► Activated charcoal treatment followed by vaccum concentration and crystallization method for xylitol extraction was followed and optimized. ► The optimized conditions were 15.0
g/l charcoal ...concentration at 30
°C for 1
h. ► The super saturation and crystallization temperature were optimized and yields 76.20%. ► Purified xylitol was studied in ethanol and tetrahydrofuran. ► The purity of the xylitol was characterized using NMR, optical rotation and mass spectra.
Xylitol, a sugar substitute, is a high value product for pharmaceutical and food industries and its purification being of commercial importance. In the present study, the purification of xylitol obtained through
Candida tropicalis by fermentation using synthetic xylose and corn cob hemicellulosic hydrolysate as substrates were studied for liquid–liquid extraction (21.72
g/l xylitol extracted in 1:5 (v/v) of ethyl acetate) and precipitation (67.44% xylitol recovery along with certain impurities). By this method xylitol recovery is difficult and expensive for large scale processes. Therefore, activated charcoal treatment followed by vaccum concentration and crystallization method for xylitol extraction was evaluated. The optimized conditions obtained for activated charcoal treatment followed by vaccum concentration and crystallization method were 15.0
g/l of charcoal concentration at 30
°C for 1
h with 10 times super saturation of initial concentration and crystallization temperature of −20
°C for initiation and then at 8
°C yielding 43.97%. After 4 cycles of crystallization, 76.20% and 68.06% xylitol crystallization yield was obtained in 50
ml and 5.0
l of the synthetic xylose fermentation broth by adapted strain of
C. tropicalis respectively. The effect of solvents on the crystalline structure of xylitol showed prismatic structure in the presence of ethanol and orthorhombic needles in the presence of tetrahydrofuran. The purity of the xylitol was characterized using
13C and
1H nuclear magnetic resonance, mass spectroscopy, and optical rotation, confirming 98.99% purity in a pure crystallized form.
An empirical pseudopotential method, in conjunction with virtual crystal approximation and the compositional disorder effect, is exploited to extract the full electronic band structure of various ZnO ...thin films to ensure excellent agreement with the experimental results, and to compare with the theoretical results obtained on the basis of various density functional theories. The lattice parameters obtained through x-ray diffraction (XRD) studies have been used to characterize the full electronic band structure of various ZnO thin films. The whole work reported here has been carried out using the TNL FullBand
TM
simulator (Tech Next Lab). The impact of intrinsic and extrinsic doping and the formation of polycrystalline planes in thin film samples on the band gap parameter have been analyzed in terms of the internal structure factor,
u
. The rigorous analysis of crystalline and polycrystalline samples show that the band gap value is strongly dependent on the internal structure parameter,
u
. The
u
value has been found to be significantly affected by lattice disorder generated by the formation of various defects and polycrystalline planes in the thin films. An innovative model demonstrating the relationship between the alloy disorder effect and the internal parameter is reported. With the help of an innovative model, the value of alloy disorder parameters,
P
, have been extracted for undoped and 1, 2, and 3 at% Cd-, Sr-, and Fe-doped ZnO thin film samples, respectively. Reasonable agreement has been obtained between the reported and experimental optical band gap results. The results reported in the current article show superiority against previously theoretical results based on first-principles methods.
Abstract
As a natural hazard, drought is a complex multivariate phenomenon that requires more comprehensive analysis. In this study, we studied meteorological, agricultural, and hydrological drought ...events with precipitation, soil moisture, and stream flow data for the study area. The risk analysis for drought duration and severity of three kinds of drought events were analyzed with univariate and three kinds of bivariate return periods based on the copula. Furthermore, the propagation of three kinds of drought was studied. From the investigation, it is observed that agricultural drought events are longer and more severe, besides the risk associated with agricultural drought is high compared to other kinds of drought. Moreover, the average time taken for meteorological drought to propagate into agricultural drought is 4.3 months and for the hydrological drought is 3.8 months for the river basin. The comprehensive study of three kinds of drought is helpful to adopt suitable drought management plans in the region.
