A fermentation process for the in situ intercalation of surfactin into layered double hydroxides

This work describes a novel in situ fermentation process to intercalate bioactive surfactin molecules into layered double hydroxides (LDH). The direct intercalation of surfactin into the LDH could only yield partially-intercalated surfactin/LDH hybrids, which were a mixture of LDH with the intercalated spacings of 10.8 angstrom and the pristine LDH at 8.3 angstrom. In contrast, the in situ fermentation process resulted in a fully intercalated surfactin/LDH hybrids. The interspacing of the surfactin/LDH hybrids was 5.8 degrees, after deducting the initial layer thickness of 5 degrees. The in situ fermentation could perform the surfactin intercalation to the LDH in < 24 h. This paper is the first report concerning about the cell-mediate intercalation of biomolecules into LDH. Organic/inorganic biohybrids, such as these nanoscale LDH, can presumably act as biomolecule reservoirs and drug carriers. This in situ fermentation process appears to be a flexible option for the biomolecules intercalation into layered nanomaterials. The self-destructive functionality of LDH made the surfactin-LDH biohybrid a potential candidate in agricultural or biomedical applications.