The possibility to degrade spent rubber and tyre waste using microorganisms to reduce environmental threats has been considered. The present study investigated the optimization of major environmental parameters (pH, temperature, dissolved oxygen concentration, inoculum size, and tyre surface area) that would enhance the Bacillus sp. growth, an indigenous bacterial isolated from scrap tyres. The optimal conditions were determined as pH 7, 30°C, 6.7 mg/L dissolved oxygen, 10% (v/v) inoculum size, and 120 mm tyre surface area. Further detailed investigation is under way to pinpoint the exact organic compound(s) leached out from tyre, as growth substrate(s) for Bacillus sp.