It seemed at one stage, a decade or two ago, that biotech was going to be the next big thing in all sorts of fields – fuel, medicine, materials. But it has proved to be more difficult than at first thought.

It’s easy to see why there is such enthusiasm for biosynthesis. Jean-François Bobier, partner and vice president of deep tech at Boston Consulting Group (BCG), points to the bioethanol industry as an example of how agriculture combined with industrial processing has reached the government-mandated 10% of the US car-fuel supply at near parity with the price of gasoline.

To get there, farmers used crops that have received some genetic engineering and intensive breeding strategies. When the US introduced its renewable fuel standard programme almost 20 years ago, proponents of synthetic biology argued they could do even better by using bacteria or algae to produce hydrocarbon fuels that do not suffer the 30% drop in energy density that comes with changing to ethanol from petrol.

Over a year...