A moderately halophilic bacterial enrichment was able to degrade 120mg/L of phenol in the presence of 1-2M of NaCl within 3d or 2.5-3M of NaCl within 6d. The optimal degradation was achieved at 1.5M of NaCl and 350mg/L of phenol. PCR-DGGE profile of the enrichment showed that the Acidobacterium sp. and Chloroflexus sp. dominated the community. The phenol-biodegradation pathways consisted of an initial oxidative attack by phenol hydroxylase, and subsequent ring fission by catechol 1,2-dioxygenase and catechol 2,3-dioxygenase. Nuclear magnetic resonance (NMR) spectroscopy profiles showed that ectoine and hydroxyectoine were the main compatible solutes to adjust the bacterial osmotic pressure. This study provides further information on the understanding of phenol-degradation over a wide range of salinity and remediation of phenol as a pollutant in the environment.
Bibliographical noteFunding Information:
Supported jointly by National Natural Science Foundation of China ( 51378208 , 41273109 , 41003031 ), Specialized Research Fund for the Doctoral Program of Higher Education ( 20110074130002 ), Program for New Century Excellent Talents in University ( NCET-13-0797 ), Fok Ying Tung Education Foundation ( 141077 ), Shanghai Rising-Star Program ( 12QA1400800 ), Innovation Program of Shanghai Municipal Education Commission ( 14ZZ059 ), Fundamental Research Funds for the Central Universities ( 222201313008 ). We also would like to thank the anonymous referees for their helpful comments on this paper.
- Compatible solutes
- Metabolic pathway
- Moderately halophilics