Purification of a Thermostable β-mannanase from Paenibacillus Thiaminolyticus - characterization and its Potential Use as a Detergent Additive

Endo-1, 4- β- D-mannanase (EC 3.2.1.78) is a glycoside hydrolase involved in random cleavage of β-1, 4- D-manno-pyranosyl linkages within mannans and heteromannans and generates branched and linear oligosaccharides. A β-mannanase was purified from a thermotolerant bacterium Paenibacillus thiaminolyticus isolated from a soil sample. Enzyme was purified to homogeneity with specific activity of 8812 U/mg protein. Sodium dodecyl sulfate (SDS) and native poly-acryl amide gel electrophoresis indicated that the purified mannanase is a monomeric protein with a molecular mass of 38 kDa. The purified enzyme was found to be maximally active at temperature and pH of 60°C and 7.0, respectively. It was stable at 55°C for 24 h and maintained more than 50 % activity up to 3 h at 60°C. The enzyme was very stable in the pH range of 5.0-9.0. Purified β-mannanase demonstrated high stability after 1 h of pre-incubation with most of the tested organic solvents. Enzyme retained significant stability in the presence of various detergent additives, commercially available detergents and dish washing liquids. The high compatibility and substantial stability in the presence of nonionic detergents and dishwashing liquids confirmed its utility as an additive to dish washing liquids and laundry detergents. Enzyme exhibited efficacious de-staining of heteromannan based stains of chocolate ice cream and salad dressing in the wash performance test for detergent application. It also exhibited anti-soil redeposition effect on cotton swatches treated with tennis court clay and heteromannans.

Evaluation of calcium oxalate deposition on different fabrics under different sodium oxalate-based detergent formulations

The builder is an important ingredient in detergents. Sodium oxalate is a good non-phosphate detergent builder, which has good calcium-removing properties and good wash performance in detergents. However, sodium oxalate-based detergent formulations face a tricky problem of “incrustation” on fabrics due to calcium oxalate deposition. If sodium oxalate is used in commercial detergents, then “incrustation” must be solved. In this study, we examined the effect of fabric type, anionic surfactant, polymer, and temperature on incrustation and soil redeposition (“secondary” washing effect) of a sodium oxalate-based detergent. The results showed that both the anionic surfactant and polymer influenced the deposition of calcium oxalate on fabrics. Overall, the amount of calcium oxalate deposition followed the order polyamide < polyester < cotton with the same formulation. Finally, good secondary washing effects (low ash deposition and high whiteness retention) formulations were selected by cumulative washing. The formulation of methyl ester sulfonate (MES)-sodium carboxymethyl cellulose (CMC), MES-polyvinyl pyrrolidone, and alcohol ether sulfate (AES)-CMC had better secondary effects, and the optimal combination of the 12 formulations was AES-CMC.

Spatial redistribution of Cs-137 and soil erosion on Orléans Island, Québec

Cs-137 redistribution data have been used to estimate the extent and the pattern of long-term soil erosion in the Québec City area. Mean annual net soil movements ranging from a deposition of 10.8 t ha−1 yr−1 to a loss of 31.8 t ha−1 yr−1 were estimated. The slope steepness and the land use significantly influenced the estimated rates of soil movement, while soil texture was less important, probably because of the soils’ sandy texture or the high content of organic carbon, which kept their erodibility low. The net soil losses estimated from Cs-137 data were consistently higher than those predicted by the USLE. Besides net soil losses, it was possible to estimate separately the magnitude of soil detachment and soil deposition. Two–thirds of the stations sampled experienced net soil loss while the remaining third showed evidence of soil accumulation. These data suggest that the small net soil losses measured for low erosive conditions (flat slopes, dairy farming) result from important soil redeposition rates as much as from small soil detachment rates. Cs-137 redistribution data not only produce reliable estimates of soil movement rates, but also allow enhanced estimates of the agronomic and environmental impacts of soil erosion.Key words: Cs-137, erosion, sedimentation, USLE, sediment delivery ratio