Antioxidant, antimicrobial and antitumor activity of bacteria of the genus Bifidobacterium, selected from the gastrointestinal tract of human

Antagonistic qualities of lactic acid bacteria (LAB), including Bifidobacteria are well known. This primarily concerns a wide variety of pathogenic microorganisms that cause both food spoilage and human diseases of varying severity. Such qualities are explained by LAB production of substances called bacteriocins. There is a certain relationship between cancer and microbes, bacteria and viruses. However, information on the possibility of cancer cell inhibition by means of their effect on activating microorganisms is practically absent. The present study suggests four active strains which have been isolated from the gastrointestinal tract of human New isolates SK1, SK2, SK8 and SK11 have been identified as Bifidobacterium. A wide range of antioxidant, antimicrobial and anticancer properties against the four strains of Bifidobacterium SK and cellular test cultures was studied. It was found that the strains of Bifidobacterium SK1, SK2, SK8, SK11 completely inhibit the growth of E. coli B-6954, Staphylococcus aureus ATCC 25923, Salmonella enterica ATCC 14028, Klebsiella pneumoniae B-7001. In relation to Clostridium tyrobutyricum LMG inhibitory activity was observed only in SK2 strain. The antitumor activity of Bifidobacterium isolates determines the promising direction of their use in the prevention and in the immediate treatment of cancer. For example, as the basis for product recovery of cancer patients in remission after chemotherapy. Introduction One of the main causes of peoples’ death, regardless of economic development, is cancer [1,2]. Existing medical technology enables to achieve a complete recovery only in limited cases, and usually in the presence of early diagnosis. A significant role in the recovery is given to the rehabilitation technologies during or after chemotherapy, to the side effects that is a serious problem [3,4]. It is vital to develop technologies that allow both to carry out prevention and to reduce risk of death and disability of cancer patients. There are papers in which the relationship between cancer and microbes, bacteria and viruses [5-11] are studied, but information about the possibility of inhibition of cancer cells by means of exposure to microbes activates them are practically absent. As potential effects of agents can be considered lactic acid bacteria that have shown inhibitory activity against pathogenic bacteria, fungi and yeast in vitro studies [12-24]. The main species of lactic acid bacteria (LAB) are Lactobacillus and Bifidobacterium, Enterococcus and Saccharomyces [25-30]. There is a centuries-old tradition of their use in the food, agriculture and processing industry, medicine, biotechnology, cosmetics, etc. [31-39]. Lactobacteria are a group of organisms most frequently used as the activity of lactic acid bacteria determines the possibility of their use as a cultural preserve [40]. A wide range of antimicrobial, antifungal activity of lactic acid bacteria determines the possibility of their use in bio-conservation technologies [15,20-23,41-48]. In order to solve practical problems a large initial screening test of different cultures requires to find active lactobacillus responsible specified quality. In the present study four active strains, previously isolated from the gastrointestinal tract of human were studied. The aim was to identify and characterize their antioxidant and antimicrobial properties, determined by allocated bacteriocins and set antitumor activity of these metabolites. The importance of taxonomic characterization and identification of the isolates is defined by insufficient knowledge of the spectrum of the human microbiota and mechanisms of action of bacteriocins on cell and microbial culture. We have studied in vitro potential of isolated Bifidobacterium and their bacteriocins to inhibit cancer of cell cultures Materials and methods Lactic acid bacteria isolates, media and cultivation conditions 4 strains of lactic acid bacteria, identified as SK1, SK2, SK8, SK11 were pre-selected for this study. They have been allocated from the gastrointestinal tract of 500 healthy and cancer patients in different age groups (Russian Federation). Pure cultures were stored at 4 ± 2°C in a lyophilized form. Before determination of the strains they were pre-cultured twice under anaerobic conditions (Biostat A plus MO fermenter, Sartorius, USA) in MRS-broth for 24 hours at 37°C. Overnight culture of micro-organisms were collected by Correspondence to: Olga Babich, Department of Bionanotechnology, Kemerovo Institute of Food Science and Technology, Kemerovo, Russia, E-mail: olich.43@mail.ru