INTRODUCTION. The excessive application of ammonium sulfate fertilizer in tea soils to increase yield and improve quality of green tea products might lower soil pH to 4.0 or even under. This makes Al in the soils more soluble, and thus may be harmful for tea consumers and activity of soil microbes. This study seeks to fill the gap of less-known microbial ecology in this extreme environment, with purpose to contribute to improve the mentioned situation. METHODS. Soils were collected from tea gardens at the Kagoshima Tea Experimental Station (Japan). The pH (H20) was measured with a glass electrode and expressed as the ratio of air-dried soil to solution, 1: 2.5. The soluble Al in soils was extracted with pure water (Iwasaki et al. 1993) and quantified by ICP-MS analysis. Aluminum sulfate solution was filter-sterilized and added to the S-LB medium autoclaved to reach a certain Al concentration. Bacteria were isolated by dilution agar method on these S-LB plates. The morphology was observed with optical microscope, physiology and biochemistry was tested using API 50 CHB kit and phylogeny was based on 16S rDNA nucleotide sequence analysis. The spent culture supernatant was separated by centrifugation at 12,000 rpm for 10 min, then filtered with a sterilized-filter, diluted with 1% HNO3 and subjected to ICP-MS analysis to determine the amount of remained Al. RESULTS. From soils with high acidity (pH 2.69- 4.18) and content of soluble Al (1.03- 9.51 mM kg-1), acidity-tolerant and Al-resistant bacteria were isolated. Based on morphological, physiological, biochemical and genetic characteristics, the selected bacterium was identified as Bacillus sp. An 3 (accession number DQ234657) contained in Bacillus cereus group and related to Bacillus cereus, Bacillus weihenstephanensis or Bacillus thuringiensis. It could grow on S-LB plates (pH 3.7) with 1.0 g L-1 Al and survive in LB broth even at 10 g L-1 Al (pH 2.0). While culture the bacterial strain in LB liquid medium containing increasing concentrations of Al (0, 100 and 200 ppm), their growth was inhibited by the presence of Al, especially at concentration of 200 ppm. It is possible due to Al's toxicity to bacteria at high content. 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. This might relate to existence of Al mechanisms. The elimination of Al from culture medium by the bacterium was also affirmed and it was more conspicuous at 100 ppm Al. CONCLUSION. Due to tolerance to high acidity, resistance to and removal of a substantial amount of Al from culture media, the bacterium may be applicable in improving acidified tea soils.