Using gamma-ray-induced mutagenesis, we have developed a mutant (named G2) of
Trichoderma virens
that produced two- to three-fold excesses of secondary metabolites, including viridin, viridiol, and ...some yet-to-be identified compounds. Consequently, this mutant had improved antibiosis against the oomycete test pathogen
Pythium aphanidermatum
. A transcriptome analysis of the mutant vis-à-vis the wild-type strain showed upregulation of several secondary-metabolism-related genes. In addition, many genes predicted to be involved in mycoparasitism and plant interactions were also upregulated. We used tamarind seeds as a mass multiplication medium in solid-state fermentation and, using talcum powder as a carrier, developed a novel seed dressing formulation. A comparative evaluation of the wild type and the mutant in greenhouse under high disease pressure (using the test pathogen
Sclerotium rolfsii
) revealed superiority of the mutant over wild type in protecting chickpea (
Cicer arietinum
) seeds and seedlings from infection. We then undertook extensive field evaluation (replicated micro-plot trials, on-farm demonstration trials, and large-scale trials in farmers’ fields) of our mutant-based formulation (named TrichoBARC) for management of collar rot (
S. rolfsii
) in chickpea and lentil (
Lens culinaris
) over multiple locations in India. In certain experiments, other available formulations were included for comparison. This formulation consistently, over multiple locations and years, improved seed germination, reduced seedling mortality, and improved plant growth and yield. We also noticed growth promotion, improved pod bearing, and early flowering (7–10 days) in TrichoBARC-treated chickpea and lentil plants under field conditions. In toxicological studies in animal models, this formulation exhibited no toxicity to mammals, birds, or fish.
Purification strategies for microbial lipases Saxena, R.K; Sheoran, Anita; Giri, Bhoopander ...
Journal of Microbiological Methods,
2003, 2003-Jan, 2003-1-00, 20030101, Letnik:
52, Številka:
1
Book Review, Journal Article
Recenzirano
Microbial lipases today occupy a place of prominence among biocatalysts owing to their ability to catalyze a wide variety of reactions in aqueous and non-aqueous media. The chemo-, regio- and ...enantio-specific behaviour of these enzymes has caused tremendous interest among scientists and industrialists. Lipases from a large number of bacterial, fungal and a few plant and animal sources have been purified to homogeneity. This has enabled their successful sequence determination and their three-dimensional structure leading to a better understanding of their unique structure–function relationships during various hydrolytic and synthetic reactions. This article presents a critical review of different strategies which have been employed for the purification of bacterial, yeast and fungal lipases. Since protein purification is normally done in a series of sequential steps involving a combination of different techniques, the effect of sequence of steps and the number of times each step is used is analyzed. This will prove to be of immense help while planning lipase purification. Novel purification technologies now available in this field are also reviewed.
Pusa 391, a mega
desi
chickpea variety with medium maturity duration is extensively cultivated in the Central Zone of India. Of late, this variety has become susceptible to Fusarium wilt (FW), which ...has drastic impact on its yield. Presence of variability in the wilt causing pathogen,
Fusarium oxysporum
f.sp.
ciceri
(
foc
) across geographical locations necessitates the role of pyramiding for FW resistance for different races (
foc
1,2,3,4 and 5). Subsequently, the introgression lines developed in Pusa 391 genetic background were subjected to foreground selection using three SSR markers (GA16, TA 27 and TA 96) while 48 SSR markers uniformly distributed on all chromosomes, were used for background selection to observe the recovery of recurrent parent genome (RPG). BC
1
F
1
lines with 75–85% RPG recovery were used to generate BC
2
F
1
. The plants that showed more than 90% RPG recovery in BC
2
F
1
were used for generating BC
3
F
1
. The plants that showed more than 96% RPG recovery were selected and selfed to generate BC
3
F
3
. Multi-location evaluation of advanced introgression lines (BC
2
F
3
) in six locations for grain yield (kg/ha), days to fifty percent flowering, days to maturity, 100 seed weight and disease incidence was done. In case of disease incidence, the genotype IL1 (BGM 20211) was highly resistant to FW in Junagarh, Indore, New Delhi, Badnapur and moderately resistant at Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM20211) was the most stable genotype at Junagadh, Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM 20211) and IL4(BGM 20212) were the top performers in yield and highly stable across six environments and were nominated for Advanced Varietal Trials (AVT) of AICRP (All India Coordinated Research Project on Chickpea) in 2018–19. BGM20211 and BGM 20212 recorded 29 and 28.5% average yield gain over the recurrent parent Pusa 391, in the AVT-1 and AVT-2 over five environments. Thus, BGM20211 was identified for release and notified as Pusa Manav/Pusa Chickpea 20211 for Madhya Pradesh, Gujarat and Maharashtra, Southern Rajasthan, Bundhelkhand region of Uttar Pradesh states by the Central Sub-Committees on Crop Standards, Notification and Release of Varieties of Agricultural Crops, Ministry of Agriculture and Farmers Welfare, Government of India, for commercial cultivation in India (Gazette notification number S.O
.
500 (E) dt. 29-1-2021).Such pyramided lines give resilience to multiple races of fusarium wilt with added yield advantage.
