Structural and Molecular Characterization of Squalene Synthase Belonging to the Marine Thraustochytrid Species Aurantiochytrium limacinum Using Bioinformatics Approach     

Sachin Vyas  Maurizio Bettiga  Ulrika Rova  Paul Christakopoulos  Leonidas Matsakas  Alok Patel 《Marine drugs》2022,20(3)

The marine microorganisms thraustochytrids have been explored for their potential in the production of various bioactive compounds, such as DHA, carotenoids, and squalene. Squalene is a secondary metabolite of the triterpenoid class and is known for its importance in various industrial applications. The bioinformatic analysis for squalene synthase (SQS) gene (the first key enzyme in the tri-terpenoid synthesis pathway), that is prevailing among thraustochytrids, is poorly investigated. In-silico studies combining sequence alignments and bioinformatic tools helped in the preliminary characterization of squalene synthases found in Aurantiochytrium limacinum. The sequence contained highly conserved regions for SQS found among different species indicated the enzyme had all the regions for its functionality. The signal peptide sequence and transmembrane regions were absent, indicating an important aspect of the subcellular localization. Secondary and 3-D models generated using appropriate templates demonstrated the similarities with SQS of the other species. The 3-D model also provided important insights into possible active, binding, phosphorylation, and glycosylation sites.  相似文献   

Excretion of DDT residues into milk of the Indian buffalo,Bubalus bubalis (L.) after oral and dermal exposure     

Rajinder L. Kalra  Ram P. Chawla  Balbir S. Joia  Mewa S. Tiwana 《Pest management science》1986,17(2):128-134

Three groups of buffaloes were fed with 20, 100 and 400 mg of p,p′-DDT in their daily rations. The DDT residues in the milk fat of the treated animals showed an initial rapid rise but soon attained a dose-dependent equilibrium. The transfer coefficient of DDT residues in milk at ‘plateau’ levels showed an average value of about 12%. Half-life values for the rate of decline of DDT residues during the post-dosing period were computed according to a two-open-compartment model. Dermal application of p,p′-DDT to buffaloes also resulted in excretion of a significant amount of its residues in milk. TDE was the predominant compound present in milk when buffaloes had ingested p,p′-DDT, whilst p,p′-DDT itself was present in greater quantity than its metabolites when animals were treated dermally.  相似文献   

Comparative excretion of DDT analogues into milk of indian buffalo,Bubalus bubalis L. following oral administration     

Sudesh K. Kapoor  Rajinder L. Kalra 《Pest management science》1993,37(3):261-266

Four groups of Indian buffaloes were fed daily with 25 mg of p,p′-DDT p,p′-TDE p,p′-DDE or o,p′-DDT for 100 days. Milk was analysed for organochlorine residues during this period and also for 100 days after pesticide administration had been discontinued. For the period showing ‘plateau level’ residues, 17.2% of p,p′-DDE, 17% of p,p′-TDE, 14% of p,p′-DDT as p,p′-DDT (3.5%); p,p′-TDE (10.5%); 3.2% of p,p′-DDT as o,p′-DDT (1.3%) and o,p'-TDE (1.9%) of their administered amounts were excreted in the milk. Since these compounds were excreted at different rates, the residue levels in the milk expected from a given feed would depend on their concentration and proportional distribution in the feed. The maximum tolerable content of DDT analogues in feed was derived to be 0.1 mg kg^?1 (dry weight basis) by using the maximum accumulation coefficient and incorporation of the necessary safety margin. It is concluded that Indian buffaloes fed with rations contaminated with a total of DDT analogues below this limit will yield milk of acceptable quality. Following the termination of feeding with contaminated rations, the elimination of p,p′-DDE in the milk took the longest time and that of o,p′-DDT the shortest. These results suggest that the time required for the initial high residue concentration to decline to less than the legal limit would be determined by the relative amounts of DDE, TDE and DDT in the milk, after elimination of the potent source of contamination.  相似文献   

A fatal cutaneous granuloma due to Entomophthora coronata in a mare   总被引：2，自引：0，他引：2  

