Establishment of a large-scale micropropagation system for anoectochilus formosanus in bioreactors

An efficient protocol was developed to optimize culture conditions for largescale micropropagation of Anoectochilus formosanus using bioreactor technology relation to the growth, pigments, metabolite content and antioxidant properties. The proliferation response was significantly influenced by aeration volume in bioreactor culture. The highest shoot multiplication and shoot length were observed at 0.06 volume of air per volume of medium per min (vvm)aeration volume. This condition also resulted in higher fresh and dry weights. Number of shoots and shoot length were reduced by increasing aeration volume (from 0.09 to 0.12 vvm). Comparative studies between solid and liquid (bioreactor)cultures revealed that shoot multiplication and growth were more efficient at 0.06 vvm air volume and 90 explants as initial inoculum size. Chlorophyll and carotenoid contents were increased with increasing inoculum density from 30 to 90 explants/culture vessel. In contrast, the lowest value was observed at an inoculum density of 120 explants. The highest contents of total phenol, flavonoid and DPPH radical scavenging activity were also obtained at an inoculum density of 90 explants. These results suggest that bioreactor technology can be successfully applied for the large-scale micropropagation of A. formosanus in a biotechnological approach.