Adsorption of Selenium and Lanthanum by Agrobacterium-mediated Hairy Roots of Hybanthus Enneaspermus (L.) F. Muell: A Greener Phytoremediation Strategy.

In this study, phytoremediation potential of toxic metals like selenium (Se) and lanthanum (La) by transformed hairy roots was investigated and compared with plantlets under in-vitro conditions. Agrobacterium rhizogenes A4RS could induce hairy roots with higher biomass in 5-7 days of infection on in-vitro leaves of Hybanthus enneaspermus. The ICP-OES data indicated that the hairy roots were able to accumulate both selenium and lanthanum efficiently compared to plantlets. The hairy roots and plantlets show optimum absorption at 50 ppm under both individual and combined metal supply. The metal accumulation performances increased by 13.6% (La) and 10.9% (Se) in hairy roots with combined metal supply (La and Se) compared to individual supply (La or Se) conditions. The Se accumulated more than La, but the La accumulation percentage was found to increase substantially under combined metal supply conditions, shows the suitability and potential of hairy roots for phytoremediation of La and Se.

Cultivation of freshwater microalga Scenedesmus sp. using a low-cost inorganic fertilizer for enhanced biomass and lipid yield.

The potential of an inorganic fertilizer as an alternative nutrient source for the cultivation of Scenedesmus sp. IMMTCC-6 was investigated. With a preliminary study at a shake-flask scale, the microalgae cultivation was scaled up in a photobioreactor containing an inorganic fertilizer medium. Microalgae cultured in a shake flask containing 0.1 g L(-1) of urea and 1.0 g L(-1) of NPK (Nitrogen: Phosphorus: Potassium) fertilizers showed a promising result in biomass productivity. During the scale-up study in a photobioreactor the specific growth rate (µ d(-1)), biomass yield (g L(-1)), and total biomass productivity (mg L(-1) d(-1)), was found to be 0.265, 1.19 and 66.1, respectively. The lipid yield (%) as per dry cell weight (DCW) and lipid productivity (mg L(-1) d(-1)) was found to be a maximum of 28.55 and 18.87, respectively, in a stationary phase of the microalgae growth. The fatty acids methyl ester profile was proven to be desirable for biodiesel production.