A Purified Alkaline and Detergent-Tolerant Lipase from Aspergillus fumigatus with Potential Application in Removal of Mustard Oil Stains from Cotton Fabric

In the present study, the lipase from Aspergillus fumigatus was purified which was found to be stable to commercial detergents and oxidising agents. A purification fold of 6.96 and yield of 11.03% were achieved when the enzyme was purified using Octyl Sepharose column chromatography. In presence of various oxidizing agents, the highest activity of lipase was 15.56 U/mg with hydrogen peroxide. Among various surfactants used, the maximum activity exhibited by lipase was with Tween 80. While studying the effect of various detergents, the highest activity of 9.3 U/mg was achieved with "Vanish" detergent. Wash performance was studied with various detergents out of which "Vanish" showed highest oil removal of 79%. Lipase from Aspergillus fumigatus possessed better stability with various surfactants and oxidizing agents. The results of this study have shown that the lipase from Aspergillus fumigatus along with detergent "Vanish" (0.7%) under optimized conditions (5 μg/ml lipase, 40°C wash temperature and 40 min wash duration) improved oil removal from cotton fabric stained with mustard oil by 84%.

Polypropylene-based long-life insecticide-treated mosquito netting

The World Health Organization (WHO) is promoting the use of insecticide treated nets (ITNs) in order to roll back malaria. Long-life netting (LLIN) is preferred and this study investigated the possibility of incorporating the insecticide in the fiber polymer. Multifilament polypropylene (PP) yarn, containing up to 0.76% of pyrethroid insecticide, was successfully produced on a conventional production-scale fiber-spinning machine. The insecticides were incorporated via masterbatches that contained up to 18.8% active with low-density polyethylene (LDPE) as the carrier. Nets knitted from the yarns were tested using bioassays with mosquitoes. Initial efficacy complied with WHO specifications but the performance deteriorated with the number of wash cycles. Crystalline insecticides, featuring a melting point above the wash temperature of 60°C (e.g., β-cyfluthrin), provided better wash resistance than amorphous insecticides (e.g., cyfluthrin).

Tetracarboxylic Acids as Formaldehyde-Free Durable Press Finishing Agents

1,2,3,4-Butanetetracarboxylic acid and all- cis-1,2,3,4-cyclopentanetetracarboxylic acid have been studied as durable press reagents for cotton. They quickly form ester-type crosslinks in the cellulose when applied to fabric by pad-dry-cure techniques. Weak bases have proven to be active catalysts, one of the most effective being mono-sodium phosphate. Durable press smoothness ratings of 3.8–4.4 were imparted by either tetracarboxylic acid. The amount of tetracarboxylic acid required could be decreased by two-thirds by having citric or tartaric acid present as a co-reactant additive. In durability to home laundering, finishes from butanetetracarboxylic acid far surpassed those from cyclopentanetetracarboxylic acid, and most of the durable press performance was retained through 65 washing and drying cycles with a wash temperature of 50°C (122°F) and a pH of 9.8 using a standard detergent. The strength retentions, bending moments, and wrinkle recovery angles of treated fabric were comparable to those imparted by dimethyloldihydroxyethyleneurea.

Development of a cell wash buffer that minimizes nucleic acid loss from Clostridium perfringens 10543 A

Autolytic activity and nucleic loss from Clostridium perfringens 10543 A was demonstrated during successive cell washes in hypotonic TES buffer. Autolysis increased nearly sixfold and nucleic acid loss nearly twofold when 10 mM EDTA was added to 0.3 M Tris–sucrose buffer. Attempts to minimize both autolysis and nucleic acid loss from C. perfringens during routine washing steps were unsuccessful when the effects of sucrose concentration, pH, CaCl2 addition, or wash temperature were examined independently. However, autolytic activity was eliminated and nucleic acid loss reduced to less than 5% when C. perfringens cells were washed at 4 or 25 °C in 1.0 M sucrose, 50 mM Tris–HCl, and 25 mM CaCl2 at pH 5.7.