嗜酸热异养菌TC-2的分离鉴定及其对微生物浸矿的影响

从云南腾冲酸性热泉分离出一株嗜酸热异养菌TC-2。该菌呈长杆状,细胞大小为(2.0～5.0)μm×(0.3～0.5)μm,革兰氏染色反应为阴性,能形成芽孢。该菌生长温度范围为45～70℃,最适生长温度为55℃,适宜生长的pH值为1.5～4.0,最适宜生长的pH值为2.5,该菌能利用多种有机物生长。16SrDNA序列分析显示其与Alicyclobacillus sendaiensis的16SrDNA相似性大于99%。该菌自身没有浸矿作用,但对Acidianus manzaensis、Sulfolobus metallicus和Metallosphaera sedula等高温浸矿菌的浸矿有一定促进作用。     

源自硫化矿区的Acidiphilium属菌的分离及其浸矿性能

从湖北大冶铜矿的铜山口硫化矿矿坑水中分离得到了一株嗜酸兼性异养细菌,暂命名为DY.该菌株为革兰氏阴性细菌,短杆状,菌体大小为(0.4±0.1)μm×(1.2±0.2)μm,最适生长温度为30 ℃,最适初始生长pH值为3.5,能利用葡萄糖、乳糖、蔗糖和单质硫生长,不能利用FeSO4进行生长.其系统发育树结果表明,菌株DY与Acidiphilium cryptum(Y18446)位于系统发育树的同一分支中,相似度为99.69%.黄铜矿(CuFeS2)摇瓶细菌浸出实验显示,DY菌株单独浸出黄铜矿的能力较弱,但和嗜酸自养的氧化亚铁硫杆菌ATCC 23270混合浸矿时,与氧化亚铁硫杆菌单独浸矿相比,30 d后黄铜矿的浸出率提高了35.98%.     

Screening and characterization of Acidiphilium sp. PJH and its role in bioleaching

A Gram-negative,facultative autotrophic bacterium strain PJH was isolated from the acidic mine drainages sampled in Dexing Mine,Jiangxi Province,China.The isolate grew in a pH range of 1.0-6.0,with pH and temperature optima of 3.5 and 40 ℃,respectively.Spectroscopic experiments show that strain PJH can synthesize polyhydroxybutyrate (PHB).A phylogenetic analysis based on 16S rRNA sequences shows that the isolate belongs to the genus Acidiphilium.Strain PJH has the capability of leaching chalcopyrite.Bioleaching experiments show that it can improve the leaching rate of chalcopyrite by 10.3% when mixed with L.ferriphilium YTW315 after 35 d.Strain PJH has the potential in application to bioleach chalcopyrite with other mesophilic leaching microbes.     

Isolation and characterization of acidophilic bacterium from Gaofeng Mine in China

An acidophilic, chemolithotrophic and ferrous oxidizing bacterium strain GF was isolated from the acid mine drainage （AMD） of Gaofeng Mine, Guangxi Province, China using 9K enrichment medium, and then purified on solid ferrous-agarose medium. The physiological experiments show that it can use ferrous or sulfur as sole energy and a low level （0.1%, w/v） of peptone can accelerate the growth of the isolated strain. The optimum pH and temperature for growth are 2.0 and 30 ℃, respectively. The isolated strain shares 99.64% identities of 16S rRNA gene with the type strain Acidthiobacillusferrooxidans ATCC 23270 and 100% identities of iro gene （CDS） with A.ferrooxidans strain Fe-1. These results show that the strain can be considered as A cidthiobacillus ferrooxidans. Because of the high activity of oxidizing ferrous and sulfide mineral, strain GF was used in bioleaching of marmatite. The Zn concentration is 0.273 g/L under the steriled control and 7.30 g/L with adapted GF strain incubated after 29 d in leaching marmatite. The isolated strain GF can be used to leach marmatite in industry application.     

