Recent Research in Science and Technology 2010, 2(1): 83–88 ISSN: 2076-5061 www.recent-science.com BIOTECHNOLOGY ISOLATION, SCREENING AND CHARACTERIZATION OF RIBOFLAVIN PRODUCING LACTIC ACID BACTERIA FROM KATPADI, VELLORE DISTRICT Sathyanarayanan Jayashree  , Kunthala Jayaraman and Gurumurthy Kalaichelvan School of Biosciences and Technology, Vellore Institute of Technology University, Vellore-632 014, Tamilnadu, India Abstract Riboflavin is a basic component of the cellular metabolism since it is the precursor of the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Riboflavin producing lactic acid bacteria are of potential importance to the fermented food industry since the chemical processes is being replaced by the fermentative biotechnological methods. The present study was carried out to identify and characterize the best riboflavin producing lactic acid bacteria from the yoghurt samples of the Vellore district. The strains isolated belong to the genus Lactobacillus, streptococcus, Pediococcus, and Leuconostoc. Lactobacillus was the predominant strain. The best riboflavin producing strain was characterized to be Lactobacillus fermentum by both biochemical as well as molecular methods from the Institute of microbial technology (IMTECH), Chandigarh, India and deposited with the accession number MTCC 8711. The strain could be a better starter replacing the conventional lactic acid bacteria where in the fermented foods could be naturally fortified with the riboflavin. Key Words: Lactic acid bacteria – Riboflavin – Lactobacillus sp.  Corresponding Author, Email: sjayashree@vit.ac.in Introduction Lactic acid bacteria (LAB) are a class of industrially prominent microorganisms used in food and dairy industry owing to their fermentative properties. LAB are considered as generally regarded as safe (GRAS) organisms and their application as probiotics is immense as they play major role in maintaining health [1]. They produce a range of metabolites that are collectively termed as ‘nutraceuticals’, which include B vitamins like riboflavin (B2), folate (B11) and cobalamine (B12), low calorie sugars like mannitol and sorbitol, exopolysaccharides, diacetyl and L-alanine. One of the vital nutraceutical produced by LAB, namely the riboflavin (Vitamin B2) is an indispensable component in the human diet, which is the precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). The recommended daily allowance of riboflavin is 1.6 mg and the deficiency of riboflavin leads to loss of hair, inflammation of the skin, sore throat, hyperemia, edema of oral and mucous membranes, cheilosis and glossitis [2]. Although riboflavin is found in a wide variety of foods, riboflavin deficiency is common in many parts of the world, particularly in developing countries [3]. The deficiency can be treated with dietary supplement of riboflavin or by consuming fermented foods such as cheese, yogurt fortified with riboflavin in the daily diet. Riboflavin has traditionally been produced by chemical processes, but in recent times this has been replaced by the microbial fermentation processes [4]. This study was aimed to isolate riboflavin producing LAB strains from yoghurt samples. Materials and Methods Sample collection and maintenance Thirty seven fermented milk samples were collected from the individual house holds in rural parts of Katpadi, in the Vellore district, Tamilnadu, India. Samples were obtained in duplicates in sterile glass vials and stored at 4ºC until they were used in the experiments. Isolation of Lactic acid bacteria The fermented milk samples were homogenized in a homogenizer (Polytron). The homogenized samples were serially diluted using physiological saline (0.9%) and plated in Lactobacillus MRS [5] and M17 [6] agar plates. The plates were incubated at 37ºC for 48 hrs. Forty eight colonies were randomly selected from all the MRS and M17 plates of lower dilutions. Selected colonies were grown in MRS and M17 broth and the purity was checked by streaking on the respective agar plates. Glycerol stocks of the isolates were prepared with 50% glycerol and maintained at -20C. A set of MRS stabs were also made and stored at 4C for use as working culture. These forty eight strains were subjected to the genus level identification of LAB and further screening of riboflavin producing ability in the modified chemically defined medium [7].