Isolation and selection of lactic acid bacteria strains present in “nem chua thit” for use as stater cultures
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Abstract
This study was conducted to isolate, select and identify lactic acid bacteria (LAB), which has properties that can be used a starter culture, from Vietnamese fermented pork sausage ‘nem chua’. The results showed that 19 bacterial strains were isolated on MRS agar medium. Most colonies were round, having opalescent white color to milky white color, raised or flat elevation, lobulated or intact margin. Among 19 lactic acid bacterial strains isolated from ‘Nem chua’, there were 36.8% homofermentative strains and 63.2% heterofermentative strains. In the study of the ability to produce lactic acid and reduce pH, strain NTL2 and NTV2 were able to reduce pH faster than the others (3.65 and 3.7 respectively). They also produced the highest amount of lactic acid (19.13 mg/mL and 18.23 mg/mL) in MRS broth. Based on the typical properties of LAB, 12 strains were selected for identification by 16s rDNA sequence analysis, showing that: 6 strains are Lacticaseibacillus rhamnosus; 2 strains are Lactobacillus casei; 2 strains are Lactiplantibacillus pentosus, 1 strain is Lactiplantibacillus argentoratensis line, 1 strain was identified as Lactobacillus saniviri strain.
Tóm tắt
Nghiên cứu được thực hiện nhằm phân lập, tuyển chọn và xác định dòng loại vi khuẩn axit lactic (LAB) từ nem chua của Việt Nam, loại vi khuẩn có các đặc tính phù hợp để sử dụng làm nguồn vi khuẩn giống. Mười chín dòng vi khuẩn lactic đã được phân lập trên môi trường MRS agar. Đa số khuẩn lạc có hình tròn, màu trắng đục, trắng ngà, nhô cao hoặc phẳng, mép phân thùy hoặc nguyên vẹn. Trong 19 dòng vi khuẩn phân lập từ nem chua, có 36,8% dòng lên men đồng hình, 63,2% dòng lên men dị hình. Thử nghiệm khả năng sinh axit lactic và làm giảm pH cho thấy NTL2, NTV2 có khả năng làm giảm pH nhanh hơn các dòng còn lại (lần lượt là 3,65 và 3,7), đồng thời cũng tạo ra lượng axit lactic cao nhất là 19,13 mg/mL và 18,23 mg/mL. Dựa vào các tính chất điển hình của vi khuẩn lactic, 12 dòng được chọn để định danh bằng phân tích trình tự 16s rDNA. kết quả cho thấy 6 dòng được xác định là dòng Lacticaseibacillus rhamnosus, 2 dòng là dòng Lactobacillus casei, 2 dòng là dòng Lactiplantibacillus pentosus, 1 dòng tương đồng với dòng Lactiplantibacillus argentoratensis và 1 dòng được xác định là dòng Lactobacillus saniviri.
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References
Afoakwa, E. O., Paterson, A., Fowler, M., & Ryan, A. (2008). Flavor formation and character in cocoa and chocolate: a critical review. Critical Reviews in Food Science and Nutrition, 48(9), 840–857. https://doi.org/10.1080/10408390701719272
Axelsson, L. (2004). Lactic acid bacteria: Classification and physiology. In Lactic Acid Bacteria Microbiological and Functional Aspects, Third Edition: Revised and Expanded. https://doi.org/10.1201/9780824752033.ch1
Buckenhüskes, H. J. (1993). Selection criteria for lactic acid bacteria to be used as starter cultures for various food commodities. FEMS Microbiology Reviews, 12(1–3), 253-271. https://doi.org/10.1111/j.1574-6976.1993.tb00022.x
Cullimore, D. R. (2010). Practical Atlas for Bacterial Identification. In Practical Atlas for Bacterial Identification. https://doi.org/10.1201/9781420087987
Doungkhwan, P., Tavitchasri, P., Laosinwattana, C., Ngamyeesoon, N., & Pilasombut, K. (2017). Comparison of fermentation process in Thai fermented pork sausage (I-San sausage) on quality and safety. International Journal of Agricultural Technology, 13(7), 2205–2217.
Farnworth, E. R. (2008). Handbook of fermented functional foods. In Handbook of Fermented Functional Foods, Second Edition. https://doi.org/10.1201/9781420053289
Gänzle, M. G. (2015). Lactic metabolism revisited: Metabolism of lactic acid bacteria in food fermentations and food spoilage. In Current Opinion in Food Science (Vol. 2), 106 -117. https://doi.org/10.1016/j.cofs.2015.03.001
Heller, K. J. (2001). Probiotic bacteria in fermented foods: Product characteristics and starter organisms. American Journal of Clinical Nutrition, 73(2 SUPPL.), 374-379. https://doi.org/10.1093/ajcn/73.2.374s
Hill, A., & Ferrer, M. A. (2021). Classification of Lactic Acid Cultures. Cheese Making Technology (e-Book).
Kołozyn-Krajewska, D., & Dolatowski, Z. J. (2012). Probiotic meat products and human nutrition. Process Biochemistry, 47(12), 1761- 1772. https://doi.org/10.1016/j.procbio.2012.09.017
Nguyen, L. A. (2015). Health-promoting microbes in traditional Vietnamese fermented foods: A review. Food Science and Human Wellness, 4(4), 147–161. https://doi.org/10.1016/j.fshw.2015.08.004
Pimentel, T. C., Brandão, L. R., de Oliveira, M. P., da Costa, W. K. A., & Magnani, M. (2021). Health benefits and technological effects of Lacticaseibacillus casei-01: An overview of the scientific literature. Trends in Food Science & Technology, 114, 722–737. https://doi.org/10.1016/j.tifs.2021.06.030
Ravyts, F., Vuyst, L. De, & Leroy, F. (2012). Bacterial diversity and functionalities in food fermentations. Engineering in Life Sciences, 12(4), 356–367. https://doi.org/10.1002/elsc.201100119
Sánchez Mainar, M., Stavropoulou, D. A., & Leroy, F. (2017). Exploring the metabolic heterogeneity of coagulase-negative staphylococci to improve the quality and safety of fermented meats: a review. International Journal of Food Microbiology, 247, 24-37. https://doi.org/10.1016/j.ijfoodmicro.2016.05.021
Sneath, P. H. A., Bergey, D. H., & Holt, J. G. (1986). Bergey’s Manual of Systematic Bacteriology (Issue 1-2). Williams & Wilkins. https://books.google.com.vn/books?id=DQL1RAAACAAJ
Szajewska, H., & Hojsak, I. (2020). Health benefits of Lactobacillus rhamnosus GG and Bifidobacterium animalis subspecies lactis BB-12 in children. In Postgraduate Medicine (Vol. 132, Issue 5). https://doi.org/10.1080/00325481.2020.1731214
Tran, K. T. M., May, B. K., Smooker, P. M., Van, T. T. H., & Coloe, P. J. (2011). Distribution and genetic diversity of lactic acid bacteria from traditional fermented sausage. Food Research International, 44(1), 338-344. https://doi.org/10.1016/j.foodres.2010.10.010