聚羟基脂肪酸酯细菌合成的生长环境依赖性

聚羟基脂肪酸酯 (Polyhydroxyalkanoate,PHA)是一类由许多细菌合成的、结构多变的能量和碳源的储藏物质 .为了得到能合成新型PHA的菌种 ,或得到能在便宜简单碳源上合成PHA的菌种 ,以我们实验室开发的傅立叶红外 (FT IR)细胞无损检测技术和常规气相色谱 (GC)法对全国各地的采集的不同样品中分离的菌种进行了筛选 .往往在不同的地理环境中 ,筛选出的菌株所合成的PHA的单体组成不同 ,有的以含四个或五个碳原子的短链单体PHA(Short chain lengthPHA ,sclPHA)为主 ,有的以含六个到十六个碳原子的中长链单体PHA(Medium chain lengthPHA ,mclPHA)为主 .在我们以六种底物为碳源培养的 371株形态不一的菌株中 ,有 40 %的菌可以合成PHA ,而其中许多可以同时合成PHB与中长链PHA共混的聚合物 .本研究为进行PHA研究的高分子同行提供了寻找能合成PHA的微生物菌种的依据

ENVIRONMENTAL DEPENDENCE OF MICROBIAL SYNTHESIS OF POLYHYDROXYALKANOATES

Polyhydroxyalkanoate(PHA) is a family of carbon and energy storage materials synthesized by many bacteria,its hydroxyalkanoate monomers have diversified structures.A broad screening process using the FT\|IR technique developed by us previously was carried out.Samples were collected from various geological locations around the country.It was found that PHA compositions depend very much on the geological locations.In some locations,bacteria mainly synthesized short\|chain\|length PHA(scl PHA) consisting of monomers with four to five carbon atoms,in other locations,medium\|chain\|length PHA(mcl PHA) consisting of monomers with six to sixteen carbon atoms were accumulated by inhabiting bacteria.Additionally,the synthesis of blend polymers consisting of PHB,scl PHA and mcl PHA is a common phenomenon among the bacteria studied.40% of the 371 strains cultivated on six substrates is able to synthesize PHA,with many of them making blends of PHB and mcl PHA.This result will help polymer researchers to identify sources of PHA synthesis.