Natural Bacteriostatic Agent On Osmophilic Yeast Killing Effect

The antibacterial activity of the plant source,23 kinds of natural antibacterial animal and microbial sources three sources of Zygosaccharomyces rouxii agent has been studed.Agar diffusion method was used to determine,according to the diameter of inhibition zone antibacterial activity of 23 kinds of antimicrobial agents;Determination of Zygosaccharomyces rouxii with minimal inhibitory concentration of antibacterial activity of antibacterial agents was two times dilution method(Minimum inhibitory concentration,MIC),selected from the inhibitory effect of two kinds of colorless,tasteless,best security food grade natural non-toxic bacteriostatic agent.(1)For the determination of Zygosaccharomyces rouxii colorimetry culture medium and fruit juice in YPD;in different proportion with fruit juice has access to Lu’s engagement in yeast,and the colorimetric method were used to determine two kinds of antimicrobial agents and their effects in the juice to observe the growth status of Zygosaccharomyces rouxii in the different proportion of research;The effect of citric acid concentration,temperature and UV irradiation time on the stability of antibacterial composite antibacterial agent.(2)Study of natamycin and ε-polylysine on Zygosaccharomyces rouxii antibacterial activity to two kinds of antimicrobial agents respectively and with different proportion is added to the apple juice,through the determination of growth curve,when the research on the synergistic effect of Zygosaccharomyces rouxii growth in fruit juice in bacteriostatic agent on the growth of and two kinds of antibacterial agents,will be satisfied natamycin andε-polylysine blend composite antibacterial agent,its research on Zygosaccharomyces rouxii antibacterial mechanism,by measuring the conductivity,cellular material leakage,the content of soluble protein in bacteria,SEM and GC-MS.(3)Study on the concentration of apple juice storage change sensory index,physical and chemical indicators and microbiological indicators in different time in the juice add antibacterial agent and antibacterial agent without treatment.The research results show that the Zygosaccharomyces rouxii engage more botanical antibacterial agent type had bacteriostasis,microbial source of antimicrobial agents on animal species Zygosaccharomyces rouxii had inhibitory effect at least,but the inhibitory effect of microbial antibacterial agents on Zygosaccharomyces rouxii best;Zygosaccharomyces rouxii engagement can grow better in YPD yeast in fruit juice;Screening of natamycin andε-polylysine two kinds of microbial antibacterial agents,and compounded by the determination of the growth curve showed that natamycin in the juice of MIC is 4 μg/m L,poly-L-lysine in the juice of MIC is 20 μg/m L,when natamycin: ε-polylysine=7:3,inhibitory effect was the best compound bacteriostatic agent MIC is 1 μg/ ML,the FIC=0.3<1.00,so they have synergistic effect;With the increase of citric acid concentration,the antibacterial activity of composite antibacterial agents decreased gradually,with the increase of heat treatment temperature,the antibacterial activity of composite antibacterial agents decreased gradually,with increasing irradiation time,the antibacterial activity of composite antibacterial agents decreased slightly,but the trend is not obvious.Natamycin can inhibit and kill Zygosaccharomyces rouxii but did not destroy the cell membrane,the ε-polylysine kills Zygosaccharomyces rouxii mainly by destroying cell membrane leakage of intracellular substances leading to the death of the cell,the composite antibacterial agent also destroyed the cell membrane to intracellular substances leakage resulting in cell death.But the same dose of compound agent than the ε-poly-lysine damage more serious.The antibacterial mechanism of natamycin on Zygosaccharomyces rouxii need to do further research.Bacteriostatic agent apple Juice was added after 90 days after storage of corruption and a sour smell,produce swell,the juice quality of 1MIC did not change bacteriostat treatment,storage 30 days of microbial growth,when the 90 days storage with microbial growth and have a slightly sour smell of corruption and swell,2MIC and 3MIC treatment after 90 days of storage fruit juice quality and no microorganism has not changed,not too much to consider additive added principle,adding amount of 2MIC.