The present study was made with the objectives of development and standardization of cattle specific paper-based loop-mediated isothermal amplification cum lateral flow assay (LAMP-LFA), as a ...Point-of-care test (POCT) for identification of tissue of cattle origin. The components of standardized LAMP reaction utilizing cattle specific primer sets were lyophilized over paper buttons, identified best as the carrier of LAMP reagents. Based on probable LAMP amplicon, a pair of probes was designed, tagged and its hybridization with the amplified product of paper LAMP reaction was optimized. The components of lateral flow assay for detection of probe hybridized LAMP products were standardized. Analysis of successful amplification was made by using HNB dye, LAMP-LFA strip, and also by the typical ladder-like pattern on gel electrophoresis. The assay was found highly specific for cattle with an analytical sensitivity of 0.1 pg of absolute DNA. Laboratory validation carried out on samples from different individuals of cattle, coded samples, binary meat admixture, and heat-processed cattle tissues substantiated the accuracy of the assay. Comparison with pre-standardized species-specific PCR assay taken as gold standards revealed 100% conformity. The field utility of the developed assay was further established by its compatibility with the commercial kit eliminating the lengthy DNA extraction step and storage stability of LAMP reagent carrier buttons for 4 months under refrigeration. Thus, the developed assay capable of the result within 3 h in resource-limited settings can be used as POCT for identification of tissue of cattle origin.
Display omitted
•Describe a paper based LAMP-LF Assay for identification of tissue of cattle origin.•Designed lyophilized paper LAMP buttons as a ready to use LAMP “master-mix”.•Storage stability of freeze-dried paper LAMP buttons at 4 °C were found 4 months.•Time from sampling to detection of end-product was less than 180 min.•Developed assay was found to be effective for species authentication in low field setting.
The proposed silicon-on-insulator Schottky barrier (SOI-SB) nanowire metal–oxide–semiconductor field-effect transistor (NW-MOSFET) is extensively investigated to further improve its ...analog/radiofrequency (RF) performance. The proposed device shows effectively improved electrostatic control and a reduced ambipolar effect in the OFF-state current. Simulations of the proposed device are conducted and compared with a dielectric pocket Schottky barrier NW-MOSFET for a channel length of 22 nm and radius 5 nm. The SOI-SB NW-MOSFET shows improved performance in terms of
I
OFF
current,
I
ON
/
I
OFF
ratio, subthreshold slope, early voltage, transconduction generation factor, and intrinsic gain.
Abstract
Bipolar plates, a critical component of proton exchange membrane fuel cell (PEMFC), are constructed out of alloys of Ti, Pt, Cr, or graphitic materials that have limitations. Electrical ...conductivity, cost, and corrosion resistance are among the critical considerations for bi‐polar plate material. Graphene, which possesses impressive conductivity and toughness, is an attractive option as coating on metallic substrates of PEMFC bipolar plates. This study investigates corrosion resistance and its durability due to graphene developed by chemical vapor deposition on a pure Ni–Cu alloy and a commercial Ni–Cu alloy in 0.5
m
H
2
SO
4
environment, with a view to exploring use of graphene coated Ni–Cu alloys for the construction of PEMFC bipolar plates. The graphene coating on the pure alloy shows remarkably superior corrosion resistance than the commercial alloy that is attributed to the former's ability to develop considerably defect‐free graphene.
Consumption of greens is a major source of vitamins and micro-nutrients for people using only vegetarian diets rich in carbohydrates. In remote rural settlements where vegetable cultivation is not ...practiced and market supplies are not organized, local inhabitants depend on indigenous vegetables, both cultivated in kitchen gardens and wild, for enriching the diversity of food. Knowledge of such foods is part of traditional knowledge which is largely transmitted through participation of individuals of households. A total of 123 households in six villages of Nanda Devi Biosphere Reserve buffer zone was surveyed using a schedule to assess the knowledge, availability and consumption pattern of wild leafy vegetables. Quantity estimations were done using regular visits with informants from 30 sample households of the six study villages during the collections. Monetization was used to see the value of wild leafy vegetables harvested during a year. The diversity of wild leafy vegetables being use by the local inhabitants is 21 species belonging to 14 genera and 11 families. This is far less than that being reported to be used by the communities from Western Ghats in India and some parts of Africa. Irrespective of social or economic status all households in the study villages had the knowledge and used wild leafy vegetables. The number of households reported to consume these wild leafy vegetables is greater than the number of households reporting to harvest them for all species except for Diplazium esculentum and Phytolacca acinosa. The availability and use period varied for the species are listed by the users. The study indicated that the knowledge is eroding due to changing social values and non participation of younger generation in collection and processing of such wild leafy vegetables.
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