The present invention relates to a method for separating a sulfur compound from a fossil fuel containing sulfur compounds comprising contacting said fossil fuel with a biosorption agent which binds said sulfur compound, thereby forming a sulfur-biosorption complex and separating said sulfur-biosorption complex. The method can further include introducing said separated sulfur biosorption complex to an aqueous phase having an effective amount of oxygen and water to form a reaction medium, optionally adding a biocatalyst which degrades the sulfur compound; incubating the medium for a sufficient period of time to produce an organic product, an inorganic sulfur and spent biocatalyst; and isolating said biosorption agent and/or biocatalyst from said organic product and said inorganic sulfur. The invention also relates to the preparation of the products of the oxidation reaction of organic sulfur compounds by a biocatalyst, such as 2-hydroxybiphenyl compounds.