关键词: 双歧杆菌；南瓜；响应面；富硒

Abstract:

In order to manufacture low cost, selenium-rich bifidobacterium preparation with effect of biostime, this paper took pumpkin as principal raw material, optimized the best culture medium formula through response surface methodology, and inspected a variety of bifidobacterium growth in optimul culture medium and selenium-rich ability. The result indicated that when the culture medium contained pumpkin juice 16.09%, soya peptone 3.24% and cysteine hydrochloride 0.28‰, the viable number of animal live Bifidobacterium 01 could reach 9.37±0.08 lgCFU/mL, which was higher than that cultured in medium MRS, GMRS, PYG and TPY. Cultured in the above mentioned optimal pumpkin juce medium, the contents of organic selenium in B. animalis, B. infantis, B.longum, B. adolescentis, B. bifidum, B. lactic and B. pseudocatenulatum were varied from 13.20±0.39~78.11±0.42 μg/g bacteria. The conversion rates of organic selenium were 1.76%~6.41%. The obtained Bifidobacterium taking pumpkin juice and skimmed milk as protective agent could achieve 70.8%±0.5% freeze-drying viability. The results proved that pumpkin was a promising substrate as cryoprotectant for Bifidobacterium spp. This study provided theoretical basis for manufacturing selenium-rich Bifidobacterium spp. pumpkin powder.

Key words: bifidobacterium, pumpkin, response surface, selenium enrichment