1 butanol

Citric acid, phosphoric acid, L(+)-ascorbic acid, 1-butanol, and ethyl acetate were from Roth (Karlsruhe, Germany). Oxidized LDL ELISA kits (Cod: 10-1143-01) were from Mercodia (Uppsala, Sweden). The 9α,11α,15S-trihydroxy-prosta-5Z,13E-dien-1-oic-3,3,4,4-d4acid (PGF2α-d4, CAS 34210-11-2), 9β,11β,15R-trihydroxy-(8β,12α)-prosta-5Z,13E-dien-1-oic acid (ent-PGF2α, CAS 54483-31-7), 9α,11α,15S-trihydroxy-(8β)-prosta-5Z,13E-dien-1-oic acid (8-iso PGF2α, CAS 27415-26-5), and (3Z)-5-[(1S,2R,3R,5S)-3,5-dihydroxy-2-[(1E,3S)-3-hydroxy-1-octen-1-yl]cyclopentyl]-3-pentenoic acid (2,3-dinor-8-isoPGF2α, CAS 221664-05-7) were purchased from Cayman Chemical (Ann Arbor, MI, USA). Formic acid was from Merck (Darmstadt, Germany). LC-MS-grade water and methanol were purchased from VWR Chemicals (Darmstadt, Germany).

S. acidocaldarius strain DSM 639 was cultivated aerobically at 76°C in basal Brock medium, pH 3.0 (8 (link)), supplemented with 0.1% (wt/vol) NZ-amine (EZMix N-Z-Amine; Merck, Sigma-Aldrich, Darmstadt, Germany), 0.2% (wt/vol) d-glucose and different concentrations of 1-butanol (0% to 2.5% [vol/vol]; ≥99.5% p.a., Roth, Karlsruhe, Germany) or other organic solvents (ethanol, 99.9% GC, Fisher Scientific, Thermo Fisher Scientific, Waltham, MA, USA; 1-propanol, ≥99.5% GC, Merck; isobutanol, ≥99% GC, Honeywell Riedel de Haën, Fisher Scientific). Liquid cultures were incubated with agitation (180 rpm). Precultures of S. acidocaldarius (OD₆₀₀ of 1.18, logarithmic phase) were used to inoculate fresh medium without or with 1-butanol (0% to 1.5% [vol/vol]) to a starting OD₆₀₀ of 0.05. Cell growth (OD₆₀₀ values) and concentrations of d-glucose and 1-butanol were determined regularly throughout 3 weeks of cultivation. Experiments were performed in four biological replicates.