Solanum chrysotrichum hairy root cultures:: Characterization, scale-up and production of five antifungal saponins for human use

The production of five antifungal saponins (SC-2 - SC-6) recently extracted from Solanum chrysotrichum leaves was performed using hairy root cultures grown in 250-mL flasks and in 2-L modified draught-tube internal-loop airlift reactors (2-L MR). In both scales, first order growth kinetics were observed, reaching specific growth rates of 0.08 and 0.12 d(-1), respectively. Root density at the end of the culture period was the same for the flasks and for the 2-L MR. In flasks the production of the most active saponin SC-2 was growth-associated, with a maximum yield of 0.04% dry weight, while in the 2-L MR an SC-2 yield of 0.7% dry weight was reached, representing a value six times greater than that observed for plant leaves. SC-3 was obtained from root biomasses grown in flasks, while SC-4 was recovered from biomasses at both levels under investigation. SC-5 and SC-6 were only detected in the culture medium of roots grown in 2-L MR. Solarium chrysotrichum hairy root cultures and their scale-up in reactors are feasible strategies for the production of these antifungal compounds for human use.