Reduction of perchlorate by salt tolerant bacterial consortia

► A salt tolerant perchlorate-reducing bacterial consortium was obtained. ► The consortium could reduce perchlorate under the coexistence of 75g-NaClL−1. ► The maximum perchlorate reduction rate was 86mg-perchlorateL−1h−1. ► Kinetic analysis showed that NaCl acted as an uncompetitive inhibitor. Two perchlorate-reducing bacterial consortia (PRBC) were obtained by enrichment cultures from polluted marine sediments. Non-salt-tolerant PRBC (N-PRBC) was enriched without the addition of NaCl, and salt tolerant-PRBC (ST-PRBC) was enriched with 30g-NaClL−1. Although the perchlorate reduction rates decreased with increasing NaCl concentration, ST-PRBC (resp., N-PRBC) could reduce perchlorate until 75g-NaClL−1 (resp., 30g-NaClL−1). The reduction yield (1.34±0.05mg-perchlorate per mg-acetate) and maximum perchlorate reduction rate (86mg-perchlorateL−1h−1) of ST-PRBC was higher than those (1.16±0.03mg-perchlorate per mg-acetate and 48mg-perchlorateL−1h−1) of N-PRBC. Kinetic analysis showed that NaCl acted as an uncompetitive inhibitor against both PRBCs. The inhibition constants were 25 and 41mg-NaClL−1 for N-PRBC and ST-PRBC, respectively.