Enhanced anthocyanin production by repeated-batch culture of strawberry cells with medium shift

Repeated-batch cultures of strawberry cells (Fragaria ananassa cv. Shikinar i) subjected to four medium-shift procedures (constant LS medium, constant B5 medium, alternation between LS and B5 starting from LS and alternation b etween LS and B5 starting from B5) were investigated for the enhanced antho cyanin productivity. To determine the optimum period for repeated batch cul tures, two medium-shift periods of 9 and 14 days were studied, which repres ent the end of the exponential growth phase and the stationary phase. By co mparison with the corresponding batch cultures, higher anthocyanin producti vity was achieved for all the repeated-batch cultures at a 9-day medium-shi ft period. The average anthocyanin productivity was enhanced 1.7-and 1.76-f old by repeated-batch cultures in constant LS and constant B5 medium at a 9 -day shift period for 45 days, respectively. No further improvement was obs erved when the medium was alternated between LS (the growth medium) and B5 (the production medium). Anthocyanin production was unstable at a 14-day sh ift period regardless of the medium-shift procedures. The results show that it is feasible to improve anthocyanin production by a repeated-batch cultu re of strawberry cells.