本文選題：溶藻細菌　切入點：短波單胞菌　出處：《山東大學》2017年碩士論文　論文類型：學位論文

【摘要】：近年來,人口數(shù)量的增加和工業(yè)化的快速發(fā)展不斷威脅著生態(tài)環(huán)境的承載能力,污染物質(zhì)濃度嚴重超出了水體自凈能力上限,造成了水體的富營養(yǎng)化。銅綠微囊藻的爆發(fā)性增長引起藍藻水華,針桿藻的爆發(fā)性增長導致硅藻水華。銅綠微囊藻具有體積小、生長周期短、可分泌微囊藻毒素及嗅味物質(zhì)等特性,對其他水生生物的生長以及飲用水的生產(chǎn)及安全造成潛在威脅。針桿藻體型大、不易被絮凝,導致其在水廠水處理過程中容易造成濾池堵塞,增加水體的處理成本,并且影響出水的凈化效果。本論文以微生物除藻為研究方向,利用實驗室分離保藏的一株短波單胞菌為受試菌種,對銅綠微囊藻和針桿藻分別開展生物除藻的相關(guān)研究,主要研究內(nèi)容和結(jié)果如下:(1)對實驗菌種進行種屬鑒定,作為研究該菌株的基礎(chǔ),本論文同時測定了溶藻細菌的生長曲線,在此基礎(chǔ)上優(yōu)化其生長條件,實現(xiàn)菌種的快速生長,探究其溶藻方式,優(yōu)化培養(yǎng)時間,為進一步實際應(yīng)用提供理論支持。結(jié)果表明,實驗菌株為一株短波單胞菌(Brevundimonas sp.),其通過間接途徑進行溶藻,最佳培養(yǎng)條件是pH=7,溫度為30℃,培養(yǎng)到36h時溶藻活性最高。(2)從生理特性、活性狀態(tài)等多方面探究了該短波單胞菌的生物除藻機理。首先,探究不同濃度溶藻物質(zhì)的除藻效率;其次,探究M.aeruginaosa 和 S.acus細胞受溶藻作用影響下的生理狀態(tài)變化;再次,探究溶藻作用對藻細胞生理活性的影響。結(jié)果表明,延長溶藻時間和增加溶藻物質(zhì)的濃度能顯著提升除藻效率,溶藻作用會引起細胞膜脂過氧化反應(yīng),激發(fā)細胞酶活性以消除細胞損傷,同時,降低了 Chlorophyll a的含量,破壞了正常的光合作用,通過流式細胞術(shù)檢測出溶藻作用會誘導藻細胞程序性死亡,進而抑制水華藻的繁殖。(3)探究藻細胞表面電荷受溶藻作用的影響,結(jié)果顯示,溶藻前期,由于銅綠微囊藻細胞分泌物的增加導致負電荷含量迅速增加,但隨著藻細胞被破壞和細胞活性下降,表面電荷的值逐漸下降,而針桿藻表面電荷的值呈逐漸下降的趨勢。實驗同時探究了溶藻作用對針桿藻沉降性能的影響,結(jié)果表明,溶藻作用不僅可以抑制針桿藻的生長,而且還能加速針桿藻的沉降,主要是由于溶藻作用破壞了藻細胞表面結(jié)構(gòu),降低了表面電荷的絕對值,從而影響了藻液體系的穩(wěn)定性。(4)為將溶藻物質(zhì)投入到實踐應(yīng)用中,本論文開展了溶藻成分的分離、純化與鑒定等相關(guān)研究。通過乙醇沉淀、甲醇浸提、有機溶劑萃取、薄層色譜法分離、硅膠柱層析提純等方法純化溶藻物質(zhì),最終確定溶藻活性組分的RF值為0.342,透析法確定活性組分的分子量小于1KD,通過HPLC-MS檢測RF=0.342的物質(zhì)成分,結(jié)果顯示其包含分子量為136、278、315和390的四種混合物質(zhì),由于分離手段及研究時間有限,目前沒有獲得單一純品,但為下一步繼續(xù)開展物質(zhì)分離工作打下基礎(chǔ)。
[Abstract]:In recent years, with the increase of population and the rapid development of industrialization, the carrying capacity of ecological environment is constantly threatened, and the concentration of pollutants seriously exceeds the limit of self-purification ability of water body. The explosive growth of Microcystis aeruginosa caused Shui Hua of cyanobacteria, and the explosive growth of Hypoderma aeruginosa led to the eutrophication of diatom Shui Hua. Microcystis aeruginosa was small in size and short in growth period. The secretion of microcystins and odorous substances may pose a potential threat to the growth of other aquatic organisms and to the production and safety of drinking water. It is easy to cause filter blockage in the process of water treatment, increase the cost of water treatment, and affect the purification effect of effluent. In this paper, microorganism algae removal is the research direction. Using a short-wave bacterium isolated and preserved in the laboratory as the tested strain, the bioremoval of microcystis aeruginosa and Acetomonas aeruginosa were carried out respectively. The main contents and results were as follows: 1) the species and genus of the experimental bacteria were identified. As the basis of the study, the growth curve of algae-lysing bacteria was determined in this paper. On this basis, the growth conditions of algae-lysing bacteria were optimized, the rapid growth of the bacteria was realized, the way of algae dissolution was explored, and the culture time was optimized. The results showed that the experimental strain was Brevundimonas sp., and the optimum culture conditions were pH7 and 30 鈩，

本文編號：1579177