Artemisinin production by plant hairy root cultures in gas- and liquid-phase bioreactors

Key message Alternative biotechnological protocol for large-scale artemisinin production was established. It featured enhanced growth and artemisinin production by cultivation of hairy roots in nutrient mist bioreactor (NMB) coupled with novel cultivation strategies. Artemisinin is used for the treatment of cerebral malaria. Presently, its main source is from seasonal plant Artemisia annua. This study featured investigation of growth and artemisinin production by A. annua hairy roots (induced by Agrobacterium rhizogenes-mediated genetic transformation of explants) in three bioreactor configurations—bubble column reactor, NMB and modified NMB particularly to establish their suitability for commercial production. It was observed that cultivation of hairy roots in a non-stirred bubble column reactor exhibited a biomass accumulation of 5.68 g/l only while batch cultivation in a custom-made NMB exhibited a higher biomass concentration of 8.52 g/l but relatively lower artemisinin accumulation of 0.22 mg/g was observed in this reactor. A mixture of submerged liquid-phase growth (for 5 days) followed by gas-phase cultivation in nutrient mist reactor operation strategy (for next 15 days) was adopted for hairy root cultivation in this investigation. Reasonably, high (23.02 g/l) final dry weight along with the artemisinin accumulation (1.12 mg/g, equivalent to 25.78 mg/l artemisinin) was obtained in this bioreactor, which is the highest reported artemisinin yield in the gas-phase NMB cultivation

In vitro study on the nematicidal activity of entomopathogenic bacteria against the root knot nematode Meloidogyne incognita

National loss of Rs. 21,068.73 million has been estimated due to plant-parasitic nematodes in India. Among plant-parasitic nematodes, one of the major nematodes, root-knot nematodes (RKNs), are well-known diseases causing major losses in vegetable crops. An in vitro experiment was conducted to evaluate the nematicidal activities of the cell-free culture filtrate (CFCF) of entomopathogenic bacteria Photorhabdus spp. and Xenorhabdus spp. isolated from entomopathogenic nematodes Heterorhabditis indica (DH3) and Steinernema abbasi (CS-39), respectively. The applied doses were 90, 50, 25 and 10% CFCFs. The experiment was performed on the plant-parasitic nematode Meloidogyne incognita, and the % mortalities were determined at 6, 12, 24 and 48 hr intervals. The results of the present study revealed that 100% mortality was achieved after 48 hrs with a 10% filtrate of H. indica isolate DH3, while no significant result was achieved even after 48 hrs and at 90% CFCF of isolate CS39. Therefore, 10% CFCFs may be recommended for application in root-knot nematode-infected fields for the control

Pulse spray gas metal arc welding of advanced high strength S650MC automotive steel

With an increasing demand for safer and greener vehicles, mild steel and high strength steel are being replaced by much stronger advanced high strength steels of thinner gauges. However, the welding process of advanced high strength steels is not developed at the same pace. The performance of these welded automotive structural components depends largely on the external and internal quality of weldment. Gas metal arc welding (GMAW) is one of the most common methods used in the automotive industry to join car body parts of dissimilar high strength steels. It is also recognized for its versatility and speed. In this work, after a review of GMAW process and issues in welding of advanced high strength steels, a welding experiment is carried out with varying heat input by using spray and pulse-spray transfer GMAW method with filler wires of three different strength levels. The experiment results, including macro-microstructure, mechanical properties, and microhardness of weld samples, are investigated in detail. Very good weldability of S650MC is demonstrated through the weld joint efficiency > 90%; no crack in bending of weld joints, or fracture of tensile test sample within weld joint or heat affected zone (HAZ), or softening of the HAZ. Pulse spray is superior because of thinner HAZ width and finer microstructure on account of lower heat input. The impact of filler wire strength on weldability is insignificant. However, high strength filler wire (ER100SG) may be chosen as per standard welding practice of matching strength

Bildungsprogramme versus Bildungsrealitäten. Einblicke in das indische Schulsystem

