Selective Enrichment Method for Isolation of Efficient Phosphate Solubilizing Bacteria from Soil

Abstract

ABSTRACT Isolation and screening of phosphate solubilizing bacteria (PSB) seems to become cumbersome using conventional methods, and there may be a chance to lose the more potent isolates during the screening methodology. To overcome these problems, a selective enrichment method has been developed to isolate and screen efficient PSB from diverse sources. Initially, this method includes enrichment of the phosphate solubilizers in the sample followed by selective isolation and screening. Looking into the physico-chemical data, it was revealed that the soil samples from cultivated soil were found to support growth and development of microbial life in general compared to soil samples from non-cultivated stringent environment, which was reflected in number of PSB isolated, or in some samples, PSB may not be obtained. Here, the selective enrichment method developed for isolation of PSB from stringent environmental samples yielded numerically higher number (14) of phosphate solubilizer isolates in comparison to conventional methods (4) from different soil sources. Moreover, isolates obtained following selective enrichment were found consistence for phosphate solubilization in different conditions and for different sources. In contrast to conventional isolation methodologies, the selective enrichment method consistently performed best for PSB isolation particularly from stringent habitats, i.e. mining region where conventional method/s did not perform well.