Department of Forest Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, Republic of Korea.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daehak-ro, Daejeon, Republic of Korea.
Bioprocess Biosyst Eng. 2019 Feb;42(2):267-277. doi: 10.1007/s00449-018-2031-z. Epub 2018 Dec 7.
Long-term space flight impairs the immune system of astronauts, rendering them vulnerable to opportunistic infections. Pseudomonas aeruginosa causes opportunistic infections, particularly in individuals with a compromised immune system; it can be a major health hazard for astronauts during space flight missions. Hence, the production of the most abundant redox active virulence factor, pyocyanin by P. aeruginosa, was assessed under low-shear modeled microgravity (LSMMG) conditions, simulated using a high aspect ratio vessel. Moreover, we evaluated changes in the expression of genes involved in pyocyanin biosynthesis and genes involved in the MexGHI-OpmD operon quorum sensing. Extracellular DNA and HO production were measured, and their correlation with pyocyanin production was examined. Interestingly, the pyocyanin quantity was 2.58-fold lower in the LSMMG conditions compared to the normal gravity. LSMMG caused downregulation of the genes associated with pyocyanin biosynthesis. Interestingly, extracellular DNA and HO release were significantly high in the normal gravity environment. Scanning electron microscopy revealed aggregation and elongated cells under LSMMG. Taken together, these findings suggest that LSMMG did not induce pyocyanin secretion in P. aeruginosa.
长期的太空飞行会损害宇航员的免疫系统，使他们容易受到机会性感染。铜绿假单胞菌引起机会性感染，特别是在免疫系统受损的个体中；它可能是宇航员在太空飞行任务中面临的主要健康危害。因此，评估了铜绿假单胞菌在低剪切模拟微重力（LSMMG）条件下（使用高纵横比容器模拟）产生最丰富的氧化还原活性毒力因子绿脓菌素的情况。此外，我们评估了参与绿脓菌素生物合成的基因和涉及 MexGHI-OpmD 操纵子群体感应的基因的表达变化。测量了细胞外 DNA 和 HO 的产生，并检查了它们与绿脓菌素产生的相关性。有趣的是，与正常重力相比，LSMMG 条件下的绿脓菌素数量低了 2.58 倍。LSMMG 导致与绿脓菌素生物合成相关的基因下调。有趣的是，在正常重力环境中外细胞 DNA 和 HO 的释放显著增加。扫描电子显微镜显示 LSMMG 下细胞聚集和伸长。综上所述，这些发现表明 LSMMG 未诱导铜绿假单胞菌分泌绿脓菌素。
