利用太空搭载("神州七号"航天飞船)对可产生胞外多糖(EPS)的干酪乳杆菌LC2W进行了太空诱变。通过筛选得到3株产EPS能力提高幅度大,并且遗传稳定性较好的菌株LC2W-1、LC2W-2、LC2W-3。运用单因素实验和正交试验对EPS产量最高的LC2W-1进行发酵条件的优化,得到其在脱脂乳培养基中产生EPS的最佳条件为:葡萄糖4%,酵母提取物0.6%,发酵温度33℃,培养26 h。所得LC2W-1胞外多糖量为(276.76±7.34)mg/L,较未优化前提高44.54%,较未诱变的菌株则提高了104.93%。
Zhou Fang-fang
,
Wu Zheng-jun
,
Chen Chen The Technology Center of Bright Dairy & Food Co.
,
Ltd
,
Shanghai 00
,
China)
. 太空搭载高产胞外多糖乳酸菌菌株的选育及其发酵条件优化[J]. 食品与发酵工业, 2011
, 37(06)
: 35
-38
.
DOI: 10.13995/j.cnki.11-1802/ts.2011.06.018
Space mutation was carried out with an exopolysaccharide(EPS)-producing strain,Lactobacillus casei LC2W,by spaceship carried experiment of manned spacecraft Shenzhou-7.Three high-yielding EPS strains,LC2W-1,LC2W-2 and LC2W-3,had been screened out and also showed good genetic stability after cultivated for 10 generations.The fermentation conditions of LC2W-1 were optimized by means of single factor tests and orthogonal tests.The optimum conditions for synthesis of EPS by LC2W-1 were as follows: adding 4% glucose and 0.6% yeast extract into the skimmed milk medium and cultured at 33℃for 26h.Under these conditions,the yield of EPS could reach(276.76±7.34) mg/L,which was increased by 44.54% and 104.93% compared with that produced by the mutant and original strain,respectively.
