The utility of DNA typing in forensic work.   总被引：16，自引：0，他引：16  

R Chakraborty  K K Kidd 《Science (New York, N.Y.)》1991,254(5039):1735-1739

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Mycophagous soil amoeba: Interactions with three plant pathogenic fungi     

S. Chakraborty  K.M. Old 《Soil biology & biochemistry》1982,14(3):247-255

An amoeba of the order Leptomyxida was isolated from wheat take-all decline soil and was found to attack and lyse hyphae and spores of Gaeumannomyces graminis var. tritici and Phytophthora cinnamomi. The amoeba enveloped portions of hyphae of both fungi and penetrated the cell walls by means of fine holes. One-week old chlamydospores and hyphal swellings of P. cinnamomi were also attacked in this way, protoplast lysis being completed within 1 h. Hyphal fragments which could be ingested by the amoeba were lysed leaving amorphous cell debris. Three-week old chlamydospores of P. cinnamomi were enclosed within large food vacuoles and completely digested in about 20 h. Pigmented conidia of Cochliobolus sativus were transported across the substratum for up to several hours but were not perforated or lysed.  相似文献   

Enzyme activities and microbial biomass in coastal soils of India   总被引：1，自引：0，他引：1  

Sudipta Tripathi  Ashis Chakraborty  Bimal Kumar Bandyopadhyay 《Soil biology & biochemistry》2007,39(11):2840-2848

Soil salinity is a serious problem for agriculture in coastal regions, wherein salinity is temporal in nature. We studied the effect of salinity, in summer, monsoon and winter seasons, on microbial biomass carbon (MBC) and enzyme activities (EAs) of the salt-affected soils of the coastal region of the Bay of Bengal, Sundarbans, India. The average pH of soils collected from different sites, during different seasons varied from 4.8 to 7.8. The average organic C (OC) and total N (TN) content of the soils ranged between 5.2-14.1 and 0.6-1.4 g kg⁻¹, respectively. The electrical conductivity of the saturation extract (ECe) of soils, averaged over season, varied from 2.2 to 16.3 dSm⁻¹. The ECe of the soils increased five fold during the summer season (13.8 dSm⁻¹) than the monsoon season (2.7 dSm⁻¹). The major cation and anion detected were Na⁺ and Cl⁻, respectively. Seasonality exerted considerable effects on MBC and soil EAs, with the lowest values recorded during the summer season. The activities of β-glucosidase, urease, acid phosphatase and alkaline phosphatase were similar during the winter and monsoon season. The dehydrogenase activity of soils was higher in monsoon than in winter. Average MBC, dehydrogenase, β-glucosidase, urease, acid phosphatase and alkaline phosphatase activities of the saline soils ranged from 125 to 346 mg kg⁻¹ oven dry soil, 6-9.9 mg triphenyl formazan (TPF) kg⁻¹ oven dry soil h⁻¹, 18-53 mg p-nitro phenol (PNP) kg⁻¹ oven dry soil h⁻¹, 38-86 mg urea hydrolyzed kg⁻¹ oven dry soil h⁻¹, 213-584 mg PNP kg⁻¹ oven dry soil h⁻¹ and 176-362 mg PNP g⁻¹ oven dry soil h⁻¹, respectively. The same for the non-saline soils were 274-446 mg kg⁻¹ oven dry soil, 8.8-14.4 mg TPF kg⁻¹ oven dry soil h⁻¹, 41-80 mg PNP kg⁻¹ oven dry soil h⁻¹, 89-134 mg urea hydrolyzed kg⁻¹ oven dry soil h⁻¹, 219-287 mg PNP kg⁻¹ oven dry soil h⁻¹ and 407-417 mg PNP kg⁻¹ oven dry soil h⁻¹, respectively. About 48%, 82%, 48%, 63%, 40% and 48% variation in MBC, dehydrogenase activity, β-glucosidase activity, urease activity, acid phosphatase activity and alkaline phosphatase activity, respectively, could be explained by the variation in ECe of saline soils. Suppression of EAs of the coastal soils during summer due to salinity rise is of immense agronomic significance and needs suitable interventions for sustainable crop production.  相似文献   

Amoebae from a take-all suppressive soil which feed on Gaeumannomyces graminis tritici and other soil fungi     

S. Chakraborty  K.M. Old  J.H. Warcup 《Soil biology & biochemistry》1983,15(1):17-24

Amoebae were isolated from soil of the Waite Institute permanent pasture plot which is suppressive to take-all of wheat. Nine species of amoebae belonging to eight genera were tested for their mycophagy against Gaeumannomyces graminis var. tritici, Cochliobolus sativus and Phytophthora cinnamomi. Members of the genera, Gephyramoeba, Mayorella, Saccamoeba, Thecamoeba and an unidentified species of the order Leptomyxida, were mycophagous. Feeding of mycophagous amoebae and their ability to perforate and lyse melanized propagules of fungi are discussed.  相似文献   

