A process for converting a substrate such as carbon monoxide to useful chemicals has been developed. The process involves providing a substrate comprising CO to a bioreactor which contains a culture of one or more micro-organisms and anaerobically fermenting the substrate to produce 2,3-butanediol (BDO). The BDO is next converted to one or more of butane, butadiene and/or methyl ethyl ketone which in turn can be converted to other compounds. The source of the CO can be an industrial process such as the ferrous metal products manufacturing. The microorganism can be Clostridium autoethanogenum, Clostridium ljundahlii or Clostridium ragsdalei.