Experimental and modeling studies on microwave-assisted extraction of mangiferin from Curcuma amada

Mangiferin, a bioactive compound having potent nutraceutical, strong antioxidant and pharmacological significance has been extracted using microwave-assisted extraction (MAE) technique from Curcuma amada, commonly known as mango ginger. The extraction solvent ethanol is eco-friendly, nontoxic and reduces the risk of environmental hazards. The influence of several independent variables such as microwave power, ethanol concentration, extraction (irradiation) time and pre-leaching time has been studied under varying conditions using one-factor-at-a-time analysis to obtain an optimal extraction ratio. The maximum mangiferin content of 1.1156 mg/g is obtained at microwave power of 550 W and extraction time of 50 s with 80 % ethanol as a solvent and pre-leaching time of 20 min. The results indicate that microwave power and ethanol concentration have the most significant effect on the yield of mangiferin content. The presence of mangiferin in final Curcuma amada extract is confirmed through high-performance liquid chromatography and the functional groups are identified through Fourier transform infrared spectroscopy analyses using standard mangiferin. The experimental profiles are fitted into a two-parameter modified first-order kinetic model and a three-parameter modified logistic model and checked using the goodness-of-fit criterion. The Curcuma amada retained its antioxidant activity after MAE treatment and the antioxidant activity of mangiferin obtained after extraction using DPPH free radical scavenging assay is studied

Microwave assisted extraction of mangiferin from Curcuma amada

Mangiferin present in Curcuma amada was extracted with the help of microwave assisted extraction (MAE). The extraction solvent used was ethanol, which is eco-friendly and reduced the risk of environmental hazard. The mangiferin content was found to increase until 500 W, but decreased as the microwave power was increased further. A similar threshold was also obtained for microwave irradiation time. Following a mathematical analysis, an optimal mangiferin yield of 41 μg/mL was obtained from an extraction time of 15.32 s for a microwave power of 500 W

Hydrogen production by Cyanobacteria

The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical), Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source

A statistically motivated choice of process parameters for the improvement of canthaxanthin production by Dietzia maris NIT-D (accession number: HM151403)

Dietzia maris NIT-D, a producer of canthaxanthin, is isolated during routine screening of pigment producing bacteria. The effects of process parameters, namely temperature, pH, shaker speed, percentage inoculum, medium volume, and concentration of glucose on the canthaxanthin production are studied by using response surface design methodology. The optimal conditions are temperature = 30 degrees C, pH = 5.9, shaker speed = 125 rpm, inoculum = 1.9 %, volume = 50 mL, and glucose = 15 g L-1, resulting in a canthaxanthin production of 152 mg L-1, which is 25% higher than that of a recently reported study

"The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work

<span style="font-size:11.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Assessment of free-radical scavenging activities of mangiferin from <i style="mso-bidi-font-style:normal">Curcuma amada</i> obtained by non-conventional extraction methods: A comparative study</span>

179-185<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Mangiferin (MgFn) is a naturally occurring bioactive glucosylxanthone having numerous pharmacological activities. A feasible microwave assisted extraction (MAE) technique for extraction of MgFn from <i style="mso-bidi-font-style: normal">Curcuma amada (mango ginger) was developed in our laboratory. To prove the efficacy of MAE technique, it was compared with other methods like maceration extraction (ME) and ultrasonic sound assisted extraction (UAE). A high yield of MgFn was obtained by MAE (1.472 mg/g) compared to 1.017 mg/g yield by UAE and 0.837 mg/g by ME technique in acetone-water (50:50 v/v). Scanning electron microscopy (SEM) photographs of C. amada cells were taken, which were subjected to different extraction forces mentioned above. The efficacy of MgFn as a radical scavenger was studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), nitrate scavenging and ferric reducing power assays. The IC50 value of MgFn extracted with MAE was recorded to be 26 µg/mL; showing it to be an effective radical scavenger more efficient than ascorbic acid.</span

Selection of Suitable Carbon, Nitrogen and Sulphate Source for the Production of Alkaline Protease by Bacillus licheniformis NCIM-2042

In this study, selection of suitable carbon, nitrogen and sulphate sources were carried out by one-variable-at-time approach for the production of alkaline protease enzyme by Bacillus licheniformis NCIM-2042. Maximum levels of alkaline protease were found in culture media supplemented with magnesium sulphate, starch and soybean meal as a good sulphate, carbon and nitrogen sources which influenced the maximum yield of this enzyme (137.69�4.57, 135.23�1.73 and 134.74�1.77, respectively) in comparison with the other sulphate, carbon and nitrogen sources

Green synthesis of iron-oxide nanoparticles using scrap iron as precursor for the removal of Pb (II) from aqueous medium

In the present study, low-cost, environmentally friendly, single-step, high productive novel Iron-oxide nanoparticles (NPs) were prepared from scrap iron using a green synthesis method to remove Pb (II) from aqueous solution. The characterization of synthesized nanoparticles was conducted by UV-vis spectroscopy. The crystalline structure and the phase change were clarified by XRD. FE-SEM was done to know the morphology of iron oxide nanoparticles, and the average surface area of 46.856 m2/g was found by the BET surface area analyzer. The XRD plot shows that the obtained magnetite Fe3O4 combines FeO and Fe2O3 as the synthesis was conducted in the open atmosphere. The SEM images confirm the formation of iron oxide nanoparticles with a size of 31 nm. The removal efficiency of the adsorbent was carried out by optimizing the different operational parameters like pH, time, adsorbent dosage, initial concentration of metal ion, contact time by batch studies. The obtained pHzpc (pH 5.7) value indicates that the adsorption process will be favorable at higher pH. The maximum removal efficiency and uptake capacity of lead were 98% and 68.07 mg/g, respectively. Adsorption data obtained were analyzed with Langmuir and Freundlich isotherm equations. The equilibrium data are fitted by Langmuir isotherm in a superior way than that of Freundlich isotherm. The results show that homogeneous adsorption of the metal ion favors heterogeneous adsorption. The maximum adsorption capacity of iron oxide NPs was calculated through Langmuir isotherm was Qmax (68.07) mg/g. Moreover, the adsorption of metal ions with time was also analyzed with the pseudo 1st and pseudo 2nd kinetic equations. The kinetic data are fitted more in the pseudo 2nd order reaction. Adsorption capacity calculated through pseudo 2nd order equation was qe (51.81) mg/g. This literature verifies that NPs synthesized from scrap iron as precursors prove to be an attractive option for removing heavy metals

Statistical Optimization of Media Components for Production of Fibrinolytic Alkaline Metalloproteases from Xenorhabdus indica KB-3

Xenorhabdus indica KB-3, a well-known protease producer, was isolated from its entomopathogenic nematode symbiont Steinernema thermophilum. Since medium constituents are critical to the protease production, the chemical components of the selected medium (soya casein digest broth) were optimized by rotatable central composite design (RCCD) using response surface methodology (RSM). The effects of all five chemical components (considered as independent variables), namely tryptone, soya peptone, dextrose, NaCl, and dipotassium phosphate, on protease production (dependent variable) were studied, and it was found that tryptone and dextrose had maximum influence on protease production. The protease production was increased significantly by 66.31% under optimal medium conditions (tryptone—5.71, soya peptone—4.9, dextrose—1.45, NaCl—6.08, and dipotassium phosphate—0.47 in g/L). To best of knowledge, there are no reports on optimization of medium component for protease production by X. indica KB-3 using RSM and their application in fibrinolysis. This study will be useful for industrial processes for production of protease enzyme from X. indica KB-3 for its application in the field of agriculture and medicine