Qian Hui, Li Wei, Guo Linxia, Tan Ling, Liu Haiquan, Wang Jingjing, Pan Yingjie, Zhao Yong
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China.
Front Microbiol. 2020 Feb 20;11:23. doi: 10.3389/fmicb.2020.00023. eCollection 2020.
The sessile biofilms of and have increasingly become a critical threat in seafood safety. This study aimed to evaluate the effects of modified atmospheres on the formation ability of and biofilms. The stress responses of bacterial biofilm formation to modified atmospheres including anaerobiosis (20% carbon dioxide, 80% nitrogen), micro-aerobiosis (20% oxygen, 80% nitrogen), and aerobiosis (60% oxygen, 40% nitrogen) were illuminated by determining the live cells, chemical composition analysis, textural parameter changes, expression of regulatory genes, etc. Results showed that the biofilm formation ability of was efficiently decreased, supported by the fact that the modified atmospheres significantly reduced the key chemical composition [extracellular DNA (eDNA) and extracellular proteins] of the extracellular polymeric substance (EPS) and negatively altered the textural parameters (biovolume, thickness, and bio-roughness) of biofilms during the physiological conversion from anaerobiosis to aerobiosis, while the modified atmosphere treatment increased the key chemical composition of EPS and the textural parameters of biofilms from anaerobiosis to aerobiosis. Meanwhile, the expression of biofilm formation genes (, , , , and ), EPS production genes (, , and ), and virulence genes (, , , β, and β) of was downregulated. For the cells, the expression of biofilm formation genes (, , and ), EPS production genes (, , , ), and virulence genes (, , , β, and β) was upregulated during the physiological conversion. All these results indicated that the modified atmospheres possessed significantly different regulation on the biofilm formation of Gram-negative and Gram-positive , which will provide a novel insight to unlock the efficient control of Gram-negative and Gram-positive bacteria in modified-atmosphere packaged food.
[具体细菌名称1]和[具体细菌名称2]的附着型生物膜日益成为海鲜安全的关键威胁。本研究旨在评估气调对[具体细菌名称1]和[具体细菌名称2]生物膜形成能力的影响。通过测定活细胞、化学成分分析、质地参数变化、调控基因表达等，阐明了细菌生物膜形成对气调（包括厌氧（20%二氧化碳，80%氮气）、微需氧（20%氧气，80%氮气）和好氧（60%氧气，40%氮气））的应激反应。结果表明，[具体细菌名称1]的生物膜形成能力有效降低，这一事实得到支持：在从厌氧到好氧的生理转变过程中，气调显著降低了细胞外聚合物（EPS）的关键化学成分[细胞外DNA（eDNA）和细胞外蛋白质]，并对生物膜的质地参数（生物体积、厚度和生物粗糙度）产生负面影响，而气调处理从厌氧到好氧增加了[具体细菌名称2]生物膜的EPS关键化学成分和质地参数。同时，[具体细菌名称1]生物膜形成基因（[基因名称1]、[基因名称2]、[基因名称3]、[基因名称4]和[基因名称5]）、EPS产生基因（[基因名称6]、[基因名称7]和[基因名称8]）以及毒力基因（[基因名称9]、[基因名称10]、[基因名称11]、β和β）的表达下调。对于[具体细菌名称2]细胞，在生理转变过程中生物膜形成基因（[基因名称12]、[基因名称13]和[基因名称14]）、EPS产生基因（[基因名称15]、[基因名称16]、[基因名称17]）以及毒力基因（[基因名称18]、[基因名称19]、[基因名称20]、β和β）的表达上调。所有这些结果表明，气调对革兰氏阴性[具体细菌名称1]和革兰氏阳性[具体细菌名称2]的生物膜形成具有显著不同的调控作用，这将为揭示气调包装食品中革兰氏阴性菌和革兰氏阳性菌的有效控制提供新的见解。
