霍山石斛类原球茎在气升式反应器中补料培养合成多糖

Fed-batch Cultivation of Protocorm-like Bodies of Dendrobium huoshanense for Producing Polysaccharides in an Air-lift Bioreactor

在10 L气升式反应器中进行了霍山石斛类原球茎悬浮培养．研究了接种量、通气量、碳、磷等营养成分对霍山石斛类原球茎生长和多糖合成的影响．在接种量为100 g/L(鲜重)、通气量为0．5 L/min时,30 g/L的蔗糖、2．5 mmol/L的磷酸盐有利于类原球茎生长,而0．312 mmol/L的磷酸盐有利于多糖积累．根据霍山石斛类原球茎生长和多糖积累的动力学特性,提出了两步培养方式,采用补料策略,确定了最佳补料时间．结果表明,采用两步培养,生物量达46．7 g/L(干重),是一步培养的1．5倍,多糖产率达8．15g/L,是一步培养的2．6倍．

The cultivation ofprotocorm-like bodies ofDendrbium huoshanense was carried out in a 10 L air-lift bioreactor. The effects of inoculum size, aeration rate, carbon, phosphate sources on the cell growth and accumulation of polysaccharides were investigated in suspension cultures of protocorm-like bodies from Dendrobium huoshanense. Thirty-day-old cells were transferred into liquid medium with the inoculum density of 100 g/L （fresh weight） cells and aeration rate of 0.5 L/min. The optimal concentrations of sucrose and phosphate in the medium for the cell growth were 30 g/L and 2.5 mmol/L, respectively. A total of 0.312 mmol/L of medium phosphate was better for the accumulation of polysaccharides. The results in two-step cultivation indicated that the maximum biomass and polysaccharides yield were 46.7 g/L （dry weight） and 8.15 g/L, which are 1.5 and 2.6 fold of those in one-step cultivation respectively.