Rottnest Island is famous for its smiling quokkas, but scientists say the real star might be hiding in its salt lakes. Researchers at Murdoch University have read the complete genetic code of bacteria found in the island's Pearse Lakes, and they say the tiny organisms could help solve one of the world's biggest pollution problems: plastic waste.
The bacteria, called Salinivibrio, naturally produce a plastic called PHA that breaks down on its own instead of piling up in landfills or oceans. Unlike regular plastic, which can last hundreds of years, PHA simply decomposes when you're done with it. The problem is, scientists didn't fully understand how these bacteria worked until now.
To change that, the research team from the Bioplastics Innovation Hub read every single letter of the genetic code for eight Salinivibrio strains collected from Pearse Lakes at Wadjemup, the Aboriginal name for Rottnest Island. They then compared these with dozens of other strains from around the world.
What they found was promising. With the complete genetic map in hand, the scientists could pinpoint exactly which genes let the bacteria make plastic. They also discovered that while these plastic-making genes stay very stable over time, the rest of the bacteria's genetic code changes constantly as the organisms adapt to their environment.
"The exciting part is that we can now point to the exact genes that matter and see how easily these bacteria handle change," said Crystal Young, a molecular ecologist at Murdoch University who led the study. "That gives us a clear, workable place to start when it comes to improving them as plastic producers."
The team also uncovered seven genes that earlier researchers had mislabeled or missed entirely. Some of these genes might let certain strains break down PHA as well as make it, which could lead to even more sustainable products. Future studies will explore this possibility.
Wadjemup, located off the coast of Western Australia, is a protected nature reserve with 12 salt lakes. The Pearse Lakes completely dry out every summer, making them a harsh environment where only the toughest life forms survive. The bacteria that call these lakes home have clearly adapted to handle extreme conditions, which makes them all the more useful for industrial purposes.
Daniel Murphy, who directs the Bioplastics Innovation Hub, said the research marks an important step toward materials that don't harm the planet. "Plastic pollution is one of the biggest problems we face, and part of the answer is making plastics that break down safely," Murphy said. "Understanding organisms like these in real detail is how we move from promising ideas to alternatives that can actually work."
The findings, published in the journal Microbial Genomics, give scientists a precise roadmap for developing these bacteria into a real alternative to traditional plastic. Instead of relying on rough estimates, researchers can now target specific genes and test how to make the process work on a larger scale.