Evaluation of bacterial strains isolated from oil-contaminated soil for production of polyhydroxyalkanoic acids (PHA)     

Jyotsana Dalal  Priyangshu M. Sarma  Meeta Lavania  Ajoy K. Mandal  Banwari Lal 《Pedobiologia》2011,54(1):25-30

Samples of eight geographically distinct soils contaminated with crude oil were screened for polyhydroxyalkanoic acid (PHA) producing bacterial strains. Twenty three bacterial strains were able to accumulate PHA when sodium gluconate or sodium octanoate was used as the sole carbon source. Biochemical tests and 16S rRNA sequencing identified bacteria of the genera Pseudomonas, Acinetobacter, Sphingobacterium, Brochothrix, Caulobacter, Ralstonia, Burkholderia and Yokenella. Three of the bacterial strains have never been reported to produce PHA. The phylogenetic analysis of the PHA synthase (phaC) gene of these bacteria showed a close homology with the phaC gene of different Pseudomonas species.This study indicates that stressed environments like oil-contaminated sites can be potential sources of medium-chain-length PHA producers.  相似文献   

��Observations on Aerosol Optical Depth Over a Period of 3 Years at Kaikhali (22.022��N, 88.614��E) Inside a Special Mangrove Ecosystem��The Sundarbans��     

Indranil Mukherjee  Niladri Chakraborty  T. K. Mandal 《Water, air, and soil pollution》2011,215(1-4):477-486

The paper reports the observations of the aerosol studies carried-out for three years (2004-2007) during the summers and winters at Kaikhali (22.0220 N & 88.6140E) lying in the east coast of India inside a special mangrove ecosystem: 'The Sundarbans'. Aerosol optical depths were measured using a five filter channel sunphotometer with wavelengths at 340, 500,870, 936 and 1020 nm respectively. The sampling site enjoys a tropical climate and is under the strong influence of the southwest or summer monsoon and weak northeast or winter monsoon. The mean aerosol optical depth (AOD) during the winters (2004-2007) for the filter channels 340, 500, 870, 936 and 1020 nm have been found to be 1.478, 1.014, 0.579, 0.541 and 0.523 respectively whereas for the summer periods, they have been found to be 1.173, 0.859, 0.603, 0.564 and 0.597 respectively. The mean values of the angstrom exponent calculated for the winter and summer months over the years 2004-2007 have been found to be 1.283, 0.999, 1.285 and 1.094, 1.167 and 1.91 respectively. Generally the higher angstrom exponent values during the winter periods over the years from 2004-2007 except for the year 2005-2006 indicate high ratio of smaller fractions to larger fractions. The values of Angstrom exponents observed at the site suggest that the aerosol comprise mostly of the small size particles. An attempt has been made in the paper to compare the aerosol optical depth and angstrom exponent values with another study conducted in a different coastal zone in India.  相似文献   

A glycine-dependent riboswitch that uses cooperative binding to control gene expression     

Mandal M  Lee M  Barrick JE  Weinberg Z  Emilsson GM  Ruzzo WL  Breaker RR 《Science (New York, N.Y.)》2004,306(5694):275-279

We identified a previously unknown riboswitch class in bacteria that is selectively triggered by glycine. A representative of these glycine-sensing RNAs from Bacillus subtilis operates as a rare genetic on switch for the gcvT operon, which codes for proteins that form the glycine cleavage system. Most glycine riboswitches integrate two ligand-binding domains that function cooperatively to more closely approximate a two-state genetic switch. This advanced form of riboswitch may have evolved to ensure that excess glycine is efficiently used to provide carbon flux through the citric acid cycle and maintain adequate amounts of the amino acid for protein synthesis. Thus, riboswitches perform key regulatory roles and exhibit complex performance characteristics that previously had been observed only with protein factors.  相似文献   

APPRAISAL OF SOIL EROSION RISK IN THE EASTERN HIMALAYAN REGION OF INDIA FOR SOIL CONSERVATION PLANNING     

D. Mandal  V. N. Sharda 《Land Degradation \u0026amp; Development》2013,24(5):430-437

Management practices to minimise soil erosion can be effectively carried out if the magnitude and the spatial distribution of soil erosion risk areas are known. Prioritisation of soil erosion risk areas is a challenging task, especially in the developing countries because of non‐availability of relevant data and analytical tools for such an assessment. As a result, it becomes difficult to establish appropriate soil conservation measures on the risk‐prone areas to reduce soil loss and ensure development of a sustainable management of soil resources. Such a database can be better generated and analysed in a geographical information system (GIS) environment to delineate and prioritise the soil erosion risk areas at state or regional level. Therefore, a methodology was developed to assess the soil erosion risks in eastern Himalayan region by integrating spatial data on prevailing erosion rates and soil loss tolerance limits in GIS environment. By comparing the potential erosion rates with permissible rates, we observed that about 58·94 per cent of total geographical area (TGA) of the region requires different degrees of erosion management and 28·38 per cent of TGA falls under no treatment category because of higher values of permissible erosion limits. It can be successfully applied to assess and prioritise soil erosion risks in any region or country and identify best management practices to bring the erosion losses within the permissible limits. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Enhancement of the productivity of tea (Camellia sinensis) secondary metabolites in cell suspension cultures using pathway inducers     

Maria John Muthaiya  Praveen Nagella  Muthu Thiruvengadam  AbulKalam Azad Mandal 《Journal of Crop Science and Biotechnology》2013,16(2):143-149

