黄铁矿脱硫菌生长和代谢的影响因素研究

研究了氧化亚铁硫杆菌（简称T．f．菌）对几种氮源、能源的利用，以及空气中氧化不同时间的黄铁矿吸附菌的代谢活性。结果表明：在选择的3种氮源中，尿素经过诱导可被T．f．菌较好地利用，说明该菌可产生诱导性脲酶。在选择的能源中，Fe^2＋是T．f．菌容易利用的能源基质。添加接种培养过的残留单质硫粉可提高菌体氧化单质硫的速率。在空气中氧化20d的黄铁矿对T．f．菌的吸附量增大，而且吸附菌体的亚铁氧化过程提前进行。     

天冬氨酸对氧化亚铁硫杆菌胞外多聚物的影响

以天冬氨酸为营养辅助因子,研究其对氧化亚铁硫杆菌生长及胞外多聚物成分的影响。结果表明,与对照组相比,最大菌体量提高17%,生长周期缩短了15 h;培养至23 h时,Fe2+氧化速率比对照高66.67%,环境pH提前15 h达到最低点,并降低8.72%。培养25 h后,胞外多聚物中蛋白质含量增加21.95%,多糖含量增加9.19%。添加天冬氨酸可有效促进氧化亚铁硫杆菌的生长,缩短生长周期;其可能的机理为其促进了氧化亚铁硫杆菌胞外多聚物中蛋白组分的表达。     

分离于酸性矿坑水的疑似钩端螺旋菌的鉴定及重金属对其铁氧化能力影响的评估

采用稀释分离法,从山西中条山铜矿的酸性矿坑水中分离出一株铁氧化细菌,命名为ZTS菌株.该菌株为革兰氏阴性细菌,螺旋状或弧状,最适生长温度为30 ℃,最适生长pH值为2.5,对低浓度的酵母浸出物较敏感.形态学和生理学分析表明,ZTS菌株可能属于钩端螺旋菌属的成员;16S rDNA序列的系统发育分析表明,该菌株与氧化亚铁钩端螺旋菌典型菌株ATCC 49879位于系统发育树的同一分支,相似度为100%,从而证实ZTS菌株属于氧化亚铁钩端螺旋菌.考虑到当前的商业利益,考察了Cu2+、Co2+ 和Ni2+对ZTS菌株氧化亚铁能力的影响.结果表明:3种金属对ZTS菌株的毒性强弱依次为Co2+＞Cu2+＞Ni2+.就Ni2+抗性能力而言,ZTS菌株能够耐受Ni2+的浓度高达160 mmol/L,这比已报道的氧化亚铁钩端螺旋菌的Ni2+抗性能力要强得多,这种能力可能与它的遗传特性有关.     

Ferrous ion oxidation by Thiobacillus ferrooxidans immobilized on activated carbon

1 Introduction One of the main applications of biotechnology to hydrometallurgy is based on the ability of bacteria such as Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans to oxidize sulfide minerals to soluble compone…     

氧化亚铁硫杆菌和氧化硫硫杆菌的协同作用对Q235钢腐蚀行为的影响

采用失重法、交流阻抗测试和扫描电镜等手段研究了氧化亚铁硫杆菌(T.f)和氧化硫硫杆菌(T.t)的协同作用对Q235钢腐蚀行为的影响。结果表明,T.f和T.t的协同作用加剧了Q235钢的均匀腐蚀速率,混合菌体系中Q235钢的腐蚀失重远大于两种微生物单独存在体系。显微分析结果表明,T.t体系中金属没有出现点蚀,混合菌体系中Q235钢的点蚀坑较T.f体系中的小而浅,T.t的存在降低了Q235钢的局部腐蚀。     

阴离子对嗜酸氧化亚铁硫杆菌生长和硫氧化活性的影响

以嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans, ATCC23270)为对象,研究NO_3~-、SO_4~(2-)、Cl~-和PO_4~(3-)对Acidithiobacillus ferrooxidans生长和硫氧化活性的影响.结果表明:不同阴离子对Acidithiobacillus ferrooxidans硫氧化表观活性的影响效应不同,其影响由大到小的顺序依次为Cl~-,NO_3~-,SO_4~(2-)和PO_4~(3-);在高浓度PO_4~(3-)的胁迫(300 mmol/L)下,细菌所表达蛋白质的总数量减少,但同时表达一些特异性蛋白质,这说明细菌可通过抑制一些在正常条件下表达的蛋白质,同时表达一些新的蛋白质来应对无机离子的胁迫效应.     

The Porto Torres biodepyritization pilot plant: Light and shade of one year operation

The nominal 50 kg h⁻¹ dry coal biodepyritization pilot plant was built at Porto Torres (Sassari, Italy) in the area of EniChem S.p.A. Chemical Works, with financial support of the Commission of European Communities and with the participation of the DMT of Essen (Germany), the Mining and Mineral Processing Department of the University of Cagliari (Italy), the Technical University of Delft (The Netherlands) and the Warren Spring Laboratory of Stevenage (UK). The plant went on stream in early September 1992. Test runs were carried in the range 6.5–41.5% solids concentration. For every solids concentration the steady state was attained in about 10 d. For all the test runs the assays showed that more than 90% pyrite removal is achieved in the first five bioreactors; for a pulp flow rate of 6.94 × 10⁻² dm³ s⁻¹, (250 l h⁻¹) and useful bioreactor volume of 7.5 m³, this corresponds to a residence time of 540 345 s, i.e., 6.254 d, and to a pyritic iron biosolubilization rate of 36 mg dm⁻³ h⁻¹. The pyrite biosolubilization rate constant is 1.53 × 10⁻² h⁻¹. The power input per bioreactor operating on a 40% solids pulp is 4 kW with cos Φ = 0.76. Hence, the power required for processing 100 kg h⁻¹ coal at 40% solids in the bioreactor section is 4 × 5 = 20 kW h, i.e. 200 kW h per tonne dry coal.     

Augmentation,par régénération électrochimique du substrat,de la production d'une biomasse (thiobacillus ferrooxidans DSM 583) pour un procédé biologique de récupération de métaux

A bioelectrochemical reactor regenerates the substrate of the acidophilic bacterium Thiobacillus ferrooxidans DSM 583 (ferrous ions). This reactor uses a through-flow porous fixed bed or carbon as cathode. A linearizing non-linear regulator insures an efficient control of the intensity imposed to the electrochemical reactor. The protein concentration, correlated to the biomass concentration, is 6.4 fold increased for a 55 h growth, including a 20 h electrolysis. The metal tolerance and the metal fixation capacity of a T. ferrooxidans biomass are presented both for solutions including one or two metallic ions and an industrial waste. A bioelectrochemical process based on these characteristics is proposed for removing metal ions from wastes.