School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
Sci Rep. 2018 Jul 30;8(1):11446. doi: 10.1038/s41598-018-28949-y.
Occasional beer spoilage incidents caused by false-negative isolation of lactic acid bacteria (LAB) in the viable but non-culturable (VBNC) state, result in significant profit loss and pose a major concern in the brewing industry. In this study, both culturable and VBNC cells of an individual Lactobacillus harbinensis strain BM-LH14723 were identified in one spoiled beer sample by genome sequencing, with the induction and resuscitation of VBNC state for this strain further investigated. Formation of the VBNC state was triggered by low-temperature storage in beer (175 ± 1.4 days) and beer subculturing (25 ± 0.8 subcultures), respectively, and identified by both traditional staining method and PMA-PCR. Resuscitated cells from the VBNC state were obtained by addition of catalase rather than temperature upshift, changing medium concentration, and adding other chemicals, and both VBNC and resuscitated cells retained similar beer-spoilage capability as exponentially growing cells. In addition to the first identification of both culturable and VBNC cells of an individual L. harbinensis strain from spoiled beer, this study also for the first time reported the VBNC induction and resuscitation, as well as verification of beer-spoilage capability of VBNC and resuscitated cells for the L. harbinensis strain. Genes in association with VBNC state were also identified by the first genome sequencing of beer spoilage L. harbinensis. The results derived from this study suggested the contamination and spoilage of beer products by VBNC and resuscitated L. harbinensis strain BM-LH14723.
在酿造工业中，由于乳酸菌（LAB）在存活但非可培养（VBNC）状态下的假阴性隔离偶尔会导致啤酒变质，这会导致重大的利润损失，引起人们的极大关注。在这项研究中，通过基因组测序，在一个变质的啤酒样本中鉴定出了个体哈尔滨乳杆菌 BM-LH14723 的可培养和 VBNC 细胞，并进一步研究了该菌株 VBNC 状态的诱导和复苏。VBNC 状态的形成分别是由低温储存啤酒（175±1.4 天）和啤酒传代培养（25±0.8 次传代）触发的，并通过传统染色方法和 PMA-PCR 进行了鉴定。通过添加过氧化氢酶而不是温度升高、改变培养基浓度和添加其他化学物质，从 VBNC 状态恢复的细胞被获得，并且 VBNC 和恢复的细胞都保留了与指数生长细胞相似的啤酒变质能力。除了首次从变质啤酒中鉴定出单个哈尔滨乳杆菌的可培养和 VBNC 细胞外，本研究还首次报道了 VBNC 的诱导和复苏，以及验证了 VBNC 和恢复的细胞对哈尔滨乳杆菌的啤酒变质能力。通过首次对啤酒变质的哈尔滨乳杆菌进行基因组测序，还鉴定了与 VBNC 状态相关的基因。本研究的结果表明，VBNC 和恢复的哈尔滨乳杆菌 BM-LH14723 菌株污染和破坏了啤酒产品。
