Effect of starvation upon activity of microorganisms degrading 4-chlorophenol

The variation of the microbial activity during starvation of microorganisms degrading 4-chlorophenol was evaluated in a sequencing batch reactor. During the acclimation, a reduction in the degradation time and an increase in the specific degradation rate were observed. After the acclimation, the biomass was exposed to different starvation periods (8 to 36 h). The results showed that the starvation could decrease the microbial activity and composition. A reduction from 44 to 21% was observed on the specific removal rate, and from 35 to 26% on the specific oxygen uptake rate. The extension of the deacclimation of starved microorganisms was affected by the history of the culture. The effect of starvation on the degradation rate was less significant when microorganisms were starved, recovered and then starved again, than in the case where starvation is cyclically presented without a recovery period. The variation of the microbial activity during starvation of microorganisms degrading 4-chlorophenol was evaluated in a sequencing batch reactor. A reduction from 44 to 21 % was observed on the specific removal rate, and from 35 to 26 % on the specific oxygen uptake rate. The extension of the deacclimation of starved microorganisms was affected by the history of the culture.