Scientists at Murdoch University have read the full genetic code of bacteria from the salt lakes of Wadjemup (Rottnest Island), giving them their clearest picture yet of how these tiny organisms could be used to make biodegradable plastic.
The bacteria, called Salinivibrio , grow fast, love salty water, and naturally make a plastic called PHA that breaks down on its own instead of piling up as waste. That makes them a promising choice for producing plastic in a more sustainable way. Until now, scientists have mostly relied on rough, incomplete versions of their genetic code, which made it hard to know exactly what these bacteria could do.
To change that, researchers from the Bioplastics Innovation Hub (BIH) at Murdoch University read the complete genetic code of eight Salinivibrio strains from Pearse Lakes at Wadjemup (Rottnest Island) and compared them with dozens of others from around the world.
The results were promising. By reading every letter of the genetic code, the team could point to the exact genes that can make plastic, see how they are set out, and confirm they had barely changed over a very long time. This is significant as having a precise map turns these bacteria from an idea into something scientists can work on and fine-tune.
In another positive sign, the scientists found the rest of their genetic code changes constantly, with the bacteria naturally picking up and swapping genes as they adapt. This may also turn out to be a helpful trait in bacteria that scientists hope to build on, with further testing.
Additionally, the team found seven genes, mislabelled and missed in earlier studies, that might let some strains break PHA down as well as make it, which they plan to explore in future work. “The exciting part is that we can now point to the exact genes that matter and see how easily these bacteria handle change,” molecular ecologist Crystal Young said. “That gives us a clear, workable place to start when it comes to improving them as plastic producers.”
Bioplastics Innovation Hub Director and microbiologist Professor Daniel Murphy said the work was a step towards more sustainable materials. “Plastic pollution is one of the biggest problems we face, and part of the answer is making plastics that break down safely,” Professor Murphy said. “Understanding organisms like these in real detail is how we move from promising ideas to alternatives that can actually work.”
Located off the coast of Western Australia, Wadjemup (Rottnest Island) is a protected Class A nature reserve and popular tourist destination, home to 12 salt lakes . The isolated Pearse Lakes, which dry out completely each summer, were an ideal place to find bacteria already adapted to tough, changing conditions.
The research, Refining Salinivibrio pangenome dynamics and biotechnological potential through comparative analysis , is published in Microbial Genomics .
The Bioplastics Innovation Hub at Murdoch University is a collaboration between Murdoch, the CSIRO and industry. Other BIH projects include SMART SPRAYS, Maximising the Benefits from Rainfall and completely compostable food packaging .
Murdoch University acknowledges the Whadjuk Noongar people as the custodians of Wadjemup (Rottnest Island) and their continued connection to the island and its waters, and we pay our respects to Elders past and present.
We pay special respect to all Aboriginal people affected by the historical use of Wadjemup as a place of unjust incarceration, especially the men and boys whose bodies still rest beneath the sands of Wadjemup, and to the families and descendants who lost them.
Microbial Genomics
Observational study
Not applicable
Refining Salinivibrio pangenome dynamics and biotechnological potential through comparative analysis
21-Jul-2026
The authors declare that there are no conflicts of interest.