Isolation and molecular identification of Lactobacillus brevis from traditional vinegar

• Main Authors: Zeynab Ebrahimi, Abolghasem Esmaeili, Tooba Sadat Ahmadi, Hamid Emami, Mohammad Rabbani
• Format: Article
• Language: English
• Published: University of Isfahan 2016-09-01
• Series: Biological Journal of Microorganism
• Subjects: Vinegar; lactic acid bacteria; Lactobacillus brevis
• Online Access: http://uijs.ui.ac.ir/bjm/browse.php?a_code=A-10-415-1&slc_lang=en&sid=1

Introduction: Vinegar is a popular condiment in the world that different materials and methods have been used to produce it. In Iran natural vinegar is also prepared mostly in a traditional way by using different fruits such as grapes and apples. Natural vinegar has beneficent properties and because of this, it is recommended to be used by traditional and Islamic medicine. Vinegar contains acetic acid bacteria, lactic acid bacteria and yeast. Acetic acid bacteria and yeasts are involved in the production of vinegar and lactic acid bacteria improve the flavor of vinegar. The aim of this study was isolation and identification of lactic acid bacteria especially Lactobacillus brevis from traditional vinegar. Materials and methods: After collecting a few traditional vinegars, the vinegar samples cultured for isolation of lactic acid bacteria on MRS broth and agar media contained nystatin as an anti-yeast antibiotic. Then some microbiological tests including catalase, gram staining and fermentation of carbohydrates were performed. Then, they were cultured at different temperatures, pH and different concentrations of salts. Finally, three isolates bacteria with biochemical properties of Lactobacillus brevis were evaluated by16 srDNA gene amplification. Results: Twelve lactobacilli were isolated from three vinegar samples. All isolated bacteria were catalase-negative and gram-positive. They could be able to grow at pH around 4.5 and 5.6, and at 2, 4 and 5.6% of salt concentrations. Most of the bacteria grew at 15oC, whereas one isolated grew at 45oC. Sequencing and Blast results showed that the three strains are Lactobacillus brevis. Discussion and conclusion: Lactobacillus brevis and Lactobacillus plantrum were found in traditional vinegars. Although isolation of Lactobacillus plantrum from vinegar was reported previously, as far as we could determine, it is for the first time that we could isolate Lactobacillus brevis from vinegar.