1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Technology development for incorporation of green synthesized silver nanoparticles on naturality dyed fabrics(Department of molecular biology and biotechnology, college of agriculture, Vellayani, 2023-07-21) Omal Surya Souraph S; Swapna AlexTechnology development for incorporation of green synthesized silver nanoparticles on naturally dyed fabrics The study entitled “Technology development for incorporation of green synthesized silver nanoparticles on naturally dyed fabrics” was conducted in the Department of Molecular Biology and Biotechnology at College of Agriculture, Vellayani with an objective to develop a technology for the incorporation of green synthesized silver nanoparticles and natural pigments from Aerva lanata L. for imparting antimicrobial property and colour to fabrics and standardization of pigment extraction from callus. Fresh leaves of Aerva lanata collected from Regional Ayurvedic Research Institute, Papanamcode, Thiruvananthapuram were used for pigment extraction via boiling method. The extract was used for dyeing of bleached white cotton fabric after scouring. Dyeing was carried out by wet dipping method using different mordants (10% alum, 1% stannous chloride) and biomordants (5% seed extract of Terminalia chebula, 100% banana pseudostem sap) and the fabric after drying was subjected to computer colour matching. The colour of the dyed fabric was identified as Earl’s green for metallic mordants and Olive green and Wild willow for Terminalia chebula and banana pseudostem sap respectively. Green synthesis of silver nanoparticles was carried out using leaf extract of Aerva lanata and confirmed using UV-Visible spectroscopy at 420 nm. Silver nanoparticles were incorporated into the dyed fabric by different methods viz., direct incorporation, in-situ synthesis, direct incorporation along with chitosan and in-situ synthesis along with chitosan and the antimicrobial activity of the fabric was tested by agar diffusion method. Naturally dyed fabric without silver nanoparticles served as control. Colour fastness of the fabric and durability of antimicrobial activity were tested after consecutive 5, 10 and 20 washing cycles. All fabrics incorporated with green synthesized silver nanoparticles by direct incorporation and in-situ method exhibited antimicrobial activity. Mordant used did not affect the antimicrobial activity exhibited by silver nanoparticles incorporated by direct method, while in in-situ method, fabrics treated with biomordants showed an increased antimicrobial activity. Fabrics treated by direct incorporation retained the original dye colour while in-situ treated fabrics exhibited shades of golden brown colour. Incorporation of silver nanoparticles in both direct and in-situ methods along with chitosan treatment did not show antimicrobial activity in the agar diffusion test which may be due to superhydrophobicity. Durability of antimicrobial fabrics was maximum for in-situ incorporated fabric biomordanted with Terminalia chebula and the presence of silver nanoparticles in the fabric was confirmed by Scanning Electron Microscopy (SEM). Cent percent callus induction was observed from nodal segments of Aerva lanata within four weeks in Murashige & Skoog (MS) medium supplemented with 1.5 mg/l BA and 0.2 mg/l IAA and reddish pink colour development was observed within seven weeks. Pigment extraction was done by cold extraction and soxhlet extraction using methanol as solvent and subjected to column chromatography and the UV-visible spectrum of the different fractions were compared. Absorption at 550 nm was higher for the extract prepared by cold extraction method indicating a higher content of anthocyanin. Ultra High Performance Liquid Chromatography Mass Spectroscopy (UHPLC-MS) of the crude methanolic extract of the callus showed the presence of compounds such as 7-methylaromadendrin, canthin-6-one, and 5-methoxycanthin-6 one which are also reported in the plant. However, other compounds such as dalspinin and O,O'-(4,4'-diaminobiphenyl-3,3‘-lene)di(glycollic acid) were also present in the callus extract which are not reported in the plant. To conclude, fabrics with durable antimicrobial property could be developed by in situ incorporation of silver nanoparticles after biomordanting followed by natural dyeing using Aerva lanata in an eco-friendly manner. This is the first report of in-situ incorporation of silver nanoparticles on naturally dyed fabric for antimicrobial activity. Callus of Aerva lanata has potential for pigment extraction for natural dyeing process.Item Shelf life extension of nendran banana (Musa. spp.) using aloe gel incorporated silver nanoparticles(Department Postharvest Management, College of Agriculture,Vellayani, 2024-03-02) Athira Preman, M.; Athulya, S KumarThe study entitled “Shelf life extension of Nendran banana (Musa spp.) using aloe gel incorporated silver nanoparticles” was conducted at Department of Postharvest Management, College of Agriculture, Vellayani during 2021-2023, with the objective of standardizing aloe gel incorporated silver nanoparticles for shelf life extension of Nendran banana. The experiment was conducted as three parts. In the first part, plant mediated synthesis of silver nanoparticles (Ag NPs) was done and characterized for its size, shape and properties using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Particle Size Analyser (PSA) and Raman Spectroscopy. In the second part, freshly harvested good quality Nendran banana bunches of commercial maturity were collected from Instructional Farm, College of Agriculture, Vellayani, de-handed fruits were ozonized (2 ppm) and subjected to different postharvest treatments in various