Mi-Jin Jeong

Enhanced production of tropane alkaloids in transgenic Scopolia parviflora hairy root cultures over-expressing putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H)

Scopolia parviflora adventitious roots were metabolically engineered by co-expression of the two gene putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H) cDNAs with the aid of Agrobacterium rhizogenes. The transformed roots developed into morphologically distinct S. parviflora PMT1 (SpPMT1), S. parviflora PMT1 (SpPMT2), and S. parviflora H6H (SpH6H) transgenic hairy root lines. Consequent to the introduction of these key enzyme genes, the production of the alkaloids hyoscyamine and scopolamine was enhanced. Among the transgenic hairy root lines, SpPMT2 line possessed the highest growth index. The treatment of transgenic hairy roots with growth regulators further enhanced the production of scopolamine. Thus, the results suggest that PMT1, PMT2, and H6H genes may not only be involved in the metabolic regulation of alkaloid production but also that these genes may play a role in the root development.

Bioethanol production by enzymatic saccharification of Salix viminalis var. gigantea biomass

The biomass of Salix viminalis var. gigantea was evaluated for the possibility of using it as a bioenergy resource. The chemical analysis of S. viminalis var. gigantea leaf biomass showed presence of components such as extractives (1.6%), lignin (44.2%), hemicellulose (16.4%), and cellulose (37.8%), whereas its stem was composed of other extractives (0.6%), lignin (19.4%), hemicellulose (35.1%), and cellulose (44.9%). Leaf and stem biomass samples of S. viminalis var. gigantea were hydrolyzed using two commercial enzymes, celluclast and viscozyme. The hydrolysis of S. viminalis var. gigantea biomass was different according to enzyme mixtures and their strengths. The optimal enzyme combination was found to be celluclast (59 FPU g−1 substrate) and viscozyme (24 FBG g−1 substrate). Glucose content in leaf and stem biomass was 16.81 g and 27.45 g per 100 g raw material, respectively, after 72 hr of enzyme treatment. The ethanol production from stem and leaf biomass was estimated as 4.45 g and 7.94 g, respectively. The biomass and enzyme hydrolysis biomass served as feedstock for ethanol production by fermentation.

Influence of Nitrogen, Phosphorous, Potassium and Sucrose on the Shoot and Bulb Growth of Allium victorialis var. platyphyllum

Effects of nitrogen (N), phosphorous (P) and potassium (K) on the shoot and bulb growth of wild garlic (Allium victorialis var. platyphyllum) were studied by adopting in vitro culture. These macronutrients influenced the growth of both the shoot and bulb of garlic depending upon their application doses. A minimum of 3% potassium nitrate (KNO3) as a source of nitrogen was found to be critical for shoot elongation while higher concentrations were inhibitory. Garlic bulb growth was profuse on the usual KNO3 strength and sucrose (7%), followed by KNO3 (9.4 mM) supplement. On providing 41.22 mM ammonium nitrate (NH4NO3) as nitrogen source highest shoot growth was observed while 82.45 mM NH4NO3 as a source of nitrogen supported high bulb growth. With regard to potassium a good shoot growth was observed in medium that contained 0.31 mM KH2PO4 and 3% sucrose, while bulb growth was high on 2.5 mM KH2PO4 and 7% sucrose. These experiments may thus direct the development of excellent growth conditions for the commercial production of edible wild garlic.