[Downloaded free from http://www.jpionline.org on Sunday, September 17, 2017, IP: 78.39.35.67] Original Research Article Antifungal effects of Lactobacillus species isolated from local dairy products Sahar Karami, Mohammad Roayaei, Elnaz Zahedi, Mahmoud Bahmani1, Leila Mahmoodnia2, Hosna Hamzavi, Mahmoud Rafieian-Kopaei3 Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahwaz, 1Department of Pharmacology, Biotechnology and Medicinal Plants Research Center, Ilam University of Medical Sciences, Ilam, 3Department of Pharmacology, Medical Plants Research Center, Basic Health Sciences Institute, 2Department of Internal Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran Abstract Objective: The Lactobacillus is a genus of lactic acid bacteria which are regularly rod‑shaped, nonspore, Gram‑positive, heterogeneous, and are found in a wide range of inhabitants such as dairy products, plants, and gastrointestinal tract. A variety of antimicrobial compounds and molecules such as bacteriocin are produced by these useful bacteria to inhibit the growth of pathogenic microbes in the food products. This paper aims to examine the isolation of Lactobacillus from local dairies as well as to determine their inhibition effect against a number of pathogens, such as two fungi: Penicillium notatum and Aspergillus fulvous. Materials and Methods: Twelve Lactobacillus isolates from several local dairies. After initial dilution (10−1–10−3) and culture on the setting, de Man, Rogosa and Sharpe‑agar, the isolates were recognized and separated by phenotypic characteristics and biochemical; then their antifungal effect was examined by two methods. Results: Having separated eight Lactobacillus isolates, about 70% of the isolates have shown the inhabiting areas of antifungus on the agar‑based setting, but two species Lactobacillus alimentarius and Lactobacillus delbrueckii have indicated a significant antifungal effect against P. notatum and A. fulvous. Except bacteriocin, lactic acid, and acetic acid, the inhibitor substance is produced by these bacteria. Conclusion: Given the vitality of Lactobacillus in human health, recognition and isolation of the species producing compound in antagonist to the pathogens existing in the food products can be a helpful and effective step toward maintaining the valuable native Lactobacillus and using them in the dairy industries. Keywords: Antifungal effects, bacteriocin, dairy products, Lactobacillus Address for correspondence: Prof. Mahmoud Rafieian‑Kopaei, Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran. E‑mail: [email protected] INTRODUCTION Penicillium produces the allergen spores and mycotoxin that threats seriously the human life.[1] The controlling measures During storage and maintenance of food products, the to prevent the fungus growing in the grains, foodstuff, and spoilage and toxicity will occur by fungi such as Fusarium storage and to inhibit the food contamination and reducing and Aspergillus. However, a major problem of such spoilage the public health hazards are of special importance.[2] is induced by Penicillium fungus which has resulted in huge Over the past few years, the interests in using of natural economic losses around the world.[1] In addition to it, the This is an open access article distributed under the terms of the Creative Commons Access this article online Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the Quick Response Code: new creations are licensed under the identical terms. Website: www.jpionline.org For reprints contact: [email protected] DOI: How to cite this article: Karami S, Roayaei M, Zahedi E, Bahmani M, 10.4103/jphi.JPHI_9_17 Mahmoodnia L, Hamzavi H, et al. Antifungal effects of Lactobacillus species isolated from local dairy products. Int J Pharma Investig 2017;7:77-81. © 2017 International Journal of Pharmaceutical Investigation | Published by Wolters Kluwer - Medknow 77 [Downloaded free from http://www.jpionline.org on Sunday, September 17, 2017, IP: 78.39.35.67] Karami, et al.: Antifungal effects of Lactobacillus species products in prevention and treatment of diseases have by molds is a concern. It is estimated that about 5%–10% increased.[3-8] Researchers have also tried to prepare natural of foodstuff are spoiled by these organisms. The LAB are drugs.[9-14] The use of microorganism or their metabolites commonly found in the nutrient-rich settings. They exist for biological protection and avoiding foodstuff spoilage naturally in many food systems producing livestock meal. and extending the time of food products retention has also These bacteria can protect the foodstuff from microbial been increased. The lactic acid bacteria (LAB) include a decay through generating the antagonist metabolic products wide range of genus as well as substantial species.