Wang Zhouli, Liang Yunhao, Wang Qi, Jia Hang, Yue Tianli, Yuan Yahong, Gao Zhenpeng, Cai Rui
College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Laboratory of Quality & Safety Risk Assessment for Agro-products (YangLing), Ministry of Agriculture, Yangling, Shaanxi 712100, China; National Engineering Research Center of Agriculture Integration Test (Yangling), Yangling, Shaanxi 712100, China.
College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
Food Res Int. 2021 Oct;148:110621. doi: 10.1016/j.foodres.2021.110621. Epub 2021 Jul 21.
Alicyclobacillus spp. can cause commercially pasteurized fruit juices/beverages to spoil and the spoilage is characterized by the formation of a distinct medicinal or antiseptic off-odor attributed to guaiacol. The aim of this study was to reveal the mechanism of guaiacol production in A. acidoterrestris by combining transcriptomic and proteomic approaches. RNA-sequencing and iTRAQ analyses were conducted to investigate differences in expression levels of genes and proteins in A. acidoterrestris when producing (with 500 μM vanillic acid) and not producing (without vanillic acid) guaiacol. A total of 225 differentially expressed genes and 77 differentially expressed proteins were identified. The transcription of genes vdcBCD encoding subunits of vanillic acid decarboxylase were 626.47, 185.01 and 52.81-fold up-regulated, respectively; they were the most up-regulated genes involved in guaiacol production. Expressions of the benzoate membrane transport protein, fusaric acid resistance protein, resistance-nodulation- division transporter, some ATP-binding cassette transporters and major facilitator superfamily transporters were increased at either mRNA, protein or both levels, indicating that they participated in the uptake of vanillic acid and extrusion of guaiacol. In the metabolic process of vanillic acid to guaiacol in A. acidoterrestris, genes related to the pathway of tricarboxylic acid cycle and ribosome were up-regulated, while the expression of some genes associated with valine, leucine and isoleucine biosynthesis was decreased. These findings provide novel insight to understand the mechanism of guaiacol production in A. acidoterrestris, which will serve as an important guide for developing strategies for the control of A. acidoterrestris problems in the fruit juice industry.
Alicyclobacillus属细菌可导致商业巴氏杀菌果汁/饮料变质，其变质特征是形成一种由愈创木酚引起的独特药味或防腐异味。本研究的目的是通过结合转录组学和蛋白质组学方法揭示嗜酸热脂环酸芽孢杆菌中愈创木酚的产生机制。进行了RNA测序和iTRAQ分析，以研究嗜酸热脂环酸芽孢杆菌在产生（添加500 μM香草酸）和不产生（不添加香草酸）愈创木酚时基因和蛋白质表达水平的差异。共鉴定出225个差异表达基因和77个差异表达蛋白质。编码香草酸脱羧酶亚基的vdcBCD基因的转录分别上调了626.47、185.01和52.81倍；它们是参与愈创木酚产生的上调幅度最大的基因。苯甲酸膜转运蛋白、抗镰刀菌酸蛋白、抗药-结瘤-分裂转运蛋白、一些ATP结合盒转运蛋白和主要促进剂超家族转运蛋白的表达在mRNA、蛋白质或两者水平上均有所增加，表明它们参与了香草酸的摄取和愈创木酚的外排。在嗜酸热脂环酸芽孢杆菌将香草酸代谢为愈创木酚的过程中，与三羧酸循环和核糖体途径相关的基因上调，而一些与缬氨酸、亮氨酸和异亮氨酸生物合成相关的基因表达下降。这些发现为理解嗜酸热脂环酸芽孢杆菌中愈创木酚的产生机制提供了新的见解，这将为制定控制果汁行业中嗜酸热脂环酸芽孢杆菌问题的策略提供重要指导。
