Studies on composition and stability of a large membered bacterial consortium degrading phenol.
A ten member microbial consortium (AS) consisting of eight phenol-degrading and two non-phenol-degrading strains of bacteria was developed and maintained in a fed-batch reactor by feeding 500 mg l(-1) phenol for four years at 28 +/- 3 degrees C. The consortium could degrade 99% of 500 mg l(-1) phenol after 24 hours incubation with a biomass increase of 2.6 x 10(7) to 4 x 10(12) CFU ml(-1). Characterization of the members revealed that it consisted of 4 principal genera, Bacillus, Pseudomonas, Rhodococcus, Streptomyces and an unidentified bacterium. Phenol degradation by the mixed culture and Bacillus subtilis, an isolate from the consortium was compared using a range of phenol concentrations (400 to 700 mg l(-1)) and by mixing with either 160 mg l(-1) glucose or 50 mg l(-1) of 2,4-dichlorophenol in the medium. Simultaneous utilization of unrelated mixed substrates (glucose/2,4-dichlorophenol) by the consortium and Bacillus subtilis, indicated the diauxic growth pattern of the organisms. A unique characteristic of the members of the consortia was their ability to oxidize chloro aromatic compounds via meta pathway and methyl aromatic compounds via ortho cleavage pathway. The ability of a large membered microbial consortia to maintain its stability with respect to its composition and effectiveness in phenol degradation indicated its suitability for bioremediation applications.
Ambujom
S
S
Regional Research Laboratory, Council of Scientific and Industrial Research, Trivandrum 695019, India. ambujom@hotmail.com
D000332:Aerobiosis; D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology*; D002733:Chlorophenols / Q000008:administration & dosage; D015169:Colony Count, Microbial; D005947:Glucose / Q000008:administration & dosage; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism*; D019800:Phenol / Q000378:metabolism*; D013379:Substrate Specificity
D002733:Chlorophenols; D019800:Phenol; D005947:Glucose; C004762:2,4-dichlorophenol; D010100:Oxygen