Md Sameul Islam, Darcey Wayment, Himanshu Raje, Ramaraj Boopathy

Pharmaceuticals are emerging aquatic contaminants due to their widespread use and incomplete removal by conventional wastewater treatment processes. Antibiotics are of particular concern because of their persistence, toxicity, and contribution to the spread of antibiotic resistance. Sulfamethoxazole (SMX), a widely used sulfonamide antibiotic, is frequently detected in wastewater and surface waters at ng/L to µg/L concentrations. While physicochemical treatment methods have been explored, microbial degradation offers a more sustainable remediation approach. This study evaluated the effects of different redox conditions on bacterial SMX degradation using anaerobic digester sludge from the Thibodaux sewage treatment plant. Distinct bacterial consortia were enriched under aerobic, sulfate-reducing, nitrate-reducing, and mixed electron acceptor conditions. SMX degradation was quantified by HPLC, and metabolites were identified by LC-MS. All consortia grew in the presence of 120 ppm SMX without inhibition; however, SMX could not serve as the sole carbon source. Under co-metabolic conditions with glucose, the highest SMX degradation (99.43%) occurred under nitrate-reducing conditions, while only 8.39% degradation was observed when SMX was provided alone with nitrate.

These findings demonstrate the role of electron acceptor availability in enhancing SMX biodegradation and highlight the potential of optimized microbial processes for sustainable bioremediation of antibiotics.

Tristan Nilsson, Ramaraj Boopathy, Bliss Broussard, Darcey Wayment, Himanshu Raje

Antibiotic resistance has been a persistent issue in public health for the past few decades and in the present. Usage of antibiotic prescriptions by medical and animal husbandry practices have led to a distribution in the environment. Antibiotics in excrement and hospital effluents travel to wastewater treatment plants and establish a selection pressure on natural bacteria. Louisiana is one of the top five states to have the highest rate of antibiotic prescriptions. The purpose of the study was to test for antibiotic resistance and biodegradation of Trimethoprim (TMP), a common antibiotic, in the Thibodaux sewage treatment plant. Anaerobic digester sludge was collected and a consortium was created. The consortium was grown in different conditions and concentrations in triplicates for 14 days and was analyzed with high performance liquid chromatography and mass spectrometry on day 0 and day 14. Kinetics of the consortium biodegradation occurred afterwards and was analyzed every 3 - 4 days until day 19. A pure culture was tested for trimethoprim degradation and trimethoprim resistant genes. The results showed that the consortium was able to degrade Trimethoprim in co-metabolic conditions, formed 4 desmethyl trimethoprim after degrading, and followed zero order kinetics. The pure culture isolate was identified as Bacillus cereus and was determined to have sulfonamide resistance genes, sul3 and sulA, but did not actively degrade trimethoprim.

Miranda Whitten, Abigail Ogea, Kayden Smith, Thomas Musgrave, Bill Storer

Parasitic nematodes are detrimental to corn production in sandy soils under long-term monoculture systems. This study evaluated the effects of crop rotation and nematicide application on soil nematode populations at a site having sandy soils and more than 20 years of continuous corn production. In 2025, a 15-acre field was planted in 24 replicates of corn, sorghum, or soybeans, with half of each replicate receiving an in-furrow application of fluopyram nematicide at planting. The field was further stratified by soil texture into sandy and silty zones. Soil samples were collected before planting and after harvest to quantify populations of stunt, spiral, stubby, ring, root-knot, and root-lesion nematodes. Root-lesion nematodes were identified as the predominant and most damaging species, occurring at economically significant levels in 78% of corn samples. Crop rotation significantly reduced root-lesion nematode densities from 761 ± 132 to less than 222 and 177 per 500 cc of soil following soybean and sorghum rotations, respectively. Nematode composition varied by crop, with stunt and ring nematodes prominent in sorghum, spiral nematodes in soybeans, and root-lesion nematodes in corn. Velum application significantly reduced only ring nematode populations, while soil texture had minimal influence on most nematode groups. These results demonstrate that crop rotation to soybeans or sorghum can reduce nematodes in continuous corn systems, whereas fluopyram provided limited control.

Braxton Bishop, Ramaraj Boopathy, Ava Wilson, Jacey Chotto

Bayou Folse is a large, impaired waterway in South Louisiana. With rising concerns of antibiotic resistance, monitoring water quality and pollution load is vital to limit antibiotic resistance spread. Antibiotic resistance genes (ARGs) are a set of genes present within bacteria populations that can spread between different bacterial species. The spread of these genes leads to increased antibiotic resistance and difficulty treating bacterial infections. To better track resistance and water quality changes, proper monitoring is required. Samples will be collected monthly for a year in triplicate at four sites along the waterway: Nicholls Campus (site 1), Nicholls Farm (site 2), Lefort Bypass Road (site 3), and Bayou Blue Bypass Road (site 4). Water quality markers such as pH, dissolved oxygen, chemical oxygen demand, nitrate, ammonia, phosphate, and sulfate will be monitored using Hach chemical analysis methods and a YSI Pro 2030. Fecal coliform tests will be performed to determine contamination. S. aureus and E. coli will be isolated using selective and differential media. Colonies from each sample will have Kirby-Bauer antibiotic resistance assay performed to determine resistance present. Bacteria that express multi-drug resistance will have PCR performed to amplify ARGs and then ran on a gel to visualize the ARGs. Current results show that site two regularly has lower DO and sulfate than other sites, Sulfate has been highest at site 1, with other quality measures varying.

