All Faculty Deposits

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The "All Faculty Deposits" collection contains works deposited by faculty and appointed delegates from the Elements (EFARs) system. For help with Elements, see Frequently Asked Questions on the Provost's website. In general, items can only be deposited if the item is a scholarly article that is covered by Virginia Tech's open access policy, or the item is openly licensed or in the public domain, or the item is permitted to be posted online under the journal/publisher policy, or the depositor owns the copyright. See Right to Deposit on the VTechWorks Help page. If you have questions email us at vtechworks@vt.edu.

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Older workers spend less time in extreme trunk and upper-arm postures during order-picking tasks: Results from field testing
Porta, Micaela; Casu, Giulia; Fastame, Maria Chiara; Nussbaum, Maury A.; Pau, Massimiliano (Elsevier, 2025-05)
Order picking tasks require repetitive trunk and upper arms movements that may increase the risk of developing musculoskeletal disorders, particularly among older workers due to the decline of their physical capabilities with aging. We proposed an approach based on a limited number of wearable inertial sensors to assessed exposures to non-neutral trunk and upper arms postures among both older and young workers during their regular work-shifts. The obtained data were processed accordingly to international standards (ISO 11226 and EN 1005-4) to detect the existence of possible differences associated with age-specific working strategies. While the results indicate similar trunk and upper arms movement frequencies in both groups, older workers spend a significantly smaller percentage of time in the most demanding (>60°) postures for both districts. Such findings suggest the adoption of specific strategies to reduce the biomechanical risk which might be originated by a combination of awareness of physical limits and superior working experience. In this context, the instrumental monitoring of upper body in the logistic sector may result useful to highlight critical conditions potentially able to promote the onset of musculoskeletal disorders, thus supporting the decision processes pertaining to workers’ health management and aging worker retainment.
Pedagogical moves related to analogy that support a unified understanding of eigentheory concepts in a quantum mechanics class
Serbin, Kaitlyn Stephens; Wawro, Megan (American Physical Society, 2024-10-30)
It is beneficial for quantum mechanics students to have a unified understanding of eigentheory concepts, so they can recognize the shared structure of mathematized phenomena from the different quantum mechanical systems of spin, energy, or position and recognize those as instantiations of the same overarching concept. Quantum mechanics instructors should, therefore, provide opportunities for their class community to develop a shared unified understanding of eigentheory concepts. One such opportunity can arise by engaging students in analogizing eigentheory concepts in one context with those from another context. We investigate the pedagogical moves related to analogies that can be used by a quantum mechanics course instructor to support a class community in developing a shared unified understanding of eigenequations. We analyze classroom data to characterize an instructor's pedagogical moves as he engaged students in analogical reasoning. Some moves include posing tasks conducive to analogizing; preparing, soliciting, and scaffolding students' participation in analogical reasoning; using deictic gestures and inscriptions; juxtaposing symbols representing the analogized concepts; and explicitly highlighting the sameness of the analogized concepts. We exemplify these pedagogical moves with analytical descriptions of illustrative class episodes. We discuss how these pedagogical moves can support the class community's expansion of their common ground by fostering the development of the class's shared unified understanding of eigentheory concepts.
