Differential effects of thiobencarb toxicity on growth and photosynthesis of Anabaena variabilis with changes in phosphate level.

A thiobencarb dose of 3 mg L(-1) reduced the protein content of Anabaena variabilis, whereas it elevated the carbohydrate content. Measurements of Anabaena growth, photosynthetic activity, and respiration rate revealed that the high dose of phosphate (0.53 mM) exerted no additional toxic effect to thiobencarb toxicity. Recovery of Anabaena cells from the inhibitory effect of thiobencarb occurred immediately after its reculture in herbicide free-medium. Maximum uptake of thiobencarb was associated with high biomass yield.