Protease, lipase and amylase extraction and optimization from activated sludge of pulp and paper industry

Sludge is a hazardous waste and their disposal is an issue of concern that needs a suitable solution. Enzyme extraction from industrial sludge, particularly paper and pulp industry, is important in terms of waste management as well as the recovery of valuable product for the multifarious application. Present research work is focused on the extraction of some hydrolytic enzymes (protease, lipase, and amylase) from the sludge of paper industry using ultrasonication, an addition of cation exchange resin (CER) and Triton X-100. We have found that maximum protease was recovered from sludge using 2% Triton X-100 and maximum lipase at 0.1% Triton X-100. Both enzymes have shown contrasting behaviour. Lipase recovery was decreased with increased Triton X-100 concentration in contrast to protease recovery which showed a significant increase. However, maximum amylase was recovered using CER at 2000 U/g of VSS (volatile suspended solid) with Triton X-100 and maximum recovery was observed at 1.0%. Results suggest that this method to be most appropriate for extraction of hydrolytic enzymes from the activated sludge and suitable to be scaled up for effective recovery of hydrolytic enzymes from the industrial sludge.

Cross-sectional study of Trichinella spp in pigs in CDR, Nepal using pepsin digestion and ELISA serology.

This epidemiological cross-sectional study was conducted in five major pig-producing districts of CDR, Nepal from November 2006 to April 2007. A total of 576 slaughtered pigs were randomly selected and diaphragmatic crus muscles (n = 551), corresponding sera (n = 487) and sera only (n = 25) were collected from them. Meat samples were examined by pepsin digestion to evaluate for larvae of Trichinella spp. The sera were investigated using ELISA to evaluate for antibodies against T. spiralis. The doubtful and positive sera from the ELISA test were investigated by end-point ELISA, and the Western blot was used for confirmatory diagnosis. Pepsin digestion did not detect the larvae of Trichinella spp. AB-ELISA showed 2 positive and 14 doubtful results, out of 344 sera analyzed. End-point ELISA and the Western blot had revealed that all 16 samples were truly negative. A questionnaire revealed no rodent control (70%), left over feeding practices (65%), dumping of farm waste (82.5%) and uncooked meat was being used as feed (100%). This study reveals that Trichinella spp has a low prevalence.