About

Jeremy S. Guest is the Department Head and David C. Crawford Faculty Scholar in the Department of Civil & Environmental Engineering at the University of Illinois Urbana-Champaign. His research group focuses on advancing the circular bioeconomy to promote equitable, healthy, and prosperous communities while supporting ecosystems. His work aims to increase access to and sustainability of sanitation in both developing and advanced communities by developing technologies and service models that treat human waste as a renewable resource. Additionally, he works on accelerating the research, development, and deployment of technologies that enhance the sustainability of agriculture and the conversion of plants into bioproducts, biofuels, and nutritious foods. Central to his research is Quantitative Sustainable Design (QSD), a methodology used to inform engineering, investment, and policy decisions. Prior to his current role, he served as the Inaugural Director of the Levenick Center for a Climate-Smart Circular Bioeconomy and held positions such as Associate Director for Research at the Institute for Sustainability, Energy, and Environment. His academic background includes a B.S. in civil engineering from Bucknell University, an M.S. from Virginia Tech, and a Ph.D. in environmental engineering from the University of Michigan. He has received notable awards including a National Science Foundation CAREER Award, the Paul L. Busch Award, and the James J. Morgan Early Career Award, recognizing his innovation and leadership in environmental science and engineering.

Research topics

• Computer Science
• Waste management
• Engineering
• Environmental science
• Business
• Environmental planning
• Economics
• Sociology
• Environmental resource management
• Computer Security
• Agronomy
• Environmental economics
• Management science
• Process engineering
• Biotechnology
• Systems engineering
• Pulp and paper industry
• Medicine
• Risk analysis (engineering)
• Environmental engineering
• Ecology
• Environmental health
• Chemistry
• Process management

Selected publications

• Decentralized Encapsulated Anaerobic Biological Treatment System for Resource Recovery from High-Strength Wastewater: A Pilot Study

  ACS ES&T Engineering · 2026-01-07

  article

  Transitioning water-intensive food and beverage industries toward energy-positive yet profitable wastewater management requires enhanced anaerobic treatment for resource recovery. We developed an encapsulated anaerobic biological treatment system and tested it at pilot scale, with the goals of recovering methane (CH4) in a low-maintenance, small-footprint system. A single-stage and a two-stage system, each with biomass encapsulated in polyethylene glycol beads, were compared with respect to soluble chemical oxygen demand (sCOD) removal and gas production during continuous operation at hydraulic retention times (HRT) of 3, 7, and 13 days at ambient temperature. Over the 289-day experiment, sCOD removal averaged 84 ± 18% and 86 ± 14% for the single-stage and two-stage systems, respectively. Gas production varied with HRT and temperature, with an average CH4 percent of 74 ± 8% for the single-stage system and 76 ± 8% for the two-stage system. An active gas extraction module was briefly implemented on the first-stage reactor of the two-stage system, with no clear auxiliary benefits to overall system performance. The excellent performance of both systems can be attributed to the high concentration of biomass that was retained in the reactors. Future research to advance additional pilot-scale tests and full-scale deployment is recommended.

  PublisherDOI

• The Potential of Thermomechanical and Thermochemical Processes to Enable Sustainable Household Sanitation

  Environmental Science & Technology · 2026-01-15

  articleOpen accessSenior author

  for PMD and SCWO, respectively, with the grid electricity contributing 87-90% in both HRTs. Poor solid-liquid separation disproportionately increases costs and GHG emissions for SCWO relative to PMD. In the short term, optimizing a few levers─number of users, flush water volume, and the detailed design of the SCWO unit─can significantly reduce cost and emissions. In the long term, operating at maximum efficiency reduces both cost and emissions by approximately 70%. Deployment in locations with low wage, low-carbon electricity, low price levels, and large household sizes offers the greatest potential, positioning HRTs as viable advanced decentralized sanitation options in specialized settings.

  PublisherDOI

• Cost and Carbon Intensity Implications of Coprocessing Sustainable Aviation Fuel at Petroleum Refineries

  Environmental Science & Technology · 2026-01-21

  articleOpen accessSenior author

  for switchgrass. Global sensitivity analysis reveals MSP declines with greater coprocessing levels. Overall, this work demonstrates the potential of cellulosic ATJ coprocessing to enable cost-effective, low-carbon aviation fuels.

