Mineralization of 4-fluorocinnamic acid by a Rhodococcus strain

• Published in: Applied microbiology and biotechnology 2014-02, Vol.98 (4), p.1893-1905
• Main Authors: Amorim, Catarina L, Ferreira, António C. S, Carvalho, Maria F, Afonso, Carlos M. M, Castro, Paula M. L
• Format: Article
• Language: English
• Subjects: Acids; Aerobic conditions; Air pollution; Analysis; Bacteria; Biodegradation; Biofilms; Biomedical and Life Sciences; Bioreactors; Bioreactors - microbiology; Bioremediation; Biotechnology; Carbon; Carbon sources; Cinnamates - metabolism; culture media; energy; Energy sources; Environmental aspects; Environmental Biotechnology; Fluorides; genes; Life Sciences; Metabolism; Microbial Genetics and Genomics; Microbiology; Mineralization; molecular weight; Phylogenetics; Physiological aspects; Pollutants; Reactors; Rhodococcus; Rhodococcus - metabolism; Rhodococcus sp; ribosomal RNA; RNA; sodium acetate; Studies; Xenobiotics
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-013-5149-6

A bacterial strain capable of aerobic degradation of 4-fluorocinnamic acid (4-FCA) as the sole source of carbon and energy was isolated from a biofilm reactor operating for the treatment of 2-fluorophenol. The organism, designated as strain S2, was identified by 16S rRNA gene analysis as a member of the genus Rhodococcus. Strain S2 was able to mineralize 4-FCA as sole carbon and energy source. In the presence of a conventional carbon source (sodium acetate [SA]), growth rate of strain S2 was enhanced from 0.04 to 0.14 h⁻¹ when the culture medium was fed with 0.5 mM of 4-FCA, and the time for complete removal of 4-FCA decreased from 216 to 50 h. When grown in SA-supplemented medium, 4-FCA concentrations up to 1 mM did not affect the length of the lag phase, and for 4-FCA concentrations up to 3 mM, strain S2 was able to completely remove the target fluorinated compound. 4-Fluorobenzoate (4-FBA) was transiently formed in the culture medium, reaching concentrations up to 1.7 mM when the cultures were supplemented with 3.5 mM of 4-FCA. Trans,trans-muconate was also transiently formed as a metabolic intermediate. Compounds with molecular mass compatible with 3-carboxymuconate and 3-oxoadipate were also detected in the culture medium. Strain S2 was able to mineralize a range of other haloorganic compounds, including 2-fluorophenol, to which the biofilm reactor had been exposed. To our knowledge, this is the first time that mineralization of 4-FCA as the sole carbon source by a single bacterial culture is reported.