Research Interests

The Sustainable Food Systems Engineering Lab (Dr. Usack's Lab) seeks to develop microbial-based bioprocessing technologies that facilitate the circular recovery of resources (food, water, energy, nutrients) and their upgrading (bioenergy, biochemicals, bio-based foods) within the bioeconomy. Primarily, his research involves three platform technologies: anaerobic digestion, microbial chain-elongation, and power-to-food. Dr. Usack and his students conduct fundamental and applied research at multiple scales, including: i) engineering individual bioprocesses in the lab; ii) overseeing bioprocess scale-up & field implementations & product commercialization; and iii) evaluating multi-stage bioprocess integrations using environmental lifecycle assessments, technoeconomic analysis, and systems engineering approaches.

Courses Taught

FDST 4012/6012: Food Processing II 

FDST 4012L/6012L: Food Processing II Lab

Education

Cornell University: Ph.D./Biological & Env. Engineering 2016

Cornell University: M.Sc./Biological & Env. Engineering 2014

SUNY-ESF:  B.Sc./Environmental Science 2008

Professional Affiliations

Faculty Member, New Materials Institute – Circular Materials Management, University of Georgia

Faculty Member, Institute for Integrative and Precision Agriculture, University of Georgia

Advisory Board Member, Bio-expression and Fermentation Facility, University of Georgia

Selected Publications

Zhou, M., Taiwo, K., Wang, H., Ntihuga, J.N., Angenent, L.T., Usack J.G., 2024. Anaerobic digestion of process water from hydrothermal treatment processes: a review of inhibitors and detoxification approaches. Bioresources and Bioprocessing, 11(1), pp. 1-20. DOI: 10.1186/s40643-024-00756-6

Ortiz-Ardila, A.E., Celis, C., Usack J.G., Angenent L., Labatut R., 2024. Microaeration promotes volatile siloxanes conversion to methane and simpler monomeric products. Bioresource Technology, Vol. 400, pp. 130673. DOI: 10.1016/j.biortech.2024.130673 

Ogundipe, S.O., Usack J.G., Pegg, R.B., Suh, J.H., 2023. Thermal and non-thermal processing on the physical and chemical properties of tree nuts: a review. Food and Bioprocess Technology, pp. 1-25,. DOI: 10.1007/s11947-023-03314-8 

Ortiz-Ardila, A.E., Restrepo, J.D., Angenent L., *Usack J.G., *Labatut R., 2023. Protecting human health and the environment against siloxanes: the role and effectiveness of wastewater treatment technologies. Critical Reviews in Environmental Science and Technology, 54(1), pp. 68-94. DOI:  10.1080/10643389.2023.2221156 (*Co-Corresponding Author)

Palomo-Briones, R., Xu, J., Spirito, C.M., Usack, J.G., Trondsen, L., Guzman, J.J., Angenent, L.T., 2022. Near-neutral pH increased n-caprylate production in a microbiome without methanogenesis. Chemical Engineering Journal, 137170. DOI: 10.1016/J.CEJ.2022.137170

Magdalena, J. A., Angenent, L. T., Usack, J.G., 2022. The measurement, application, and role of oxygen in anaerobic microbiomes: focusing on methane and carboxylate production. Fermentations, Vol. 8, No. 138. DOI: 10.3390/fermentation8040138

Angenent, L. T., Usack, J. G., Sun, T., Fink, C., Molitor, B., Labatut, R., Posmanik, R., Hörl, M., Hafenbradl, D., 2022. Chapter 6: Upgrading anaerobic digestion within the energy economy – the methane platform. In: Resource Recovery from Water: Principles and Application. Eds.: Pikaar, I., Guest J., Ganigué, R., Jensen, P., Rabaey, K., Seviour, T., Trimmer, J., van der Kolk, O., Vaneeckhaute, C., Verstraete, W., IWA Publishing, London, UK. DOI: 10.2166/9781780409566 

Angenent, L.T., Magdalena, J.A., Jeon, B.S., Usack, J.G., 2020. Eco-Mimicry Opens New Doors for Bioprocess Engineers. Joule, Vol. 4, pp. 1-3. DOI: 10.1016/j.joule.2020.09.013

Daly, S. E., Usack, J.G., Harroff, L.A., Booth, J.G., Keleman, M.P., Angenent, L. T., 2020. A systematic analysis of factors that affect food-waste storage: toward maximizing lactate accumulation for resource recovery. ACS Sustainable Chemistry & Engineering, Vol. 8, No. 37, pp. 13934-13944. DOI: 10.1021/acssuschemeng.0c03161

Posmanik, R., Kim, A.H., Labatut, R.A., Usack, J.G., Angenent, L.T., 2020. Granular sludge is a preferable inoculum for the biochemical methane potential assay for two complex substrates. Bioresource Technology, Vol. 309. DOI: 10.1016/j.biortech.2020.123359

