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Phenol degradation by a Graphium sp. FIB4 isolated from industrial effluents
Author(s) -
Santos Vera L.,
Heilbuth Nádia M.,
Braga Danúbia T.,
Monteiro Andrea S.,
Linardi Valter R.
Publication year - 2003
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.200390027
Subject(s) - phenol , catechol , mycelium , chemistry , nuclear chemistry , bioreactor , chromatography , organic chemistry , biology , botany
In this work, we show that the fungal strain Graphium sp. FIB4 was able to use phenol as the sole carbon source. Higher degradation of phenol was accomplished by alginate‐immobilized mycelial mass than by mycelial suspensions of Graphium sp. FIB4. Free mycelium exhibited higher degradation rates when compared with the alginate‐immobilized mycelium in the presence of 14 m M of phenol or less. Above this concentration, degradation rates by free mycelium decreased and the immobilized mycelium showed higher values. The maximum degradation rate for 8 m M phenol was found to be 20.13 mg/l × h by free mycelia and 16.24 mg/l × h by immobilized mycelial mass in the presence of 18 m M phenol. When the fungus was grown on medium without phenol, catechol 1,2‐dioxygenase activity was not detected. This enzyme activity was induced at phenol concentrations as low as 0.05 m M and up to 6 m M at 24 h incubation at 30 °C, suggesting that catechol was oxidized by the ortho type of ring fission. Addition of glucose reduced phenol consumption rate, and both substrates were used simultaneously. Glucose concentrations higher than 0.075% repressed the induction of phenol oxidation by Graphium sp. FIB4 grown on glucose. But glucose did not fully repress utilization of phenol by phenol‐pre‐induced cells. Immobilization and addition of calcium and barium ions were detrimental to the stability of catechol 1,2‐dioxygenase activity and phenol degradation by Graphium sp. FIB4.