自然水体生物膜胞外聚合物的提取及优化

Extraction of Extracellular Polymers from Natural Biofilms

以自然水体生物膜为研究对象,蛋白质和多糖的提取量作为生物膜胞外聚合物(EPS)提取总量的衡量指标,核酸含量用于表征细胞破裂程度,本文作者以高速离心法为对照,分别研究了加热法、EDTA法、Na OH+Na Cl法和超声+CER法对自然水体生物膜胞外聚合物的提取效果,从而确定自然水体生物膜最适提取方法并对实验条件进行优化。研究结果表明,Na OH+Na Cl法因提取胞外聚合物总量高,核酸含量较少为最适提取方法。在Na OH浓度为2 mol/L,Na Cl质量分数为0.85%,萃取2.5 h,分离转速为7 000 g条件下,EPS提取量为157.57 mg/L。

Using the content of protein and polysaccharide and the content of nucleic acid separately as indicators of total extracellular polymeric substances（EPS） and cell autolysis,five different extraction methods,including thermal,EDTA,NaOH＋NaCl,ultrasonic＋CER and high speed centrifugation（control） treatments,for EPS from natural biofilms were studied. Results showed that NaOH＋NaCl treatment was the most effective for EPS extraction with less nucleic acid contamination. The optimal extraction conditions were 2 mol/L NaOH,0.85% NaCl,extraction time 2.5 h and centrifugal force 7 000 g. With these parameters,the extraction content of EPS was 157.57 mg/L.