SOLIDIFICATION OF SANDY SOIL AND ITS MICROSTRUCTURE BY MICROORGANISMS COLLECTED FROM THE COASTAL AREA OF OKINAWA ISLAND, JAPAN

Abstract

 Microbially induced carbonate precipitation (MICP) can bind discretized soil particles and improve soil strength and bearing capacity. When microorganisms are added to the actual environment, it is desirable to use indigenous microorganisms in consideration of their impact on the surrounding ecosystem. However, little study has been conducted on stocking indigenous microorganisms useful for soil solidification as microbial resources. Hence, in order to apply MICP technology using indigenous microorganisms to the Okinawa region, this study collected a number of microorganisms from the actual environment and identified useful microorganisms in the Okinawa region through simple solidification experiments and 16S rRNA analysis of the bacterial flora. The results confirmed the presence of useful microorganisms at all sampling sites. Interestingly, the degree of solidification varied between the sampling sites. Additionally, phylogenetic tree analysis revealed that microorganisms useful for soil stabilization had relatively closely related DNA sequences.