Screening of different media for sporulation of Bacillus megaterium

Abstract

Five different sporulation medium such as tryptone yeast extract (TYE) broth, tryptone glucose yeast extract
(TGYE) broth, minimal media, Sucrose salt medium, Arret & Krishbaum (AK)sporulation agar were screened for
spore production in Bacillus megaterium ATCC 9885. During this study, it was observed that out of different
combinations of tryptone, yeast extract and dextrose sporulation was maximum (70%) in tryptone yeast extract
broth. Effect of different salts on sporulation was studied by incorporation in TYE. It was observed that 41.7%
sporulation in KCl followed by CaCl2.2H2O, FeSO4.7H2O, MgSO4.7H2Oand MnSO4.7H2Orespectively. Maximum
sporulation (90 ± 0.6988%) was observed in AK sporulation agar with modified protocol followed by minimum
sporulation in minimal medium and sucrose salt medium respectively. Spores and vegetative cells of ATCC
9885 was observed under Andor EMCCD (Electron Multiplying charge coupled device) camera showed that
spores were arranged singly and small in size (2.8 ±0.2 µm2
) compared to vegetative cells that were in chains
and larger in size (4.0 ±0.2 µm2
). Spores of Bacillus megaterium ATCC 9885 produced in A. K. Sporulation
medium with modified protocol can be further utilized as bio-molecules for the development of bioassay for
monitoring non-bacterial contaminants in milk (Aflatoxin M1).