夹竹桃根系耐铅锌细菌的筛
发布时间：2018-11-06 16:48
【摘要】：生物修复方法由于其具有经济、生态效益等优点而在重金属污染治理中占据优势地位,而微生物作为生态修复的一个主体,在治理重金属污染中起着重要作用。本研究取样于湖南资兴铅锌矿耐铅锌植物盆栽试验中长势较好的植株夹竹桃的根系,对筛选、驯化所得菌株进行了耐受性、生理生化等特性的研究,并进行了分类学鉴定与电镜扫描、傅里叶变换红外光谱分析。具体实验结论如下：(1)经过一系列分离、筛选及驯化实验得到了26株铅锌抗性菌,编号B1-B26。通过比较26株细菌在所设计的Pb (Ⅱ)、Zn (Ⅱ)不同浓度梯度培养基中的OD600,将生长量较高的B1、B4、B14确定为优势菌株。B1、B4、B14对Pb(Ⅱ)、Zn (Ⅱ)的最高耐受浓度分别可达800mg/L、800mg/L、600mg/L。(2)通过三株优势菌的富集特性研究,发现菌株B1在温度为30℃、Pb (Ⅱ)和Zn (Ⅱ)初始浓度为50 mg/L、转速为180r·min-1、pH5.0、吸附时间为50mmin、初始菌量为0.06g时,对Pb (Ⅱ)、Zn (Ⅱ)的吸附率分别为84.22%、70.66%；菌株B4在温度为30℃、Pb (Ⅱ)和Zn (Ⅱ)初始浓度为50 mg/L、转速为180r·min-1,pH为6.0、吸附时间为50min、初始菌量为0.18g时,对Pb (Ⅱ)、Zn (Ⅱ)的吸附率分别为72.63%、54.17%；菌株B14在温度为30℃、Pb (Ⅱ)和Zn (Ⅱ)初始浓度为50mg/L、转速为180r·min-1,pH为4.0、吸附时间为60min、初始菌量为0.10g时,对Pb (Ⅱ)、Zn (Ⅱ)的吸附率分别为77.56%、50.63%。以上试验结果表明,筛选的三株优势菌在铅、锌污染土壤的修复和含Pb (Ⅱ)、Zn (Ⅱ)废水的处理中将具有良好的应用前景。(3)对三株优势菌株进行了菌落形态观察、革兰氏染色、16S rDNA分子鉴定,然后把所得的三株菌的16S rDNA序列输入NCBI进行Blast比对,得到与该细菌16S rDNA序列的同源性最高的已知序列。经比对确定B1为蜡样芽孢杆菌(Bacillus cereus)或炭疽杆菌(Bacillus anthracis);B4为解硫胺素硫胺素芽孢杆菌(Aneurinibacillus aneurinilyticus);B14为藤黄微球菌(Micrococcus luteus)。(4)电镜扫描显示在含Pb (Ⅱ)、Zn (Ⅱ)培养基中培养过的菌体细胞发生了畸变,部分菌体细胞发生破裂或聚集,菌体表面产生大量晶体以及絮状或球形沉淀。傅里叶变换红外光谱分析(FTIR)说明B1、B4、B14菌体细胞富含羟基(-O-H)、胺基(-N-H)、烷基、酰胺基(CONH-)、羧基(O=C-O-)、磷酸基(-PO43-)等多种活性基团。对吸附前、后菌体的傅里叶变换红外光谱图进行对比分析,发现羟基(O-H)、胺基(N-H)、烷基、酰胺基(CONH-)是吸附、络合或螯合重金属离子或原子的主要活性基团,重金属与菌株表面的活性基团结合反应是其吸附Pb (Ⅱ)、Zn (Ⅱ)的主要作用机制。
[Abstract]:Bioremediation plays an important role in the treatment of heavy metal pollution because of its economic and ecological benefits. As a main body of ecological remediation, microorganisms play an important role in the treatment of heavy metal pollution. In this study, we sampled the roots of nectarine, which grew well in the pot experiment of lead-zinc tolerant plants in Zixing lead-zinc mine, Hunan Province, and studied the tolerance, physiological and biochemical characteristics of the selected and domesticated strains. The taxonomic identification, scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) were carried out. The results are as follows: (1) after a series of isolation, screening and acclimation experiments, 26 strains of lead and zinc resistant bacteria were obtained, numbered B1-B26. By comparing the OD600, of 26 strains of bacteria in the Pb (鈪，
本文编号：2314873
[Abstract]:Bioremediation plays an important role in the treatment of heavy metal pollution because of its economic and ecological benefits. As a main body of ecological remediation, microorganisms play an important role in the treatment of heavy metal pollution. In this study, we sampled the roots of nectarine, which grew well in the pot experiment of lead-zinc tolerant plants in Zixing lead-zinc mine, Hunan Province, and studied the tolerance, physiological and biochemical characteristics of the selected and domesticated strains. The taxonomic identification, scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) were carried out. The results are as follows: (1) after a series of isolation, screening and acclimation experiments, 26 strains of lead and zinc resistant bacteria were obtained, numbered B1-B26. By comparing the OD600, of 26 strains of bacteria in the Pb (鈪，
本文编号：2314873
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