Changes in Kinematics and Muscle Activity When Learning to Use a Whole-Body Powered Exoskeleton for Stationary Load Handling
Park, Hanjun; Kim, Sunwook; Nussbaum, Maury A.; Srinivasan, Divya (SAGE Publications, 2022-10-27)
Effects of Back-support Exoskeletons on Task Performance and Usability During Simulated Construction-relevant Tasks
Ojelade, Aanuoluwapo; Morris, Wallace; Kim, Sunwook; Harris-Adamson, Carisa; Barr, Alan; Nussbaum, Maury A. (SAGE Publications, 2022-10-27)
Predicting patients with septic shock and sepsis through analyzing whole-blood expression of NK cell-related hub genes using an advanced machine learning framework
Du, Chao; Tan, Stephanie C.; Bu, Heng-Fu; Subramanian, Saravanan; Geng, Hua; Wang, Xiao; Xie, Hehuang; Wu, Xiaowei; Zhou, Tingfa; Liu, Ruijin; Xu, Zhen; Liu, Bing; Tan, Xiao-Di (Frontiers, 2024-11-28)
Background: Sepsis is a life-threatening condition that causes millions of deaths globally each year. The need for biomarkers to predict the progression of sepsis to septic shock remains critical, with rapid, reliable methods still lacking. Transcriptomics data has recently emerged as a valuable resource for disease phenotyping and endotyping, making it a promising tool for predicting disease stages. Therefore, we aimed to establish an advanced machine learning framework to predict sepsis and septic shock using transcriptomics datasets with rapid turnaround methods. Methods: We retrieved four NCBI GEO transcriptomics datasets previously generated from peripheral blood samples of healthy individuals and patients with sepsis and septic shock. The datasets were processed for bioinformatic analysis and supplemented with a series of bench experiments, leading to the identification of a hub gene panel relevant to sepsis and septic shock. The hub gene panel was used to establish a novel prediction model to distinguish sepsis from septic shock through a multistage machine learning pipeline, incorporating linear discriminant analysis, risk score analysis, and ensemble method combined with Least Absolute Shrinkage and Selection Operator analysis. Finally, we validated the prediction model with the hub gene dataset generated by RT-qPCR using peripheral blood samples from newly recruited patients. Results: Our analysis led to identify six hub genes (GZMB, PRF1, KLRD1, SH2D1A, LCK, and CD247) which are related to NK cell cytotoxicity and septic shock, collectively termed 6-HubGss. Using this panel, we created SepxFindeR, a machine learning model that demonstrated high accuracy in predicting sepsis and septic shock and distinguishing septic shock from sepsis in a cross-database context. Remarkably, the SepxFindeR model proved compatible with RT-qPCR datasets based on the 6-HubGss panel, facilitating the identification of newly recruited patients with sepsis and septic shock. Conclusions: Our bioinformatic approach led to the discovery of the 6-HubGss biomarker panel and the development of the SepxFindeR machine learning model, enabling accurate prediction of septic shock and distinction from sepsis with rapid processing capabilities.
Vertically graded Fe-Ni alloys with low damping and a sizable spin-orbit torque
Maizel, Rachel E.; Wu, Shuang; Balakrishnan, Purnima P.; Grutter, Alexander J.; Kinane, Christy J.; Caruana, Andrew J.; Nakarmi, Prabandha; Nepal, Bhuwan; Smith, David A.; Lim, Youngmin; Jones, Julia L.; Thomas, Wyatt C.; Zhao, Jing; Michel, F. Marc; Mewes, Tim; Emori, Satoru (American Physical Society, 2024-10-21)
Energy-efficient spintronic devices require a large spin-orbit torque (SOT) and low damping to excite magnetic precession. In conventional devices with heavy-metal/ferromagnet bilayers, reducing the ferromagnet thickness to approximately 1 nm enhances the SOT but dramatically increases damping. Here, we investigate an alternative approach based on a 10-nm-thick single-layer ferromagnet to attain both low damping and a sizable SOT. Instead of relying on a single interface, we continuously break the bulk inversion symmetry with a vertical compositional gradient of two ferromagnetic elements: Fe with low intrinsic damping and Ni with sizable spin-orbit coupling. We find low effective damping parameters of αeff<5×10-3 in the Fe-Ni alloy films, despite the steep compositional gradients. Moreover, we reveal a sizable antidamping SOT efficiency of |θAD|≈0.05, even without an intentional compositional gradient. Through depth-resolved x-ray diffraction, we identify a lattice strain gradient as crucial symmetry breaking that underpins the SOT. Our findings provide fresh insights into damping and SOTs in single-layer ferromagnets for power-efficient spintronic devices.