Usack, J. G., Gerber Van Doren, L., Posmanik, R., Tester, J. W., Angenent, L. T., 2019. Harnessing anaerobic digestion for combined cooling, heat, and power on dairy farms: an environmental life cycle and techno-economic assessment of added cooling pathways. Journal of Dairy Sciences, Vol. 102, No. 4, pp. 3630-3645. DOI: 10.3168/jds.2018-15518 

Uman, A. E., Usack, J. G., Lozano, J. L., Angenent, L. T., 2018. Controlled-experiment contradicts the apparent benefits of the Fenton reaction during anaerobic digestion at a municipal wastewater treatment plant. Water Science and Technology, Vol. 78, No. 9, pp. 1861-1870. DOI: 10.2166/wst.2018.362

Usack, J.G., Gerber Van Doren, L., Posmanik, R., Labatut, R.A., Tester, J.W., Angenent, L.T., 2018. An evaluation of anaerobic co-digestion implementation on New York State dairy farms using an environmental and economic life-cycle framework. Applied Energy, Vol. 211, pp. 28-40. DOI: 10.1016/j.apenergy.2017.11.032

Angenent, L. T., Usack, J. G., Xu, J., Hafenbradl, D., Posmanik, R., Tester, J. W., 2017. Integrating electrochemical, biological, physical, and thermochemical process units to expand the applicability of anaerobic digestion. Bioresource Technology, Vol. 247, pp. 1085-1094. DOI: 10.1016/j.biortech.2017.09.104

Gildemyn, S., Molitor, B., Usack, J. G., Nguyen, M., Rabaey, K., Angenent, L. T., 2017. Upgrading syngas fermentation effluent using Clostridium kluyveri in a continuous fermentation. Biotechnology for Biofuels, Vol. 10, No. 83. DOI: 10.1186/s13068-017-0764-6 

Posmanik, R., Labatut, R. A., Kim, A. H., Usack, J. G., Tester, J. W., Angenent L. T., 2017. Coupling hydrothermal liquefaction and anaerobic digestion for energy valorization from model biomass feedstocks. Bioresource Technology, Vol. 233, pp. 134-143. DOI: 10.1016/j.biortech.2017.02

Usack, J.G., Angenent, L.T., 2015. Comparing the inhibitory thresholds of dairy manure co-digesters after prolonged acclimation periods: Part 1 – Performance and operating limits. Water Research Vol. 87, pp. 446-457. DOI: 10.1016/j.watres.2015.05.055

Regueiro, L., Spirito, C.M., Usack, J.G., Hospodsky, D., Werner, J.J., Angenent, L.T., 2015. Comparing the inhibitory thresholds of dairy manure co-digesters after prolonged acclimation periods: Part 2 – correlations between microbiomes and environment. Water Research Vol. 87, pp. 458-466. DOI: 10.1016/j.watres.2015.05.046

Perano, K.M., Usack, J.G., Angenent, L.T., Gebremedhin, K.G., 2015. Production and physiological responses of heat-stressed lactating dairy cattle to conductive cooling. Journal of Dairy Science. Vol. 98, No. 8, pp. 5252-5261. DOI: 10.3168/jds.2014-8784 

Ge, S., Usack, J.G., Spirito, C.M., Angenent, L.T., 2015. Long-term n-caproic acid production from yeast-fermentation beer in an anaerobic bioreactor with continuous product extraction. Environmental Science and Technology, Vol. 49, No. 13, pp. 8012-8021. DOI: 10.1021/acs.est.5b00238

Del Agua, I., Usack, J.G., Angenent, L.T., 2015. Comparison of semi-batch vs. continuously fed anaerobic bioreactors for the treatment of a high-strength, solids-rich pumpkin processing wastewater. Environmental Technology. Vol. 36, No. 15, pp. 1974-1983. DOI: 10.1080/09593330.2015.1018842

Usack, J.G., Wiratni, W., Angenent, L.T., 2014. Improved design of anaerobic digesters for household biogas production in Indonesia: one cow, one digester, and one hour of cooking per day. The Scientific World Journal, 2014, 8. DOI: doi.org/10.1155/2014/318054

Agler, M. T., Spirito, C. M., Usack, J. G., Werner, J. J., Angenent, L. T., 2014. Development of a highly specific and productive process for n-caproic acid production: applying lessons from methanogenic microbiomes. Water Science and Technology. Vol. 69, No. 1, pp. 62-68. DOI: 10.2166/wst.2013.549 

Usack, J.G., Spirito, C.M., Angenent, L.T., 2012. Continuously-stirred anaerobic digester to convert organic wastes into biogas: system setup and basic operation. Journal of Visualized Experiments (JoVE), e3978, DOI: 10.3791/3978. 

Agler, M.T., Spirito, C.M., Usack, J.G., Werner, J.J., Angenent, L.T., 2012. Chain elongation with reactor microbiomes: upgrading dilute ethanol to medium-chain carboxylates. Energy and Environmental Science, Vol. 5, No. 8, pp. 8189-8192. DOI: 10.1039/C2EE22101B