Advances in BioScience
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Regenerative callus induction and biochemical analysis of Stevia rebaudiana Bertoni
Get PDFStevia Leaves are the principal source of stevioside, which is estimated to be 100-300 times sweeter than table sugar. Stevioside has clinical significance as they are reported to maintain glucose levels in human blood. Owing to the difficulties in propagation of stevia through seeds and vegetative methods, callus culture has been an efficient alternative for generation of stevioside. The aim of this study is to develop an efficient and standardized protocol for maximum induction and multiplication of callus from a leaf. Callus culture was established from leaves in MS basal media fortified with various combinations (BAP, NAA, 2,4-D, KN, IBA) and concentrations of phytohormones. The best callusing (100%) was recorded in MS media supplemented with (2,4-D 1.0mg/l + NAA 1.0mg/l). The callus was harvested after 4 weeks and screened for the presence of various bioactive compounds. The qualitative results showed that the extracts of callus contained bioactive compounds like flavonoids, glycosides, phenol, tannins, sterols and saponins thereby making callus one of the sources for extraction of various secondary metabolites
Relation of Particle size with Toxicity of Calcite Particles
Get PDFThe importance of certain types of nanomaterials and mineral nanoparticles, namely clays and the smallest mineral colloids, has been known for a long time. Mineral nanoparticles also behave differently than larger micro and macroscopic crystals of the same mineral. The variations in chemical properties are most likely due to differences in surface and near surface atomic structure, as well as crystal shape and surface topography as a function of size in this smallest of size regimes. Although most of the nanotoxicological studies were performed using unrealistic exposure conditions. Knowledge about potential human and environmental exposure combined with dose response, toxicity information will be necessary to determine real or perceived risks of nanomaterials following inhalation, oral or dermal routes of exposure. Because the respiratory tract is the major portal of entry for airborne nanoparticles, this exposure route can be used as an example to discuss some key concepts of nanotoxicology, including the significance of dose, dose rate, dose metric and biokinetics
Chromatographical Analysis of Amino Acids in Sepia Mutant of Drosophila melanogaster under Stress of Cypermethrin and Alphamethrin
Get PDFInsects are invertebrates that are taxonomically referred to as the class Insecta. They are the most numerous and most widespread terrestrial taxon within the phylum Arthropoda, and indeed the most diverse group of animals on the earth, with around 925,000 species described—more than all other animal groups combined. Insects may be found in nearly all environments on the planet, although only a small number of species have adapted to life in the oceans where crustaceans tend to predominate instead. HPTLC is a method commonly applied for the identification, assay and the testing for purity, stability, dissolution or content uniformity of raw materials (herbal and animal extracts, fermentation mixtures, drugs and excipients) and formulated products (pharmaceuticals, cosmetics, nutrients). These flexible and cost-effective techniques present the advantage of the simultaneous processing of standards and samples with versatile detection possibilities, including a great variety of post-chromatographic derivatization reagents
Phenotypic and Genotypic Characterization of facultative and obligate Alkalophilic Bacillus sp. isolated from Saudi Arabia alkaline soils
Get PDFIsolation and identification of new alkalophilic Bacillus strains have been increasing interest due to their possessing valuable and commercially interesting enzymes. In the present study, a total six obligate and facultative alkalophilic isolates were isolated from desert soil around the Al-qunfotha city, Saudi Arabia. All isolates were phenotypically and genotypically characterized. Among these isolates; AS3, AS4, AS5 and AS6 could grow at pH 9, 10, 11 and 12, but could not grow at pH 7, indicates that these isolates are obligate alkalophiles. While, isolates AS1 and AS2 grew at pH ranged from 7 to 10, but could not grow at pH 11 and 12, suggesting that they could be facultative alkalophiles. All isolates could hydrolyze casein and starch, indicating that they possess interesting amylase and protease enzymes. Based on 16S rDNA data, the phylogenetic analysis of these strains showed that all six alkalophilic Bacillus belonged to Bacillus cohnii with 99% similarity. The nucleotide sequences of 16S rRNA gene for the six isolates were deposited in a Gene-bank under accession numbers; KP053301, KP053302, KP053303, KP053304, KP053305 and KP053306, respectively
Cutaneous Leishmaniasis (CL) in Saudi Arabia: Current Status
Get PDFCutaneous leishmaniasis (CL) is a major tropical infection of public health importance. It is caused by a group of protozoan intracellular parasites. Several factors contribute to the prevalence and transmission of CL. More than 1400 cases of CL were reported in Saudi Arabia in 2012. Although several studies have looked at CL in Saudi Arabia and emphasized on the Eastern province of the country, the highest prevalence of CL was reported in Al-Qaseem area. In this review, we report on the species of Leishmania parasites causing CL in Saudi Arabia, its distribution and its incidence in the past seven years. We also report on the methods used to diagnose this infection and the treatment protocols used to treat CL in the country
A Review of Plant Growth Substances: Their Forms, Structures, Synthesis and Functions
