While isolation of bacteria. Those colonies appeared after 24 hour can inhibit growth of other microorganisms though these do not have non-antibiotic characteristics. Is it possible? If yes what are these?
YES, it is possible, because many bacteria are capable to púroduce various peptides and some other compounds with anitabcterial activity. Such bacteria can be various Bacillus spp. Please see for eaxmple the following paper:
Article A Broad-Spectrum Antimicrobial Activity of Bacillus subtilis RLID 12.1