Studies on Lactic Acid Bacteria from Tropical Fish and Shellfish

In this study, an attempt has been made to gather enough information regarding lactic acid bacteria from fish and shellfish of tropical regions. The occurrence and distribution of lactic acid bacteria in fresh and frozen marine fish and shellfish, farmed fish and shellfish, cured and pickled fish and shellfish have been investigated. Lactic Acid Bacteria (LAB) have for centuries been responsible for the fermentative preservation of many foods. They are used to retard spoilage and preserve foods through natural fermentations. They have found commercial applications as starter cultures in the dairy, baking, meat, fish, and vegetable and alcoholic beverage industries. They are industrially important organisms recognized for their fermentative ability as well as their nutritional benefits. These organisms produce various compounds such as organic acids, diacetyl, hydrogen peroxide and bacteriocins or bactericidal proteins during lactic fermentations.Biopreservation of foods using bacteriocin producing LAB cultures is becoming widely used. The antimicrobial effect of bacteriocins and other compounds produced during fermentation of carbohydrates are well known to inhibit the growth of certain food spoiling bacteria as well as a limited group of food poisoning and pathogenic bacteria LAB like Lactobacillus plantarum are widely used as starter cultures for the Production of fish ensilage. The present study is the first quantitative and qualitative study on the occurrence and distribution of lactic acid bacteria in fresh and frozen fish and prawn. It is concluded that Lactobacillus plantaruni was the predominant lactobacillus species in fresh and frozen fish and shellfish. The ability of selected Lactobacillus cultures to grow at low temperatures, high salt content, produce bacteriocins, rapidly ferment sugars and decrease the pH make them potential candidates for biopreservation of fish and shellfish.

Thermdstable alpha amylase production by bacillus coagulans

Microbial enzymes are in great demand owing to their importance in several industries such as brewing, baking, leather, laundry detergent, dairy. starch processing and textiles besides pharmaceuticals. About 80% of the enzymes produced through fermentation and sold in the industrial scale are hydrolytic enzymes. Due to recognition of new and new applications, an intensive screening of different kinds of enzymes with novel properties, from various microorganisms, is being pursued all over the world. Bacillus sp are largely known to produce a-amylase, among the different groups of microoganisms, at industrial level. They are known to produce both saccharifying and liquefying a-amylases (Fukumoto 1963; walker and Campbell, 1967a). which are distinguishable by their mechanisms of starch degradation by the fact that the saccharifying asamylases produce an increase in reducing power about twice that of the liquefying enzyme (Fukumoto, 1963; Pazur and Okada, 1966). Under this circumstances, the present study was undertaken, with a View to utilise a fast growing B.coagu1ans isolated from soil, for production of thermostable and alkaline oz-amylase under different fermentation processes