Purification And Character Of Bacteriocin Produced By Bacillus Subtilis FB123

In the present study, bacteriocins produced by Bacillus subtilis FB123 were purified and characterized, and their primary structures were studied.A Bacillus spp FB123 with strong depuration capacity was selected among 5 strains based on their cleanse effects on the aquaculture wastewater. The strain was identified as a Bacillus subtilis and named as Bacillus subtilis FB123. The optimal media and culture condition for production bacteriocins by the strain was obtained by series single/double factors trials and orthogonal comparisons.Three types of bacteriocins (bacteriocin A, B and C) were separated and purified from the fermentation culture of Bacillus subtilis FB123 by steps of ammonium sulfate precipitation, Sephacryl S-200, DEAE Sepharose Fast Flow chromatography.Bacteriocin A was identified to be homogenous with SDS-PAGE, and its molecular weight and pI value were 54 kD and 5.24. Bacteriocin A was a glycoprotein based on the result of periodic acid schiff reaction (PAS) and not sensitive to the treatments of papain, trypsinase, alkaline proteinase. It showed good thermal stability, and kept activity within wide pH value. Bacteriocin A showed broad ranges of anti-microbiai activities not only to gram-positive and negative bacteria but, also to some fungi. The activity of Bacteriocin A could be increased by Fe²⁺,Zn²⁺, Al³⁺ and Ca²⁺, and be inhibited by Mg²⁺,K⁺ and Cu²⁺.Bacteriocin B was identified to be homogenous too with SDS-PAGE and with a molecular weight of 25 KD. It was also a glycoprotein indicated by the result of PAS.Bacteriocin C might be a kind of fat suggested by phosphomolybdic acid color test. Bacteriocin C was not sensitive to the treatments with papain, trypsinase, alkaline proteinase, and showed highly heat sensitivity.