  PublisherOA PDFDOI

• Data for High Yield Production of 3-Hydroxypropionic Acid Using Issatchenkia orientalis

  Illinois Data Bank · 2026-01-01

  datasetOpen access

  Biomanufacturing provides a more sustainable alternative to fossil-based chemical manufacturing. 3-Hydroxypropionic acid (3HP) is a top Department of Energy value-added chemical and precursor to bioplastics, yet cost-effective microbial production remains elusive. Here, we establish the acid-tolerant yeast Issatchenkia orientalis as a robust host for low-pH 3HP biosynthesis. Genome-scale modeling identifies the β-alanine pathway as optimal, offering the highest theoretical yield and lowest oxygen requirement. Thermodynamic analysis confirms its favorability under acidic conditions. Using sequence similarity network analysis, we discover highly active aspartate 1-decarboxylase (PAND), β-alanine-pyruvate aminotransferase (BAPAT), and 3HP dehydrogenase (YDFG), which significantly improve the pathway efficiency. Next, to further elevate the production, pathway optimization through multi-copy PAND integration, byproduct elimination (knockouts of pyruvate decarboxylase and glycerol-3-phosphate dehydrogenase), and reinforcement of aspartate flux by overexpression of pyruvate carboxylase and aspartate amino transferase improves the titer to 29 g/L in shake flasks. Fed-batch fermentation at pH 4 with low-cost corn steep liquor medium further increases the production to 92 g/L with 0.7 g/g yield and 0.55 g/L/h productivity. Techno-economic analysis indicates that such performance could potentially enable a financially viable process for sustainable acrylic acid production. This work establishes I. orientalis as a next-generation platform for cost-effective 3HP production and paves the way toward industrial commercialization.

  PublisherDOI

• Systematic comparisons between long-read and short-read based amplicon sequencing to characterize mixed microalgal communities

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-04-18

  article

  Abstract The 18S rRNA gene has emerged as the primary molecular marker for amplicon-based characterization of microalgal communities, including in wastewater treatment systems, yet trade-offs between short- and long-read approaches remain poorly defined. We systematically compared V8–V9 short-read sequencing (Illumina MiSeq), full-length long-read sequencing with ss5ss3 primers (PacBio Sequel II), and computationally extracted V8–V9 regions from long-read data. Both in silico and in vitro analyses confirmed V8–V9 captured broader taxonomic coverage than ss5ss3, though partial reference sequences and taxonomic mis-annotations biased in silico assessments. Long-read’s taxonomic advantage was database-dependent, constrained by SILVA databases genus-level curation but fully realized when paired with the species-level-curated and eukaryotes-focused PR² (Protist Ribosomal Reference) database. Long-read sequencing uniquely identified amplicon sequence variants (ASVs) assigned to key phosphorus assimilators ( Scenedesmus obliquus , Desmodesmus sp., and Acutodesmus sp.) at species level during successful phosphorus removal in a full-scale microalgal cultivation system, while V8–V9 short-read sequencing revealed ASVs assigned to algal-predatory (Leptophryidae) and bacterivorous (Choanoflagellata and Rhogostoma-lineage) protists when performance declined, suggesting grazing pressure on the phosphorus-removing community. Although both approaches performed comparably for operational monitoring, these complementary strengths support short-read sequencing for routine community profiling and long-read sequencing for detailed functional investigations of Chlorophyta.

