International Journal of Scientific Research in Biological Sciences
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Characterization and fungistatic activity of Eucalyptus globulus leaf extract mediated phytosynthesized silver nanoparticles
Get PDFIn the present study silver nanoparticles were synthesized through green approach using leaf extract of Eucalyptus globules and confirmed by change in colour of reaction mixture, the peak obtained at 425nm in UV-visible spectroscopic study and characterized by XRD, DLS, SEM, EDAX and FTIR for their structure, size, shape and possible biomolecules responsible for the reduction of silver ion to silver nanoparticles. XRD spectrum confirmed the particles were face centered cubic in nature with an average particle size of 25nm which is in agreement with DLS data (25.31nm). SEM images of nanoparticles revealed the spherical shape of particles and the Energy Dispersive X-ray analysis (EDAX) confirmed the significant presence of elemental silver. Synthesized silver nanoparticle showed good fungicidal activity against Didymella bryoniae, Fusarium oxysporum, Aspergillus flavus and Rhizoctonia solani.
 
Anatomy and stomatal micromorphology of Psophocarpus tetragonolobus (L.) DC. (Winged Bean)
Get PDFPsophocarpus tetragonolobus (winged bean) belongs to the family Fabaceae. It is self-pollinated and growing in the tropical regions of the world. Present study investigated the anatomy of stem, node, petiole, leaf, root and stomatal micro- morphological characters of this species. Stem anatomy showed epidermis, cortical layers (collenchyma and chlorenchyma) schlerencymatous bundle sheath with conjoint, collateral vascular bundle and unilacunar node. One of the distinguishing features in leaf anatomy was the presence of sac like outgrowths filled with simple parenchyma and were usually seen opposite side to the midrib vascular bundle. In the petiole, vascular strands were cylindrical and arc shaped and in roots, four xylem and four phloem patches were present. Paracytic stomata were seen on both sides of the leaves. The stomatal index on adaxial and abaxial surface was 5.54-9.27% and 53.57-61.29% respectively. In general anatomical characteristics of P.tetragonolobus were used for the identification key of this species.
 
Spatio-Temporal Variations in Mangrove Vegetation in conjunction with Related Environmental Factors in Pichavaram (India): 1996-2016
Get PDFThe major objective of the study is to explore the inter-annual vegetation changes of Pichavaram mangroves over two decades (from 1996 to 2016). The study mainly focuses on the summer and onset monsoon season, where the variability in vegetation is easily noticed. Vegetation indices like Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST) and Land Surface Water Index (LSWI) were estimated from the remotely sensed data of Landsat imagery. A comprehensive evaluation of the relationship among the vegetation indices reveals that there is an increase in the area occupied by the mangroves throughout the years. Correspondingly, the area under the mangrove cover have also faced an increase in the surface temperature, but much lesser when compared to the adjacent areas. According to the results obtained, NDVI, LSWI, LST, can be used to understand the status of mangrove vegetation with increase and decrease of temperature and water. It is found that the correlation among the remotely sensed indices depend on the season of the year. The summer season in general exhibited higher negative correlation with NDVI and LST and also between LST and LSWI than the onset monsoon season. It is also apparent that with the passing of years, the correlations among the indices are also found to be increasing. Thus in the global scenario of variable climate change, it is important to monitor the seasonal changes in vegetation, especially mangroves, for their effective conservation.
 
A Study on Diversity and Habitat Characterisation of Odonata at Nalsarovar Bird Sanctuary, India
Get PDFA study was carried out in Nalsarovar Bird Sanctuary to assess habitat characteristics preferred by Odonates (Dragonflies and Damselflies) in Nalsarovar Bird Sanctuary (Ramsar Site), Gujarat. The entire study area was stratified into 6 different habitat type. Transects Survey was carried out covering all habitats. Each transect was repeatedly surveyed covering all seasons. A total of 30 species of dragonflies and damselflies were encountered belonging to 5 families namely Libellulidae, Gomphidae, Aeshnidae, Coenagrionidae, and Lestidae during the entire study. The most habitat type utilized by Odonates, out of total individual encountered during survey are Habitat-Type-4 and Habitat-Type-2 and it contributes to around 64.3 % of Odonate within study area. However, most preferred habitat by Anisoptera (Dragonflies) is Habitat-Type-4. Similarly, most preferred habitat by Zygoptera (Damselflies) is Habitat-Type- 6 and Habitat-Type-2. Relative frequency (%) and relative abundance (%) of each Odonate species (Dragonflies and Damselflies) were calculated based on data collection. Relative frequency (%) of Trithemis pallidinervis was recorded highest in most of the habitats and Relative abundance (%) of Trithemis pallidinervis highest in Habitat-Type-3 compared other species within habitat irrespective of seasonality. However, Pantala flavescens were recorded maximum in the majority of habitat due to its monsoon season migratory behaviour.
 
