation characteristics for efficient poly (butylenes succinate) degradation

摘要:

从蔬菜地表微环境空气微生物中分离筛选获得了一株高效降解聚丁二酸丁二醇酯(PBS)的真菌菌株BFM-X1, 通过形态学和ITS rDNA 序列测定分析, 确认该菌株为淡色生赤壳属真菌(Bionectria ochroleuca)。该菌株降解PBS 薄膜的最适温度为25 °C?30 °C, 培养基初始pH 为4.0, 以甘油、大豆油、葡萄糖及PBS 乳剂分别作为唯一碳源时对PBS 薄膜均具有很高的降解率; 菌株对PBS 薄膜的降解率随PBS 乳剂含量变化的曲线呈倒“U”型, 最佳PBS 乳剂浓度为1 g/L, 且对PBS 的降解呈现诱导期、指数降解期和加速降解期等3 个阶段。降解初期薄膜表面首先粗糙化, 失去原有的黑色光泽, 随后出现孔洞, 逐渐呈现破碎化, 最后薄膜被完全降解, 降解部位仅残留黑色色素。

Abstract:

A fungal strain BFM-X1 was isolated from air environment on vegetable field, which had a strong ability to degrade poly (butylenes succinate, PBS). Morphological and phylogenetic analysis revealed that strain BFM-X1 was closely related to Bionectria ochroleuca. The optimum temperature for strain BFM-X1 degrading PBS film ranged from 25 °C to 30 °C and the initial pH of medium was 4.0. A high degradation rate for PBS film was observed with glucose, glycerole, soybean oil or PBS emulsion as a single carbon source for this strain. The curve of PBS film degradation rate with the increase of the PBS emulsion concentration showed a resupinate “U”, and the optimum PBS emulsion concentration was 1 g/L. Three phases were exhibited during PBS degradation by BFM-X1. Scanning electron micrographs showed that the surface of PBS film firstly became rough, then some holes appeared on the PBS film and the PBS film gradually disintegrated, at last the PBS film completely degraded.