Bacterial degradation of natural rubber: a privilege of actinomycetes?
Using natural rubber latex as the sole source of carbon and energy 50 rubber-degrading bacteria were isolated. Out of those 50 isolates, 33 were identified as Streptomyces species and 8 as Micromonospora species. Screening of 1220 bacteria obtained from different culture collections revealed 46 additional rubber-degrading bacteria (Streptomyces 31 strains, Micromonospora 5, Actinoplanes 3, Nocardia 2, Dactylosporangium 1, Actinomadura 1, unidentified 3). All rubber-degrading isolates were identified as members of the actinomycetes, a large group of mycelium-forming Gram-positive bacteria. Interestingly no Gram-negative bacterium could be isolated. In most strains expression of extracellular rubber-degrading enzymes was repressed by glucose and/or succinate. The reduction of the average molecular mass of solution-cast films of natural rubber from 640000 to 25000 in liquid culture upon bacterial growth indicates the participation of an endo-cleavage mechanism of degradation.
Jendrossek
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Institut für Mikrobiologie, Georg-August-Universität Göttingen, Germany. djendro@gwdg.de
Tomasi
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Kroppenstedt
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RM
D000192:Actinomycetales / Q000378:metabolism*; D001673:Biodegradation, Environmental; D050260:Carbohydrate Metabolism; D004734:Energy Metabolism; D004783:Environmental Microbiology; D004790:Enzyme Induction / Q000187:drug effects; D005060:Europe; D005202:Asia, Eastern; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D010641:Phenotype; D012408:Rubber / Q000378:metabolism*; D013045:Species Specificity; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid
D013386:Succinates; D012408:Rubber; D019802:Succinic Acid; D005947:Glucose