Lactic acid bacteria producing extracellular phytase isolation characterization and application in improving the nutritional quality of food

Abstract

Food is the delivery vehicle of nutrition and energy to human beings and animals. The amount of nutrients present in foods is not equivalent to their amount absorbed by living beings. Antinutrients such as phytate is one of the attributable reasons for nutrient deficit. Phytate has the tendency to chelate and forms insoluble complexes with micro-nutrients such as metal ions, amino acids etc present in food. In this regard, the most viable alternative is the use of phytase from micro-organisms. But when it comes to safety aspects, use of microorganisms or enzymes derived from them as human food supplement is questionable. Use of lactic acid bacteria which are safer and generally recognized as safe for food applications is preferable. In the present study, an Isolate Lactobacillus pentosus KA1 producing extracellular phytase and exhibiting probiotic characteristics was isolated from ethnic fermented Indian food, Kanjika. Conditions were optimized to hyperproduce the enzyme under submerged and solid state fermentation conditions followed by enzyme purification and characterization. High catalytic affinity of phytase toward sodium phytate made it a highly suitable candidate for its application in food processing. Conditions were standardized for maximum dephytinization of substrates such as whole wheat flour, rice flour, defatted rice bran, soymilk and increased concentration of solubilized minerals was achieved on treatment of various food matrices and food products formed from these matrices with the enzyme. L. pentosus KA1 was found to exhibit probiotic characteristics also. When whole organism was used for dephytinization of substrates, increase in soluble contents of minerals was found to be even better than when the enzyme was used. newline newline