ABSTRACT
An in vitro propagation method is outlined for Ocimum basilicum Linn. var. pilosum (Willd.) Benth., a wild aromatic plant belongs to Lamiaceae family. Shoot buds were used as source of explants on MS media supplemented with different concentrations of growth regulators for callus growth, induction of multiple shoots and roots respectively. MS media with 1.5 mg/L of kinetin and 0.5 mg/L of NAA showed 95.5% shooting, maximum number of shoots (7.33) and relatively better shoot lengths (4.15 cm). Excised shoots were carefully transferred to halfstrength MS medium supplemented with 1.0 mg/L indole-3-butyric acid (IBA) for root induction and it yields 86.6% rooting. Whereas, average root length and number of roots observed were 1.73 cm and 3.31 respectively per explants. Rooted plantlets were hardened and successfully established in natural soil, where they grew and matured normally. GC-MS studies in methanolic leaf extract of naturally grown Ocimum species yielded 15 compounds. Two compounds viz. cis-9-Hexadecenal (35.06%) and n-Hexa decanoic acid (21.6%) accounted for the major share (56.66%). On the other hand, 2-hydroxy-6-methylbenzaldehyde (10.99%) as well as 4H-1-Benzopyran-4-one and 5-Hydroxy-6, 7-Dimethoxy-2-(4- Methoxyphenyl) (7.75%) represented only 18.74%. Establishment of reliable in vitro propagation protocol, with phytochemical profile of hitherto unreported Ocimum species further widens the scope to evaluate its therapeutic properties.
ABSTRACT
The influence of aeration on algal growth and gamma-linolenic acid (GLA) production in a bubble column photobioreactor was investigated. Studies were performed in a 20-L reactor at different aeration rates (0.2-2.5 vvm). Static, continuous, and periodic operation of air resulted in 41.9%, 88.4%, and 108% air saturation of dissolved oxygen, for which the corresponding values of GLA were 2.3, 6.5, and 7.5 mg·g-1 dry cell weight, respectively. An increase in the aeration rate from 0.2 to 2.5 vvm enhanced both the specific growth rate and GLA content under periodic sparging in the bicarbonate medium. With a 6-fold increase in the aeration rate, the GLA content of the alga increased by 69.64% (5.6-9.5 mg· g-1 dry cell weight). In addition, the total fatty acid (TFA) content in dry biomass increased from 2.22% to 4.41%, whereas the algae maintained a constant GLA to TFA ratio within the aeration rate tested. The dependence of GLA production on the aeration rate was explained by interrelating the GLA production rate with the specific growth rate using the Luedeking and Piret mixed growth model.