Microbial Biomass and Activity in a Laterite Soil Amended with Municipal Solid Waste Compost     

P. Bhattacharyya  R. Pal  A. Chakraborty  & K. Chakrabarti 《Journal of Agronomy and Crop Science》2001,187(3):207-211

The dynamics of soil quality indicators, such as microbial biomass-C, soil respiration, and urease and acid phosphatase activities, in a laterite soil (Typic Haplustalf ) amended with different doses of Calcutta municipal solid waste compost (MSWC) were studied over 120 days of incubation at 30 °C under 60 % soil water holding capacity. The parameters were found to increase with the increase in doses of MSWC. Soil microbial biomass-C (MBC) and soil respiration activity reached peak values at 30 days of incubation and then gradually decreased up to 120 days of incubation. Urease and acid phosphatase activities showed peak values at 60 and 90 days of incubation, respectively. The increase in soil enzyme activities with the fall in MBC suggested that the release of enzymes was associated with lysis of microbial cells at the end of their life cycle. There was no indication of any detrimental effect on soil quality indicators of application of MSWC to soil.  相似文献   

Effect of Climatic Variation on Yield of Sesame (Sesamum indicum L.) at Different Dates of Sowing     

R. Nath  P. K. Chakraborty  & A. Chakraborty 《Journal of Agronomy and Crop Science》2001,186(2):97-102

Although experiments have previously been carried out to determine the optimum sowing time of sesame, very few attempts have been made to determine the effects of macro and micro climatic variation on yield. Thus a field experiment was conducted at the University Research Farm, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, India on an Entisol (alluvial, sandy loam) in the summer seasons of 1996 and 1997 to assess the effects of macro and micro climatic variations on yield of sesame for various dates of sowing. The number of seeds per capsule of sesame was highest in the crop sown on 19 February, although up to the 18 April sowing there was no significant variation. There was no appreciable variation in thousand-seed weight with date of sowing. Crops sown on 19 February and 1 March produced statistically similar yields. The average reduction in yield of sesame was 78.5 and 213 %, respectively, for crops sown on 10 February and 28 April, compared with the crop sown on 19 February. The cultivar Rama produced higher yields than B-67 and Kanke-1. Ambient temperature above 30 °C up to 100 % flowering had a direct positive effect on sesame yield. Crop exposure to 60–70, 70–80 and  80 % relative humidity up to 100 % flowering had a direct negative effect. Temperature profile at 50 days after emergence (DAE), relative humidity at 60 DAE, and photosynthetically active radiation (PAR) at 30 and 40 DAE within the crop canopy had direct positive effects on yield. Regression models suggested that temperature profile and PAR within the crop canopy produced 72 and 35 % variation in yield, respectively.  相似文献   

Toxico-kinetics, recovery, and metabolism of napropamide in goats following a single high-dose oral administration     

Pahari AK  Majumdar S  Mandal TK  Chakraborty AK  Bhattacharyya A  Chowdhury A 《Journal of agricultural and food chemistry》2001,49(4):1817-1824

Toxicokinetic behavior, recovery and metabolism of napropamide (a pre-emergent herbicide) and its effect on Cytochrome P(450) of liver microsomal pellet were studied following a single high-dose oral administration of 2.5 g kg(-1) and continuous (7 days) oral administration of 500 mg kg(-1) in black Bengal goat. Napropamide was detected in blood at 15 min and the maximum quantity was recovered at 3 h after administration. The absorption rate constant (Ka) value was low indicating poor absorption from the gastrointestinal tract. High elimination half-life (t(1/2) beta) and low body clearance (Cl(B)) values coupled with higher transfer of compound from tissue to central compartment (K(21)) suggest that napropamide persisted in the blood for a long time, i.e., after 72 h of oral administration. The recovery percentage of napropamide, including metabolites, from goats varied from 75.94 to 80.08 and excretion of the parent compound through feces varied from 18.86 to 21.59%, indicating that a major portion of the orally administered napropamide was absorbed from the gastrointestinal tract of goat. Napropamide significantly increased the Cytochrome P(450) content of liver microsomal pellet. The recovery of metabolites from feces, urine, and tissues ranged from 4.2--6.2, 40.81--49.42, and 2.7--11.6%, respectively, during a 4--7 day period. The material balance of napropamide (including metabolites) following a single high-dose oral administration at 2.5 g kg(-1) during 4--7 days after dosing was found to be in the range of 75--80%.  相似文献   