concentrations of aloe gel incorporated silver nanoparticles (20% aloe gel with 40 ppm, 60 ppm, 80 ppm Ag NPs; 30% aloe gel with 40 ppm, 60 ppm, 80 ppm Ag NPs; 40% aloe gel with 40 ppm, 60 ppm, 80 ppm Ag NPs; 50% aloe gel with 40 ppm, 60 ppm, 80 ppm Ag NPs), aloe gel (20%, 30%, 40%, 50%) by dipping for 5 minutes along with absolute control (without any treatment). The treated banana fruits were air dried and stored under ambient temperature in Corrugated Fibre Board (CFB) boxes till the end of shelf life. The effectiveness of treatments was analysed based on physiological, biochemical and sensory parameters. Nendran banana fruits coated with 20% aloe gel incorporated with 40 ppm, 60 ppm, 80 ppm Ag NPs and fruits with 20% aloe gel coating exhibited maximum shelf life (14 days) with minimum physiological loss in weight and superior biochemical and sensory parameters, whereas the fruits without any treatment (absolute control) had a shelf life of 9 days. These four superior treatments were selected for further storage studies in the third part of the experiment. Nendran banana fruits were harvested at commercial maturity, sanitized (2 ppm ozone) and subjected to the four superior postharvest treatments. The treated fruits packaged in CFB boxes, were kept under cold storage (13± 2ºC) and low temperature conditions (below 10ºC) along with untreated fruits (absolute control) till the end of shelf life. Nendran banana fruits coated with 20% aloe gel incorporated with 80 ppm Ag NPs recorded maximum shelf life (34.25 days) with minimum physiological loss in weight (10.19%) under cold storage condition. When biochemical parameters were analysed, fruits coated with 20% aloe gel incorporated with 80 ppm Ag NPs recorded the minimum moisture content (61.70%), Total Soluble Solids (14.47°brix), reducing sugar (13.84%) and total sugar (14.44%) were recorded after 32 days of storage. They also exhibited maximum antioxidant activity (76.91%), ascorbic acid content (13.56 mg 100 g-1) with superior mean score for sensory parameters at the end of shelf life. The fruits without any treatment had a shelf life of 27.50 days with high physiological loss in weight (12.20%). Nendran banana fruits stored under low temperature condition exhibited chilling injury and hence discarded after 3 days of storage. The postharvest treatments extended the shelf life of Nendran banana fruits by delaying ripening and reducing physiological activities. Postharvest treatment of commercial maturity Nendran banana hands with 20% aloe gel incorporated with 80 ppm Ag NPs could give a shelf life of 34.25 days with superior physiological, biochemical and sensory quality parameters when stored in CFB boxes under cold storage (13± 2ºC) compared to 27.5 days for untreated fruits.Item In vitro studies on the anti-infective properties of flower and fruit extracts of selected medicinal plants against enteropathogens(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2019) Muhsina, A S; Shiburaj SugathanThe thesis entitled “In vitro studies on the anti-infective properties of flower and fruit extracts of selected medicinal plants against enteropathogens” was carried out in the Microbiology division of Jawaharlal Nehru Tropical Botanic Garden and Research Institute, Palode, during 2018-2019 academic years.The objective of the study was Screening of medicinal plant extracts for anti infec-tive property against enteropathogens and identification of lead compounds, targeted efficacy testing of selected compounds against FtsZ proteins through in vitro and in silico approaches, demonstrating the effect of these compounds on virulence factors and bio-film formation of enteropathogens. Diarrhoeal diseases remain a leading cause of preventable death, especially among children under five in developing countries. Acute watery diarrhoea mainly affecting children of developing countries that results in dramatic dehy-dration and it is most dangerous in the very young. Enterotoxigenic Escherichia coli or Vibrio cholerae are most common causative agent of acute watery diar-rhoea. Diarrhoea also cause huge economic burden on people of impoverished countries. There is need for need for novel anti-infective agents that can prevent disease and economic burden of diarrhoea. Developing countries are rich source of traditional knowledge and natural resources. These resources can be channel-ized to develop novel anti-diarrhoeal agents that can prevent emergence and dissemination of gastrointestinal pathogen including drug-resistant strains. Many diarrhoeal diseases are known to be treated with herbal remedies throughout the history of humankind. Even today, plant materials continue to play a major role in primary health care as therapeutic remedies in many devel-oping countries. For centuries, many secondary compounds of fruits are 75 found to have an outstanding role in medicine. Most of these com-pounds belong to a few families of substances such as alkaloids, terpenoids and phenolics. Fruits and flowers are ethno medically valuable products of a plant. They have been extensively used in folk and mod-ern medicine for treating various diseases. We have explored anti-infective activity of fruit and flower extract using mi-crobiological assays. Hot ethanol extracts exhibited antibacterial activity against gastrointestinal pathogens such as E. coli, V. cholera, E. faecalis, S. Typhi and S. aureus. It induced filamentation of Bacillus subtilis 168 which is an indication of cell division inhibition. Active compound can be used to devel-op novel anti-diarrhoeal agents.Item Efficacy of silver nanoparticles as delivery system in genetic transformation(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Gorantla Nagamani; Swapna Alex