Abstract: An apparatus produces a target metabolite in a bioreaction. The apparatus has a reactor vessel that contains a bulk liquor in which the bioreaction is conducted, with a headspace provided above the bulk liquor. In some instances, the target metabolite is favorably partitioned into a foam formed at an interface of the bulk liquor and the headspace. A foam collector is arranged to receive this foam from the bioreactor and break it into a condensed foam liquid, from which the target metabolite may be isolated and purified. In one exemplary application, paenibacillin is produced by fermentation of a medium by Paenibacillus polymyxa OSY-DF, and is preferentially concentrated in the foam. In another exemplary application, fermentation of a medium by Bacillus velezensis GF610 produces amyloliquecidin GF610 is which is preferentially concentrated in the foam.