芽孢杆菌来源的酯酶酶学性质及对邻苯二甲酸酯类降解的初步研究
发布时间：2018-07-24 09:13
【摘要】：Bacillus sp.HJ14和Bacillus sp.SD01、Bacillus sp.SD02分别筛选自云南和山东特殊环境土壤样本。通过对三株菌进行全基因组测序及注释分析,发现其基因组序列中含酯酶基因EstZ1、EstZ14和EstZ22。本研究成功克隆3段基因,并利用Escherichia coli BL21(DE3)进行异源表达,纯化得到重组酯酶EstZ1、EstZ14和EstZ22,同时对他们的酶学性质及对DBP、DEP、DiBP和DCHP的降解潜力进行了研究,具体研究结果如下:(1)重组酶Est Z1可以水解酰基链长度为2 10的人工合成pNP底物,最适底物是pNPC4;最适pH为9.0,在pH 5.0 9.5处理1 h酶活力仍剩余60%以上;最适温度为50℃,在40℃ 70℃保持50%以上的酶活力,37℃和60℃时的热稳定性很好,80℃下半衰期为20 min;大多数金属离子和化学试剂对其活性影响较小,部分有促进作用;能催化水解DEP和DiBP的一个酯键生成相应的醇和单酯。(2)重组酶Est Z14可以水解酰基链长度为2 6的人工合成pNP底物,最适底物是pNPC4;最适pH为7.0,在pH 6.0 11.0处理1 h酶活力仍剩余60%以上;最适温度为45℃,在低于25℃和高于50℃时酶活较低(≤20%),37℃时的热稳定性良好;大部分金属离子及化学试剂对其活性无影响或影响微弱。(3)重组酶Est Z22可以水解酰基链长度为2 8的人工合成pNP底物,最适底物是pNPC4;最适pH为9.0,在pH 6.0 9.0处理1 h酶活仍保持60%以上;最适温度为70℃,37℃时的热稳定性很好,60℃下半衰期为40 min,70℃下处理15 min酶活还剩余40%以上;大多数金属离子和化学试剂对其活性均影响不大,少数有促进作用;对DEP、DiBP、DBP和DCHP有水解活性。本研究获得3个酯酶EstZ1、EstZ14和EstZ22。其中,EstZ1和EstZ22均为嗜热酶并且对DEP、DiBP、DBP和DCHP有水解活性。嗜热酯酶包含了嗜热酶和酯酶的双重性质,在食品工业、生物医疗、环境治理等方面有着非常巨大的应用潜力。
[Abstract]:Bacillus sp.HJ14 and Bacillus sp.SD01Bacillus sp.SD02 were screened from special environment soil samples of Yunnan and Shandong, respectively. By sequencing and annotating the whole genome of three strains of bacteria, it was found that the esterase genes EstZ1, EstZ14 and EstZ22 were found in the genomic sequence. In this study, three segments of genes were cloned and expressed heterogeneously by Escherichia coli BL21 (DE3). The recombinant esterases EstZ1, EstZ14 and EstZ22 were purified, and their enzymatic properties and biodegradation potential of DBP DEPDiBP and DCHP were studied. The results are as follows: (1) the recombinant enzyme Est Z1 can hydrolyze synthetic pNP substrate with acyl chain length of 2 ~ 10, the optimum substrate is pNPC4, the optimum pH is 9.0, and the enzyme activity remains above 60% at pH 5.0 for 1 h, and the optimum temperature is 50 鈩，
本文编号：2140906
[Abstract]:Bacillus sp.HJ14 and Bacillus sp.SD01Bacillus sp.SD02 were screened from special environment soil samples of Yunnan and Shandong, respectively. By sequencing and annotating the whole genome of three strains of bacteria, it was found that the esterase genes EstZ1, EstZ14 and EstZ22 were found in the genomic sequence. In this study, three segments of genes were cloned and expressed heterogeneously by Escherichia coli BL21 (DE3). The recombinant esterases EstZ1, EstZ14 and EstZ22 were purified, and their enzymatic properties and biodegradation potential of DBP DEPDiBP and DCHP were studied. The results are as follows: (1) the recombinant enzyme Est Z1 can hydrolyze synthetic pNP substrate with acyl chain length of 2 ~ 10, the optimum substrate is pNPC4, the optimum pH is 9.0, and the enzyme activity remains above 60% at pH 5.0 for 1 h, and the optimum temperature is 50 鈩，
本文编号：2140906
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