Bharathiar University

About: Bharathiar University is a education organization based out in Coimbatore, Tamil Nadu, India. It is known for research contribution in the topics: Thin film & Adsorption. The organization has 5812 authors who have published 8628 publications receiving 143934 citations. The organization is also known as: BU.

Evaluation of leaf aqueous extract and synthesized silver nanoparticles using Nerium oleander against Anopheles stephensi (Diptera: Culicidae).

Abstract: Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and ecofriendly reducing and capping agents The present study was carried out to establish the larvicidal activity of synthesized silver nanoparticles (AgNPs) using leaf extract of Nerium oleander (Apocynaceae) against the first to fourth instar larvae and pupae of malaria vector, Anopheles stephensi (Diptera: Culicidae) Nanoparticles are being used in many commercial applications It was found that aqueous silver ions can be reduced by the aqueous extract of the plant parts to generate extremely stable silver nanoparticles in water The results were recorded from UV–Vis spectrum, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy analysis The production of the AgNPs synthesized using leaf extract of N oleander was evaluated through a UV–Vis spectrophotometer in a wavelength range of 200 to 700 nm This revealed a peak at 440 nm in N oleander leaf extracts, indicating the production of AgNPs The FTIR spectra of AgNPs exhibited prominent peaks at 50912 cm−1 (C–H bend alkenes), 1,07705 cm−1 (C–O stretch alcohols), 1,60063 cm−1 (N–H bend amines), 2,73649 and 2,47904 cm−1 (O–H stretch carboxylic acids), and 3,41531 cm−1 (N–H stretching due to amines group) An SEM micrograph showed 20–35-nm-size aggregates of spherical- and cubic-shaped nanoparticles EDX showed the complete chemical composition of the synthesized nanoparticles of silver Larvicidal activity of aqueous leaf extract of N oleander and synthesized AgNPs was carried out against Anopheles stephensi, and the results showed that the highest larval mortality was found in the synthesized AgNPs against the first to fourth instar larvae and pupae of Anopheles stephensi with the following values: LC50 of instar larvae 2060, 2490, 2822, and 3399 ppm; LC90 of instar larvae 4162, 5033, 5778, and 6841 ppm; and LC50 and LC90 of pupae 3955 and 7910 ppm, respectively The aqueous leaf extract exhibited larval toxicity against the first to fourth instar larvae and pupae of Anopheles stephensi with the following values: LC50 of instar larvae 23290, 27371, 31894, and 36996 ppm; LC90 of instar larvae 45595, 56310, 63986, and 73030 ppm; and LC50 and LC90 of pupae 42601 and 80513 ppm, respectively The chi-square value was significant at p < 005 level The possible larvicidal activity may be due to penetration of nanoparticles through a membrane The results could suggest that the use of plant N oleander to synthesize silver nanoparticles is a rapid, environmentally safer, and greener approach for mosquito control This could lead us to a new possibility in vector-control strategy

Recent developments on encapsulation of lactic acid bacteria as potential starter culture in fermented foods – a review

Abstract: Fermented foods are the first processed staple human diet that have been produced and consumed since development of human civilizations. Majority of the fermented foods are made through controlled microbial growth and enzymatic conversions of major and minor food components that gain high values because of its enhanced organoleptic properties. Ease of fermentation, risk in fermentation failure and several functional properties of lactic acid bacteria makes them as suitable starter culture in production of fermented foods. The viability and stability of starter cultures in the fermented foods and gastro intestinal environment are key challenges at industrial scale. Use of encapsulated starter cultures has been considered more in the recent years, due to its improvement in survival and viability under adverse environmental conditions. This paper mainly focuses on reviewing lactic acid bacteria as functional starter cultures in fermented foods including different techniques and coating materials used for microencapsulation, factors affecting the microencapsulation, methods for evaluating the efficiency of starter cultures and future perspectives to be overcome in this area.