2.3 Analytical methods
Optical densities (OD600) were measured using an
Ultrospec 10 Cell Density Meter (GE Healthcare).
Culture supernatants were analyzed in a 1260 Infinity II HPLC equipped
with a 1260 DAD WR (Agilent Technologies) and an ISAspher 100-5 C18 BDS
reversed-phase 202 column (ISERA) at 30 °C and a flow rate of 0.8 mL
min−1. Elution took place with a binary mixture of
0.1% (v/v) aqueous trifluoroacetic acid and acetonitrile according to
the following program: 0-2 min: 10% acetonitrile; 2-6 min: linear
increase to 100% acetonitrile; 6-8 min: 100% acetonitrile; 8-10 min:
linear decrease to 10% acetonitrile; 10-14 min: 10% acetonitrile.trans -Cinnamate and benzoate were detected at 245 nm, muconate at
260 nm, and catechol at 280 nm.