Potentiality for value-added technical use of Indian sisal     

G. Basu  A.N. RoyK.K. Satapathy  Sk.Md.J. AbbasL. Mishra  R. Chakraborty 《Industrial Crops and Products》2012,36(1):33-40

India is one of the major exporters of sisal ropes and cordages but the raw fibres are imported from Africa and some other places. Import of sisal fibre in India is increasing at the rate of 25% per year for last few years. Sisal is grown in randomly distributed pockets all over Indian sub-continent mainly for some other purpose without giving any attention to the selective variety or species of Agave family. It is commonly stated that quality of Indian sisal fibre is not up to the mark of making standard quality of ropes, binder, twines, etc. The paper reports the textile related structure and properties (viz. tensile behavior, bending rigidity, thickness, coefficient of friction, moisture, thickness, surface appearance, transversal structure) of Indian variety of sisal fibres grown in two different agro-climatic regions in India to find out its suitability for producing standard quality products. The properties of Indian sisal fibres have also been compared to the imported one to explore the potentiality of the Indian fibres for making standard international quality products. The present work reveals that it is possible to grow sisal fibre of specified variety/species (Agave sisalana) having much balanced property parameters for producing international quality products (viz., ropes, cordages agricultural binders). Agave sisalana grown in certain agro-climatic regions (viz., Orissa) in India showed much comparable property parameters, even sometimes better, to the fibres imported from Tanzania.  相似文献   

Anti-Inflammatory Concentrate Enriched with Substituted Oligofucans Derived from Brown Seaweed Turbinaria conoides (J. Agardh) Kützing and Its Safety Assessment on Wistar Rats     

Kajal Chakraborty  Deepu Joseph  Vamshi Krishna Raola 《Journal Of Aquatic Food Product Technology》2013,22(8):1323-1338

ABSTRACT

Aqueous extract of the seaweed Turbinaria conoides was purified to obtain an oligofucan-enriched seaweed concentrate (OESC). Oligofucans isolated were characterized as two types with (→1)-fucose-(2,3-diSO₃^?)-(1→4)-fucose-(2-SO₃^?)-(1→3)-fucose-(2,3-diSO₃^?)-(1→4)-fucose-(2-SO₃^?, 3-OAc)-(4→) and (→1)-fucose-(3-SO₃^?)-(1→4)-fucose-(2-SO₃^?)-(1→4)-fucose-(3-SO₃^?)-(1→4)-fucose-(2-SO₃^?)-(4→) motifs. A 90-day accelerated shelf-life study (50°C) showed that OESC maintained its antioxidant properties (free radical scavenging, reducing, lipid peroxidation inhibition, and chelating activities) even after 30 days. In vitro COX-2 and 5-LOX inhibitory properties of OESC (67.2 and 95.2%, respectively) showed no significant variation even at the 30th day. OESC significantly mitigated the carrageenan-induced inflammation in rats at 0–2 h (59.7–70.3% inhibition), which were greater compared to the synthetic NSAID aspirin. The safety of OESC has been assessed by acute (14 days) and subchronic (90 days) oral toxicity studies, which showed no toxicity-related significant changes in renal or hepatic function, hematological indices, and serum biochemical parameters in the OESC-treated Wistar rats. No histopathological alterations were observed in the vital organs of rats treated with OESC. LD₅₀ and sub-chronic no-observed-adverse-effect level (NOAEL) for this concentrate were found to be > 5,000 and 2,000?mg/kg BW, respectively. Hence, oligofucan-enriched seaweed concentrate is safe to consume without any adverse effects in the body.  相似文献   

Antioxidative Status of a Nutrient Enriched Formulation of Perna viridis in a Time Series Shelf-Life Study     

Kajal Chakraborty  Selsa J. Chakkalakal  Deepu Joseph 《Journal Of Aquatic Food Product Technology》2013,22(5):666-683

ABSTRACT

The freeze-dried concentrate of green mussel, Perna viridis, was added with naturally derived antioxidative oleoresins of rosemary and turmeric along with trace amounts of other natural additives to prepare different treatments and was subjected to accelerated shelf life study (50°C) to evaluate its oxidative stability. The total oxyradical scavenging activities of samples with higher concentrations of turmeric over rosemary demonstrated the prominent role of the turmeric extracts to arrest free radical chain reactions. Time dependent antioxidative status in relation to the nutritional compositions was evaluated to identify the oxidative changes for different treatments. The addition of natural additives with polyphenolic moieties in the treatments shielded the mussel’s unsaturated fatty acids against oxidation as evident by higher polyunsaturated fatty acids in the two treatments as compared to control after 90 days of accelerated shelf-life study. Higher n-3/n-6 ratios after 90 days’ storage were also observed in these treatments. A threshold level of combined turmeric (0.8 g/100 g) and rosemary (0.4 g/100 g) was sufficient for optimum antioxidant activity and to maintain nutritional composition of the green mussel extract at desired levels.  相似文献