Get PDFPlant growth substances are compounds, either natural or synthetic that modifies or controls through physiological action, the growth and maturation of plants. If the compound is produced within the plant, it is called a plant hormone or phytohormone. In general, it is accepted that there are five major classes of plant hormones. They are Auxins (IAA), Cytokinins, Gibberellins, Ethylene and Abscisic Acid. However, there are still many plant growth substances that cannot be grouped under these classes, though they also perform similar functions, inhibiting or promoting plant growth. These substances include Brassinosteroids (Brassins), Salicylic Acid, Jasmonic Acid, Fusicoccin, Batasins, Strigolactones, Growth stimulants (e.g. Hymexazol and Pyripropanol), Defoliants (e.g. Calcium Cyanamide, Dimethipin). Researchers are still working on the biosynthetic pathways of some of these substances. Plant growth substances are very useful in agriculture in both low and high concentrations. They affect seed growth, time of flowering, the sex of flowers, senescence of leaves and fruits, leaf formation, stem growth, fruit development and ripening, plant longevity, and even plant death. Some synthetic regulators are also used as herbicides and pesticides. Therefore, attention should be paid to the production and synthesis of these substances so that they affect plants in a way that would favour yield
Secondary metabolites and nutrient balance in casuarinas: An insight into Protein Competition Model (PCM)
Get PDFThe total phenolics, total condensed tannins (TCT), nitrogen (N) and total protein (TP) in needles of Casuarina equisetifolia and Casuarina junghuhniana were studied to understand the carbon-nutrient balance (CNB) and the growth-differentiation balance (GDB) hypotheses. The carbon-nutrient balance (CNB) hypothesis postulates that phenolic levels in plants are determined by the balance between carbon and nutrient availability1. The growth-differentiation balance (GDB) hypothesis2 considers factors that limit growth and differentiation. The production of phenolics dominates when factors other than photosynthate supply are suboptimal for growth (e.g., under nutrient limitation). Resource-based theories assume that the synthesis of defensive compounds is constrained by the external availability of resources and internal trade-offs in resource allocation between growth and defense. It is stated that growth processes dominate over the production of defensive compounds and that more carbon is left for defensive compounds only when plant growth is restricted by a lack of mineral nutrient (emphasized by the CNB hypothesis) or by any factor (according to the GDB hypothesis). Jones and Hartley3 presented a protein competition model (PCM) for predicting total phenolics allocation and content in leaves of higher plants. Protein competition model (PCM) stated that “protein and phenolics synthesis compete for the common, limiting resource phenylalanine,” so nitrogen (N) rather than C is the limiting resource for synthesis of phenolics. In our study, the contents of Total Phenolics, and Total Condensed Tannin (TCT) in needles of C. equisetifolia were higher than the C. junghuhniana. However, Total protein and nitrogen (N) contents were higher in C. junghuhniana than C. equisetifolia. There was a significant negative correlation between Total phenolics, TCT and Total Protein, N contents. Therefore, it is found from the present investigation that C. equisetifolia follows CNB hypothesis. However, C. junghuhniana follows GDB hypothesis, since it contains low defense chemicals viz., phenolics & TCT and high nitrogen and protein contents. Hence, the adaptability of C. equisetifolia in coastal areas and C. junghuhniana in drier inland condition is realized
Bacillus thuringiensis var. aizawai HD-137 as a Potential Agent for Biological Control
Get PDFFour strains of Bacillus thuringiensis were screened for their chitinolytic activity on colloidal chitin. B. thuringiensis var. aizawai HD-137 with the GenBank accession number HM173355 showed the highest chitinase activity, which was recorded after 2 days of incubation. The optimum condition for high chitinase production was Nutrient Yeast extract, Salt Medium, NYSM, with 0.2% colloidal chitin, two days of incubation, pH 6 and 30°C. The novel strain B. thuringiensis var. aizawai HD-137 is also considered as a powerful phytopathogenic control agent in which it showed inhibition of the mycelial growth of some phytopathogenic fungi, Alternaria solani, Rhizopus B1 and B2, Fusarium solani and Aspergillus flavus. The clear zones of mycelial inhibition ranged from 12 to 19mm. The partial nucleotides sequence of chitinase gene from B. thuringiensis var. aizawai HD-137 showed similarities to the chitinase producing bacteria in the GenBank, and it was more related to B. thuringiensis (AB699714, GQ921840 and GQ921842) and B. ehimensis chi60 (AB110081). It is obvious that the B. thuringiensis var. aizawai HD-137 is considered as a significant biocontrol agent against phytopathogenic fungi
Histopathological changes in Kidney of Channa punctatus (Bloch) under stress of Folidol
Get PDFThe concentration of pesticides is increasing day by day in the aquatic ecosystem. These concentrations are highest to limits; there is bioconcentration and bioaccumulation of these pesticides in the tissues and organ of fish which has a harmful effect on the human being when consumed by them. The effects of Folidol at 20 ppm sublethal doses were investigated on histopathology of kidney in full grown specimen of Channa punctatus (Bloch). Significant alterations were observed in kidney sections of treated fishes as compared to control group. These changes may be due to damage caused to the hepatic tissue
Effect of Carbamate Insecticide, Lannate, on the Gonads of Mice
Get PDFThe effect of the carbamate insecticide, lannate, on the gonads of mice was studied. Treating mice with lannate at a dose level of 10mg/kg body weight daily for 3-6 weeks had induced degenerative effects in the gonads, as follows, first in testis, a significant reduction in the diameter of the seminiferous tubules and germinal epithelial height. Histological examination of the testis showed that the seminiferous tubules were elongated and contained reduced spermatogenic cells. The number, of mature sperms was markedly reduced and after 3 weeks the sperm bundles were completely absent. On the other hand, the effect on the ovarian structure showed that, decrease in the number of secondary ovarian follicles and corpora lutea was recorded, while, the number of atretic follicles showed a significant increase. It is speculated that it may be resulted from the inhibition of RNA synthesis due to the effect of lannate