纳米Fe_2O_3靶向鸡肉腐败菌光催化抑菌效能特性研究

Photocatalytic inactivation effects of nano-Fe_2O_3 on chicken spoilage bacteria under visible light

目的探索可见光下纳米Fe2O3对鸡肉腐败菌的光催化抑菌效能特性及机制。方法以Escherichia coli及鸡肉腐败菌Pseudomonas fluorescens和Macrococcus caseolyticus为受试菌株,可见光照为激发条件,研究纳米Fe2O3对细菌菌落数量和菌体脂质氧化程度的影响。结果纳米Fe2O3在可见光下能够有效抑制E.coli、P.fluorescens和M.caseolyticus生长繁殖,1.2 mmol/L的H2O2能够增强Fe2O3的光催化抑菌活性;当Fe2O3质量浓度为0.4 g/L时,对P.fluorescens和M.caseolyticus的抑菌作用效果最强;在光催化过程中,P.fluorescens和M.caseolyticu的脂质氧化值随着反应时间延长呈先升高后降低的趋势,在120 min分别达到最大值1.31nmol/mg(细胞干重)和2.14 nmol/mg(细胞干重)。结论可见光条件下,M.caseolyticus对光催化反应比P.fluorescens更加敏感,纳米Fe2O3先引起细菌体内脂质氧化,进而导致菌体细胞破裂而死亡。

Objective To study photocatalytic inactivation effects of nano-Fe2O3 on chicken spoilage bacteria and its mechanism under visible light. Method Escherichia coli, Pseudomonas fluorescens and Macrococcus caseolyticus, isolated from spoilage chicken carcass, were taken as main materials, and bacteria colony number and lipid oxidation were measured. Results Nano-Fe2O3 showed good disinfection effects to E. coli, P. fluorescens and M. caseolyticus under visible light, 1.2 mmol/L H2O2 could enhance the photocatalytic inactivation of nano-Fe2O3. It reached the highest disinfection effects to both P. fluorescens and M. caseolyticuswhen concentration of Fe2O3 was 0.4 g/L. The lipid oxidation of both P. fluorescens and M. caseolyticus were increased at first and decreased with time prolonging, the highes values of lipid oxidation of P. fluorescens and M. caseolyticus were 1.31 nmol/mg(cell dry weight) and 2.14 nmol/mg(cell dry weght) respectively at 120 min. Conclusion It indicated that M. caseolyticus was more sensitive to nano-Fe2O3 than P. fluorescens, and lipids oxidation of bacteria cells were first carried out during photocatalytic processing then caused the death of cells.