Oxidative state in idiophase links reactive oxygen species (ROS) and lovastatin biosynthesis: Differences and similarities in submerged- and solid-state fermentations

► sod1 gene (oxidative stress defence enzyme) was intensely expressed only in trophophase. ► But ROS measurements detected high concentrations only in idiophase. ► A relatively low redox balance confirmed the oxidative state in idiophase. ► This pattern was similar in SmF and SSF. ► In SSF, lower but more steady ROS concentrations could explain higher production.