A process and resulting product is provided in which vulcanized rubber crumb has selected chemical bonds broken and sulphur removal by biotreatment with hydrophobic bacteria, such as mycolic acid containing actinomycete bacteria of `mycolata`, without significant degradation of the hydrocarbon polymer. The products obtained from the use of these bacteria may be processed alone or in blends with virgin rubber and revulcanized to yield products of much higher quality than conventional reclaimed rubber materials.