USE OF SOME CLAY MATRICES IN BIOTECHNOLOGY OF ACID DAIRY PRODUCTS

Abstract

In this paper we analyze the use of some clay matrices in the cultivation process of lactic acid bacteria, in dairy industry. The object of this paper is the use of anionic clays - hydrotalcite type, with food purity grade, that are synthesized in laboratory, and can be conditioned in porous tablets or pellets form. These are introduced into the culture medium and help optimal growth parameters achievement of lactic acid bacteria by temporary retention of lactic acid. After multiplication and cellular growth, the tablet or pellet insoluble clays, can be removed, washed and recovered. The lifetime (using) of such materials and devices is practically unlimited. According to this study, the cultivation process of lactic acid bacteria includes the immersion in culture medium of a hydrotalcite clay matrix, with anions exchange role, cultivated through continuous cycle of hydrotalcite matrices immersion, removing and recovering, the lactic anion is continuously fixed, achieving at the same time the proton neutralization of lactic acid, with an aqueous phase, separated from the culture medium, with subsequent extraction and separation of lactic acid. The advantages of the proposed process are: about four time decrease of achieved period of lactic bacteria cultivation phase; 2 - 3 time decrease of final cultures productivity growth; increase with 50-70% rate of bacteria growth in fermentative process; decrease with 30-60% of lactic bacteria cost for industrial fabrication of acid dairy products.