Venkataramanan Keerthi P, Kurniawan Yogi, Boatman Judy J, Haynes Cassandra H, Taconi Katherine A, Martin Lenore, Bothun Geoffrey D, Scholz Carmen
Biotechnology Science and Engineering Program, University of Alabama in Huntsville, 301 Sparkman Dr NW, MSB 333, Huntsville, AL 35899, USA.
Department of Chemical Engineering, University of Rhode Island, 16 Greenhouse Rd., 205 Crawford Hall, Kingston, RI 02881, USA.
J Biotechnol. 2014 Jun 10;179:8-14. doi: 10.1016/j.jbiotec.2014.03.017. Epub 2014 Mar 15.
Clostridium pasteurianum ATCC 6013 achieves high n-butanol production when glycerol is used as the sole carbon source. In this study, the homeoviscous membrane response of C. pasteurianum ATCC 6013 has been examined through n-butanol challenge experiments. Homeoviscous response is a critical aspect of n-butanol tolerance and has not been examined in detail for C. pasteurianum. Lipid membrane compositions were examined for glycerol fermentations with n-butanol production, and during cell growth in the absence of n-butanol production, using gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance ((1)H-NMR). Membrane stabilization due to homeoviscous response was further examined by surface pressure-area (π-A) analysis of membrane extract monolayers. C. pasteurianum was found to exert a homeoviscous response that was comprised of an increase lipid tail length and a decrease in the percentage of unsaturated fatty acids with increasing n-butanol challenge. This led to a more rigid or stable membrane that counteracted n-butanol fluidization. This is the first report on the changes in the membrane lipid composition during n-butanol production by C. pasteurianum ATCC 6013, which is a versatile microorganism that has the potential to be engineered as an industrial n-butanol producer using crude glycerol.
当以甘油作为唯一碳源时，巴斯德梭菌ATCC 6013可实现高产正丁醇。在本研究中，通过正丁醇挑战实验考察了巴斯德梭菌ATCC 6013的同型粘性膜反应。同型粘性反应是正丁醇耐受性的一个关键方面，而对于巴斯德梭菌尚未进行详细研究。利用气相色谱 - 质谱联用仪（GC-MS）和质子核磁共振仪（(1)H-NMR），对产生正丁醇的甘油发酵过程以及在不产生正丁醇的细胞生长过程中的脂质膜组成进行了检测。通过对膜提取物单层的表面压力 - 面积（π-A）分析，进一步考察了同型粘性反应引起的膜稳定性。结果发现，随着正丁醇挑战的增加，巴斯德梭菌会产生同型粘性反应，表现为脂质尾长增加，不饱和脂肪酸百分比降低。这导致了更刚性或更稳定的膜，从而抵消了正丁醇的流化作用。这是关于巴斯德梭菌ATCC 6013在正丁醇生产过程中膜脂质组成变化的首次报道，该菌是一种多功能微生物，有潜力被改造成为利用粗甘油生产工业正丁醇的菌株。
