Optimization Of Culture Conditions For Antifungal Lactic Acid Bacteria And Application In Whey Abtisepsis

Antifungal lactic acid bacteria themselves or metabolites have a certain inhibitory effect on fungi.In fermented foods,they are both a starter and a natural preservative,which meet the requirements of people for green safe food and have the value of development and application.Firstly,this paper uses 24 strains of lactic acid bacteria as materials and 5kinds of fungi as indicator bacteria;5 excellent antifungal lactic acid bacteria are obtained.Secondly,the optimum culture conditions for the high-yield antifungal substances of five antifungal lactic acid bacteria were optimized by single factor experiment and response surface methodology.Finally,an antifungal lactic acid bacteria was selected for use in the fermented whey beverage to improve the antiseptic ability of the product.The experimental results are as follows:1.Pichia pastoris,Aspergillus niger,Geotrichum candidum,Kluyveromyces cerevisiae,Penicillium chrysogenum,5 fungi as indicator bacteria It was learned that Lactobacillus paracasei N22,Lactobacillusplantarum N27,P10,N7,Lactobacillus rhamnosus N14 had better antifungal effect.2.The optimal nitrogen source,carbon source,culture time,culture temperature and initial pH value of antifungal lactic acid bacteria were obtained by single factor experiment.3,Screening found that N22 inhibition Pichia pastoris,N14 inhibition Aspergillus niger,P10 inhibition P.chrysogenum BBCC336234,N27 and N7 inhibition Kluyveromyces cerevisiae better antibacterial effect.The response surface method was further used to optimize the optimal culture conditions.4.Kluyveromyces cerevisiae is one of the causes of whey beverage spoil-age,so Lactobacillus plantarum N7 was selected for the development of fermented whey beverage.The results showed that the addition of N7 po-wder or N7 culture supernatant powder can inhibit the K.cerevisiae in the whey,maintain the good flavor of the whey beverage and improve the product quality.