Bioprocessing and Biomanufacturing Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
Probiotics Antimicrob Proteins. 2021 Apr;13(2):422-440. doi: 10.1007/s12602-020-09690-3.
Determination of a microbial strain for the joining into sustenance items requires both in vitro and in vivo assessment. A newly isolated bacteriocin-like inhibitory substance (BLIS) producing lactic acid bacterium, Lactococcus lactis Gh1, was isolated from a traditional flavour enhancer and evaluated in vitro for its potential applications in the food industry. Results from this study showed that L. lactis was tolerant to NaCl (≤ 4.0%, w/v), phenol (≤ 0.4%, w/v), 0.3% (w/v) bile salt, and pH 3. BLIS from L. lactis showed antimicrobial activity against Listeria monocytogenes ATCC 15313 and was susceptible to 10 types of antibiotics. The absence of haemolytic activity and the presence of acid phosphatase and naphthol-AS-BI-phosphohydrolase were observed in L. lactis. L. lactis could coagulate milk and showed a negative response to amylolytic and proteolytic activities and did not secrete β-galactosidase. The antimicrobial activity of BLIS was completely abolished at 121 °C. The BLIS was conserved at 4 °C in BHI and MRS medium up to 6-4 months, respectively. BLIS activity was more stable in BHI as compared to MRS after four freeze-thaw cycles and was not affected by a wide range of pH (pH 4-8). BLIS was sensitive to proteinase k and resistant to catalase and trypsin. The antimicrobial activity was slightly reduced by acetone, ethanol, methanol, and acetonitrile at 10% (v/v) and also towards Tween-80, urea, and NaCl 1% (v/v). Results from this study have demonstrated that L. lactis has a vast potential to be applied in the food industry, such as for the preparation of starter culture, functional foods, and probiotic products.
确定用于添加到食品中的微生物菌株需要进行体外和体内评估。从传统的风味增强剂中分离出一种新的产细菌素样抑制物质 (BLIS) 的乳酸菌 Lactococcus lactis Gh1，并在体外评估其在食品工业中的潜在应用。研究结果表明，L. lactis 能够耐受 NaCl（≤4.0%，w/v）、苯酚（≤0.4%，w/v）、0.3%（w/v）胆盐和 pH 3。来自 L. lactis 的 BLIS 对单核细胞增生李斯特菌 ATCC 15313 具有抗菌活性，并且对 10 种抗生素敏感。在 L. lactis 中观察到没有溶血活性，存在酸性磷酸酶和萘酚-AS-BI-磷酸水解酶。L. lactis 能够凝结牛奶，对淀粉水解和蛋白水解活性呈阴性反应，并且不分泌β-半乳糖苷酶。BLIS 的抗菌活性在 121°C 时完全被破坏。BLIS 在 BHI 和 MRS 培养基中分别在 4°C 下保存至 6-4 个月。BLIS 活性在经过四个冻融循环后在 BHI 中比在 MRS 中更稳定，并且不受广泛的 pH（pH 4-8）影响。BLIS 对蛋白酶 k 敏感，对过氧化氢酶和胰蛋白酶有抗性。BLIS 在 10%（v/v）的丙酮、乙醇、甲醇和乙腈以及吐温-80、尿素和 1%（v/v）的 NaCl 中活性略有降低。本研究结果表明，L. lactis 具有广泛的应用潜力，可应用于食品工业，如制备发酵剂、功能性食品和益生菌产品。
