Nguyen Van Giang, To Thi Hoai, Vuong Minh Trang, Khuat Huu Trung, Tran Dang Xuan, Vu Xuan Duong, Pham Khanh Huyen, Vu Thi Ngoc Diep, Nguyen Thanh Trung, Tran Dang Khanh and Pham Thi Ly Thu

DOI: 

Potassium (K) is the third essential macroelement for plant growth after nitrogen and phosphorous. However, over 90% K exists in the soils is insoluble mineral form that is unavailable for plants uptake. Soil bacteria can dissolve potassium from insoluble K-bearing minerals. This study was carried out with aims to characterize potassium solubilizing bacteria isolated from soils. Form different soil samples collected from 4 different provinces where eleven bacterial strains of potassium solubilizing bacteria were isolated on Aleksandrov containing potassium aluminiumaluminum silicate media. Among them, two strains namely C1.1 and YN3 showed significant potassium solubilizing capacity based on the potassium solubilizing index. They caused maximum potassium solubilization when they were cultured in medium with pH.7.0, temperature 30°C, and KCl was used as a potassium source. Strain C1.1 was identified as Burkholderia sp. based on the nucleotide sequence of 16S rRNA, and named as Burkholderia sp. C1.1. The results have provided useful information on the cultural conditions of potassium solubilizing bacteria for sustainable agriculture system.

Keywords: Potassium, Potassium-solubilizing bacteria (KSB), solubilisation index, solubilisation effect. 

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