Department of Food Science and Technology, Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan.
J Food Prot. 2018 Jun;81(6):1030-1034. doi: 10.4315/0362-028X.JFP-17-260.
Although lactic acid bacteria (LAB) are used widely as starter cultures in the production of fermented foods, they are also responsible for food decay and deterioration. The undesirable growth of LAB in food causes spoilage, discoloration, and slime formation. Because of these adverse effects, food companies test for the presence of LAB in production areas and processed foods and consistently monitor the behavior of these bacteria. The 3M Petrifilm LAB Count Plates have recently been launched as a time-saving and simple-to-use plate designed for detecting and quantifying LAB. This study compares the abilities of Petrifilm LAB Count Plates and the de Man Rogosa Sharpe (MRS) agar medium to determine the LAB count in a variety of foods and swab samples collected from a food production area. Bacterial strains isolated from Petrifilm LAB Count Plates were identified by 16S rDNA sequence analysis to confirm the specificity of these plates for LAB. The results showed no significant difference in bacterial counts measured by using Petrifilm LAB Count Plates and MRS medium. Furthermore, all colonies growing on Petrifilm LAB Count Plates were confirmed to be LAB, while yeast colonies also formed in MRS medium. Petrifilm LAB Count Plates eliminated the plate preparation and plate inoculation steps, and the cultures could be started as soon as a diluted food sample was available. Food companies are required to establish quality controls and perform tests to check the quality of food products; the use of Petrifilm LAB Count Plates can simplify this testing process for food companies.
虽然乳酸菌（LAB）广泛用作发酵食品生产中的起始培养物，但它们也是导致食物腐烂和变质的原因。LAB 在食物中的不良生长会导致食物变质、变色和形成粘液。由于这些不利影响，食品公司在生产区域和加工食品中检测 LAB 的存在，并持续监测这些细菌的行为。3M Petrifilm LAB 计数平板最近推出，作为一种节省时间且易于使用的平板，旨在检测和定量 LAB。本研究比较了 Petrifilm LAB 计数平板和 de Man Rogosa Sharpe（MRS）琼脂培养基在确定各种食品和从食品生产区域采集的拭子样本中 LAB 计数的能力。通过 16S rDNA 序列分析鉴定从 Petrifilm LAB 计数平板分离的细菌菌株，以确认这些平板对 LAB 的特异性。结果表明，使用 Petrifilm LAB 计数平板和 MRS 培养基测量的细菌计数没有显著差异。此外，Petrifilm LAB 计数平板上生长的所有菌落均被确认为 LAB，而 MRS 培养基中也形成了酵母菌落。Petrifilm LAB 计数平板省去了平板准备和接种平板的步骤，只要有稀释的食物样本即可开始培养。食品公司需要建立质量控制并进行测试以检查食品产品的质量；使用 Petrifilm LAB 计数平板可以简化食品公司的测试过程。
