جداسازي و تعيين ويژگي باكتري مارپيچي"لپتوسپيريلوم مانند اكسيد كنندة آهن" از معدن ذغال سنگ ناحيه زيرآب و سنجش فروشويي كاني سولفيدي باما توسط آن

Isolation and characterization of iron-oxidizing, "Leptospirillum-like" bacterium, from Zirab

In this research, mineral samples from Zirab coal mines were collected for isolating of native spiral acidophilic strains. The samples were cultured at DSMZ 882 and the isolation and enrichment processes has been done at 2:2 and DSMZ 882 medium. A Ferrous oxidizing "Leptospirillum-like" bacterium isolated from these samples. Bamaʹs zinc & lead bear sulfidic ore were applied for bioleaching purposes and also for the strain adaptation. Then, the best growth conditions were obtained after determination of pH, rh values and ferrous ion concentrations. The factors included temperature, mesh size, shaking rate and time. A General Linear Model used for statistical analysis of the results. The bacterium showed best growth at ore mesh size: 100, temp: 35 C, shaking rate: 200 rpm during the 3 days. Then, Bamaʹs ore was leached in shake flasks for 20 days and was used from atomic absorption spectroscopy for liquid samples, XRD & XRF methods for leached ore analysis. Results showed 76.87% enhancement in amount of zinc at Bamaʹs leaching solution, compared to 26.35% for control. Furthermore, amount of lead in this solution showed 85% reduction that compared to 30.91% for control at the same time and there was a significant difference (p<0.01) among experiments. Bamaʹs ore XRD analysis showed an elimination of sphalerite [card No 3-524] exactly by agitation leaching at 8 days, compared to a slight reduction of control, and XRF comparative analysis showed 81.35% (W%) zinc reduction. Thereupon, LLB-ZS is an effective strain for zinc recovery from the related sulfidic ores and a lead detoxifier. Keywords: "Leptospirillum-like" bacterium, Zirab coal mine, Isolation, Bama Sulfidic ore, Agitation leaching