Correlation Between Numerical Profiles Generated for Soil Spore Forming Bacilli and Their Inhibitory Potential Against Staphylococcus aureus ATCC 6538

Numerical profiling using conventional tests for studying bacterial diversity of soil have probably never been employed. The main objective of this work was to describe the heterogeneity of spore forming bacilli in a vegetative soil using numerical profiling and to establish the possible application of this approach for the prediction of the antimicrobial potentials of soil dwelling Bacillus species. A total of 100 spore forming Gram positive bacilli were recovered from soil samples and their characters were determined using 9 conventional tests. A 3 digit numerical profile was constructed for each isolate. This labelling system resulted in the generation of 12 different profiles which indicated the diversity of soil Bacillus isolates. The highest frequency of occurrence was detected among the isolates labelled with the profile 4.1.5 and the lowest among those labelled with 4.7.5; 4.6.6 and 1.0.3 profiles. Out of 13 isolates labelled with 4.4.3, the cell free extract of 12 exhibited no antimicrobial activity against Staphylococcus aureus ATCC 6538 whereas, extracts obtained from 15 out of 18 isolates labelled with the profile 4.1.5 were inhibitory to the test organism. It is concluded that the numerical profiling system is a significant tool for the establishment of diversity among soil spore forming bacilli which can also be used for the prediction of the potentials of isolates to produce antimicrobial metabolites.