本文選題：鉛　切入點：菲　出處：《華東理工大學(xué)》2017年碩士論文

【摘要】：多環(huán)芳烴和鉛是復(fù)合污染土壤中較為常見的兩類污染物,目前報道多為多環(huán)芳烴生物降解功能菌株,而針對能夠降解多環(huán)芳烴且耐受鉛的多功能菌群報道較少。本研究從沈陽某受多環(huán)芳烴和鉛等多種污染物復(fù)合污染的冶煉廠土壤中富集、分離,獲得了一個具有降解菲又能耐受鉛的雙功能菌群。在對菌群降解菲耐受鉛特性的基礎(chǔ)上,基于高通量測序技術(shù)重點闡明了菌群的結(jié)構(gòu)、功能多樣性及功能基因的豐度。主要結(jié)果如下:(1)在菲和鉛的選擇壓力下對采集污染土壤樣品進(jìn)行多次富集、分離得到了一個既能降解菲又能耐受鉛的雙功能菌群。在150 r/min,30℃培養(yǎng)條件下,該菌群能夠在含菲(200mg/L)和鉛(120mg/L)的無機(jī)鹽培養(yǎng)基中生長,48h內(nèi)可降解92.7%的菲。(2)利用高通量測序技術(shù)分析該菌群在不同污染物選擇壓力下的群落結(jié)構(gòu)演變規(guī)律,結(jié)果顯示,菌群在只含有鉛的壓力(S2)下多樣性最高,菌群在不含污染物的環(huán)境(S1)下微生物數(shù)量最大。該菌群主要菌屬包括Paracoccus、Achromobacter、Massilia、Shinella和Stenotrophomonas等。Massilia在菲的壓力下(S3、S4)豐度在 18.31～30.04%,不含菲時(S1、S2)豐度在0.11～2.87%,說明Massilia只在含有菲的環(huán)境(S3、S4)中豐度高。Paracoccuy和Achromobacter在鉛的壓力下(S2、S4)豐度分別維持在26.94～31.82%和14.77～17.86%。綜上,推測 Paracoccus、Achromobacter可能為菌群耐鉛的主導(dǎo)菌株,Massilia可能為菌群降解菲的主導(dǎo)菌株。(3)利用RealtimePCR對菌群在不同污染物選擇壓力下,菌群降解多環(huán)芳烴的起始雙加氧酶基因(RHDα)豐度和耐鉛基因進(jìn)行研究,結(jié)果表明,在含有菲的條件下菌群的RHDa豐度為8.18×104～2.18×105copies/mL,在不含菲的條件下菌群的RHDα豐度為2.81×102～4.99×102copies/mL,菲是決定菌群雙加氧酶豐度的主要因素。同時對菌群的耐鉛基因進(jìn)行PCR檢測,但并沒有在菌群內(nèi)發(fā)現(xiàn)已有過報道的耐鉛基因。(4)在菲和鉛的選擇壓力下篩選了兩株能夠在含有100 mg/L菲和60 mg/L鉛的液體培養(yǎng)基中生長的菌。分別命名為B1和B2,對得到的兩株菌進(jìn)行功能驗證,結(jié)果表明B1和B2均不具有降解菲的能力,但是均具有耐鉛能力,B1最高能耐受100 mg/L的鉛濃度,B2最高能夠耐受1000 mg/L的鉛濃度,而且B2在100和200 mg/L鉛濃度環(huán)境中的生長比在50mg/L鉛濃度中快。分離得到的菌對闡明菌群的耐鉛特性有一定參考價值。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) and lead (Pb) are two common pollutants in the soil contaminated with polycyclic aromatic hydrocarbons (PAHs). At present, polycyclic aromatic hydrocarbons (PAHs) biodegradable functional strains are mostly reported, but there are few reports on the multi-functional bacteria that can degrade PAHs and tolerate lead.In this study, a bifunctional bacteria group with phenanthrene degradation and lead tolerance was obtained from the soil of a smelter polluted by polycyclic aromatic hydrocarbons (PAHs) and lead and other pollutants in Shenyang.Based on the characteristics of phenanthrene tolerance to lead, the structure, functional diversity and functional gene abundance of phenanthrene were elucidated based on high-throughput sequencing technique.The main results are as follows: (1) under the selective pressure of phenanthrene and lead, the contaminated soil samples were enriched for many times, and a bifunctional microbial community was obtained, which could degrade phenanthrene and tolerate lead.At 150 r / min 30 鈩，

本文編號：1693838