Research Interests

The Rehmann group works at the interface of microbiology, chemistry, and process engineering to convert low-value biomass and industrial side-streams into fuels, platform chemicals, and recovered resources. A common thread runs through the work: taking a waste or residue stream that is difficult to use, and engineering the biological and chemical steps needed to turn it into something of value. Projects span solvent-based biomass fractionation, fermentation with both wild-type and adapted microbial strains, biosurfactant production, and bioelectrochemical systems, and they frequently combine experimental bioprocess development with process modelling and scale-up considerations.

Biomass Fractionation with Natural Deep Eutectic Solvents (NADES)

Agri-food processing generates large volumes of residues — husks, hulls, pomace, spent biomass — that are rich in carbohydrates and other usable fractions but chemically complex. This line of work uses natural deep eutectic solvents to fractionate these side-streams under mild conditions, separating the components in a form that downstream fermentations can use. The goal is a fractionation step that is effective, low-toxicity, and compatible with the microbial processes that follow.

Platform Acids via Designed Microbial Consortia

Building on the fractionation work, this direction targets the production of platform acids — itaconic and lactic acid among them — from the recovered biomass fractions. Rather than relying on a single organism, the approach uses designed microbial consortia, distributing the metabolic work across complementary strains to improve conversion of mixed substrates. The work includes strain selection, consortium design, and fermentation development.

Yeast-Based Biosurfactants

Biosurfactants are attractive, biodegradable alternatives to petrochemical surfactants. This work focuses on yeast-based sophorolipid production by fermentation, addressing the process-engineering questions — substrate use, productivity, and recovery — that stand between promising strains and practical production.

Solventogenic Clostridia and Butanol Fermentation

The group has a sustained interest in solventogenic clostridia, including Clostridium pasteurianum, for the fermentative production of butanol and related solvents. This includes adaptive evolution of strains for improved performance on challenging substrates, characterization of the resulting phenotypes, and the bioprocess engineering needed to operate these fermentations continuously.

Bioelectrochemical Systems for Resource Recovery and Water Treatment

This applied line integrates bioelectrochemical systems, including microbial fuel cells, with physical treatment steps for the remediation of contaminated waters. Recent work has examined the treatment of mine-influenced water, combining biological and cryogenic (freeze-based) purification approaches to recover clean water and manage contaminants.

 

Opportunities in My Group

The group's work is interdisciplinary and suits students from chemical and biochemical engineering, microbiology, chemistry, and related fields. Prospective graduate students with an interest in fermentation, bioprocess engineering, or applied microbiology are encouraged to get in touch.