Microbial selection of indigenous phosphate solubilizing microbe of tidal land as an inoculant in biochar

This study was aimed to obtain phosphate solubilizing microorganism (PSM) isolates, which can be tolerant high Al and Fe content and low pH, to be utilized as an inoculant in biochar. Microbial isolation of indigenous PSMs was carried out on intertidal zone, with samples from four typological landscape (A, B, C, and D) collected from four villages in Delta Telang, Banyuasin, South Sumatra. The isolates that produced clear zones were purified and assayed with varying levels of AlPO 4 , FePO 4 , and pH. The selected PSM isolate was further tested to evaluate the phosphate-dissolving ability with liquid Pikovskaya media. The microbes obtained were three bacterial isolates and one phosphate-solubilizing fungus, which were identified as Paenibacillus alvei, Burkholderia cepacia, Acinetobacter baumannii, and Penicillium variabile . The identified microbes were tolerant to Al and Fe at concentrations up to 1500 mg L -1 and pH 3.0. Mixed cultures of the four isolates on liquid Pikovskaya media were able to dissolve Ca 3 (PO 4 ) 2 at 57.45 mg L -1 , AlPO 4 at 13.98 mg L -1 and FePO 4 at 8.46 mg L -1 . PSM viability on four types of biochar after three months of storage ranged from log population of 1.57 x 10 8 –1.73 x 10 9 (log population 8.20–10.23 CFU g -1 ). The highest PSM viability was obtained in coconut shell biochar.