NOVELTY - Dual biocatalytic conversion of carbon dioxide in carbon dioxide containing gas into carbon containing bioproducts, involves enzymatically catalyzing the hydration reaction of dissolved carbon dioxide into bicarbonate and hydrogen ions in the presence of carbonic anhydrase and metabolically converting the bicarbonate ions into the carbon containing bioproducts in a biological culture.    USE - The method is useful for dual biocatalytic conversion of carbon dioxide in carbon dioxide gas into carbon containing bioproducts such as bio-oils for lubrication, liquid fuel for energy supply and biomass as solid fuel and feedstock (all claimed).    ADVANTAGE - The method allows economical dual biocatalytic conversion of carbon dioxide into carbon containing bioproducts with high efficiency and reliability.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a process for treating a carbon dioxide containing gas to produce carbon containing bioproducts, comprising contacting an aqueous absorption solution comprising water and an absorption compound with the carbon dioxide containing gas in the presence of carbonic anhydrase, enzymatically catalyzing the hydration reaction of dissolved carbon dioxide into bicarbonate and hydrogen ions within the aqueous absorption solution to produce a bicarbonate loaded solution, metabolically converting the bicarbonate ions in the bicarbonate loaded solution into carbon containing compounds by a biological culture, and harvesting and treating the biological culture to extract the carbon containing compounds and transforming the same into the carbon containing bioproducts;    (2) an apparatus for dual biocatalytic conversion of carbon dioxide gas in flue gas into carbon containing bioproducts, comprising an enzymatic bicarbonate production and carbon dioxide gas absorption unit comprising a gas inlet for receiving the flue gas, a liquid inlet for receiving an aqueous absorption solution, a reaction chamber configured for receiving the flue gas and the aqueous absorption solution such for contact in the presence of carbonic anhydrase for catalyzing the hydration reaction of dissolved carbon dioxide from the flue gas into bicarbonate and hydrogen ions to produce a bicarbonate loaded solution and a treated gas, a gas outlet for releasing the treated gas and a liquid outlet for releasing the bicarbonate loaded solution, a biological culture unit comprising an inlet for receiving the bicarbonate loaded solution, a culture compartment for metabolically converting the bicarbonate ions by a biological culture into carbon containing bio-products and an outlet for releasing biological culture material containing the carbon containing bioproducts from the culture compartment, and an extraction unit for extracting at least some of the carbon containing bioproducts from the released biological culture material;    (3) use of carbonic anhydrase and a biological culture for sequential dual biocatalytic conversion of carbon dioxide gas in flue gas into carbon containing bioproducts;    (4) use of carbonic anhydrase in a biological culture to accelerate the dissolution and conversion of carbon dioxide gas into bicarbonate and hydrogen ions for biological metabolism and conversion into carbon containing bioproducts; and    (5) a dual biocatalytic formulation for conversion of carbon dioxide in a carbon dioxide containing gas into carbon containing bioproducts, comprising water, carbon dioxide dissolved in the water, carbonic anhydrase in suspension in the water to catalyze the hydration reaction of dissolved carbon dioxide into bicarbonate and hydrogen ions in the water in a nutritive bicarbonate concentration, and biological culture material in the water to have sustained metabolic activity in the nutritive bicarbonate concentration for conversion of the bicarbonate ions into the carbon containing bio-products.