title: Azadirachtin production by hairy root cultivation of Azadirachta indica in a modified stirred tank reactor.
abstract: Present investigation involves hairy root cultivation of Azadirachta indica in a modified stirred tank reactor under optimized culture conditions for maximum volumetric productivity of azadirachtin. The selected hairy root line (Az-35) was induced via Agrobacterium rhizogenes LBA 920-mediated transformation of A. indica leaf explants (Coimbatore variety, India). Liquid culture of the hairy roots was developed in a modified Murashige and Skoog medium (MM2). To further enhance the productivity of azadirachtin, selected growth regulators (1.0 mg/l IAA and 0.025 mg/l GA(3)), permeabilizing agent (0.5 % v/v DNBP), a biotic elicitor (1 % v/v Curvularia (culture filtrate)) and an indirectly linked biosynthetic precursor (50 mg/l cholesterol) were added in the growth medium on 15th day of the hairy root cultivation period in shake flask. Highest azadirachtin production (113 mg/l) was obtained on 25th day of the growth cycle with a biomass of 21 g/l DW. Further, batch cultivation of hairy roots was carried out in a novel liquid-phase bioreactor configuration (modified stirred tank reactor with polyurethane foam as root support) to investigate the possible scale-up of the established A. indica hairy root culture. A biomass production of 15.2 g/l with azadirachtin accumulation in the hairy roots of 6.4 mg/g (97.28 mg/l) could be achieved after 25 days of the batch cultivation period, which was ~27 and ~14 % less biomass and azadirachtin concentration obtained respectively, in shake flasks. An overall volumetric productivity of 3.89 mg/(l day) of azadirachtin was obtained in the bioreactor.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110 016, India.
authors.forename: Smita
authors.initials: S
authors.lastname: Srivastava
authors.forename: A K
authors.initials: AK
authors.lastname: Srivastava
mesh_terms: D031601:Azadirachta / Q000166:cytology / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D036701:Limonins / Q000096:biosynthesis*; D059828:Plant Cells / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism
chemical_list: D036701:Limonins; C010329:azadirachtin