Keratinase mediated fabrication and partial characterization of gold nanoparticles and its antibacterial potential

Keratinase is mainly involved in recycling of keratin waste. Of late, researchers extended its application to nanotechnology. In the present study, we have made an attempt to fabricate and characterize gold nanoparticles using crude keratinase enzyme from Serratia ficaria and also study their biological application, particularly antibacterial activity. The formation of gold nanoparticles (AuNPs) was first verified by UV-Visible Spectroscopy. FTIR spectra confirmed the presence of responsible secondary metabolites for stabilization of nanoparticles. The morphological characteristics and particle size of synthesized nanoparticles were analyzed. The AuNPs showed significant antibacterial activity against Klebsiella pneumonia, Bacillus cereus and Staphylococcus aureus. The highest radical scavenging activity, 60.62% for AuNPs was observed at 500 µg/mL. Results of this study reveals significance of keratinase application in nano-based biological applications.

Chemical and biological assessment of high value pharmaceutical raw material from Egyptian orange peel

In Egypt, orange juice industries generate huge amount of waste peel that could be a source of raw materials with high value and economic return. Here, we explored a better model for waste management of citrus processing waste in Egypt by developing an ecofriendly method for preparation of value added materials. A high grade pectin (HGP) was obtained from the crude acidic water extract of the peel after passing through Diaion HP20 column. The HGP showed potent antidiabetic activity at lower dose than those reported in literature. It possessed significant effect on blood glucose (BG) level, as well as parameters relevant to liver and kidney functions in streptozotocin (STZ) induced diabetic rats. On the other hand, the essential oil (EO) prepared by cold press showed the highest yield (0.72% w/w) and it is the most applicable method of isolate orange oil on pilot scale. EO showed significant antimicrobial activity against the tested food borne pathogens. In conclusion, high value materials — HGP and EO were prepared on pilot scale from the waste orange peel. While the HGP can be included in food supplement for diabetic patients, EO can be used as a natural food preservative.

Síntesis y caracterización de la mezcla polipropileno-poliestireno expandido (icopor) reciclado como alternativa para el proceso de producción de autopartes / Synthesis and characterization of expanded mixed polystyrene - polypropylene (styrofoam) recycled as an alternative for production process of autoparts

En el proceso de fabricación de autopartes se incluye el polipropileno (PP) como materia prima principal y la fibra de vidrio como insumo para la producción de ventiladores utilizados en los sistemas de refrigeración de los automotores. Los estándares de fabricación deben garantizar la resistencia de los productos en condiciones a las que estarán sometidos dentro del motor. Para lograrlo, el polipropileno es mezclado con fibra de vidrio en el proceso de inyección para aumentar la resistencia y la dureza del producto final, debido a que está expuesto a cambios de temperatura, choques con otras piezas, desgaste e impactos inesperados en el vehículo. Este estudio sintetizó y caracterizó un material obtenido a partir de la mezcla polipropileno puro-poliestireno expandido (EPS) (icopor) reciclado como una alternativa de aprovechamiento para el icopor dentro del proceso de fabricación de autopartes a modo de sustituto de la fibra de vidrio en el proceso de producción, siguiendo pasos como el tamizaje de los tamaños de material, la mezcla de los mismos, la obtención de probetas y la realización de ensayos mecánicos y térmicos. El objetivo fue comparar las propiedades mecánicas y térmicas del material obtenido (PP-EPS) con el material actualmente utilizado (PP-fibra de vidrio) para el que no se tenían estudios previos y de esta forma determinar la viabilidad de incorporación de un residuo a un proceso productivo y evitar su disposición directa favoreciendo el reciclaje del mismo. Las mezclas se caracterizaron mediante ensayos de tensión-deformación, dureza Shore A y análisis termogravimétrico (TGA) de los cuales se obtuvo favorecimiento en las propiedades térmicas y reducción de la resistencia mecánica en el uso de icopor, resaltando por supuesto el ahorro significativo en el cambio de insumos del proceso productivo.

