ABILITY TO DISSOLVE MANY INSOLUBLE ZINC-BEARING MINERALS OF INDIGENOUS RHIZOBACTERIA

Zinc solubilizing bacteria (ZSB) have been considered as one of the green solutions to improve the deficiency of availability zinc in soil which have been appearing in many farms in the world. In Vietnam, studies on ZSB have not received researchers' attention even though ZSB have been widely present in many different soil types. The aim of this study was to create an initial collection of indigenous ZSBs for future studies. The results collected twenty-nine ZSB isolates by isolation on Zinc Solubilizing Agar. The three screened strains included Đ2, TG2, and TG6.2 with high ability to dissolve ZnO with solubility index of 5.87, 3.42 and 3.81, respectively. The strain TG2 also had an additional high ability to solubilize ZnSO4 and ZnCO3 with solubility indexes of 2.58 and 5.39, respectively. The two strains Đ2 and TG6.2 had more high ability to dissolve both ZnSO4, Zn3(PO4)2 and ZnCO3 with SI values ​​of 6.17 and 3.80, 2.20 and 4.19, 5.30 and 4.32, respectively. The three strains were identified as Serratia sp., Pseudomonas aeruginosa, and Acinetobacter sp., respectively, by the specific protein springers. This was the first report on ZSB in Vietnam and the collection included the potential strains due to the high solubility in a wide range of insoluble zinc-bearing minerals.