【摘要】：20世紀80年代以來興起的微生物除錳技術,以其效果好、投資省等優(yōu)點逐漸受到關注。微生物作為生態(tài)修復的一個主體,在重金屬污染治理中起著重要作用。 本研究利用在湘潭鶴嶺鎮(zhèn)錳礦欒樹恢復區(qū)采集的土壤樣本,通過逐級提高Mn2+濃度的方法篩選和馴化獲得優(yōu)勢耐錳菌株,采用優(yōu)勢菌株進行了除錳試驗,分析測試了優(yōu)勢菌株的生長曲線、耐受性和相關生理生化特性,并對優(yōu)勢菌株進行了分類學鑒定。研究結果如下： (1)篩選獲得了3株耐錳性強的桿菌(2、3、80號)。在低濃度范圍內,Mn2+對篩選菌種的生長有促進作用,但在高Mn2+濃度點上,Mn2+抑制菌體生長。菌種抗Mn2+性能有一定差異,80號菌耐受性最強。 (2)在測試的最低Mn2+濃度(16mg/L)點上,3號菌種的錳的去除率最高(82.6%),其次是2號(72.3%),80號最低(64.1%),在測試的最高Mn2+濃度(約2000mg/L)點上,80號菌種的去除率最高(41.0%),其次是2號(22.0%),3號最低(18.3%),在Mn2+濃度約200mg/L點上,單一菌種和混合菌樣本Mn2+的去除率最高(90%)。菌種混合后在每個濃度點上均保持較高的去除率。 (3)通過菌落形態(tài)觀察、革蘭氏染色、16s rDNA分子鑒定表明：菌株2為巨大芽孢桿菌；菌株3為產酸克雷伯氏桿菌；菌株80為弗氏檸檬酸桿菌。 (4)篩選的菌株在18～21h左右基本達到生長最高峰,穩(wěn)定期較長；80號菌株生長比其他兩株菌稍慢。3株菌的生長導致培養(yǎng)基pH值升高,這有利于Mn2+的氧化而形成氧化物沉淀。篩選的3株菌適應的pH值范圍較寬(5-9)在溫度28～37℃C之間,2、3、80號菌株最適生長溫度分別為35℃、37℃、33℃。電鏡掃描顯示的特征說明,3株菌的除錳方式可能是將Mn2+氧化為MnO2沉淀�？股乜剐栽囼灡砻�,3號菌株能抗氨芐青霉素,在濃度達到200ug/ml時也能生長,但對硫酸卡那霉素及氯霉素敏感。2、80號菌對三種抗生素均敏感。 (5)從應用角度用泥炭土作為載體,制作了篩選菌株的菌制劑。
[Abstract]:Since 1980's, the technology of microbial manganese removal has been paid more and more attention due to its advantages of good effect, low investment and so on. As a main body of ecological remediation, microorganisms play an important role in the treatment of heavy metal pollution. In this study, soil samples collected from Luan tree restoration area of Heling Town Manganese Mine in Xiangtan were used to screen and acclimate the dominant manganese-tolerant strains by increasing the concentration of Mn2 step by step, and the manganese removal test was carried out by the dominant strains. The growth curve, tolerance, physiological and biochemical characteristics of the dominant strains were analyzed and tested, and the taxonomic identification of the dominant strains was carried out. The results were as follows: (1) three strains of manganese-tolerant bacilli (2,3,80) were obtained. In the low concentration range, Mn2 promoted the growth of the screened strain, but at the high Mn2 concentration point, Mn2 inhibited the growth of the strain. The strain had some difference in anti-Mn2 performance, and strain 80 had the strongest tolerance. (2) at the lowest Mn2 concentration (16mg/L) point tested, strain 3 had the highest manganese removal rate (82.6%), followed by No. 2 (72.3%), and No. 80 had the lowest removal rate (64.1%). At the highest Mn2 concentration (about 2000mg/L) point tested, strain 80 had the highest removal rate (41.0%), followed by No. 2 (22.0%), No. 3 (18.3%), and at the Mn2 concentration of about 200mg/L point, the removal rate of strain 80 was the highest (41.0%), followed by No. 2 (22.0%), the lowest (18.3%). The Mn2 removal rate of single strain and mixed bacteria sample was the highest (90%). After mixing, the bacteria kept high removal rate at each concentration point. (3) the colony morphology, Gram staining and 16s rDNA molecular identification showed that strain 2 was Bacillus giganticus, strain 3 was Klebsiella acidogenes, and strain 80 was citric acid bacillus. (4) the selected strains reached the highest growth peak at about 18 h after 21 h, and the stable period was longer; The growth of strain 80 was slightly slower than that of the other two strains. The growth of the three strains resulted in the increase of pH value of the medium, which was beneficial to the oxidation of Mn2 and the formation of oxide precipitation. The suitable pH ranges of the three strains were between 28 鈩，

本文編號：2434254