海藻酸钠降解菌的筛选及其发酵条件的优化

Isolation of a strain degrading sodium alginate and optimization of its fermentation conditions

从大连附近海域腐烂的海带中筛选得到一株能够降解海藻酸钠的菌株,经16S rDNA序列测定,该菌属于假交替单胞菌属(Pseudoalteromonas)。通过正交实验对其发酵条件进行优化,结果表明,该菌株的最佳产酶条件及培养基组成为(w/v):海藻酸钠0.7%,蛋白胨0.3%,NaCl2.5%,MgSO4·7H2O 0.025%,KH2PO4 0.5%,NaNO3 0.025%,FeSO4·7H2O 0.001%,pH7.2,接种量4%,转速180 r/min。条件优化后菌株酶活力达到51.498 U/mL,比优化前提高了11.5倍。

A strain degrading sodium alginate was isolated from the decayed sea weeds（Laminaria Japonica Aresch） in the sea area of Dalian, and it proved it belonged to the genus of Pseudoalteromonas by sequencing of 16 S rDNA. Then optimization of fermentation conditions were performed based on orthogonal experiments. The optimized condition was as followed（w/v）： sodium alginate 0.7%, peptone 0.3%, NaCl 2.5%, MgSO4？7H2O 0.025%, KH2PO4 0.5%, NaNO3 0.025%, FeSO4？7H2O 0.001%, pH at 7.2, with 4% inoculation and a rotation rate of 180 r/min. The activity of sodium alginate lyase under this condition reached 51.498 U/mL, which was 11.5 times higher than that before optimization.