Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, UPM, Serdang, Selangor 43400, Malaysia.
China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, Selangor 43900, Malaysia.
Molecules. 2019 Jul 17;24(14):2606. doi: 10.3390/molecules24142606.
Kefir is a homemade, natural fermented product comprised of a probiotic bacteria and yeast complex. Kefir consumption has been associated with many advantageous properties to general health, including as an antioxidative, anti-obesity, anti-inflammatory, anti-microbial, and anti-tumor moiety. This beverage is commonly found and consumed by people in the United States of America, China, France, Brazil, and Japan. Recently, the consumption of kefir has been popularized in other countries including Malaysia. The microflora in kefir from different countries differs due to variations in culture conditions and the starter media. Thus, this study was aimed at isolating and characterizing the lactic acid bacteria that are predominant in Malaysian kefir grains via macroscopic examination and 16S ribosomal RNA gene sequencing. The results revealed that the Malaysian kefir grains are dominated by three different strains of Lactobacillus strains, which are Lactobacillus harbinensis, Lactobacillusparacasei, and Lactobacillus plantarum. The probiotic properties of these strains, such as acid and bile salt tolerances, adherence ability to the intestinal mucosa, antibiotic resistance, and hemolytic test, were subsequently conducted and extensively studied. The isolated Lactobacillus spp. from kefir H maintained its survival rate within 3 h of incubation at pH 3 and pH 4 at 98.0 ± 3.3% and 96.1 ± 1.7% of bacteria growth and exhibited the highest survival at bile salt condition at 0.3% and 0.5%. The same isolate also showed high adherence ability to intestinal cells at 96.3 ± 0.01%, has antibiotic resistance towards ampicillin, penicillin, and tetracycline, and showed no hemolytic activity. In addition, the results of antioxidant activity tests demonstrated that isolated Lactobacillus spp. from kefir G possessed high antioxidant activities for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing ability of plasma (FRAP), and 1,1-diphenyl-2-picryl-hydrazine (DPPH) assay compared to other isolates. From these data, all Lactobacillus spp. isolated from Malaysian kefir serve as promising candidates for probiotics foods and beverage since they exhibit potential probiotic properties and antioxidant activities.
开菲尔是一种由益生菌细菌和酵母复合物组成的自制天然发酵产品。开菲尔的消费与许多对一般健康有益的特性有关,包括抗氧化、抗肥胖、抗炎、抗微生物和抗肿瘤。这种饮料在美国、中国、法国、巴西和日本很常见,人们也经常饮用。最近,包括马来西亚在内的其他国家也开始流行饮用开菲尔。由于培养条件和起始培养基的不同,不同国家的开菲尔中的微生物区系也有所不同。因此,本研究旨在通过宏观检查和 16S 核糖体 RNA 基因测序,从马来西亚开菲尔粒中分离和鉴定主要的乳酸菌。结果表明,马来西亚开菲尔粒主要由三种不同的乳杆菌菌株组成,分别是哈尔滨乳杆菌、副干酪乳杆菌和植物乳杆菌。随后对这些菌株的益生菌特性,如耐酸和耐胆盐能力、对肠道黏膜的黏附能力、抗生素耐药性和溶血试验进行了广泛研究。从开菲尔 H 中分离的乳杆菌 spp. 在 pH 3 和 pH 4 下孵育 3 小时内保持 98.0±3.3%和 96.1±1.7%的细菌生长存活率,在 0.3%和 0.5%胆汁盐条件下的存活率最高。相同的分离株对肠道细胞也表现出高黏附能力,达到 96.3±0.01%,对氨苄西林、青霉素和四环素具有抗生素耐药性,且无溶血活性。此外,抗氧化活性测试结果表明,从开菲尔 G 中分离的乳杆菌 spp. 在总酚含量(TPC)、总黄酮含量(TFC)、血浆铁还原能力(FRAP)和 1,1-二苯基-2-苦基肼(DPPH)测定中均表现出较高的抗氧化活性,与其他分离株相比。从这些数据可以看出,从马来西亚开菲尔中分离的所有乳杆菌 spp. 都具有成为益生菌食品和饮料的潜力,因为它们表现出潜在的益生菌特性和抗氧化活性。