摘要
LuxS/AI-2群体感应系统可介导乳酸菌种内和种间信号,其中自诱导因子-2(autoinducer-2,AI-2)对乳酸菌的益生菌活性(环境胁迫耐受、黏附和定植能力等)至关重要。然而,目前对于LuxS/AI-2群体感应系统在植物乳杆菌抵御多种环境胁迫中的调控作用仍有待系统研究。通过群体感应信号分子研究及实时荧光定量聚合酶链式反应,分析了环境胁迫下植物乳杆菌KLDS 1.0328信号分子AI-2产量及群体感应关键基因luxS和pfs的转录情况。结果表明:酸胁迫可诱导信号分子AI-2的产生,强酸及强碱胁迫下可显著促进luxS及pfs的转录(P<0.05)。低温25℃、高温50℃、质量分数6.0%NaCl及质量分数3.0%NaCl+3.0%KCl诱导的高渗透压胁迫均会显著抑制菌体的增殖和代谢产酸,并抑制信号分子AI-2的产生;25℃低温胁迫会上调luxS及pfs基因的转录。随着高渗胁迫程度的增强,luxS及pfs基因的转录水平均逐步上调。营养胁迫诱导植物乳杆菌KLDS 1.0328产生更多的信号分子AI-2;随营养胁迫程度的加剧,luxS的转录水平显著上调,在营养物质体积分数为20%时,luxS及pfs基因的转录均达到最高水平,而pfs基因的转录在营养物质被稀释至体积分数为40%~60%时被显著抑制(P<0.05)。研究结果表明,多种环境胁迫下LuxS/AI-2群体感应系统具有不同的变化规律,且在植物乳杆菌KLDS 1.0328的抗逆过程中发挥重要作用。
The LuxS/AI-2 quorum sensing(QS)system mediates intraspecific and interspecific signals of lactic acid bacteria,among which autoinducer-2(AI-2)is crucial for probiotic activities of lactic acid bacteria,including environmental stress tolerance,adhesion and colonization ability.However,the regulatory effect of LuxS/AI-2 QS system in the resistance of Lactobacillus plantarum to various environmental stresses still needs to be systematically studied.The production of the signaling molecule AI-2 and the transcription of QS key genes luxS and pfs of Lactobacillus plantarum KLDS 1.0328 under environmental stress were analyzed by biological study and real-time fluorescence quantitative polymerase chain reaction.The results showed that acid stress could induce the production of signal molecule AI-2 and the transcription of luxS and pfs was significantly promoted under strong acid and alkali stress(P<0.05).Low temperature 25℃,high temperature 50℃and hyperosmotic stress induced by mass fraction 6.0%NaCl and mass fraction 3.0%NaCl+3.0%KCl could significantly inhibit cell proliferation,acid production and signal molecule AI-2 production.The transcription of luxS and pfs was up-regulated under low temperature stress at 25℃.The transcription of luxS and pfs was up-regulated with the increase of hypertonic stress.Furthermore,L.plantarum KLDS 1.0328 was induced to produce more signal molecule AI-2 by nutrient stress.With the aggravation of nutrient stress,the transcription of luxS was significantly up-regulated.The transcription of luxS and pfs reached the highest level when the nutrient volume fraction was 20%,while the transcription of pfs was significantly inhibited when the nutrient substance was diluted to volume fraction 40%-60%(P<0.05).These results indicated that LuxS/AI-2 QS system had different variation patterns under various environmental stresses,and played an important role in the stress resistance of L.plantarum KLDS 1.0328.
作者
马佳歌
谭中美
田子豪
吴梦果
韦旋
任洁
姜瞻梅
于微
侯俊财
MA Jiage;TAN Zhongmei;TIAN Zihao;WU Mengguo;WEI Xuan;REN Jie;JIANG Zhanmei;YU Wei;HOU Juncai(College of Food Science/Key Laboratory of Dairy Science,Ministry of Education,Northeast Agricultural University,Harbin 150030,China)
出处
《食品科学技术学报》
EI
CAS
CSCD
北大核心
2024年第1期106-113,共8页
Journal of Food Science and Technology
基金
国家自然科学基金资助项目(32202062)
新时代龙江优秀硕士、博士学位论文项目(LJYXL2022-033)
东北农业大学青年才俊基金资助项目(21QC25)
黑龙江省自然科学基金项目(LH2020C027)。
关键词
植物乳杆菌
环境胁迫
应激反应
群体感应
自诱导因子-2
Lactobacillus plantarum
environmental stress
stress response
quorum sensing
autoinducer-2
