Abstract

An acidity-tolerant, aluminum resistant bacterium was isolated from tea soils in Kagoshima Experimental Station (Japan). Based on the morphological, physiological and biochemical characteristics and 16S rDNA nucleotide sequence analysis, the bacterium was identified as Bacillus sp. An 3 (DQ234657) in Bacillus cereus group. The bacterium was able to grow on S-LB plates (pH 3.7) with 1.0 g/L Al and survived in LB broth even at 10 g/L Al (pH 2.0). While cultured, the growth of the bacterial strain in LB liquid medium containing increasing concentrations of Al (0, 100 and 200 ppm), was inhibited by the presence of Al, especially at concentration of 200 ppm. The pH of culture medium without Al increased steeply and reached pH 7.0 after 10 days, meanwhile it was almost constant in the other cases. The elimination of Al from culture medium by the bacterium was also affirmed and it was more conspicuous at 100 ppm Al. Due to their tolerance to high acidity, resistance to and removal of a substantial amount of Al, the bacterium might be applicable in restoring acidic soils, particularly acidified tea garden soils.

Key words: Tea garden soil, acidity-tolerant bacterium, aluminum-resistant bacterium.