The residue produced by the bacterial decomposition of synthetic rubber has potential for reuse in industrial applications. We attempted to cultivate Bifidobacterium bifidum, which produces conjugated bile-salt hydrolase (CBHase), in Bifidus medium supplemented with rubber residue filtrate with Sep-Pak^TM (RRF-Sep).

RRF-Sep promoted CBHase activity but did not promote the growth of Bifidobacterium.

In addition, RRF-Sep was extracted with different organic solvents and the components were separated by thin layer chromatography. Multiple fractions were detected in this extract, which varied depending on the type of solvent used for extraction.

CBHase activity of bifidobacteria and the nisin productivity of lactic acid bacteria were measured in growth media supplemented with these extracts. A range of activities were observed, depending on the type of extraction solvent used.

The results indicate that the metabolism in Bifidobacteria and lactic acid bacteria might be influenced by different components of the extract.