%0 Journal Article
%T Biodegradation of phenol in static cultures by Penicillium chrysogenum ERK1: catalytic abilities and residual phototoxicity Biodegradaci車n de fenol en cultivos est芍ticos por Penicillium chrysogenum ERK1: habilidades catal赤ticas y fitotoxicidad residual
%A Erika A Wolskm
%A Viviana Barrera
%A Claudia Castellari
%A Jorge F Gonz芍lez
%J Revista argentina de microbiologˋ-a
%D 2012
%I Asociaci車n Argentina de Microbiolog赤a
%X A phenol-degrading fungus was isolated from crop soils. Molecular characterization (using internal transcribed spacer, translation elongation factor and beta-tubulin gene sequences) and biochemical characterization allowed to identify the fungal strain as Penicillium chrysogenum Thorn ERK1. Phenol degradation was tested at 25 ∼C under resting mycelium conditions at 6, 30, 60, 200, 350 and 400 mg/l of phenol as the only source of carbon and energy. The time required for complete phenol degradation increased at different initial phenol concentrations. Maximum specific degradation rate (0.89978 mg of phenol/day/mg of dry weight) was obtained at 200 mg/l. Biomass yield decreased at initial phenol concentrations above 60 mg/l. Catechol was identified as an intermediate metabolite by HPLC analysis and catechol dioxygenase activity was detected in plate assays, suggesting that phenol metabolism could occur via ortho fission of catechol. Wheat seeds were used as phototoxicity indicators of phenol degradation products. It was found that these products were not phytotoxic for wheat but highly phytotoxic for phenol. The high specific degradation rates obtained under resting mycelium conditions are considered relevant for practical applications of this fungus in soil decontamination processes. Un aislamiento f迆ngico capaz de degradar fenol como 迆nica fuente de carbono y energ赤a fue aislado de suelos agr赤colas. La caracterizaci車n molecular (basada en el empleo de secuencias de espaciadores de transcriptos internos, de factores de la elongaci車n de la traducci車n y del gen de la beta-tubulina) y la caracterizaci車n bioqu赤mica permitieron identificar a esta cepa como Penicillium chrysogenum Thom ERK1. Se estudi車 la degradaci車n de fenol a 25 ∼C en cultivos est芍ticos con 6, 30, 60, 200, 350 y 400 mg/l de fenol inicial. El tiempo requerido para completar la degradaci車n de fenol aument車 al elevarse las concentraciones iniciales de dicho compuesto. La m芍xima tasa de degradaci車n espec赤fica (0,89978 mg de fenol/d赤a/mg de peso seco) se obtuvo con 200 mg/l. El rendimiento en biomasa disminuy車 con concentraciones Iniciales de fenol mayores de 60 mg/l. Se identific車 al catecol como intermediarlo metabolico por HPLC y se observ車 actividad de catecol dioxigenasa en placa, lo que sugiere que el metabolismo de degradaci車n del fenol ocurre v赤a orto fisi車n del catecol. Se utilizaron semillas de trigo como indicadores de fitotoxicidad de los productos de degradaci車n. Estos productos no fueron fitot車xicos para trigo, mientras que el fenol mostr車 una alta fitotoxicidad. La alta tasa de degr
%K Penicillium chrysogenum
%K Hongos del suelo
%K Fenol
%K Biodegradaci車n
%K Fitotoxicidad
%K Penicillium chrysogenum
%K Soil fungus
%K Phenol
%K Biodegradation
%K Phytotoxicity
%U http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-75412012000200011