Determination of Phosphate and Potassium Solubilizing Bacteria from Weathered Materials of Denatured Rock Mountain, HaTien, KienGiang Province, Vietnam

Phosporus (P) and potassium (K) are the major essential macronutrients for plants. Utilization of bio-fertilizers contained phosphate and potassium solubilizing bacteria is an alternative solution to maintain the available P and K in the soil. In order to develop such as bio-fertilizer, it is necessary to find out phosphate- and potassium-solubilizing bacteria from weathered materials of denatured rock mountain. Twenty-five strains were isolated on modified Aleksandrov medium from samples of soils/weathered rocks of HaTien Mountain, KienGiang, Vietnam. Their colonies were round or irregular, white to yellow and their cells were rod-shaped and motile. Seventeen of twenty-five bacterial strains were identified by PCR technique with specific primers fd1 and rP, showed that they were capable of dissolving both phosphate and potassium. Among of them, the seven strains had high phosphate and potassium dissolution capacites (>10 mgL-1 P2O5 and >50 mgL-1 K2O) effectively. The seven strains were chosen to sequence DNAs and then compared with GenBank database of NCBI by BLAST N software. The results showed that DNV16 strain was 99.30 % of identity with Microbacterium trichothecenolyticum strain A3RC1 (JQ689178); TC1D strain was 99.27 % of identity with Flectobacillus rhizosphaerae strain PeD7 (MN258894); CH9E strain was 99.43 % of identity with Agrobacterium tumefaciens strain ICMP5856 (KX621317); TC1A strain was 99.90 % of identity with Bacillus paramycoides strain 2914 (MT611870); CH7D strain was 99.88% of identity with Bacillus megaterium strain LCR107 (FJ976616); TD6B strain was 99.81 % of identiy with Bacillus subtilis strain R0-14 (MN330151) and CH7A strain 99.80 % with Bacillus albus strain FORCN138 (MW363338). The strain TC1A was the high phosphate and potassium solubilizing ability and its potential for use in bio-fertilizer prodution in the future.