Tea cell suspension culture is an alternative method for the synthesis of secondary metabolites. For the separation of cells, different concentrations of pectinase were used and a concentration of 0.5% was found to be the optimum concentration for the separation of cells (41.7%) in the culture medium than the other two concentrations (33.3 and 25.0%). The separated cells were cultured in liquid MS medium using different PGR combinations. The time taken for the cells to reach stationary phase, under different PGRs, ranged from 17 to 21 d. The maximum cell density was found in IAA and 2, 4-D medium at 21 d followed by 2, 4-D. Results revealed that the amount of secondary metabolites such as catechins were high with stationary phase when compared to other growth phases (lag and log phases). Different concentrations of shikimic acid (10, 20, and 30 mM) were added to the stationary phase of cell culture in the bioreactor and the secondary metabolite content was analyzed. Synthesis of polyphenols, catechins, caffeine, and other secondary components were high (33.87, 22.85, and 4.66%) with 20 mM shikimic acid treatment than the other two concentrations.  相似文献   

Antidiarrhoeal activity of carbazole alkaloids from Murraya koenigii Spreng (Rutaceae) seeds     

Suvra Mandal  Anupam Nayak  Manoj Kar  Samir K. Banerjee  Ashes Das  S.N. Upadhyay  R.K. Singh  Avijit Banerji  Julie Banerji 《Fitoterapia》2010

The bioassay guided fractionation of the n-hexane extract of the seeds of Murraya koenigii Spreng (Rutaceae) resulted in the isolation of three bioactive carbazole alkaloids, kurryam (I), koenimbine (II) and koenine (III). The structures of the compounds were confirmed from their ¹H-, ¹³C-, and 2D-NMR spectral data. Of the three compounds (I) and (II) exhibited significant inhibitory activity against castor oil-induced diarrhoea and PGE₂-induced enteropooling in rats. The compounds also produced a significant reduction in gastrointestinal motility in the charcoal meal test in Wister rats.  相似文献   

Studies on the Breeding of Pangasius sutchi Using Different Inducing Agents     

B. K. Chand  M. K. Singh  Basudev Mandal 《Journal Of Applied Aquaculture》2013,25(1):32-40

A breeding experiment on Pangasius sutchi was conducted from July 2008 to September 2008 in a hatchery in West Bengal, India, using three different inducing agents, each injected at two different dosages: carp pituitary extract (CPE) and two synthetic hormones, Ovaprim and Ovatide. The fertilization rate was 82% to 91%. Hatching took place within 34 to 36 hours from the time of fertilization, with a hatching rate 73% to 79%. The response to spawning with CPE was best with Ovatide and Ovaprim in terms of percentage of fertilization, high hatching rate, and ease of stripping.  相似文献   

Synthesis of poly(hydroxamic acid) ligand from polymer grafted khaya cellulose for transition metals extraction     

Md Lutfor Rahman  Bablu Hira Mandal  Shaheen M. Sarkar  Nor Asiken Abdul Wahab  Mashitah Mohd Yusoff  Sazmal E. Arshad  Baba Musta 《Fibers and Polymers》2016,17(4):521-532

A cellulose-graft-poly(methyl acrylate) was synthesized by free radical initiating process and the ester functional groups were converted into the hydroxamic acid ligand. The intermediate and final products are characterized by FT-IR, FE-SEM, HR-TEM and XPS technique. The pH of the solution acts as a key factor in achieving optical color signals of metalcomplexation. The reflectance spectra of the [Cu-ligand]n+ complex was found to be a highest absorbance at 99.8 % at pH 6 and it was increased upon increasing of Cu²⁺ ion concentrations and a broad peak at 700 nm was observed which indicated the charge transfer (π-π transition) metals-Cu complex. The adsorption capacity of copper was found to be superior (336 mg g^?1) rather than other transition metals such as Fe³⁺, Co³⁺, Cr³⁺, Ni²⁺, Mn²⁺ and Zn²⁺ were 310, 295, 288, 250, 248 and 225 mg g^-1, respectively at pH 6. The experimental data of all metal ions fitted significantly with the pseudo-second-order rate equation. The transition metal ions sorption onto ligand were well fitted with the Langmuir isotherm model (R²>0.99), which suggested that the cellulose-based adsorbent known as poly(hydroxamic acid) ligand surface is homogenous and monolayer. The reusability of the poly(hydroxamic acid) ligand was checked by the sorption/desorption process up to ten cycles without any significant loss in its original sensing and removal performances.  相似文献   

Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats     

Mandal TK  Parvin N  Mondal S  Saxena V  Saxena AK  Sarkar S  Saha M 《Journal of animal physiology and animal nutrition》2012,96(2):191-197

Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions.  相似文献   

Genetic and environmental influences on faecal nematode egg counts of Jamunapari goats in India     

Mandal A  Sharma DK  Roy R 《The Veterinary record》2012,170(13):337

The present study was carried out from 1999 to 2003 to determine the genetic and environmental influences of faecal egg count (FEC), an indicator of host resistance, in adult Jamunapari goats with naturally acquired gastrointestinal nematode parasite infections (predominantly Haemonchus contortus). FEC data on 670 records of Jamunapari goats descended from 54 bucks and 208 does were used in this study. Analyses were carried out by restricted maximum likelihood estimation, fitting an animal model. Four different animal models ignoring or including maternal genetic or permanent environmental effects were fitted. Different environmental effects, that is, sampling year, month and the sex of the animals, significantly (P<0.01) influenced FECs in the goats. Direct heritability estimates were inflated substantially for this trait when maternal effects were ignored. The direct heritability estimates for the trait ranged from 0.11 to 0.16 depending on the model used. Low estimates of maternal heritability (m(2)=0.06) and the fraction of variance due to maternal permanent environmental effects (c(2)=0.09) for FECs were observed in the present study. The results suggest that direct and permanent environmental maternal effects were important for this trait; however, maternal additive effects had less impact on this trait. These results also indicate that modest rates of genetic progress appear possible for FECs.  相似文献