[3S06e] 22. Microbial Biotechnology

4:30 PM - 5:10 PM JST(7:30 AM - 8:10 AM UTC)

[2MBT-02-KL] Microbial Biotechnology for Environmental Sustainability

Spiros N. Agathos^1,2 and Jian Li ² (¹ Laboratory of Bioengineering, Earth and Life Institute, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
² Laboratory of Marine Bioengineering, Qingdao Innovation & Development Base, Harbin Engineering University, Qingdao 266000 Shandong, China)

The main thrust of this lecture is to update the multifaceted roles of microbial biotechnology in environmental sustainability using evolving concepts of biodegradation, synthetic microbial ecology and bioengineering. Industrial, agricultural, and urban activities release toxic pollutants into the environment, ranging from high-concentration groundwater plumes to low-level bioactive micropollutants. While physical and chemical cleanup methods exist, they are often expensive and risk creating harmful secondary pollution. As a result, biotechnology is offering alternatives for the effective clean-up of contaminated sites via microorganisms that can oxidize/reduce, bind, immobilize, volatilize, or transform contaminants. Bioremediation outcomes vary, requiring a critical re-evaluation of mainstream concepts like steady-state transport and biodegradation rate assessments. Low cleanup rates do not automatically mean degrader microorganisms are missing from the site. Instead, adopting modern concepts like the plume fringe and transient condition analysis can help optimize and enhance cleanup performance. Integrating new ORP sensors with DNA/RNA microbiome analysis helps clarify how active microbial communities respond to biostimulation in contaminated soils. This combined approach reveals precise spatial and temporal details of the biodegradation process. Applying concepts like syntrophic metabolism and cell-level substrate concentration can explain complex field results in bioremediation. These microbial strategies offer new, sustainable ways to manage and treat low concentration micropollutants effectively. Finally, ecological bioengineering allows for the manipulation of microbial communities, including bacterial-microalgal consortia, in open ecosystems by using operational parameters and distinct process configurations as selective forces. A key example is granular sludge technology, where dense, engineered microbiomes are created through stress-induced self-immobilization. While the exact formation mechanisms of these granules are still being studied, factors like extracellular polymers and shear force play critical roles. Combining these insights with single-granule sequencing could provide a blueprint for precision-engineered, efficient microbial waste management systems.