Understanding the impact of Bacillus thuringiensis proteins on non-target organisms
Get PDFBacillus thuringiensis (Bt) is a spore-forming, gram-positive, aerobic, rod-shaped bacterium. During sporulation, Bt produces proteinaceous crystals called Cry proteins that are lethal to many insects’ species, so are commonly used as biological pesticide. Transgenic Bt crops are genetically altered to express insecticidal toxins that cause fatality of a number of general agricultural pests. The insecticidal toxins formed by Bt crops possess narrow range of toxicity and therefore less non-target impacts as compared to conventional insecticides. A decrease in the amount and regularity of insecticide applications are financially advantageous. In numerous regions of the world, insecticide inputs have been significantly reduced because of Bt. The use of Bt crop technology might help in worldwide food security by escalating the amount and steadiness of crop yields. Though impact of Bt toxin on non-targeted organism is a serious issue yet no conclusion could still be drawn from several studies. This review summarizes the benefits of Bt crops including the impact on non-targeted organisms and Bt toxins having potential risks with respect to the environment.
 
Effects of synthetic pyrethroids Cyfluthrin and Fenvalerate on Nucleic acid contents of fresh water fish Gambusia affinis
Get PDFIndia is a country with more than 60–70% of its population dependent on agriculture. Rapid industrialization and successful green, white and blue revolutions have necessitated a large variety of chemicals/pesticides usage resulting environmental pollution which has become not only a national but a global problem. Fish occupy a prominent position in the field of aquatic toxicology and have been employed in studies concerning ecological health. In the present investigation two synthetic pyrethroids were selected namely Cyfluthrin and Fenvalerate to evaluate their toxicity on Gambusia affinis. In the present study there is significant decline in DNA content in the gill, liver and kidney tissues is observed, when the fish Gambusia affinis is exposed to the cyflthrin and fenvalerate. Decreases in the DNA content due to inhibition of the enzymes in DNA synthesis. The declines in RNA level in treated fish due to obstruction in RNA synthesis. Resulting in the swelling and chromatolysis of Nissle bodies which are rich in RNA. Pesticides may influence directly or modify DNA, other cellular process associated with the integrity of the genome.
 
Determination of heavy metals and phytochemical analysis of some selected medicinal plants
Get PDFNatural products had been essentially used by many cultures and traditions from thousands of years. Plants synthesize massive varieties of substances called secondary metabolities (Phytocompounds) and accumulated in it. The possible bioactive phytocompounds like alkaloids, flavanoids, and phenolic compounds, steroids and coumarins etc., are possible sources for drug discovery. A study was conducted to analyse the presence of traces of essential and non essential heavy metals in the preferred medicinal plants. AAS is used to examine the presence of heavy metals in the selected medicinal plant. Results obtained in the present study showed that the medicinal herb analysed contain heavy metals (Fe, Cu, Mn, Zn, Ni, Co, Pb, Al, V, Cr, Mo, Hg, As and Cd). The concentration (ppm) of heavy metals in the plant extracts like Plectranthus mollis, Elaeagnus conferta and Grewia tilaefolia leaf extracts were found using atomic absorption spectrophotometer. The qualitative analysis showed that alkaloids were mainly seen in most of the samples of Hydro alcoholic leaf extracts. Total phenol, Flavonoid, Steroids, Alkaloid and Tannins were present in all the three samples extracted by Hydro alcoholic leaf extracts. Total phenol and Alkaloid were seen more in leaf samples, from the judgment of the results with the defined permissible limits, it was accomplished that the levels of heavy metals present in the herb falls in the permissible limits for consumed medicinal herbs. Purpose of this study is to determine heavy metals contents in chosen herbal plants and also to highlight the health concerns related to the presence of toxic levels of heavy metals. The presence of high amount of phytochemical compounds put forward that the Grewia tilaefolia plant has higher medicinal value and can be extensively studied to extract the natural compounds which are beneficial to human beings and that could be commercialized for higher production than using synthetic drugs with side effects.
 
