ARTICOLI ORIGINALI   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2000 August;159(4):115-9

Copyright © 2000 EDIZIONI MINERVA MEDICA

lingua: Inglese

Potential of Stenotrophomonas maltophilia GB1 in the Biodegradation of weathered heavy crude oil (Maya)

Okoh I. A. ¹, Valencia-Morales E. ², Romero D. ¹, Babalola G. O. ³, Quintero R. ¹, Trejo-Hernandez M. ³

¹ Department of Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria; ² Centro de Investigación en biotecnologia, UAEM, Cuernavaca, Morelos, Mexico; ³ Centro de Investigación sobre Fijacion de Nitrogeno, UNAM, Cuernavaca, Mexico

Back­ground. CC (GB1) ­strain was iso­lat­ed ­from a ­crude oil ­flow sta­tion sav­er pit efflu­ent in Nige­ria. Our orig­i­nal obser­va­tion of it as an organ­ism of med­i­cal impor­tance was ­borne on its mul­ti­ple resis­tance to anti­bi­o­tics. How­ev­er, its abil­ity to uti­lize hydro­car­bons sole­ly as a car­bon ­source bio­deg­ra­da­tion encour­aged our assess­ing its poten­tial for use in bio­re­me­di­a­tion of ­crude oil pol­lut­ed envi­ron­ment.
Meth­ods. In ­this ­study, the poten­tial of a Sten­o­troph­o­mo­nas mal­to­phil­ia (GB1) ­strain in the deg­ra­da­tion of weath­ered ­heavy Mex­i­can ­crude oil (­Maya) ­using 0.1 and 0.4% (w/v) con­cen­tra­tions of the oil was exam­ined.
­Results. In ­both con­cen­tra­tions, mul­ti­phas­ic bio­mass ­peaks ­were ­observed ­with aver­age ­growth ­rates of 0.055 hr-1 and 0.036 hr-1 for 0.1% and 0.4% oil respec­tive­ly. The cor­re­spond­ing bio­deg­ra­da­tion ­rates ­were 0.007 mg·day-1 and 0.0023 mg·day-1, ­with the ­total metab­o­lized oil ­being 2.9 mg and 6.5 mg dur­ing 12 ­days reac­tion peri­od for the two con­cen­tra­tions respec­tive­ly. The bac­te­ri­um car­ries a mul­ti­ple anti­bi­o­tic resist­ant fac­tor for ten of the ­twelve anti­bi­o­tics ­used, and was sen­si­tive ­only to sul­fam­e­thox­a­zol-tri­meth­o­prim. It ­also har­bours a plas­mid of ­about 10 kb ­that ­lacked restric­tion ­sites for six ­base cut­ters ­KpnI, Bam­HI, ­BglII, Eco­RI, ­XbaI, ­EcoRV, Pst1 and Hin­dIII, but was digest­ed by the ­four ­base cut­ters Rsa1 and Sau3a1.
Con­clu­sions. ­This Sten­o­troph­o­mo­nas mal­to­phil­ia has a poten­tial for appli­ca­tion in bio­re­me­di­a­tion of ­crude oil pol­lu­tion but its mul­ti­ple resis­tance to anti­bi­o­tics con­sti­tutes a seri­ous set­back and empha­sis­es the ­need for prop­er scru­ti­ny of can­di­date organ­isms for bio­re­me­di­a­tion appli­ca­tions.