N-Dodecanoyl-L-high serine lactone (C12-HSL)-mediated interbacterial signaling mechanism. Courtesy of the Chinese Academy of Agricultural Sciences
Recently, the innovation team of livestock and poultry manure treatment and resource utilization of the Biogas Science Research Institute of the Ministry of Agriculture and Rural Affairs analyzed the occurrence mechanism of biological flocculation in the symbiotic purification system of biogas symbiotic bacteria, and discovered a new signal exchange mechanism between algae bacteria, laying a foundation for sewage treatment and resource utilization of livestock and poultry breeding, carbon sequestration and pollution reduction. The research was published in Environmental Science & Technology.
According to Wang Wenguo, a researcher in the team, algal bacteria symbiosis purification is a technology that combines sewage treatment and resource utilization, and has the dual effect of carbon sequestration and pollution reduction. In some algal symbiosis systems, biological flocculants can be formed to achieve the sedimentation and collection of microalgae, and reduce the cost of sewage treatment and microalgae farming.
The research team built a symbiotic purification system for algal bacteria in livestock and poultry manure biogas slurry, and obtained a stable bioflocation system.
The study found that the population sensing signaling molecule (high serine lactone) secreted by gram-negative bacteria from the activated sludge flora mediated cell communication between algal bacteria, inducing microalgae cells to produce aromatic proteins, thereby promoting the formation of algal flocculation particles and improving the flocculation efficiency of the system. The quorum-sensing signaling molecule (C12-HSL) secreted by Gram-negative bacteria is key to inducing microalgae cells to synthesize and secrete aromatic proteins.
Further research, by adding quorum sensing inhibitor (vanillin), the induction effect of the above-mentioned quorum sensing signaling molecule C12-HSL on microalgae cells was effectively blocked, resulting in inhibition of aromatic protein synthesis and poor flocculation effect. Vanillin inhibits the phenomenon of bacterial quorum sensing by competing with signaling molecules for recognition sites on the cell membrane. This suggests that there are similar sites on the cell membranes of microalgae that are used to recognize C12-HSL secreted by bacteria and regulate the synthesis of their own aromatic proteins, thereby promoting the formation of bioflocculant.
The research has been funded by the National Natural Science Foundation of China, the Innovation Project of the Chinese Academy of Agricultural Sciences, the “Young Talents Program” of the Chinese Academy of Agricultural Sciences, and the Special Project for the Construction of the National Modern Agricultural Industrial Technology System. (Source: China Science Daily Li Chen)
Related paper information:https://doi.org/10.1021/acs.est.2c00905