Sunggeun Woo

All Publications

• Isolation and characterization of aHalomonasspecies for non-axenic growth-associated production of bio-polyesters from sustainable feedstocks. Applied and environmental microbiology Woo, S., Averesch, N. J., Berliner, A. J., Deutzmann, J. S., Pane, V. E., Chatterjee, S., Criddle, C. S. 2024: e0060324

  Abstract

  Biodegradable plastics are urgently needed to replace petroleum-derived polymeric materials and prevent their accumulation in the environment. To this end, we isolated and characterized a halophilic and alkaliphilic bacterium from the Great Salt Lake in Utah. The isolate was identified as a Halomonas species and designated "CUBES01." Full-genome sequencing and genomic reconstruction revealed the unique genetic traits and metabolic capabilities of the strain, including the common polyhydroxyalkanoate (PHA) biosynthesis pathway. Fluorescence staining identified intracellular polyester granules that accumulated predominantly during the strain's exponential growth, a feature rarely found among natural PHA producers. CUBES01 was found to metabolize a range of renewable carbon feedstocks, including glucosamine and acetyl-glucosamine, as well as sucrose, glucose, fructose, and further glycerol, propionate, and acetate. Depending on the substrate, the strain accumulated up to ~60% of its biomass (dry wt/wt) in poly(3-hydroxybutyrate), while reaching a doubling time of 1.7 h at 30°C and an optimum osmolarity of 1 M sodium chloride and a pH of 8.8. The physiological preferences of the strain may not only enable long-term aseptic cultivation but also facilitate the release of intracellular products through osmolysis. The development of a minimal medium also allowed the estimation of maximum polyhydroxybutyrate production rates, which were projected to exceed 5 g/h. Finally, also, the genetic tractability of the strain was assessed in conjugation experiments: two orthogonal plasmid vectors were stable in the heterologous host, thereby opening the possibility of genetic engineering through the introduction of foreign genes.IMPORTANCE: The urgent need for renewable replacements for synthetic materials may be addressed through microbial biotechnology. To simplify the large-scale implementation of such bio-processes, robust cell factories that can utilize sustainable and widely available feedstocks are pivotal. To this end, non-axenic growth-associated production could reduce operational costs and enhance biomass productivity, thereby improving commercial competitiveness. Another major cost factor is downstream processing, especially in the case of intracellular products, such as bio-polyesters. Simplified cell-lysis strategies could also further improve economic viability.

  View details for DOI 10.1128/aem.00603-24

  View details for PubMedID 39058034

• Impacts of nitrogen-containing coagulants on the nitritation/denitrification of anaerobic digester centrate ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY Wang, Z., Yao, Y., Steiner, N., Cheng, H., Wu, Y., Woo, S., Criddle, C. S. 2020; 6 (12): 3451–59

  View details for DOI 10.1039/d0ew00938e

  View details for Web of Science ID 000592649100021

• In Vivo Polymerization ("Hard-Wiring") of Bioanodes Enables Rapid Start-Up and Order-of-Magnitude Higher Power Density in a Microbial Battery. Environmental science & technology Dubrawski, K. L., Woo, S. G., Chen, W. n., Xie, X. n., Cui, Y. n., Criddle, C. S. 2020

  Abstract

  For microbial electrochemical technologies to be successful in the decentralized treatment of wastewater, steady-state power density must be improved and cost must be decreased. Here, we demonstrate in vivo polymerization ("hard-wiring") of a microbial community to a growing layer of conductive polypyrrole on a sponge bioanode of a microbial battery, showing rapid biocatalytic current development (∼10 times higher than a sponge control after 4 h). Moreover, bioanodes with the polymerized inoculant maintain higher steady-state power density (∼2 times greater than the control after 28 days). We then evaluate the same hard-wired bioanodes in both a two-chamber microbial fuel cell and microbial battery with a solid-state NaFeIIFeIII(CN)6 (Prussian Blue) cathode, showing approximately an order-of-magnitude greater volumetric power density with the microbial battery. The result is a rapid start-up, low-cost (no membrane or platinum catalyst), and high volumetric power density system (independent of atmospheric oxygen) for harvesting energy and carbon from dilute organics in wastewater.

