Therapeutic applications of lactic acid bacteria based on the nano and micro biosystems

A plethora of natural metabolites has been identified as antimicrobial and antioxidant agents. Pathogenic and spoilage microorganisms can be inhibited by antimicrobial agents produced by lactic acid bacteria (LAB) via strong antagonistic activity toward them. These bacteria can synthesize bioactive metabolites such as bacteriocins, reutericyclin, reuterin, hydrogen peroxide, carbon dioxide, acetoin, diacetyl, ethanol, acetaldehyde, and organic acids (acetic and lactic acid) as antimicrobial agents. Both Gram-negative and Gram-positive pathogenic bacteria have shown different levels of sensitivity towards these materials. In addition, chelating ferrous ions as well as degrading cholesterol and nitrite have been found for LAB as its main antioxidant activity. These bacteria may be isolated from fermented foods including stinky tofu, corn noodle, chili sauce, glutinous rice dough, meat, vegetable, yogurt, sauerkraut, cultured butter, cheese, cocoa, and potherb mustard pickles. These bacteria can be employed to produce minicells and SimCells in nanosized drug delivery systems to load a range of different chemotherapeutic drugs as a new technology that is functionalized by specific ligands to active targeting tumor cells with minimum toxicity against healthy cells. Moreover, LAB is able to synthesize various types of organic and inorganic nanomaterials as nano-bioreactors.