Numerous environments, natural and engineered, host microbial communities that may be intermittently exposed to chemical stressors. This study investigates the effect of sublethal stress responses on the metabolism of a pure bacterial culture, pseudomonas aeruginosa. First, the study quantified how chemical stress affects growth parameters, differentiating between toxic effects and metabolic shifts. Second, adaptive responses were tested by determining whether microbial populations are strengthened or weakened by pre-exposure to chemical stressors, replicating the perturbations that occur in treatment plants as well as natural sediments and soils. The chemical stressors tested were 2,4 dinitrophenol, pentachlorophenol (PCP) and N-ethylmaleimide (NEM). Cumulative oxygen uptake was measured by respirometry, and growth parameters were inferred using the Monod model. The results show that 2,4 dinitrophenol causes metabolic energy to be diverted from growth processes within a concentration window of 77 mg/L to 300 mg/L. At lower concentrations, no effect was observed. Above this range, a fraction of the cells died due to the initial onslaught of the chemical. This same toxicity effect was observed at and above 0.5 mg/L for NEM and 40 mg/L for PCP. NEM was therefore the most potent of all three chemicals, its effects being observed an order of magnitude below that of the others. The effect of pre-exposure to PCP enables the cells to become stronger up to a concentration of 80 mg/L, above which there is evidence of toxicity. This work may ultimately be useful in better monitoring of treatment plants and in risk assessment of contaminated environments.