盐度和营养限制对盐生隐杆藻生长和胞外多糖产率的影响

EFFECTS OF SALINITY AND NUTRITIONAL LIMITATION ON THE GROWTH AND EXOPOLYSACCHARIDE PRODUCTION OF APHANOTHECE HALOPHYTICA

盐生隐杆藻在整个生长期内都不断地释放胞外多糖 ,而且进入静止期后释放量增大 .盐生隐杆藻胞外多糖的不断释放 ,使培养液相对粘度不断增加 .0 .75mol/LNaCl盐度是盐生隐杆藻生长和释放胞外多糖的最适盐度 ,更高或更低的盐度不利于生长和胞外多糖的释放 ,营养限制对盐生隐杆藻生长的影响从大到小为 :NO3- >Mg2 +>K+>Ca2 +>SO4 2 - >PO4 3 - .从每个藻细胞胞外多糖的产率看 ,Mg2 +、Ca2 +、K+营养限制有利于胞外多糖的释放 ,PO4 3 - 营养限制严重抑制了胞外多糖的释放 ,SO2 - 4、NO3- 营养限制对胞外多糖的释放影响不大 .研究结果将有助于盐业生产中两大难题的解决 。

Aphanothece halophytica continuously releases exopolysaccharide during growth phase. The exopolysaccharide productivity increases during stationary phase. Increased relative viscosity is observed owing to the continuous release of exopolysaccharide. 0.75?mol/L NaCl level is the best level for growth and exopolysaccharide production of A. halophytica. Higher or lower NaCl levels are not suitable for growth and exopolysaccharide production. Influence of nutritional limitation on growth of A. halophytica is: NO 3 ->Mg 2+ >K +>Ca 2+ >SO 4 2- >PO 4 3- . Mg 2+ ,Ca 2+ and K + limitation causes an increase in exopolysaccharide productivity per cell. Exopolysaccharide productivity per cell is seriously inhibited by PO 4 3- limitation. Influence of SO 4 2- and NO 3 - limitation on exopolysaccharide productivity per cell is not obvious. These results would help to solve the 2 key problems in salt production and benefit the exploitation of A. halophytica .