Detection of endospore producing Bacillus species from commercial probiotics and their preliminary microbiological characterization

Abstract

Aim : The main objective of the study was to characterize a mixture of bacterial species, found in commercial probiotic preparation and originally designed for cleaning, biodegradation and wastewater treatment. Methodology : Lyophilized preparation of environmental strains was microbiologically characterized to determine the growth temperature range, pH resistance and boiling temperature survivability. Gram staining and Wirtz's spores staining were performed for microscopic estimation of cell morphology and sporulation. The MALDI-TOF mass spectrometry method was used to identify bacterial species found in thepreparation. Results: The composition ofprobiotic bacterial species, isolated from commercial lyophilized preparation, exhibited wide range of growth temperatures, extreme boiling survivability and wide range of pH survivability. The isolated species belonged to Bacillus genus, Gram positive and sporulating rods. MALDI-TOF bacterial identification method was carried out for detection of four non-pathogenic, environmental, closely related strains: Bacillus subtilis, Bacillus mojavensis, Bacillus vallismortis and Bacillus pumilus. Interpretation : The endospore producing environmental Bacillus species were detected in commercial probiotics and preliminary characterised. The results of the present study, point out the possible applications ofthe described Bacillus sp. mixture in health, food and cleaning technologies, involving high temperaturesorhigh/lowpH processes.