摘要
为了研究乳酸菌高产EPS的条件,以产EPS量为指标,从8种复合菌株中筛选出1株嗜热链球菌,通过单因素和正交试验对该菌EPS合成培养基中的碳源、氮源、培养条件进行了研究。结果显示:该菌在优化的培养基中EPS生成量可达到145.48mg/L;合成胞外多糖最适培养条件为:接种量2%,初始pH6.5,发酵温度34℃,发酵时间36h。在此条件下EPS生产量可高达270mg/L,提高了116%。因此氮源组合和pH值为影响EPS合成的显著因素(p<0.05)。在恒定pH值条件下发酵培养可以提高EPS的生成量,即474mg/L,又提高了72%。
In order to study conditions of highly EPS-producing, an S. thermophilus was selected as the strains for the production of EPS from 8 compound lactic acid bacterias using EPS-producting capacity as index. The single factor and the orthogonal trial on the optimization of carbon and nitrogen source in medium and culture condition for S. thermophilus were also carried out in this paper. The result showed that the EPS-producing capacity of this strain was 145,48mg/L cultured in the optimal medium; the best culture conditions for EPS-producing were： inoculation rate was 2%, fermentation at 34 ℃ and initial pH 6.5 for 36 h. Under these conditions the EPS-producing capacity was enhanced to about 270 mg/L, raise 116%; Conclusion： nitrogen source and pH were significantly influential factors for EPS producing （p〈0.05）, the EPS-producing capacity was further enhanced to 474 mg/L, raise again about 72% by the culture at maintained pH 6.5.
出处
《中国食品学报》
EI
CAS
CSCD
2007年第3期64-68,共5页
Journal of Chinese Institute Of Food Science and Technology
基金
黑龙江省博士后科学基金资助项目(LRB00085)
