Impact of subculture cycles and inoculum sizes on suspension cultures of Vitis vinifera / 生物工程学报

The commercial application of plant cell cultures is often hindered by the instability of secondary metabolite biosynthesis, where the metabolite yield fluctuates and decline dramatically over subcultures. This study proposed that such instability is due to the fluctuations of culture variables. To validate this hypothesis, the effects of the fluctuations of two culture variables (subculture cycle and inoculum size) on the biomass, anthocyanin biosynthesig, intracellular carbon, nitrogen and phosphate during continuous 10 subculture cycles were investigated. The subculture cycle was fluctuated for 12h in a 7 day cycle (6.5, 7 and 7.5 d), and the inoculum size was fluctuated by 20% on basis of 2.00 g (1.60, 2.00 and 2.40 g). It was found that all the measured culture parameters fluctuated over the 10 subculture cycles. The fluctuation in terms of inoculum sizes had a greater effect on the stability of anthocyanin biosynthesis in suspension cultures of V. vinifera. Among all the subculture conditions investigated, 7d-subculture cycle and 1.60 g-inoculum size was the best one to hold the relatively stable anthocyanin production. The anthocyanin yield presented a negative correlation with intracellular sucrose content or intracellular total phosphate content.

Significant improved anthocyanins biosynthesis in suspension cultures of Vitis vinifera by process intensification / 生物工程学报

The low-production is a ubiquitous problem and has prevented the commercialization of secondary metabolite production in plant cell culture. In order to examine the effective approaches to improvement of secondary metabolite production in plant cell culture, the investigation of anthocyanins accumulation in suspension cultures of Vitis vinifera, as a model system, had been initiated in our laboratory. In this present research, various elicitors and the precursor of phenylalanine were used in combination to enhance the anthocyanins production in suspension cultures of Vitis vinifera. And an integrated process with the combination of elicitation, precursor feeding and light irradiation was reported for rational bioprocess design. Among the combination treatment of phenylalanine feeding and several elicitors (methyl-beta-cyclodextrin, dextran T-40, methyl jasmonate, extracts of Aspergillus niger and Fusarium orthoceras), the combination with methyl jasmonate gave the highest anthocyanins production in suspension cultures of Vitis vinifera. When compared to the controls, the anthocyanins content (CV/g, FCW) and production (CV/L) increased by 2.7-fold and 3.4-fold, respectively. The optimum time for the addition of phenylalanine and methyl jasmonate was 4 days after inoculation. Two cell lines with different anthocyanins-producing capacity responded differently to the optimum combination treatment of 30 micromol/L phenylalanine feeding, 218 micromol/L methyl jasmonate elicitation and 3000 to approximately 4000 1x light illumination. The high-and low-anthocyanins-producing cell lines of VV05 and VV06 produced the maximum of 2975 and 4090 CV/L of anthocyanins that were 2.5- and 5.2-fold of the controls, respectively.

Effect of homogeneity on cell growth and anthocyanin biosynthesis in suspension cultures of Vitis vinifera / 生物工程学报

The instability of secondary metabolite production is a ubiquitous problem in plant cell culture. To understand the instability, the investigation of anthocyanin accumulation in suspension cultures of Vitis vinifera, as a model system, has been initiated in our laboratory. Suspension culture of a relatively homogeneous cell line E of V. vinifera, was established by long-term cell line selection by anthocyanin content differentiation. The aggregate size of E was smaller than that of other cell lines obtained by routine screening method. The variation coefficients of anthocyanin content in suspension cultures of E were 8.7% in long-term subcultures and 5% in repeated flasks, respectively. The effects of elicitor, precursor feeding and light irridiation on biomass and anthocyanin accumulation in suspension cultures of E had been investigated and the results showed that all the variation coefficients were lower than 12% and this indicated the importance of homogeneity on stable production in plant cell culture. With the combination treatment of 30micromol/L phenylalanine and 218micromol/L methyl jasmonate in the dark in suspension cultures of E, the anthocyanin content and production in suspension culture of E was 5.89-fold and 4.30-fold of the controls, respectively, and all the variation coefficients of biomass and anthocyanin accumulation were lower than those of the controls in 5 successive subcultures.