Studies on microbial production of and#946; galactosidase for use in making low lactose dairy products and other value added food ingredients

Abstract

Investigations carried out in this thesis entitled Studies on microbial production of and#946;-galactosidase for use in making low lactose dairy products and other value added food ingredients have been presented in five chapters. newlineChapter 1: General Introduction newlineand#946;-galactosidase (EC 3.2.1.23) or lactase, a significant enzyme used commercially, has diverse applications in food and pharmaceutical industries. The main property of this enzyme is hydrolyzing disaccharide lactose into glucose and galactose. Lactose intolerance is one of the prevalent issues across the globe. The term lactose intolerance refers to a condition in which various disorders are experienced by lactose intolerant people after consuming lactose containing food items. The reason behind this disorder is low or no secretion of and#946;-galactosidase enzyme from the brush border of the small intestine. Through transgalactosylation process, and#946;-galactosidase can also produce galactooligosaccharides which are prominent prebiotics. This chapter presents an overview of and#946;-galactosidase from microbial sources and emphasis is given on production, characterization, immobilization and application of and#946;-galactosidase in various fields. The effects of various parameters (nutritional and physical parameters) of growth medium for the enhancement of enzyme production are outlined in this chapter. The utilization of cheap substrates for the enhancement of enzyme production reduces the production cost. Immobilization process increases the stability and catalytic efficiency of free enzyme. This chapter also describes the applications of and#946;-galactosidase enzyme on dairy products for lactose hydrolysis and the production of transgalactosylated products. newlineChapter 2: Production, partial purification and characterization of and#946;-galactosidase from soil bacterium around cattle shed area newlineThe present investigation was undertaken to isolate and#946;-galactosidase producing bacteria by screening the soil duly collected from the area around a cattle shed nearby Kolkata. The isolation was carried out b