S04 - Session P6 - Efficient airlift bioreactor for high-throughput multiplication of embryogenic cell suspension in banana (Musa spp.)

Authors: Subbaraya Uma Binit *, Karthic Raju, Kalpana Sathiamoorthy , Backiyarani Suthanthiram, Saraswathi Marimuthu Somasundaram

Banana is a pioneer crop, efficiently exploit in vitro shoot tip culture technique for commercial propagation of planting material. The increasing demand for planting material and the requirement of higher productivity necessitate technological advancements. Thus, a novel embryogenic cell suspension (ECS) culture system has been considered for commercial propagation of banana. Mass multiplication of ECS is the first step and vital for the process. Generally, it has been carried out in a shake flask system which requires several subculture passages and long-time maintenance to get sufficient cells. It may lead to possible DNA methylations, chromosome rearrangements and point mutations, affect genetic integrity of the cells. This report demonstrates to reduce the duration of mass multiplication of embryogenic cells using three different airlift bioreactors and regeneration of plantlets. The friable embryogenic calluses with somatic embryos were developed from male floral buds of five different banana cultivars. These calluses were cultured repetitively on a liquid medium supplemented with 1.1 mg/l (2, 4-D) and 0.25 mg/l Zeatin till the fine cell suspension obtained. The fine cells were cultured on three different air-lift bioreactors, the growth characteristics (pH, EC, TDS) and settle cell volume (SCV in ml) were examined. The type 3 bioreactor yields 117+-6.3 ml of SCV in a fed-batch culture system within 21 days. The cells grown in air-lift bioreactors were regenerated plantlets through somatic embryogenesis. These plants were examined for genetic fidelity using ISSR markers, the results showed that the plants were true to type. Thus, this air-lift bioreactor prototype could be used for high-throughput multiplication of ECS for the production of commercial tissue culture plants and can be utilized in crop improvement programs. Suggestions: in bananas, efficient use is made of the in vitro cultivation of shoot tips for the commercial propagation of planting material. The increasing demand for planting material and the need for higher productivity necessitate technological advances. Therefore, a new system for the culture of embryogenic cell suspension (ECS) was considered. Mass propagation of ECS is the first step and vital to the process. Generally, this is performed in a shaking flask system that requires several subculture passages and prolonged maintenance to obtain sufficient cells. This can lead to potential DNA methylations, chromosomal rearrangements and point mutations, compromising the genetic integrity of the cells. This report demonstrates that the duration of mass propagation of embryogenic cells can be shortened using three different airlift bioreactors and plantlet regeneration. Fragile embryogenic calluses containing somatic embryos were developed from male flower buds of five different banana cultivars. These calluses were repeatedly cultured on liquid medium supplemented with 1.1 mg/l (2,4-D) and 0.25 mg/l Zeatin until a fine cell suspension was obtained. These cells were cultured in three different air-lift bioreactors, growth characteristics (pH, EC, TDS) and settling cell volume (SCV in ml) were examined. The type 3 bioreactor yielded 117+-6.3 ml SCV in a fed-batch culture system within 21 days. The cells grown in air-lift bioreactors were regenerated into plantlets via somatic embryogenesis. These plants were examined for genetic fidelity using ISSR markers. The results showed that the plants were true to type. Thus, the air-lift bioreactor prototype can be used for high-throughput propagation of ECS for the production of commercial tissue culture plants and can be used in crop improvement programs.