For decades now, we’ve been promised cheap biofuels from algae. But there’s no free lunch. Growing these mini oil factories in vast ponds requires fertiliser and mechanical aeration; and then the oil has to be extracted. It all costs energy and money so the yields need to be high to make it worthwhile.
One promising industrial species is Nannocholoropsis gaditana, which can produce a lipid – the oil and fat energy store – content up to about 60% of the algae’s ash-free dry weight. But Eric Moellering and colleagues at the company Synthetic Genomics Inc in California, wanted to do better.