Polypropylene (PP) as main raw material and fiberglass as input for the production of fans used in the cooling systems of motor is included in the process of manufacturing parts. Manufacturing standards must guarantee the resistance of the product in conditions that will be subject within the engine. To achieve this, the polypropylene is mixed with fiberglass in the injection process to increase the strength and hardness of the final product, as it is exposed to temperature changes, impacts with other parts, wear and unexpected impacts on the vehicle. This study synthesized and characterized a material obtained from the pure-polypropylene blend expanded polystyrene (EPS) (polystyrene) recycling as an alternative use for polystyrene in the auto parts manufacturing process as a substitute for fiberglass production process, following steps as screening media sizes, the mixture thereof, and obtaining specimens performing mechanical and thermal tests. The aim was to compare the mechanical and thermal properties of the material obtained (PP-EPS) with the material currently used (PP-fiberglass) for which they had no previous studies and thus determine the feasibility of incorporating a waste to a production in order to avoid direct disposal and thus promote the recycling process itself. The blends were characterized by stress-strain tests, Shore A hardness and thermogravimetric analysis (TGA) of which was obtained favoring the thermal properties and mechanical strength reduction in the use of polystyrene, of course emphasizing the significant savings in change of inputs in the production process.

Extra-cellular isoamylase production by Rhizopus oryzae in solid-state fermentation of agro wastes

Extra-cellular isoamylase was produced by Rhizopus oryzae PR7 in solid-state fermentations of various agro wastes, among which millet, oat, tapioca, and arum (Colocasia esculenta) showed promising results. The highest amount of enzyme production was obtained after 72 h of growth at 28°C. The optimum pH for enzyme production was - 8.0. Among the various additives tested, enzyme production increased with ions such as Ca2+, Mg2+ and also with cysteine, GSH, and DTT. The enzyme synthesis was reduced in the presence of thiol inhibitors like Cu2+ and pCMB. The surfactants like Tween-40, Tween-80 and Triton X-100 helped in enhancing the enzyme activity. The production could be further increased by using the combinations of substrates. The ability to produce high amount of isoamylase within a relatively very short period and the capability of degrading wastes could make the strain suitable for commercial production of the enzyme.

An evaluation of fibrous structure and physical characteristics of Cutia nut (Couepia edulis Prance) shell

The Cutia-nut (Couepia edulis Prance), a species originally from the Amazon region, has a kernel with reasonable nutritional value and a hard and thick woody shell that constitute most of the fruit. After the kernel removal, the shells are regarded as waste. The possibility of using such shells, as raw material for burning or charcoal production, as well as milled residue for structural reinforcement materials is quite feasible, considering environmental and economical aspects. There is, however, a complete lack of characterization of the Cutia-nut shell and other similar species which can aggregate desirable qualities for application as engineering material. In this study some analyses are presented aiming at providing information for potential uses of these residues. In general, the shells follow a regular shape with certain dimensional proportionality to the kernel. The shell is a fibrous material with high lignin content, present low water absorption and high resistance to natural degradation.

A castanha-de-cutia(Couepia edulis Prance), uma espécie típica da região amazônica, é possuidora de uma amêndoa de razoável valor nutricional e caracterizada por ter uma casca espessa e altamente resistente, que constitui a maior parte do fruto. Esta casca, após a retirada da amêndoa, é totalmente descartada. A possibilidade do aproveitamento das cascas, seja como matéria prima para a queima ou simples confecção de carvão, ou como elemento para uso como aditivo de reforço em materiais estruturais é plenamente viável, não somente do ponto de vista ambiental mas também econômico. Há, contudo, uma ausência total de caracterizações da casca da castanha-de-Cutia e de demais espécies tropicais similares que potencialmente podem agregar qualidades desejadas para aplicações como materiais de engenharia. Neste trabalho são apresentadas algumas análises realizadas que podem vir a subsidiar o potencial emprego desses resíduos. De um modo geral, as cascas apresentam formatos regulares com certa proporcionalidade dimensional com a amêndoa. São fibrosas e com alto teor de lignina o que garante baixa absorção de água e alta resistência à degradação natural.