648 research outputs found
AN ANTIMICROBIAL PHTHALATE DERIVATIVE FROM BACILLUS CEREUS, THE SYMBIOTIC BACTERIUM ASSOCIATED WITH A NOVEL ENTOMOPATHOGENIC NEMATODE, RHABDITIS (OSCHEIUS) SP
Objective: To isolate and identify the bioactive metabolites from the culture filtrates of a bacterium (Bacillus cereus) symbiotically associated with a novel entomopathogenic nematode Rhabditis (Oscheius) species.Methods: The bacterium was cultured in three different media and the antimicrobial activity was determined by the well diffusion assay. The ethyl acetate extract of the cell free culture filtrate was then purified by silica gel column chromatography and thin layer chromatography. Identification of the active metabolite was done with HPLC, GC-MS and LC-MS.Results: The cell free culture filtrate of a nematode symbiotic bacterium showed both antibacterial and antifungal activities. Fermentation conditions were standardized and optimum antibacterial activity was observed in tryptic soy broth at 72 h of incubation at 30 °C. When the ethyl acetate extract was purified by silica gel column chromatography and thin layer chromatography, an active fraction was obtained which was subjected to HPLC analysis along with GC-MS and LC-MS leading to the identification of a major compound Bis (2-ethyl hexyl) phthalate. The compound was active against Gram positive bacteria Bacillus subtilis MTCC2756, Staphylococus aureus MTCC902, Gram negative bacteria Escherichia coli MTCC 2622 and fungi such as Aspergillus flavus MTCC277, Candida albicans MTCC183, Fusarium oxysporum MTCC 284, Rhizoctonia solani MTCC 4634.Conclusion: Bis (2-ethyl hexyl) phthalate was identified as one of the metabolites produced by a nematode symbiotic bacterium associated with a novel entomopathogenic nematode Rhabditis (Oscheius) species. Thus similar compounds isolated from novel entomopathogenic bacteria would pave the way for identifying new drugs for the pharmaceutical and agricultural sector.Â
Isolation, identification and culture of the marine rotifer Colurella adriatica Ehrenberg, 1831 (Family: Lepadellidae) from Andaman & Nicobar Islands: A promising live feed for larval rearing of high value shellfishes and finfishes
An extremely small rotifer was isolated from the micro zooplankton
samples collected during February, 2014 from Havelock islands of
Andaman and Nicobar Islands. The species was identified as Colurella
adriatica Ehrenberg, 1831 (Family: Lapadellidae). Its lorica length under
culture period ranged from 47.530 to 98.868 μm and width from
34.308 to 56.277 μm. The size of the eggs, neonates and adults are
also documented. Comparison of size of C. adriatica with Brachionus
plicatilis (L type) and B. rotundiformis (S and SS type) revealed that
C. adriatica is smaller in length and width than the SS-type rotifer which
is currently used as a first feed in marine tropical fish larval rearing.
However, the larvae of many marine food fishes including groupers and
high value marine ornamental fishes are unable to consume the SS-type
rotifers as a first feed due to their extremely small mouth gape. The
culture of C. adriatica was carried out using Nannochloropsis oculata
Diet-I), N. oculata and yeast (0.01g/litre) (Diet-II), Yeast (0.01g/litre)
alone (Diet-III). Average population density of C. adriatica with these
diets reached a maximum of 1000 nos. of individuals /ml on 10th day
of culture on feeding with Diet-I; 950 nos. /ml on 14th day (Diet-II) and
650 nos. /ml on 15th day of culture (Diet-III). Diet I &II and Diet II &III
did not show any significant difference (P>0.05) whereas, Diet I and III
showed significant difference (P<0.01). Preliminary studies of
C. adriatica as a feed to the larvae of Stenopus hispidus, Lysmata
amboinensis and Pomacentrus caeruleus showed better survival than
larvae fed with B. routundiformis during first phase of larval rearing
Evidence for Molecular Evolutionary Conservedness of Small Heat-Shock Protein Sequence in Solanaceaeous Crops Using in silico Methods
Drought and heat contribute to much of the yield decline in agricultural lands all over the world. The basic physiological responses developed against drought and heat stress overlie each other, as; both these stresses eventually lead to dehydration of the cell and to osmotic imbalance. To cope with abiotic stresses, it is necessary to understand plant responses to stresses that disturb homeostatic equilibrium at the cellular and molecular level. Although there has been remarkable progress in this with development of microarray-based expression profiling methods (together with genomic sequence data), understanding on ways to employ these data to engineer plants with improved stresstolerance is still at a nascent stage. However, these data can be used for discovering genes, functional microsatellites and regulatory elements using in silico methods. In this context, single nucleotide repeat marker sequences have been identified which is associated with small heat-shock protein sequence (sHSP) for heat tolerance in Capsicum annuum. These sHSP sequences have some structural features in common; its characteristic is that it is homologous and highly conserved. These sequences have been analyzed for molecular evolutionary conservedness in solanaceaeous crops and have been found to have a single nucleotide repeat sequence and a highly conserved sHSP sequence
Marine ornamental fishes and their breeding: CMFRI initiatives
The marine ornamental fish trade is a sunrise industry in
aquaculture and has become a growing industry worldwide. As a
result the trade of marine ornamentals has been expanding in
recent years and has grown into a multimillion dollar enterprise
mainly due to the emergence of modern aquarium gadgets and
technologies for setting and maintenance of miniature reef aquaria.
