Effect of organics and alkalinity on the sulfur oxidizing bacteria (SOB) biosensor

► A biosensor based on sulfur-oxidizing bacteria (SOB) for detection of toxic chemicals in water was developed. ► The bioassay based on SOB inhibition in the presence of toxic chemicals by measuring changes in EC and pH. ► The presence of organic matters increases the SOB activity. ► The sensitivity of SOB to toxic chemicals increased at low alkalinities. ► SOB biosensor can operate in low nutrient environments.