嗜酸硫化杆菌(Sulfobacillus sp.)的分离鉴定及其在黄铁矿浸取中的应用

Isolation and identification of Sulfobacillus sp. strains and their application in pyrite bioleaching

摘要:

摘要:【目的】分离、培养获得中高温硫化矿浸取菌，为利用其进行生物冶金研究及应用奠定基础。【方法】利用二价铁或单质硫为底物，对酸性热泉泥水样品进行富集培养，以获得能够氧化二价铁或还原性硫的菌株;根据形态学、生理生化特点及系统发育分析对分离菌株进行分类鉴定;通过分析黄铁矿的铁氧化速率评估菌种在生物冶金中应用的潜力。【结果】从哥斯达黎加酸性热泉泥水样品中分离得到两株好氧嗜酸兼性自养细菌Costa C和Costa E。两株菌革兰氏染色反应为阳性，细胞大小相近，分别为(0.4－0.6)μm ×(2.5－4.0)μm和(0.4－0.7)μm×(2.4－4.9)μm，端生芽胞，生长温度范围均为30 ℃－55 ℃，最适生长温度分别为50℃和40℃，生长pH 范围分别为1.2－5.0和1.4－5.0，最适生长pH均为2.8。可以利用Fe(Ⅱ)、S、K2 S4O6等为能源进行自养生长，也可利用酵母浸粉等有机物生长。两株菌的16S rRNA基因与硫化杆菌属(Sulfobacillus)其他菌种的最高相似性大于99%，(G + C)% 含量分别为56.1 mol%和56.7mol%。【结论】形态学、生理生化特点及系统发育分析表明，研究中筛选获得的两株菌均属于Sulfobacillus属，分别定名为Sulfobacillus sp. strain Costa C 和Sulfobacillus sp. strain Costa E。浸矿结果显示两株菌在45℃时可以氧化黄铁矿，氧化速率分别为63.0 mg/L·d 与56.8 mg/L·d，表明两株菌具有在中高温条件下浸取硫化矿的能力。

Abstract:

Abstract:［Objective］The work aimed to isolate and culture the acidophilic and moderately thermophilic microorganisms for leaching the sulfide ore.［Methods］We enriched and incubated iron- or sulfur-oxidizing strains from muddy water of acuric hot spring utilizing ferrous irons or elemental sulfur as substrates． Then，we identified the strains by their morphological，physiological，biochemical properties and phylogenetic positions，and estimated their bioleaching potential according to their oxidation rate of pyrite.［Results］Two acidophilic，aerobic and facultative heterotrophic bacterial strains，Costa C and Costa E，were isolated from the samples of sulfuric hot springs of Costa Rica. Cells of the two strains were gram-positive，spore-forming and rod-shaped [(0.4－0.6)μm×(2.5－4.0)μm and (0.4－0.7)μm×(2.4－4.9)μm，respectively].Strain Costa C grew at a temperature range of 30℃ －55℃ and a pH range of 1.2－5.0，optimally at 50oC and 2.8．Strain Costa E grew at a temperature range of 30℃－55℃ and at a pH range of 1.4－5.0， optimally at 40oC and 2.8. Two strains could autotrophically grow on inorganic substrates such as ferrous irons，element sulfur and K2 S4O6 and also could utilize organic substrates like yeast extract for heterotrophic growth．Phylogenetic analysis based on 16S rRNA gene sequences alignment demonstrated that the highest similarity between strain Costa C，Costa E and other species of the genus Sulfobacillus was above 99%.［Conclusion］Based on morphological，physiological and biochemical analysis，Costa C and Costa E can be affiliated to the genus Sulfobacillus，for which the names Sulfobacillus sp. strain Costa C and Sulfobacillus sp. strain Costa E were proposed． Both strains could oxidize pyrite，and the oxidation rates arrived 63.0 mg/L·d and 56.8 mg/L·d，respectively.