  View details for DOI 10.1021/acs.est.0c05000

  View details for PubMedID 33119289

• Nitrogen removal as nitrous oxide for energy recovery: Increased process stability and high nitrous yields at short hydraulic residence times. Water research Wang, Z. n., Woo, S. G., Yao, Y. n., Cheng, H. H., Wu, Y. J., Criddle, C. S. 2020; 173: 115575

  Abstract

  The Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a two-stage process for nitrogen removal and resource recovery: in the first, ammonia is oxidized to nitrite in an aerobic bioreactor; in the second, oxidation of polyhydroxyalkanoate (PHA) drives reduction of nitrite to nitrous oxide (N2O) which is stripped for use as a biogas oxidant. Because ammonia oxidation is well-studied, tests of CANDO to date have focused on N2O production in anaerobic/anoxic sequencing batch reactors. In these reactors, nitrogen is provided as nitrite; PHA is produced from acetate or other dissolved COD, and PHA oxidation is coupled to N2O production from nitrite. In a pilot-scale study, N2O recovery was affected by COD/N ratio, total cycle time, and relative time periods for PHA synthesis and N2O production. In follow-up bench-scale studies, different reactor cycle times were used to investigate these operational parameters. Increasing COD/N ratio improved nitrite removal and increased biosolids concentration. Shortening the anaerobic phase prevented fermentation of PHA and improved its utilization. Efficient PHA synthesis and utilization in the anaerobic phase correlated with high N2O production in the anoxic phase. Shortening the anoxic phase prevented reduction of N2O to N2. By shortening both phases, total cycle time was reduced from 24 to 12 h. This optimized operation enabled increased biomass concentrations, increased N2O yields (from 71 to 87%), increased N loading rates (from 0.1 to 0.25 kg N/m3-d), and shorter hydraulic residence times (from 10 to 2 days). Long-term changes in operational performance for the different bioreactor systems tested were generally similar despite significant differences in microbial community structure. Long-term operation at short anaerobic phases selected for a glycogen-accumulating community dominated by a Defluviicoccus-related strain.

  View details for DOI 10.1016/j.watres.2020.115575

  View details for PubMedID 32058151

• Disassembly and reassembly of polyhydroxyalkanoates: Recycling through abiotic depolymerization and biotic repolymerization BIORESOURCE TECHNOLOGY Myung, J., Strong, N. I., Galega, W. M., Sundstrom, E. R., Flanagan, J. C., Woo, S., Waymouth, R. M., Criddle, C. S. 2014; 170: 167-174

  Abstract

  An abiotic-biotic strategy for recycling of polyhydroxyalkanoates (PHAs) is evaluated. Base-catalyzed PHA depolymerization yields hydroxyacids, such as 3-hydroxybutyrate (3HB), and alkenoates, such as crotonate; catalytic thermal depolymerization yields alkenoates. Cyclic pulse addition of 3HB to triplicate bioreactors selected for an enrichment of Comamonas, Brachymonas and Acinetobacter. After each pulse, poly(3-hydroxybutyrate) (P3HB) transiently appeared: accumulation of P3HB correlated with hydrolysis of polyphosphate; consumption of P3HB correlated with polyphosphate synthesis. Cells removed from the cyclic regime and incubated with 3HB under nitrogen-limited conditions produced P3HB (molecular weight>1,000,000Da) at 50% of the cell dry weight (<8h). P3HB also resulted from incubation with acetate, crotonate, or a mixture of hydrolytic depolymerization products. Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) resulted from incubation with valerate or 2-pentenoate. A recycling strategy where abiotic depolymerization of waste PHAs yields feedstock for customized PHA re-synthesis appears feasible, without the need for energy-intensive feedstock purification.

  View details for DOI 10.1016/j.biortech.2014.07.105

  View details for Web of Science ID 000341357600022

• Production of Nitrous Oxide From Anaerobic Digester Centrate and Its Use as a Co-oxidant of Biogas to Enhance Energy Recovery. Environmental science & technology Scherson, Y. D., Woo, S., Criddle, C. S. 2014; 48 (10): 5612-5619

  Abstract

  Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a new process for wastewater treatment that removes nitrogen from wastewater and recovers energy from the nitrogen in three steps: (1) NH4(+) oxidation to NO2(-); (2) NO2(-) reduction to N2O gas; and (3) N2O conversion to N2 with energy production. In this work, we optimize Steps 1 and 2 for anaerobic digester centrate, and we evaluate Step 3 for a full-scale biogas-fed internal combustion engine. Using a continuous stirred reactor coupled to a bench-scale sequencing batch reactor, we observed sustained partial oxidation of NH4(+) to NO2(-) and sustained (3 months) partial reduction of NO2(-) to N2O (75-80% conversion, mass basis), with >95% nitrogen removal (Step 2). Alternating pulses of acetate and NO2(-) selected for Comamonas (38%), Ciceribacter (16%), and Clostridium (11%). Some species stored polyhydroxybutyrate (PHB) and coupled oxidation of PHB to reduction of NO2(-) to N2O. Some species also stored phosphorus as polyphosphate granules. Injections of N2O into a biogas-fed engine at flow rates simulating a full-scale system increased power output by 5.7-7.3%. The results underscore the need for more detailed assessment of bioreactor community ecology and justify pilot- and full-scale testing.

  View details for DOI 10.1021/es501009j

  View details for PubMedID 24780056