紫外线诱变选育聚丁二酸丁二醇酯（PBS）高降解活性菌株

以PBS降解菌HJ03（Alternariasp．）为出发菌株，通过紫外诱变，透明圈初筛及PBS薄膜复筛，获得一株降解能力增强且对温度和pH耐受力均得到提高的突变株HJ10。与出发菌株相比，HJ10在培养初期气生菌丝少，而培养7d时菌落致密且生长速度较快。经过连续继代培养7代后发现，突变株的降解活力保持了良好的遗传稳定性，其降解率较出发菌株提高百分比达14．4％以上；在最适降解温度范围内（25℃～30℃）和不适宜降解的温度条件下突变菌株Ⅻ10的降解率均高于出发菌株；各pH条件下，突变株对PBS的降解能力明显优于出发菌株，尤其在pH5．0时降解率提高了22．80％。

Screening of poly(butylenes succinate)(PBS) high-degrading activity strain by UV mutagenesis

By UV mutation, clear-zone method for initial screening and test of degrading PBS film for re-screening, a mutant strain HJ10 with higher ability of degrading PBS film and higher endurance to the temperature and pH value was obtained from the original strain Alternaria sp. HJ03. Compared with the original strain, HJ10 had less aerial mycelium at the beginning of culture, but after 7 days the colony turned compact and the growth rate was faster. In addition, the hereditary character of higher degrading ability of the mutant was stable after 7 generations, and its degradation rate increased over 14.4℃. The degrading ability of the mutant strain HJ10 was higher than that of the initial strain at the optimum temperature （25 ℃ -- 35℃ ）, even at inappropriate temperature. Besides, the degradation rate of HJ10 was also improved at different pH values, especially when the pH value was 5.0, which increased by 22.80 %.