Research Bacteriocins From Bacillus Amyloliquefaciens Y-32-1

Bacteriocin which showed obvious micro-biostatic effects and strongantagonism for ribosomal ways, is synthesized by ribosomal ways. Bacteriocin haslots of advantages, such as the thermal stability, broad spectrum, no resistance, noremains, the certain nutrition, ect. Bacteriocin is the most effective substitute forantibiotics, and it has essential distinction with antibiotics. Bacteriocin is goodmaterial of the biological pesticides, health products, food, feed, cosmetic and sharea wide range application fields in the medicine, chemical, food processing, etc. Theresearch includes the following aspects: the screening of high-yield strains, theprimary study on the quality and structure of bacteriocin and the optimization of thefermentation conditions.First isolated from Yantai Aspergillus flavus severe contaminated with soilsamples to Escherichia coli, Staphylococcus aureus and Candida albicans haveantibacterial activity strains, named as Y-32-1，based on morphological features,physiological and biochemical test and related type species based on the16S rDNAdomain sequences, therefore strain was identified as Bacillus amyloliquefaciens.Y-32-1strains produced bacteriocins with good acid and alkali resistance, showfermentation broth pH value of1-13antibacterial activity; very stable to heat,fermentation broth boiling water bath for1.5h, without significant loss of activity;not sensitive to trypsin, sensitive lipase, description of the bacteriocins may containester bonds.Based on the single factor experiments, follows by Plackett-Burman design andresponse surface analysis, fermentation conditions were determined as and theoptimal medium composition: seed age20h, inoculation arnount5%, mediumvolume70mL/250mL, temperature31.6℃, initial pH7.2, rotation speed120r/min,NaCl6g/L, corn steep liquor31.7g/L, molasses sugar2.0g/L, KH2PO45g/L, Na2HPO45g/L. After optimization of bacteriocins produced inhibition zone diameter24.6667mm, than before optimization improves12.16%.By acid precipitation, organic solvent extraction, column chromatography andother methods for Y-32-1strains by the bacteriocin bacteria were isolated andpurified, and the use of mass spectrometry electrospray ionization ions werecharacterized its structure.