another way of ramping up the production of l-dopa. They try and find "bugs" which have an enzyme or an enzymatic system, that converts common l-amino acids such as phenylalanine or tyrosine, efficiently into l-dopa, which is not a common amino acid.I guess one could grow and avres of fava beans and try build a massive extraction plant, however when they can make drugs or drug intermediates efficiently in a tank, with a "bug" which excretes the sought after substance, the economics of the process are often better, and the process can be done continuously, all year round. Just like making alcohol from yeast and sugar fermentation, rather than using a more costly chemical synthesis using fractionated petroleum (the hydration of ethylene).