Diesem Beitrag zum indischen Schulsystem liegt eine repräsentative Literaturanalyse der Pädagogischen Psychologie in Indien zwischen 1993 und 2003 zugrunde, die um weiterführende, themenspezifische Informationen ergänzt wird. So entsteht zum einen ein Überblick über die Entwicklung des Schulsystems in dieser bevölkerungsstarken Nation, andererseits stellen die Autorin und der Autor Bildungsprogramme Bildungsrealitäten gegenüber und vertiefen in diesem Zusammenhang die in Indien relevante Sprachproblematik und die Situation von Lehrerinnen und Lehrern. (DIPF/Orig.)The article provides a general overview of the Indian school system. At the same time the main issues and challenges the system in this context is facing today are addressed. Insights to some of the today\u27s goals of the educational politics are offered and general data on the educational system and present situation in India are given. Gender inequality, access to and success in education, efforts for quality improvement in educational contents and processes are discussed as well as modern movements regarding the privatisation of education and the emergence of confessional schools like the so called Madrasas. (DIPF/Orig.)

Petrographic investigation of selected natural cokes from Damodar Valley coalfields

The natural coke is a kind of fossil fuel and its reserves are scattered in almost coalfields covering approx. 2600 Km 2. In Indian coalfields, the igneous intrusion varies, causing regional in-situ burning of coal seams. The intrusion process itself is quite complex and does not follow any fixed trend everywhere. The chemical composition of the intrusion also varies from place to place. Petrographic, physical and chemical characterizations of some selected natural coke samples of Damodar Valley coalfields were done. The comprehensive study on above samples helped a lot in differentiation of natural cokes, slightly heat affected coal and normal coals obtained after washability at different specific gravities. The yield of the samples after washability varied from sample to sample. Through petrographic studies by microscopy, an effort has been made to decipher the new classification schemes for microtextures and microstructures of natural coke, which are generated through in-situ carbonisation of coal seams. Isotropic, anisotropic components and mineral matters were differentiated. Some selected natural coke fractions were explored for value addition in different studies. The study was helpful in establishing industrial use of natural coke in Power, Cement and Carbon Artifact industry

Monolayer, Bilayer and Heterostructures of Green Phosphorene for Water Splitting and Photovoltaics

We report the results of density functional theory (DFT) based calculations on monolayer and bilayer green phosphorene and their heterostructures with MoSe2. Both monolayer and bilayer green phosphorene are direct band gap semiconductors and possess anisotropic carrier mobility as high as 10^{4} cm^{2}V^{-1}s^{-1}. In bilayers, pressure of about 9 GPa induces the semiconductor-metal transition. Moreover, the band gap depends strongly on the thickness of the films and the external electric field. By employing strain-engineering under suitable solution conditions, monolayer and AC-stacked bilayer green phosphorene offer the band edge alignments which can be used for water splitting. The upper limit of the power conversion efficiencies for monolayer, AB- and AC-stacked bilayer green phosphorene heterostructures with MoSe_{2} is calculated to be 18-21 %. Our results show the possibility of green phosphorene to be used as photocatalytic and photovoltaic material in the energy-related applications.Comment: 23 pages, 7 figures, 2 table

Modulatory Role of Nitric Oxide/cGMP System in Endothelin-1-Induced Signaling Responses in Vascular Smooth Muscle Cells

Nitric oxide (NO) is an important vasoprotective molecule that serves not only as a vasodilator but also exerts antihypertrophic and antiproliferative effects in vascular smooth muscle cells (VSMC). The precise mechanism by which the antihypertrophic and antiproliferative responses of NO are mediated remains obscure. However, recent studies have suggested that one of the mechanisms by which this may be achieved includes the attenuation of signal transduction pathways responsible for inducing the hypertrophic and proliferative program in VSMC. Endothelin-1 is a powerful vasoconstrictor peptide with mitogenic and growth stimulatory properties and exerts its effects by activating multiple signaling pathways which include ERK 1/2, PKB and Rho-ROCK. Both cGMP-dependent and independent events have been reported to mediate the effect of NO on these pathways leading to its vasoprotective response. This review briefly summarizes some key studies on the modulatory effect of NO on these signaling pathways and discusses the possible role of cGMP system in this process