Abstract of the doctoral research:

Freshwater ecosystems are hotspots of biodiversity, biogeochemical processes, and provide numerous societal services (e.g., drinking water production, wastewater treatment). The microbial communities that inhabit these systems form complex networks of interacting populations, for which the structure and function are not yet fully understood. This PhD research presents new insights into the microbial community ecology of both natural (i.e., lakes) and managed (i.e., cooling and drinking water) freshwater systems by developing and validating new technologies to study them and by investigating the genomic adaptations to their freshwater habitat.

A novel flow cytometric fingerprinting method for measuring microbial diversity was developed that correlated strongly with the benchmark marker gene sequencing approach typically used in diversity surveys. This new approach was applied in the monitoring of cooling water systems, the detection of microbial disturbances in drinking water, and the tracking of lake microbial diversity during exposure to invasive species. In parallel, the genomic adaptations of the prevalent microbial populations which shape the diversity in these managed and natural freshwater communities were investigated. We found that positive selection on nutrient scavenging genes and morphological plasticity may be adaptations to phosphate-limited environments commonly found in managed systems. In natural freshwater systems, our results indicated that small genetic or expression differences between populations can facilitate adaptation to steep temperature gradients, while larger genetic and expression differences underpin adaptation to nutrient gradients.

Dissertation Supervisors:

Prof. Dr. Ir. Nico Boon, Prof. Dr. Ir. Vincent Denef & Dr. Ir. Pieter Monsieurs

Dr Marjolein Vanoppen from PaInT will discuss the topic of "Energy Generation: the Power of Mixing Salt and Fresh Water" during a seminar series in the public library of Ghent entitled Kraks@DeKrook. More info and registration can be found here.

• Single-cell optical fingerprinting for microbial community characterization [download] (Benjamin Buysschaert, promoter Nico Boon, Bart De Gusseme)
• Towards innovative technologies for nutrient recovery from human urine [download] (Sebastiaan Derese, promoter Arne Verliefde)
• Surrogate-based online monitoring and control framework for trace organic contaminant removal during ozonation of secondary wastewater effluent: from lab-scale to practical application [download] (Michael Chys, promoter Stijn Van Hulle, Kristof Demeestere, Ingmar Nopens)
• Impact of speciation on the removal and recovery of trace elements from aqueous streams, [download] (Karel Folens, promoter Gijs Du Laing and Frank Vanhaecke)
• The interaction of bacteria with volcanic rocks on Earth and in space [download] (Bo Byloos, promoter Nico Boon, Natalie Leys and Rob Van Houdt)
• Innovative strategies to maximize carbon and energy recovery from domestic wastewater, [download] (Cristina Cagnetta, promoter Korneel Rabaey and Arne Verliefde)
• Production of lactic acid and derivatives from grass using mixed populations, [download] (Way Cern Khor, promoter Korneel Rabaey and Han Vervaeren)
• Advanced reduction and adsorption for trace organic contaminant removal from water, [download] (Klaas Schoutteten, promoter Arne Verliefde)

You are kindly invited to the seminar given by Robbert Kleerebezem, assistant professor from TUDelft. Robbert has years of experience in biotechnology and he is going to share his opinion in the molecular techniques that are used in understanding bioprocesses.

“Using basic redox chemistry, thermodynamics, mass balances, simple kinetic expressions, and fundamental transport terms, the essence of the functional behaviour of microbial ecosystems can be captured and analyzed. I try to convey this approach from an engineering perspective and an ecological perspective. Thermodynamic state analysis of microbial ecosystems provides a firm foundation and first generalization of microbial processes and is often overlooked. “