A Gram-negative bacterium, identified as Pseudomonas aeruginosa AL98, is apotent degrader of natural rubber and synthetic cis-1,4-polyisoprene

A Gram-negative bacterium, strain AL98, was isolated from foul water inside of a deteriorated car tire on a farmer's field in Munster, Germany. The st rain was able to considerably disintegrate natural rubber (NR), either in t he raw state as NR latex concentrate or in the vulcanized state as NR latex glove, as well as raw synthetic cis-l,4-polyisoprene (IR). Determination o f carbon dioxide evolution and living cell number during batch cultivation with each of the materials as sole source of carbon, revealed mineralizatio n of the rubber polymer during biomass increase. Surface investigation by s canning electron microscopy gave evidence for an adhesive growth behavior o f the strain proceeding by colonizing the rubber surface, merging into the rubber and forming a biofilm prior to disintegration of the material. Schif f's reagent staining performed with NR latex gloves indicated production an d accumulation of aldehyde groups during colonization. The solid glove subs trate disappeared completely after a prolonged cultivation period as a resu lt of continuous degradation. Taxonomic analyses of the strain, which were also based on similarity examination of the complete 16S rRNA gene, reveale d classification of strain AL98 as a strain of Pseudomonas aeruginosa. This is the first report about the isolation of a Gram-negative bacterium exhib iting strong rubber decomposing properties. (C) 2000 Published by Elsevier Science B.V. All rights reserved.