  PublisherDOI

• Data for "Adsorptive Separation and Recovery of Triacetic Acid Lactone from Fermentation Broth"

  Illinois Data Bank · 2026-01-01

  datasetOpen access

  Triacetic acid lactone (TAL) can be microbially produced and further chemically upgraded to several high-value chemicals. In this work, several acidic and basic ion-exchange resins and activated charcoal were evaluated for their ability to adsorb microbially produced TAL. Activated charcoal and a weak base resin, Dowex 66, showed similar TAL adsorption capacity of 0.18 ± 0.002 g/g. At 15% w/v activated charcoal, about 98% of TAL present in fermentation broth could be adsorbed. Further, ethanol washing allowed recovery of 72% of adsorbed TAL. A biorefinery producing TAL from sucrose was designed, simulated, and evaluated (through technoeconomic analysis) under uncertainty, for an estimated TAL minimum product selling price (MPSP) of $4.27/kg [$3.71−4.94/kg; 5th-95th percentiles] for the current state of technology and $2.83/kg [$2.46–3.29/kg] following potential near-term improvements to fermentation. Thus, this work provides an adsorptive process to recover microbially produced TAL that can be chemically upgraded to several industrial products.

  PublisherDOI

• Cost and Carbon Implications of Industrial Organic Load Reduction across Water Resource Recovery Facility Typologies

  Environmental Science & Technology · 2026-01-20

  articleOpen accessSenior author

  The valorization of waste organics through upstream treatment of high-strength industrial wastewaters is being pursued to reduce the costs and greenhouse gas (GHG) emissions of food and beverage (F&B) industries, the fourth-highest carbon-intensive manufacturing subsector in the U.S. However, industrial wastewater valorization may have unintended impacts on centralized water resource recovery facilities (WRRFs) that either enhance or undermine efforts to advance the sustainability of waste organic management. Here, we characterize the environmental and economic impacts of industrial organic loading reductions on centralized WRRFs via process modeling, life cycle assessment (LCA), and techno-economic analysis (TEA) under uncertainty. We demonstrate sustainability benefits of upstream organic carbon valorization will be amplified at WRRFs designed for BOD removal and nitrification but undermined at biological nutrient removal (BNR) or enhanced nutrient removal (ENR) WRRFs. Through uncertainty and sensitivity analyses, we find that operational cost changes at WRRFs following industrial load reduction are driven by unit electricity cost, solids disposal cost, and blower efficiency─along with external carbon addition in nutrient removal systems─while changes in GHG emissions are primarily driven by grid carbon intensity and fugitive methane emissions. A national spatial linkage of 4500 F&B facilities to their nearest WRRFs highlights regional clusters where industrial pretreatment could most improve WRRF sustainability.

  PublisherOA PDFDOI

• Co-Location of Cellulosic Bioethanol and Alcohol-to-Jet (ATJ) Production Facilities for Targeted Scale-Up of Sustainable Aviation Fuel (SAF) Production

  Environmental Science & Technology · 2026-01-27 · 1 citations

  articleOpen accessSenior author

  ), our results indicate that site-specific deployment of ATJ with low-CI feedstocks can improve sustainability outcomes. The framework provides a systematic approach to assess cost and sustainability trade-offs across locations, considering the end-to-end supply chain and supporting an informed investment in SAF production.

  PublisherOA PDFDOI

• Data for Rewiring Yeast Metabolism for Producing 2,3-Butanediol and Two Downstream Applications: Techno-Economic Analysis and Life Cycle Assessment of Methyl Ethyl Ketone (MEK) and Agricultural Biostimulant Production

  Open MIND · 2026-01-01

  dataset

  Rising concerns for sustainability and global climate change have driven the development of sustainable production pathways for biofuels and chemicals from lignocellulosic biomass via integrated biological and chemical processes. We constructed an engineered Saccharomyces cerevisiae capable of producing 2,3-butanediol (2,3-BDO) from glucose without accumulating ethanol and glycerol, which hinder downstream processing of 2,3-BDO, through extensive metabolic reprogramming. Specifically, we introduced heterologous 2,3-BDO biosynthetic enzymes and deleted the major isozymes of ethanol and glycerol biosynthetic enzymes. In addition, we introduced an NAD+ regenerating Pyruvate-Malate (PM) cycle and enhanced the NAD+ regenerating capability of the PM cycle to resolve the redox imbalance from the deletion of ethanol and glycerol production pathways. The resulting engineered yeast produced 109.9 g/L of 2,3-BDO with a productivity of 1.0 g/L/h and a yield of 0.36 g/g glucose in a fed-batch fermentation. We also conducted techno-economic analysis (TEA) and life cycle assessment (LCA) of the production of methyl ethyl ketone (MEK) through catalytic dehydration of 2,3-BDO. A TEA based on the experimental results indicated that the minimum product selling price (MPSP) was estimated to be $1.90/kg. Regarding cradle-to-grave LCA, 100-year global warming potential (GWP100) and fossil energy consumption (FEC) were found to be 0.37 kg CO2 eq/kg and 3.1 MJ/kg, respectively. These results demonstrated the feasibility of cost-competitive and sustainable bio-based MEK production via yeast fermentation. In addition, we explored the possibility of using the fermentation broth containing 2,3-BDO as a biostimulant inducing drought tolerance in plants. As a result, the yeast 2,3-BDO fermentation broth can induce drought tolerance in Arabidopsis thaliana without a complicated purification process.

