There are over 3,000 gas stations in Taiwan，containing more than 10,000 oil storage tanks underneath. About half of the gas stations have been operated for over ten years，and a recent investigation by Taiwan's EPA showed that leaking problems began to occur at a number of aged oil storage tanks，causing oil contamination in nearby soils and groundwater. Therefore，extremely critical to clean up and soundly control the oil-contaminated sites before the situation further deteriorates. Biourfactants could increase solubility of oils in water to enhance the bioavailability of the hydrophobic substrates，leading to higher oil degradation rates. Thus，biosurfactants，natural products of variety of microorganisms，appear preferable for the environmental applications. In addition to bioremediation，biosurfactants also find their applications in medical，cosmetic，and food industries，etc. However，the factors restricting commercial application of biosurfactants have been the low yield and high cost for producing biosurfactants. Therefore，there is an urgent need to develop an efficient and cost-effective bioprocess for the production of biosurfactants. This study demonstrated a powerful and feasible way to produce biosurfactant from Bacillus subtitles more efficiently through a solid-carrier-stimulating fermentation. Addition of 25 g/L of activated carbon into fermentation broth triggered a remarkable enhancement in biosurfctant production from 100 to 3600mg/L. Moreover，this study utilized a modified ferment or module to enhance biosurfactants production. The ferment or could solve the problem of sever foaming and enhanced cell concentration，thereby increasing biosurfactant production dramatically. Under the modified ferment or，a maximum overall productivity（106 mg/L/h) and biosurfactant concentration（6450 mg/L) were achieved. These results demonstrate the potential of low-cost and higher-rate production of biosurfactant.
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