Microcosom investigation of Mn mobilization in basalt rock by potential bacteria R6 from Carlsberg ridge ecosystem

Abstract

The biomining can happen in basalt rocks from ridges which contains around 25% Mn in the form of different minerals and oxides due to deep sea hydrothermal activity. The prime goal of this experiment was to demonstrate Mn mobilization from natural Mn minerals and oxides using striping voltammetry from basalt near deep-sea hydrothermal vents (DSHVs) by a potential bacterial isolate R6 which was isolated from this environment. Natural basalt sample was collected from the carls berg ridge during ABP-36 cruise and was characterized by scanning electron microscopy (SEM) and X-ray diffractometry. Bacterial isolation was done in laboratory by spread plate method using 100 muM Mn amended NA media plates. Isolated bacteria R6 (Accsession No. LK934696) and basalt sample were used in a laboratory batch experiment. The isolate R6 (identified as marine Bacteria Imtechella halotolerans sp.) and natural basalt rock were placed in 100 persent seawater in the presence and absence of an organic carbon supplement as 0.01% glucose (analogous abiotic and chemical controls systems were also included). This laboratory batch experiment was incubated in the dark at 28 plus or minus 2 degrees C for 6 months and cell bio mass, pH, Eh and concentrations of mobilized Mn ions were measured over time. The presence of the bacteria induced the release of Mn from the basalt relative to the controls, especially with the addition of the organic carbon supplement. Bacteria was able to draw significant mobilization rate 27985.91 and 4797.37 mu g sup(-1) d sup(-1) with and without glucose added in biological experiment part when compared with abiotic and chemical controls. Bacterial colonies on the basalt fragments surfaces were examined by SEM which shows evidence of extrapolysaccherides secretion and mineral precipitation. The results of this study suggest that chemoorganotrophic bacteria are involved in the cycling of Mn mobilization in basalt near DSHVs.