Central Tuber Crops Research Institute

About: Central Tuber Crops Research Institute is a facility organization based out in Thiruvananthapuram, Kerala, India. It is known for research contribution in the topics: Starch & Fermentation. The organization has 475 authors who have published 587 publications receiving 10285 citations.

Cyclo(D-Tyr-D-Phe): a new antibacterial, anticancer, and antioxidant cyclic dipeptide from Bacillus sp. N strain associated with a rhabditid entomopathogenic nematode.

Abstract: A new microbial cyclic dipeptide (diketopiperazine), cyclo(d-Tyr-d-Phe) was isolated for the first time from the ethyl acetate extract of fermented modified nutrient broth of Bacillus sp. N strain associated with rhabditid Entomopathogenic nematode. Antibacterial activity of the compound was determined by minimum inhibitory concentration and agar disc diffusion method against medically important bacteria and the compound recorded significant antibacterial against test bacteria. Highest activity was recorded against Staphylococcus epidermis (1 µg/ml) followed by Proteus mirabilis (2 µg/ml). The activity of cyclo(d-Tyr-d-Phe) against S. epidermis is better than chloramphenicol, the standard antibiotics. Cyclo(d-Tyr-d-Phe) recorded significant antitumor activity against A549 cells (IC50 value: 10 μM) and this compound recorded no cytotoxicity against factor signaling normal fibroblast cells up to 100 μM. Cyclo(d-Tyr-d-Phe) induced significant morphological changes and DNA fragmentation associated with apoptosis in A549 cells. Acridine orange/ethidium bromide stained cells indicated apoptosis induction by cyclo(d-Tyr-d-Phe). Flow cytometry analysis showed that the cyclo(d-Tyr-d-Phe) did not induce cell cycle arrest. Effector molecule of apoptosis such as caspase-3 was found activated in treated cells, suggesting apoptosis as the main mode of cell death. Antioxidant activity was evaluated by free radical scavenging and reducing power activity, and the compound recorded significant antioxidant activity. The free radical scavenging activity of cyclo(d-Tyr-d-Phe) is almost equal to that of butylated hydroxyanisole, the standard antioxidant agent. We also compared the biological activity of natural cyclo(d-Tyr-d-Phe) with synthetic cyclo(d-Tyr-d-Phe) and cyclo(l-Tyr-l-Phe). Natural and synthetic cyclo(d-Tyr-d-Phe) recorded similar pattern of activity. Although synthetic cyclo(l-Tyr-l-Phe) recorded lower activity. But in the case of reducing power activity, synthetic cyclo(l-Tyr-l-Phe) recorded significant activity than natural and synthetic cyclo(d-Tyr-d-Phe). The results of the present study reveals that cyclo(d-Tyr-d-Phe) is more bioactive than cyclo(l-Tyr-l-Phe). To the best of our knowledge, this is the first time that cyclo(d-Tyr-d-Phe) has been isolated from microbial natural source and also the antibacterial, anticancer, and antioxidant activity of cyclo(d-Tyr-d-Phe) is also reported for the first time. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

Studies on Dioscorea rotundata starch properties

Abstract: Starch from six clonal selections of Dioscorea rotundata was isolated by standard procedure. The yield was between 20–24%. Various properties of these starches were compared. Granule size, 2% viscosity, peak viscosity, clarity, sol stability, total and soluble amylose contents were studied and only small variations were observed in the properties except paste viscosities among the clonal selections. The phosphorus content of Dioscorea starch was found to be three times as much as cassava starch, but low compared to potato starch. The higher gel strength of D. rotundata starch paste compared to cassava gel may be attributed to the phosphate linkages among the starch molecules in the granules. Untersuchungen uber die Eigenschaften der Starke von Dioscorea rotundata. Die Starke von sechs klonalen Auswahlen von Dioscorea rotundata wurde mittels eines Standard-Verfahrens isoliert Die Ausbeute betrug 20–24%. Verschiedene Eigenschaften der Starken wurden verglichen. Korngrose, Viskositat 2%iger Suspensionen. Spitzenviskositat, Klarheit. Solstabilitat, gesamte und losliche Amylose wurden untersucht und nur geringe Abweichungen in den Eigenschaften beobachtet, abgesehen von den Kleisterviskositaten unter den klonalen Auswahlen. Der Phosphorgehalt von Dioscorea-Starke war dreimal so hoch wie der von Cassavastarke, aber niedrig im Vergleich zu Kartoffelstarke. Die hohere Gelstarke von D. rotundata-Starkekleister im Vergleich zu Cassava-Gelen durfte den Phosphatbindungen zwischen den Starkemolekulen in den Kornern zuzuschreiben sein.

Collection of plant genetic resources from Andaman and Nicobar Islands

Abstract: The Andaman and Nicobar (A&N) group of islands is immensely rich in plant biodiversity. Andaman’s native tribes are hunter-gatherers, sustaining on wild or marine food and practically do not have any cultivation. Diversity in cultivated crops is presently maintained in home gardens by settlers from the mainland and other adjoining countries. The National Bureau of Plant Genetic Resources (NBPGR) through explorations either alone or in association with CARI or with other ICAR institutes has collected 1234 accessions in 48 exploration and collection missions. Variability was collected in rice, cowpea, black gram, green gram, okra, Chinese spinach, ash gourd, taro, cucumber, pumpkin, bottle gourd, ridge gourd, bitter gourd, chilli, greater yam and coconut. Indigenous landraces are absent. The in situ conservation of the wild relatives of crops is well taken care of by a large number of protected forest reserves.

Bioleaching of copper from pre and post thermally activated low grade chalcopyrite contained ball mill spillage

Abstract: Bioleaching of a low grade chalcopyrite (ball mill spillage material) was tested for copper recovery in shake flasks. The original samples (as received) were thermally activated (600°C, 30 min) to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing Acidithiobacillus ferrooxidans strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characterization studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy (FESEM-EDS) and X-ray Fluorescence (XRF) analysis indicated mostly SiO2. With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30°C, 150 r·min−1, 49% copper could be recovered in 30 days from the finest particle size (−1 + 0.75 mm) of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution.

Antioxidative enzymes and isozymes analysis of taro genotypes and their implications in Phytophthora blight disease resistance.

Abstract: Assessment of the differential expression of antioxidative enzymes and their isozymes, was done in 30 day-old ex vitro raised plants of three highly resistant (DP-25, Jhankri and Duradim) and one highly susceptible (N-118) genotypes of taro [Colocasia esculenta (L.) Schott]. Antioxidative enzymes were assayed in the ex vitro plants, 7 days after inoculation with the spores (15,000 spores ml−1 water) of Phytophthora colocasiae Raciborski to induce taro leaf blight disease. Uninoculated ex vitro plants in each genotype were used as control. The activity of superoxide dismutase (SOD) and guaiacol peroxidase (GPX) increased under induced blight condition when compared with control. Increase in antioxidative enzymes was more (67–92%) in the resistant genotypes than that (21–29%) of the susceptible genotype. The zymograms of SOD and GPX in the resistant genotypes, with pathogenic infection, showed increased activity for anodal isoform of SOD and increased expression and/or induction of either POX 1 or POX 2 isoforms of GPX. In susceptible genotype, expression of the above isoforms was faint for SOD and nearly absent for GPX under both blight free and induced blight conditions. Induction and/or increased activity of particular isoform of SOD and GPX against infection of Phytophthora colocasiae in the resistant genotypes studied led to the apparent conclusion of linkage of isozyme expression with blight resistance in taro. This might be an important criterion in breeding of taro for Phytophthora leaf blight resistance.