Effects Of Lactic Acid Bacteria From Viili On The Lifespan Of Caenorhabditis Elegans

In order to study physiological function of Viili and lactic acid bacteria, lactobacterias were isolated and preliminarily identified, and evaluated the anti-age effect of lactobacterias isolated using physiological property of Caenorhabditis elegans (C.elegans). Experiment expanded the research field of physiological function of lactobacteria, as well as provided basis for development of functional yoghourt.Nine strains of lactic acid bacterial were isolated from the traditional Finnish yoghourt, Viili. According to the morphological characters, physiological and biochemical reaction, they were identified as:Lacl, Lac2were Lactococcus lactis subsp. Lactis; Lac4, Lac5were Lactococcus lactis subsp. Cremoris; Lac3, Lac7were Leuconostoc mesenteroides subsp. Cremoris; Lac6, Lac8, Lac9were Streptoccus thermophiluocs.Inhibiting pathogenic bacterium test of leavening and metabolite of Lacl, Lac4, Lac7isolated showed that leavening and metabolite had antagonistic activity to Escherichia cloi, Staphylococcus aureus, Proteus vulgaris, Bacillus cereous, Bacillus subtilis, Salmonella.In order to evaluate the anti-aging effect of leavening and metabolite of Lacl, Lac4, Lac7isolated we selected C.elegans as our experimental model, which is the premier model for aging research. Compared with E.coli OP50as food, the isolates of LAB, Lactococcus lactis subsp. Lactis (Lacl), Lactococcus lactis subsp. cremoris (Lac4) and Leuconostoc mesenteroides subsp. cremoris (Lac7) increased the mean lifespan of C.elegans by26.973%～31.562%, and maximum lifespan by14.817%～36.111%. In addition, metabolite of Lacl, Lac4, Lac7also increased the mean lifespan and maximum lifespan of C.elegans. With the increasing concentration, the effect of anti-aging was enhanced.The experiments of treating C.elegans by acute heat showed that metabolite of Lacl, Lac4, Lac7lifted the stress resistance ability of C.elegans significantly. Compared to the control group, metabolite(100mg/L) increased mean survival time at35℃by14.400%～18.400%.Through orthogonal experimental design decided optimized technology condition of fermentation yoghourt using Lac4and Lac7. The test result showed that with sensory evaluation and acidity as index, optimized technology condition is Lac4and Lac7as2:1, addition of3%, temperature as27℃, fermentation time as16h.