  DOI

• High yield production of 3-hydroxypropionic acid using Issatchenkia orientalis

  Nature Communications · 2026-01-09 · 4 citations

  articleOpen access

  Biomanufacturing provides a more sustainable alternative to fossil-based chemical manufacturing. 3-Hydroxypropionic acid (3HP) is a top Department of Energy value-added chemical and precursor to bioplastics, yet cost-effective microbial production remains elusive. Here, we establish the acid-tolerant yeast Issatchenkia orientalis as a robust host for low-pH 3HP biosynthesis. Genome-scale modeling identifies the β-alanine pathway as optimal, offering the highest theoretical yield and lowest oxygen requirement. Thermodynamic analysis confirms its favorability under acidic conditions. Using sequence similarity network analysis, we discover highly active aspartate 1-decarboxylase (PAND), β-alanine-pyruvate aminotransferase (BAPAT), and 3HP dehydrogenase (YDFG), which significantly improve the pathway efficiency. Next, to further elevate the production, pathway optimization through multi-copy PAND integration, byproduct elimination (knockouts of pyruvate decarboxylase and glycerol-3-phosphate dehydrogenase), and reinforcement of aspartate flux by overexpression of pyruvate carboxylase and aspartate amino transferase improves the titer to 29 g/L in shake flasks. Fed-batch fermentation at pH 4 with low-cost corn steep liquor medium further increases the production to 92 g/L with 0.7 g/g yield and 0.55 g/L/h productivity. Techno-economic analysis indicates that such performance could potentially enable a financially viable process for sustainable acrylic acid production. This work establishes I. orientalis as a next-generation platform for cost-effective 3HP production and paves the way toward industrial commercialization.

  PublisherOA PDFDOI

Recent grants

• CAREER: Advancement of Microalgal Biotechnology via Quantitative Sustainable Design: An Integrated Research and Education Plan

  NSF · $462k · 2014–2019

• SusChEM: Algal-Based Resource Positive Sanitation (ARPS) Systems - An Integrated Modeling Framework to Advance Wastewater Infrastructure Sustainability

  NSF · $309k · 2014–2017

Frequent coauthors

• Yalin Li

  Qingdao Agricultural University

  44 shared

• Sarang S. Bhagwat

  22 shared

• Roland D. Cusick

  University of Illinois Urbana-Champaign

  20 shared

• Brian D. Shoener

  Black & Veatch (United Kingdom)

  20 shared

• Ian Bradley

  University at Buffalo, State University of New York

  20 shared

• Yoel R. Cortés‐Peña

  University of Illinois Urbana-Champaign

  20 shared

• George W. Huber

  University of Wisconsin–Madison

  20 shared

• Hannah A. C. Lohman

  University of Illinois Urbana-Champaign

  19 shared

Labs

• Jeremy Guest Research GroupPI

Education

• Ph.D., Civil Engineering

  University of Illinois at Urbana-Champaign

  1990

• M.S., Civil Engineering

  University of California, Berkeley

  1985

• B.S., Civil Engineering

  University of California, Berkeley

  1983

Awards & honors

• NSF CAREER Award
• Paul L. Busch Award for innovation in applied water quality…
• James J. Morgan Environmental Science & Technology Early Car…
• Best Scientific Book Prize Winner; IWA Publishing