The team also proved that the sponge can enrich selected bacteria, if it is prepared accordingly. For instance, microorganisms processing glyphosate were "lured" into the sponge using this pesticide. And in contact with soil samples, the porous material was colonized by microbes within a few days.
To make medical silicone habitable for microorganisms, the researchers had to process the material in a new way. The team added table salt to the polymer, which was dissolved again afterwards. As a result, small holes connected by small passageways developed. The desired sponge-like structure was obtained. For applications, the researchers then formed a "chip." This small unit consists of the same silicone as the sponge, but in its homogeneous rather than porous form.
"The silicone chip, that is the combination of sponge and chip, can be produced easily with standard methods in nearly any size and number," Niemeyer says. "The robust research tool obtained can be used in nearly any environment. There is every indication that this chip is highly suited for the systematic investigation of microbial dark matter. It opens up interesting options for the cultivation of microorganisms that could not be cultivated so far."
The main authors have filed a patent application for the silicone chip.