Zu, Theresah N. K.Athamneh, Ahmad I. M.Senger, Ryan S.2017-09-202017-09-202016-01-25Zu, T.N.K.; Athamneh, A.I.M.; Senger, R.S. Characterizing the Phenotypic Responses of Escherichia coli to Multiple 4-Carbon Alcohols with Raman Spectroscopy. Fermentation 2016, 2, 3.http://hdl.handle.net/10919/79267The phenotypic responses of <i>E. coli</i> cells exposed to 1.2% (<i>v</i>/<i>v</i>) of 1-butanol, 2-butanol, isobutanol, <i>tert</i>-butanol, and 1,4-butanediol were studied in near real-time using Raman spectroscopy. A method of “chemometric fingerprinting” was employed that uses multivariate statistics (principal component analysis and linear discriminant analysis) to identify <i>E. coli</i> phenotypic changes over a 180 min post-treatment time-course. A toxicity study showed extreme variability among the reduction in culture growth, with 1-butanol showing the greatest toxicity and 1,4-butanediol showing relatively no toxicity. Chemometric fingerprinting showed distinct phenotype clusters according to the type of alcohol: (i) 1-butanol and 2-butanol (straight chain alcohols); (ii) isobutanol and <i>tert</i>-butanol (branched chain alcohols); and (iii) control and 1,4-butanediol (no terminal alkyl end) treated cells. While the isobutanol and <i>tert</i>-butanol treated cells led to similar phenotypic responses, isobutanol was significantly more toxic. In addition, the phenotypic response was found to take place largely within 60 min of culture treatment; however, significant responses (especially for 1,4-butanediol) were still occurring at 180 min post-treatment. The methodology presented here identified different phenotypic responses to seemingly similar 4-carbon alcohols and can be used to study phenotypic responses of virtually any cell type under any set of environmental conditions or genetic manipulations.application/pdfenCreative Commons Attribution 4.0 InternationalRaman spectroscopychemometric fingerprintinglinear discriminant analysisalcohol toxicityCharacterizing the Phenotypic Responses of Escherichia coli to Multiple 4-Carbon Alcohols with Raman SpectroscopyArticle - Refereed2017-09-20Fermentationhttps://doi.org/10.3390/fermentation2010003