Isolation and identification of moderately thermophilic acidophilic iron-oxidizing bacterium and its bioleaching characterization

A moderately thermophilic acidophilic iron-oxidizing bacterium ZW-1 was isolated from Dexing mine, Jiangxi Province, China. The morphological, biochemical and physiological characteristics, 16S rRNA sequence and bioleaching characterization of strain ZW-1 were studied. The optimum growth temperature is 48 ℃, and the optimum initial pH is 1.9. The strain can grow autotrophically by using ferrous iron or elemental sulfur as sole energy sources. The strain is also able to grow heterotrophically by using peptone and yeast extract powder, but not glucose. The cell density of strain ZW-1 can reach up to 1.02×108 /mL with addition of 0.4 g/L peptone. A phylogenetic tree was constructed by comparing with the published 16S rRNA sequences of the relative bacteria species. In the phylogenetic tree, strain ZW-1 is closely relative to Sulfobacilus acidophilus with more than 99% sequence similarity. The results of bioleaching experiments indicate that the strain could oxidize Fe2+ efficiently, and the maximum oxidizing rate is 0.295 g/(L·h). It could tolerate high concentration of Fe3+ and Cu2+ (35 g/L and 25 g/L, respectively). After 20 d, 44.6% of copper is extracted from chalcopyrite by using strain ZW-1 as inocula.     

Screening and characterization of Acidiphilium sp. PJH and its role in bioleaching

A Gram-negative, facultative autotrophic bacterium strain PJH was isolated from the acidic mine drainages sampled in Dexing Mine, Jiangxi Province, China. The isolate grew in a pH range of 1.0 6.0, with pH and temperature optima of 3.5 and 40 ℃, respectively. Spectroscopic experiments show that strain PJH can synthesize polyhydroxybutyrate （PHB）. A phylogenetic analysis based on 16S rRNA sequences shows that the isolate belongs to the genus Acidiphilium. Strain PJH has the capability of leaching chalcopyrite. Bioleaching experiments show that it can improve the leaching rate of chalcopyrite by 10.3% when mixed with L. ferriphilium YTW315 after 35 d. Strain PJH has the potential in application to bioleach chalcopyrite with other mesophilic leaching microbes.     

Dominance of Acidithiobacillus at ore surface of Zijinshan commercial low-grade copper bioleaching heap

The microbial community structure in the ore surface of Zijinshan commercial low-grade copper bioleaching heap was investigated by 16S rRNA gene clone library.For both bacteria and Archaea,105 clones were sequenced.The dominant bacteria species present in the ore surface were Acidithiobacillus and Leptospirillum,accounting for 51.42% and 48.57%,respectively. However,for the Archaea,only one operational taxonomic unit(OUT)belonged to Ferroplasma acidiphilum.These results indicate that function of genus Ac...     

Dominance of Acidithiobacillus at ore surface of Zijinshan commercial low-grade copper bioleaching heap

The microbial community structure in the ore surface of Zijinshan commercial low-grade copper bioleaching heap was investigated by 16S rRNA gene clone library. For both bacteria and Archaea, 105 clones were sequenced. The dominant bacteria species present in the ore surface were Acidithiobacillus and Leptospirillum, accounting for 51,42% and 48.57%, respectively. However, for the Archaea, only one operational taxonomic unit （OUT） belonged to Ferroplasma acidiphilum. These results indicate that function of genus Acidithiobacillus in the commercial low-grade copper bioleaching heap may be underestimated. More detailed and quantitative information on microbial community structure over time are now under investigation.     

Bioleaching of chalcopyrite by UV-induced mutagenized Acidiphilium cryptum and Acidithiobacillus ferrooxidans

The original strains Acidithiobacillus ferrooxidans GF and Acidiphilium cryptum DX1-1 were isolated from the drainage of some caves riched in chalcopyrite in Dexing Mine in Jiangxi Province of China.The optimum temperature and pH for growth were 30℃and 3.5 for Ac.cryptum DX1-1,and 30℃and 2.0 for At.ferrooxidans GF,respectively.For Ac.cryptum DX1-1,the optimum UV radiating time was 60 s and the positive mutation rate was 22.5%.The growth curves show that Ac.cryptum after mutagenesis reached stationary phase ...     

元素硫对黄铜矿生物浸出行为及群落结构的影响(英文)

研究3种典型铁/硫代谢菌—Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum及Acidithiobacillus thiooxidans混合浸出黄铜矿过程中铁/硫氧化活性、群落结构(PCR-RFLP)的变化,以及不同浓度的元素硫对其影响。结果发现,加入3.193g/L元素硫能促进细菌的表观硫氧化活性,改变浸矿体系的群落结构,并进一步影响钝化层的形成、金属离子的溶出,其浸出率(71%)较未添加硫的(67%)有一定程度的提高。而过量的元素硫会抑制铜的浸出(浸出率44%)。