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

Samriti Dhawan

doi:10.22207/jpam.15.1.31

Abstract

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.

Highlights

Mannans and heteromannans are natural polysaccharides existing as part of the hemicellulose fraction in plant cell walls[1]
Endo-1, 4-β-Dmannanase (EC 3.2.1.78) is an endohydrolase, which randomly cleaves pyranosyl linkages within the main chain of various heteromannans and mannan to release oligosaccharides of different lengths. β-mannanase production is elaborated by diverse grups of bacteria, actinomycetes, and fungi isolated from natural sources[2]
A bacterium Paenibacillus thiaminolyticus was isolated in our laboratory and reported previously because of its rapid growth, capacity to secrete a high level of extracellular β-mannanase (1100 ± 50U/ml), into the growth medium and for its potential prebiotic properties[5]

Summary

Introduction

Mannans and heteromannans are natural polysaccharides existing as part of the hemicellulose fraction in plant cell walls[1]. Substrate specificity of the purified mannanase was determined by incubating the enzyme with one of the following substrates (1% w/v): Locust bean gum, Xylan (oat spelt), Mannan (ivory nut), Starch, Guar gum, Pectin, Chitin, Konjac glucomannan, and CM-cellulose prepared in potassium phosphate buffer (50 mM)pH 7.0.

Results

Conclusion