Isolation and characterization of silicate-solubilizing bacteria from paddy rhizosphere (Oryza sativa L.)

Abstract

Silicate is known as a beneficial element that has important role for growth and development of paddy. Paddy is the greatest accumulator of Si up to 10% of its dry weight, but this plant can't absorb that element by itself. The uses of paddy rhizosphere bacteria as a silicate solubilizing agent should be studied furthermore. This study aims to isolate and characterize silicate bacteria from paddy rhizosphere that solubilize silicate optimally in Bunt and Rovira medium. The isolation, qualitative, quantitative test and characterization of silicate bacteria up to 39 characters, which is include of colony morphological, cell morphological and physiological-biochemical test. This study was conducted on February-June 2018 in Microbiology Laboratory and Plant Physiology Laboratory, Faculty of Mathematics and Natural Sciences, State University of Surabaya. Five isolates silicate solubilizing bacteria were found OS4, OS5, OS7, OS12 and OS13. The highest Solubilizing Index was gained by OS7 on 1,10, while the highest silicate concentration was solubilized by OS12 on 1,053 ppm in Bunt and Rovira broth.