[15] The or establishing the other antimicrobial compounds.[20] lactic acid bacteria are generally recognized as secure microorganisms in which they have been used in the In addition to the publications, in which the active fragmented food product and for protection for centuries.[2] antifungal substances are recognized, the studies on These bacteria are utilized a main starter compound for antifungal products of LAB showed that the substances fragmentation, especially for dairy products or some of inhibiting the fungi are different among species. Those them. They also are the natural flora of digestive tract.[1] species belonging to Lactobacillus genus are reported in The LAB play an important role as a culture starter in the most of studies. Since the fungi are eukaryote organism, food industries in producing flavor, odor, color, and texture the common target mechanism of effective material for and natural characteristics.[2] The interest and attention their growth inhibition is cellular walls, cellular membrane, to LAB in biological protection of foodstuff have been protein synthesis, and cellular division.[2,20] grown because they generate antimicrobial compound and products such as lactic acid and bacteriocin.[15] The purpose of this study was to investigate the effects of antifungal activity of probiotic bacteria Lactobacillus isolated The LAB are a family comprised a group of heterogenic, from various local dairy Ahvaz. Gram-positive, nonspore, catalase, and negative cytochrome, MATERIALS AND METHODS anaerobe bacteria. The recent taxonomical studies suggest that LAB are consisted of 13 genera. The antimicrobial effects Sampling and immunity of some of the genera such as Lactobacillus and In this study, twenty local diary samples (yogurt, milk, Lactococcus in the protection of foodstuff have been widely and cheese) were gathered from different districts of [16] accepted. Some useful effect of probiotics on health Ahvaz. The samples were stored in the tubes then, they includes the development of natural microflora, prevention were enriched in the culture setting de Man, Rogosa, and of infectious diseases and allergy, reduction of serum Sharpe (MRS)-broth (Merck, Germany) at temperature cholesterol, anticancer activity, reinforcement of immune 37°C for 24 h. After enrichment, they were incubated [17] system, and improvement of lactose digest in the host. on the culture setting MRS-Agar (Merck, Germany) at Some genus used as probiotics are Lactobacillus, Bifidobacterium, temperature 37°C for 48 h. The observed colonies on [17] Streptococcus, Lactococcus and some fungi and yeast species. setting MRS-Agar (Merck, Germany) were subcultured for [1] Lactobacillus is one of the most important genera of LAB. purification.[21] The isolates at genus levels were identified The lactobacilli homofragmentation fragments the hexose using morphological, phenotype, and biochemical tests to lactic acid alone or accompanied with acetic acid, ethanol, characteristics such as: (Gram-staining, catalase, (mobility and formic acid during glucose deficiency. The lactobacilli examination) SIM, indale test, oxidase, carbohydrate heterofragmentation fragments the hexose to Lactobacillus, fermentation (Lactose-Socrose-Arabinose-Trehalose- [18] acetic acid, ethanol CO2. There is a large number of these Salissin), then the effects of their antifungal were examined bacterial species and some dominate species that can produce by two methods: (I) Use of extract on bacteria culture (II) lactic acid from carbohydrate and that the LAB not only sonication (using ultrasonic waves).[20] are desirable for this reaction but also are necessary for its promotion. The bacteria and fungi are two microorganism Biochemical tests such as Gram-stain, catalase, oxidase, groups which can produce lactic acid. Although most indole production and motion study, growth at different researches investigating the production of lactic acid have temperatures (15°C-37°C-45°C) and various fermentation focused on LAB and filamentous fungi such as rhizopus, of sugars (sucrose, lactose, maltose, trehalose, galactose, use of glucose under aerobic condition has produced lactic arabinose, mannitol, fructose, and salicin) were studied.[22] acid as well.[19] The antifungal effect was assessed by two methods: Mold of fungi and yeasts are the organisms that produce substantial spoilage in the food products. In addition, In the first method using supernatant bacteria (supernatant generation of cancer-bearing and toxic mycotoxins potentially culture