IDENTIFIKASI BAKTERI PEREDUKSI KROMIUM DARI TANAH SERPENTIN

Abstract

Serpentine soil is derived from the weathering of ultramafic rock that characterized by high levels of heavy metals such as Cr, Mn, Co, Ni, Mg, and Fe, but contain low levels iofessential elements, for examples Ca, N, and P. Serpentine soil of Mandiangin and Awang Bangkal of Kalimantan Selatan highly contains metals such as Cr, Ni, and Mn, which is a good source for heavy metalstolerant microbes for bioremediation development. Eight isolates obtained from the soil were able to grew on the LB agar containing 150-200 mg.L-1 of chromium hexavalent (Cr (VI)). The isoloates were confirmed able to reduce at least 90 % of Cr (VI) (30 ppm). Seven isolates have 16S rRNA gene DNA sequence which highly similar to B. cereus grup sequence including B. anthracis, B. thuringensis, B. myconoides, dan B. toyonensis. The sequence of 16S rRNA gene DNA of this grup is highly similar and differs only in a few of nucleotides. Another isolate has highly similar of 16S rRNA gene sequence to that of Acinetobacter radioresistens that known able to reduce chromium hexavalent with their chromate reductase.