biochemical downstream engineering英 [ˌbaɪəʊˈkemɪkl ˌdaʊnˈstriːm ˌendʒɪˈnɪərɪŋ]美 [ˌbaɪoʊˈkemɪkl ˌdaʊnˈstriːm ˌendʒɪˈnɪrɪŋ]【化】生化下游工程化学