Since the marine ornamental trade is operated throughout the
tropics, the global marine ornamental trade is estimated at US$ 200-
330 million. Since India is endowed with a vast resource potential
of marine ornamentals distributed in the coral seas and rocky
coasts with patchy coral formations and the increasing the demand
in the domestic trade, it appears very much lucrative for India to
venture into this industry
Microsatellite Identification in Solanaceae Crops Associated with Nucleoside Diphosphate Kinase (NDK) Specific to Abiotic Stress Tolerance through in silico Analysis
Abiotic stress often causes a series of morphological, physiological, biochemical and molecular changes that affect plant growth, development and productivity. To cope with abiotic stresses, it is necessary to understand plant responses to stresses that disturb homeostatic equilibrium at the cellular and molecular level. Genomic information on Capsicum annuum has been explored to identify microsatellite markers associated with abiotic stress tolerance and assign them to cognate functional groups related to specific stress responses. Several in silico methods have been used to identify simple sequence repeats associated with stress responsive gene candidates in Capsicum annuum. In this study, a microsatellite marker has been identified in Capsicum annuum associated with Nucleoside Diphosphate Kinase (NDK) having multiple environmental stress tolerance (oxidative, high temperature and salt stress) and which is also highly conserved in crops of Solanaceae. These are house-keeping enzymes that maintain intracellular levels of all nucleoside triphosphates (NTP) with the exception of adenosine triphosphate (ATP). These are also involved in phytochrome A response, UV-B signaling, auxin responses and oxidative stress signaling
Peak expiratory flow rate nomogram in relation to anthropometric determinants of South Indian school children
Background: The predictive normal value of peak expiratory flow rate (PEFR), used in monitoring of healthy andasthmatic children, is correlated with height, but it may vary with other anthropometric measurements and ethnicdifferences. Purpose: To study the correlation of PEFR with age, sex, body mass index (BMI), chest circumference(CC), and MUAC and to formulate PEFR nomograms in relation to these anthropometric variables in a ruralschool going children of age group 6-12 years in southern India. Methods: A descriptive cross-sectional studywas conducted in 2000 children consist of 993 boys and 1007 girls who fulfilled the selection criteria from eightrandomly selected government schools from a rural area. PEFR was measured age wise using Mini-Wright peakflow meter and the highest among the three values was taken. PEFR nomograms were formulated, and its correlationwith BMI, height, weight, CC, and MUAC were estimated using linear regression analysis. Results: PEFR hasstrong (p < 0.001) positive correlation with age, height, weight, MUAC, and CC, but it has poor correlation withBMI (p = 0.985) which showed flat regression line with narrow 95% confidence limits. Conclusion: In this study,PEFR has nonsignificant correlation with BMI but has strong positive correlation with other anthropometricmeasurements. This underlines the need of a local reference nomogram as anthropometric measurements affect thePEFR reference values
Johnson-Kendall-Roberts theory applied to living cells
Johnson-Kendall-Roberts (JKR) theory is an accurate model for strong adhesion
energies of soft slightly deformable material. Little is known about the
validity of this theory on complex systems such as living cells. We have
addressed this problem using a depletion controlled cell adhesion and measured
the force necessary to separate the cells with a micropipette technique. We
show that the cytoskeleton can provide the cells with a 3D structure that is
sufficiently elastic and has a sufficiently low deformability for JKR theory to
be valid. When the cytoskeleton is disrupted, JKR theory is no longer
applicable
Mobile genetic element excision footprints of Drosophila melanogaster found in heat shock protein coding regions of Solanaceous crops
Not AvailableMobile genetic elements are discrete sequences in the genome that are able to transport themselves to other locations within genome, which may have direct consequences on gene expression. More than 96 per cent of the transposable elements, occurring in heat shock promoters are P transposable element. In natural populations of Drosophila melanogaster, the promoters of heat-shock genes are especially susceptible to the insertion of transposable elements. These mobile elements often leave small rearrangements called transposon footprints at sites where they excise. It was proved that transposable elements insertion and subsequent excision resulted in the production of 8 bp direct repeats. The transposable elements often insert into the genes regulatory regions is due to their high expression level. In this context, Heat Shock Protein sequences, mainly HSP90 and HSP83 in Solanaceae crops were analysed for presence of transposable element excision footprints using in silico methods. It was found that out of the 17 hsp sequences, 14 hsp coding sequences were having 8 bp transposable element excision footprints consistently at the same location. These footprints left in individual sequences are surprisingly not random; excision footprints predominate consistently in each sequence. This suggests that the excision event and footprint formation involves DNA repair of hsp sequences flanking the transposable element. Identifying these footprints are useful for discovering genes that encodes for heat shock proteins in Solanaceae crops.Not Availabl
Marine Microalgae: Culture and their Industrial Applications
Microalgae such as Chaetoceros gracilis, C. calcitrans, Chlorella salina, C. marina,
Chromulina pleoides, Dunaliella tertiolecta, Isochrysis galbana, Nannochloropsis oculata,
Pavlova lutheri, Skeletonema costatum, Tetraselmis chuii, Thalassiosira sp., are microscopic
unicellular phytoplankton having size less than 10 μ, and have widely used in the aquaculture
industry. The selection of these live feed organisms are based on many factors such as
nutritional requirements of the cultured larvae, size of the mouth gape of larvae, development
of the digestive tract of the cultured larvae, nutritional value and availability of the live feed
and suitability for mass scale production. Though much efforts are been taken world-wide
to supplement live feed totally or partially with artificial feeds, various studies pointed out
that supply of suitable live feed organisms fortified with vitamins and fats are essential for
the successful completion of the larval stages
Pournami - A high yielding black pepper selection tolerant to root-knot nematode (Meloidogyne incognita)
A high yielding selection (CoIl. 812) from the germplasm, named Pournami, was tolerant to root-knot nematode (Meloidogyne incognita), damaging roots of black pepper and causing yellowing of leaves and significant yield decline. This selection when tested for its comparative yield performance, was on par with Karimunda and Panniyur-I and was recommended for release.
 
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