H V Chauhan  G L Sharma  D S Kalra  F C Malhotra  M P Kapur 《The Veterinary record》1973,92(16):425-427

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Primary pasteurellosis in igs--studies on outbreaks on Punjab     

R P Vig  D S Kalra 《The Indian veterinary journal》1969,46(10):842-847

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Multiple Induced Spawnings of the Indian Catfish Heteropneustes fossilis (Bloch) within a Prolonged Spawning Season     

Deoraj  Alok  T. Krishnan    G. P. Talwar    Lalit C.  Garg 《Journal of the World Aquaculture Society》1998,29(2):252-258

Abstract Singhi, the Indian catfish Heteropneustes fossilis , attained gonadal maturity repeatedly in a single spawning cycle by photothermal treatment. After the first spawning, maintenance at 30 C and 14 h light/10 h dark for 3 wk induced recruitment of the next batch of mature oocytes for subsequent spawnings. The number of eggs released declined with each spawning. However, fertilizability of the eggs was maintained until the fifth spawning. Mature fish were induced to spawn by D-Lys⁶ salmon gonadotropin-releasing hormone agonist administration. The dose of salmon gonadotropin-releasing hormone agonist for the second and subsequent spawnings was determined to be 25-fold less compared to the dose administered for the first spawning. Fish released the maximum number of eggs upon induction when they were maintained continuously at 30 C and 14 h light/10 h dark for 6 wk. The result obtained in the present study points to a possibility of obtaining multiple spawnings from those species of farmed fish which spawn once a year.  相似文献   

Thermal Infrared Radiation for Assessing Crop Water Stress in Wheat   总被引：1，自引：0，他引：1  

Alok  Kumar R. P. Tripathi 《Journal of Agronomy and Crop Science》1990,165(4):268-272

Field studies on differentially irrigated wheat ( Triticum aestivum L.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress-degree-day index (mid day canopy-air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress-degree-day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil-induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation management programme.  相似文献   

Retention and extractability of phenol,cresol, and dichlorophenol exposed to two surface soils in the presence of horseradish peroxidase enzyme     

Xu F  Bhandari A 《Journal of agricultural and food chemistry》2003,51(1):183-188

The retention of phenol, o-cresol, 2,4-dichlorophenol (DCP), and their peroxidase-catalyzed polymerization products was evaluated on two surface soils. The extractability of the parent solutes and their polymerization products was also investigated. (14)C-Labeled radioisotopes were used to quantify the contaminant retained on soil as water-extractable, methanol-extractable, humic/fulvic (HA/FA) acid-bound, and soil/humin bound. Between 2 and 20% of the solute retained on soil after a 7-day contact period remained bound to the HA/FA and soil/humin components in unamended soils; in the presence of peroxidase this amount was as high as 40-75%. The alkali-extractable HA/FA component contained the largest fraction of radioactivity in peroxidase-amended soils. Whereas the soil organic matter content was the predominant factor controlling the extent of sorption of the parent phenols, the clay content and particle surface area appeared to contribute to the retention of the polymerization products. High molecular weight oligomers produced during peroxidase-mediated polymerization of phenols associate strongly with soil components and are likely incorporated into the soil organic matter via oxidative coupling reactions.  相似文献   

Estimation of natural pollution loads from streamflow measurements in remote catchments     

Teja Singh  Y. P. Kalra 《Water, air, and soil pollution》1977,7(1):111-116

In a study conducted in Marmot Creek Basin (total area 9.40 kmz) situated in the Rocky Mountains of Alberta, equations were developed to obtain gross estimates of the total inorganic solutes dislodged from three forest catchments on a monthly and annual basis. The r ² range of the equations was 99% or greater, indicating excellent fit in all cases. The equations are suitable for in situ estimation of the pollution loads directly from streamflow measurements, especially for remote catchments.  相似文献   

Biodegradable polymers for the environment   总被引：1，自引：0，他引：1  

Gross RA  Kalra B 《Science (New York, N.Y.)》2002,297(5582):803-807

Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.  相似文献