Alex Laurent, Christopher Lyles, Hillary Bennett, Trenton O'Neal

2,4-Dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide that commonly enters freshwater systems through agricultural and urban runoff. In closed freshwater environments such as Cane River Lake, microbial degradation is the primary mechanism controlling 2,4-D attenuation; however, degradation rates at environmentally relevant concentrations are often slow and variable, increasing the potential for persistence. This study evaluated whether the native microbial community in the Cane River Lake watershed can naturally attenuate 2,4-D under aerobic conditions.  Aerobic enrichment cultures were established in a defined basal medium amended with 2 µM 2,4-D. Medium pH was verified as neutral to account for NaOH-prepared 2,4-D stock solutions. Fifty-milliliter enrichments were prepared for the experimental treatment, along with substrate-unamended and uninoculated controls. Microbial growth was monitored by OD₆₀₀ using a Bio-Rad SmartSpec 3000 over a 41-day incubation. Following incubation, cultures were extracted three times with ethyl acetate (1:1, v/v) for chemical analysis.  After 41 days, growth was observed in both the 2,4-D-amended enrichments and substrate-unamended controls, while no growth occurred in uninoculated controls. These results suggest growth may be supported by an alternative carbon source. Ongoing GC-MS analysis will determine whether 2,4-D degradation occurred, with verification based on detection of 2,4-dichlorophenol (2,4-DCP) at m/z 162 and 163.

Layla Thomas, Shila Kandel, Abubakar Abdulkadir, Raphyel Rosby, Md Ekhtear Hossain

1,3-Dicyclohexylurea (DCU) is a widely used vulcanization additive in tire manufacturing, yet its ecological consequences as a tire-wear–derived contaminant remain largely overlooked. As tires undergo abrasion and environmental weathering, DCU can be released into aquatic environments, raising urgent concerns about its effects on freshwater primary producers. Here, we present a focused ecotoxicological assessment of DCU using Lemna minor, a sentinel aquatic macrophyte model. Healthy L. minor colonies were cultivated under controlled laboratory conditions and exposed to environmentally relevant concentrations of DCU (10-100 μg/L). Growth- and physiology-based endpoints were evaluated, including frond morphology, relative growth rate, photosynthetic pigment composition, and starch accumulation. DCU exposure produced striking, concentration-dependent phytotoxic effects, including visible morphological stress, significant growth inhibition, and pronounced reductions in chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids- hallmarks of impaired photosynthetic performance. Notably, higher DCU concentrations triggered marked starch accumulation, indicating disrupted carbon allocation and metabolic stress. Together, these results show that DCU, an understudied tire-derived chemical, impairs aquatic plant health by disrupting photosynthesis and carbon metabolism, identifying tire-wear constituents as emerging threats to freshwater ecosystem function.

Mia Wilson, Ramaraj Boopathy

Acetaminophen (APAP) is a pollutant in waterways and wastewater systems throughout the world. Biodegradation of APAP using certain bacterial strains has proven to be a safe and eco-friendly method in removal from water systems. Many bacterial strains are known to break down APAP, but the pathways in which they do so are not well understood. In this study, samples from an anaerobic digester collected from a wastewater treatment plant were used to develop bacterial enrichments in the presence of APAP.  The bacterial enrichment was tested for the biodegradation of APAP under various conditions including APAP as the sole carbon source and co-metabolic condition with glucose as the co-substrate. The results showed bacteria grew even at the maximum concentration of 400 mg/L APAP.  The culture condition with APAP as the sole carbon source produced a dark metabolite in the culture medium.  Total organic carbon analysis showed 85.7% carbon removal from the sole carbon source, and 93.0% carbon removal from the co-metabolic conditions. This study is ongoing and the APAP metabolites will be analyzed using a LC/MS in the future and the biodegradation metabolic pathway will be constructed using the identified metabolites.

Andrew Holmes

Urban heat islands (UHIs) create severe climate, health, and socioeconomic burdens in historically underserved communities, particularly in North Baton Rouge, where temperatures can exceed surrounding areas by 10–15°F due to low tree canopy, extensive impervious surfaces, and widespread blight. Green Roots: A Bioenergy–Urban Heat Island Framework for Transforming North Baton Rouge into a Cool, Connected Oasis proposes a decentralized, equity-driven strategy centered on micro-scale Community Hero Parks (0.1–0.5 acres) that convert vacant or blighted lots into shaded, biodiverse, and culturally meaningful green spaces. These parks mitigate extreme heat while restoring ecological function and honoring local heroes such as educators, firefighters, caregivers, and mentors.

Grounded in UHI science, urban forestry, and bioenergy principles, the framework integrates native canopy expansion, rain gardens, permeable surfaces, cool reflective paths, and edible plantings to reduce heat absorption and enhance evapotranspiration. GIS-based heat vulnerability mapping and climate datasets guide site selection in neighborhoods such as Scotlandville, Eden Park, and Zion City, where canopy coverage often falls below 15%. Unlike corridor-focused redevelopment efforts, this initiative targets hyper-local cooling to distribute environmental benefits across residential neighborhoods.

By 2030, the project aims to convert over 100 blighted lots, achieve localized temperature reductions of 5–10°