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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 explore the photocatalytic antibacterial efficacy and mechanism of nanometer Fe2O3 on spoilage chicken under visible light. Methods Escherichia coli and spoilage bacteria Pseudomonas fluorescens and Macrococcus caseolyticus were used as tested strains. The effect of Fe2O3 on the number of bacterial colonies and the degree of lipid oxidation of the cells was studied under light irradiation conditions. Results The nano-Fe2O3 could effectively inhibit the growth and proliferation of E.coli, P. fluorescens and M. caseolyticus in the presence of visible light, and 1.2 mmol / L of H2O2 could enhance the photocatalytic activity of Fe2O3. When the mass concentration of Fe2O3 was 0.4 g / L, P.fluorescens and M. celluolyticus had the strongest bacteriostasis effect. During the photocatalysis, the lipid oxidation values of P.fluorescens and M. celluolyticu increased first and then decreased with the extension of reaction time, min reached a maximum of 1.31 nmol / mg (dry cell weight) and 2.14 nmol / mg (dry cell weight), respectively. Conclusion Under visible light conditions, the photocatalytic reaction of M. celluolyticus is more sensitive than P. fluorescens. The nano-Fe2O3 causes the oxidation of lipid in bacteria, which leads to cell rupture and death.