Scientists have developed a new method to transform human urine into hydroxyapatite, a valuable mineral used in medical implants and other products. This breakthrough was achieved by a team of researchers, including Professor David Kisailus from the University of California, Irvine. The process involves using genetically engineered yeast, known as “osteoyeast,” to convert urine into hydroxyapatite.
“This process achieves two goals at the same time,” said co-author David Kisailus, UC Irvine professor of materials science and engineering. “On the one hand, it helps remove human urine from wastewater streams, mitigating environmental pollution and the buildup of unwanted nutrients; and on the other hand, it produces a material that can be commercially marketed for use in a variety of settings.”
The research received support from several agencies, including the U.S. Department of Energy and DARPA. Human urine contains nutrients like nitrogen and phosphorus that can pollute waterways if not treated properly but also provides key ingredients for hydroxyapatite production.
Inspired by mammalian bone cells’ natural processes, scientists designed yeast cells to mimic this function. These modified microbes break down urea in urine while absorbing calcium and phosphate before secreting crystallized hydroxyapatite.
“The fact that it uses yeast as a chassis… shows that this can be done easily without major infrastructural needs,” Kisailus says.
Kisailus is now collaborating with Yasuo Yoshikuni from Lawrence Berkeley National Laboratory to explore further applications for this technology.
Hydroxyapatite has various uses beyond medicine—potentially replacing plastics in building materials—and offers an eco-friendly alternative through its cost-effective manufacturing method via yeast fermentation.
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