Chinese Scientists Combine Microorganisms with Seawater to Convert Light into Sugar, Then Use Sugar to Generate Electricity.
According to SCMP on October 10, this type of biosensor can provide up to 380 microwatts and operates stably for over a month, making it suitable for ultra-low power facilities. Currently, the efficiency of the biosensor cannot match that of semiconductor photovoltaics, but it demonstrates a more environmentally friendly approach and has the potential for cost savings in generating electricity directly from light.
The research, conducted by the State Key Laboratory of Microbial Resources, the Institute of Biological Energy, and the Qingdao Institute of Biological Processing Technology, along with the Tianjin Institute of Industrial Biotechnology under the Chinese Academy of Sciences, has been published in the journal Nature Communications.
Simulation of marine microbial ecosystem (left) and biosensor (right). (Photo: Zhu Huawei)
“The miniaturized biosensor is inspired by marine microbial ecosystems,” said lead author Zhu Huawei from the State Key Laboratory of Microbial Resources.
Types of algae, such as cyanobacteria, are the primary producers in marine microbial ecosystems. They absorb sunlight and fix carbon dioxide to produce organic matter. Through this process, solar energy is transferred to electrons and stored in organic matter.
After decomposition, some organic matter settles into sediments on the seafloor, where it becomes nutrients for microorganisms and participates in their metabolic processes.
Solar energy is the main driver in these biogeochemical cycles. To enhance efficiency, scientists have developed a special device to perform this cycle within a biosensor.
The research team introduced four species of microorganisms, including algae, into a device filled with seawater to mimic the structure of the microbial ecosystem: one species acts as the primary producer, one as the primary decomposer, and the remaining two as final consumers.
Types of algae are the primary producers of the ocean ecosystem. (Photo: SCMP)
Initially, the producer organism generates sucrose through photosynthesis. Then, the decomposer organism breaks down sucrose into lactate. Next, the consumer organisms further decompose lactate and ultimately generate electricity.
“This not only demonstrates that the four-species system is optimal in terms of energy density and stability, but also shows that maintaining a complete three-tier ecological structure is an effective way to convert biological photovoltaics,” Zhu emphasized. “The biosensor can serve as an alternative power source for ultra-low power facilities, such as environmental sensors in the Internet of Things. A miniaturized biosensor generating hundreds of microwatts is sufficient to support such facilities.”
With sunlight as the sole input, this biosensor even has the potential to operate on Mars, as long as there is water, carbon dioxide, and minerals.
The research team is exploring efficient ways to increase electricity output. “Currently, the fabrication of seawater biosensors is relatively complex. We are considering automating this process using 3D printing technology,” Zhu added.