Anti-oxidative Potential Survival of E. crassipes Under Oxidative Stress
Get PDFThe present study evaluates the kinetic constants of enzymatic assays in crude extracts of roots and shoots of E. crassipes growing in wastewater bodies situated in the trans-Ganges/Yamuna regions of Allahabad. The increased kinetic constants in crude extracts of shoots and roots of E. crassipes showing the ability to protect plants from heavy metal induced oxidative stress by activating multi-defense mechanisms and for better growth in polluted environments. This study demonstrates the phytoremediation potential of E. crassipes for the removal of polluted effluents and their ability to survive under oxidative stress.
 
Bioprospecting of Fungi for Melanin fabrication: A Comprehensive Review
Get PDFMelanin is a gloomy diffusive shade, present as a self-protective operator in miscellaneous life forms including microorganisms, plants, animals and human beings. Melanin assumes numerous self-defensive parts, for example, hindering of UV radiation, free radical adsorption, and lethal iron chelation, penetrating of phenolic mixes and defending against ecological pressure. Therefore, it is a conventional compound in remedy, pharmacology and beauty care products. Melanin is arranged from L-tyrosine by means of a development of enzymatic and non-enzymatic reactions by the chemical tyrosinase (EC 1.14.18.1). To begin with, tyrosinase catalyzes the hydroxylation of L-tyrosine to L-dihydroxyphenylalanine (L-DOPA). The L-DOPA is reacted to dopachrome, which is changed over to melanin by a progression of non-enzymatic oxido-reduction reactions. Chemical production of melanin is cost effective so microbial production of melanin is considered to be good in industrial scale. Melanin is critical component of some the microorganisms as reported. This review is concerned with transformed classes of melanin, pathway of melanin; factors influence the melanin production and application of melanin isolated from different fungi.
 
Induction of ovarian toxicity in the freshwater fish, Pseudetroplus maculatus (Bloch, 1795) after sublethal exposure of dibutyl phthalate
Get PDFDibutyl phthalate, a plasticizer, is widely used as a softener in several commercial industrial products. The study investigated the sublethal effects of dibutyl phthalate on ovary of the freshwater fish, Pseudetroplus maculatus. Dibutyl phthalate exposed at 0.2 mg/ L concentration for 24, 72 and 96 h showed behavioural modifications in the fish. The body weight showed significant reduction after 72 h of toxicant exposure with concomitant increase in mucous deposition, which indicated whole-organism response against the toxicant. The weight of ovary and gonadosomatic index decreased significantly in all treatment groups thereby suggested the stress exhibited on female reproductive organ. Dibutyl phthalate prevented normal activities of steroidogenic enzymes as 3β- and 17β-hydroxysteroid dehydrogenase in ovary of the fish. The alterations in the level of vitellogenin measured through indirect endpoints such as alkali-labile phosphoprotein and total protein in ovary and blood plasma indicated the estrogenic effects of the toxicant. Dibutyl phthalate disrupted hypothalamo-pituitary-gonadal axis as demonstrated by the increase in the levels of luteinizing hormone and testosterone with reduction in serum estradiol without remarkable changes in the level of follicle stimulating hormone. In the ovary, number of vitellogenic oocyte increased whereas the population of pre-vitellogenic oocyte declined without any changes in the number of post-vitellogenic oocyte. Histological evaluation revealed severe morphological damages associated to apoptosis such as empty follicle and atretic oocytes, membrane blebbing, nuclear condensation, vacuolization and broken theca granulosa membrane. The present findings suggested that sublethal exposure of DBP induced ovarian toxicity in the freshwater fish, Pseudetroplus maculatus