title: Degradation of cresols by phenol-acclimated aerobic granules.
abstract: High-strength cresol isomers were treated with phenol-acclimated granules in batch experiments. The aerobic granules effectively metabolized cresol isomers at concentrations up to 1,500 mg l(-1). The modified Haldane kinetic model, used to assess the kinetic behavior during cresol degradation by granule cells, yielded a high maximum specific growth rate (1.13-1.45 h(-1)) and inhibition constant (617-952 mg l(-1)). The microbial community structure, which was stable under cresol stress, was principally composed of genera Bacillus, Acinetobacter, Corynebacterium, and Nocardioides. Enzyme assay results suggest simultaneous expression of ortho- and meta-cleavage pathways during cresol degradation. Under high cresol concentrations, however, cresol isomers were largely degraded via the meta-cleavage pathway, likely attributable to the activity of Bacillus. The aerobic granular sludge system is a promising biotechnology for degrading wastewater containing high-strength cresols.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10617, Taiwan, Republic of China. djlee@ntu.edu.tw
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
authors.forename: Kuo-Ling
authors.initials: KL
authors.lastname: Ho
authors.forename: Yu-You
authors.initials: YY
authors.lastname: Chen
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D001673:Biodegradation, Environmental; D003408:Cresols / Q000737:chemistry / Q000378:metabolism*; D049308:Dioxygenases / Q000378:metabolism; D007536:Isomerism; D019800:Phenol / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D003408:Cresols; D012722:Sewage; D019800:Phenol; D049308:Dioxygenases; C077977:cresol