Effects of inoculum size and age on biomass growth and paclitaxel production of elicitor-treated Taxus yunnanensis cell cultures

Abstract

Suspension cultures of Taxus yunnanensis cells were inoculated with cells of different culture ages (12-24 days) at various densities [50-250 g fresh weight (fw)/l], and treated (on day 7) with a mixture of elicitors, including Ag(+), chitosan and methyl jasmonate. The biomass productivity (during the production stage) increased dramatically with inoculum size, but decreased with inoculum age over 16 days. The volumetric yield and productivity of taxol (paclitaxel) also increased with inoculum size, while the specific taxol yield (per cell) was mainly dependent on inoculum age, with an optimum of 20 days, during the early stationary phase. The highest taxol yield and productivity, 39.8 mg/l and 1.9 mg/l per day, respectively, were obtained with a 20-day-old inoculum at 200 g fw/l. Taxol excretion by the cells increased with inoculum age but decreased with inoculum size. The elicitor-induced activities of catalase (CAT) and phenylalanine ammonia-lyase (PAL) also depended mainly on inoculum age; higher PAL activity and lower CAT activity were obtained with an older inoculum, corresponding to a higher taxol yield. The results show that both inoculum size and age are important variables for taxol production, though the latter more profoundly influences elicitor-induced taxol biosynthesis of the cells. Inoculum size and age are also interrelated and should be optimized together in a two-stage culture process.

Biosynthesis of Silver Nanoparticles Using Taxus yunnanensis Callus and Their Antibacterial Activity and Cytotoxicity in Human Cancer Cells

“…Due to the enormous commercial value of paclitaxel and the scarcity of T. yunnanensis trees in China, callus and cell cultures have been established as a practical alternative source for paclitaxel production [14]. Many studies on cell culture of T. yunnanensis focused on enhancing paclitaxel production by means of elicitation, ultrasound treatment and medium renewal [15,16]. However, little has been reported on biosynthesized AgNP using Taxus tree or callus.…”

Assessment of Cultivation Factors that Affect Biomass and Geraniol Production in Transgenic Tobacco Cell Suspension Cultures

“…The inoculum size and the addition of conditioned medium had also a beneficial effect on alkaloid production in immobilized Catharanthus roseus cells [35]. Previous reports showed that the enhancement of inoculum density usually leads to higher biomass productivity but lower growth rate [13], [15]. The high inoculum size can contribute for the elimination or even diminishment of the lag phase during the cultivation [11].…”

“…Physical factors that have a major impact on the performance of plant-derived cultures include the inoculum state, size and age [11], [13]–[15], the volume of medium in the culture vessel and the shaking speed, both of which influence on the oxygen supply during cultivation [16], [17]. Biological factors also play an important role, including the use of conditioned medium to influence the accumulation of plant cell biomass [18] and the selection of carbohydrates as sources of energy and carbon due to the low levels of CO 2 in the closed-glass cultivation vessels during the photoperiod [19].…”

TAXOIDES: METABOLITOS SECUNDARIOS DEL ÁRBOL DEL TEJO (Taxus spp.)

“…cuspidata 0.11 Son et al (2000) T. media 0.53 Cusidó et al (2002) T. wallichiana 0.75 Navia-Osorio et al (2002) T. chinensis 1.50 Wang et al (2001) T. yunnanensis 1.90 Zhang et al (2002) T. baccata 2.71 Bentebibel et al (2005) …”

“…cuspidata 0.11 Son et al (2000) T. media 0.53 Cusidó et al (2002) T. wallichiana 0.75 Navia-Osorio et al (2002) T. chinensis 1.50 Wang et al (2001) T. yunnanensis 1.90 Zhang et al (2002) T. baccata 2.71 Bentebibel et al (2005) 7-epi-10-diacetyl taxol (KetchumTandon, Gibson, Begley, & Shuler, 1999), and 10-diacetyl taxol in T. baccata (Vander et al, 1994), among others. Table 2 shows the production rate of taxol in in vitro cultures of Taxus spp.…”