Quantifying the orbital-to-spin moment ratio under dynamic excitation
Emori, Satoru; Maizel, Rachel E.; Street, Galen T.; Jones, Julia L.; Arena, Dario A.; Shafer, Padraic; Klewe, Christoph (AIP Publishing, 2024-03-18)
The orbital component of magnetization dynamics, e.g., excited by ferromagnetic resonance (FMR), may generate “orbitronic” effects in nanomagnetic devices. Yet, distinguishing orbital dynamics from spin dynamics remains a challenge. Here, we employ x-ray magnetic circular dichroism (XMCD) to quantify the ratio between the orbital and spin components of FMR-induced dynamics in a Ni80Fe20 film. By applying the XMCD sum rules at the Ni L 3 , 2 edges, we obtain an orbital-to-spin ratio of 0.108 ± 0.005 for the dynamic magnetization. This value is consistent with 0.102 ± 0.008 for the static magnetization, probed with the same x-ray beam configuration as the dynamic XMCD experiment. The demonstrated method presents a possible path to disentangle orbitronic effects from their spintronic counterparts in magnetic media.
Predisposition to arrhythmia and autonomic dysfunction in Nhlh1-deficient mice
Cogliati, Tiziana; Good, Deborah J.; Haigney, Mark; Delgado-Romero, Petra; Eckhaus, Michael A.; Koch, Walter J.; Kirsch, Ilan R. (American Society for Microbiology, 2002-07)
Nhlh1 is a basic helix-loop-helix transcription factor whose expression is restricted to the nervous system and which may play a role in neuronal differentiation. To directly study Nhlh1 function, we generated null mice. Homozygous mutant mice were predisposed to premature, adult-onset, unexpected death. Electrocardiograms revealed decreased total heart rate variability, stress-induced arrhythmia, and impaired baroreceptor sensitivity. This predisposition to arrhythmia is a likely cause of the observed death in the mutant mice. Heterozygosity for the closely related transcription factor Nhlh2 increased the severity of the Nhlh1-null phenotype. No signs of primary cardiac structural or conduction abnormalities could be detected upon necropsy of the null mice. The pattern of altered heart rhythm observed in basal and experimental conditions (stress and pharmacologically induced) suggests that a deficient parasympathetic tone may contribute to the arrhythmia in the Nhlh1-null mouse. The expression of Nhlh1 in the developing brain stem and in the vagal nuclei in the wild-type mouse further supports this hypothesis. The Nhlh1 mutant mouse may thus provide a model to investigate the contribution of the autonomic nervous system to arrhythmogenesis.
Effect of stressors during COVID-19 lockdown on malnutrition and health-risk behaviors among Jordanian college students: A cross-sectional study
Alkhalidy, Hana; Al-Shami, Islam; Alnaser, Khadeejah; Alkharabsheh, Ana'am; Nawaiseh, Hala; Liu, Dongmin (Lippincott Williams & Wilkins, 2024-10-11)
A stressful condition such as the emergence of the coronavirus and its related lockdown measures might trigger alterations in college students' behaviors. This cross-sectional study aimed to identify the changes in college students' dietary and lifestyle behaviors during the lockdown and the effect of lockdown-related stressors on health-risk behaviors. A web-based survey was conducted among undergraduate college students in Jordan. Weight and height were reported by the students. The students' dietary and lifestyle behaviors and their changes during 1 month of the countrywide lockdown were assessed. The Perceived Stress Scale-4 was utilized to assess stress levels. Results indicated that 77.2% of the students reported weight changes. Notably, 45.9% increased their intake of unhealthy food, while and 38% opted for healthier food choices. Most students experienced alterations in physical activity (80.0%), screen time (86.2%), smoking, and sleep patterns (85.4%), with a higher tendency toward adopting health-risk behaviors. Perceptions of curfew-related stress were associated with distance learning-related stress (OR = 2.73, CI: 1.08-6.90, P = .034), and a greater change in physical activity (OR = 3.59, CI: 1.36-9.48, P = .010). Additionally, weight changes were associated with perception of other types of stressors (OR = 3.39, CI: 1.39-8.28, P = .007). Overall, there was a considerable increase in malnutrition and health-risk behaviors among students during the lockdown. Understanding students' responses to these stressful conditions and the role of stress in driving behavioral changes are crucial for developing interventions that enhance college students' adaptation to such changes and maintaining healthy dietary and lifestyle behaviors in the future.
Conservation of a Chromosome 8 Inversion and Exon Mutations Confirm Common Gulonolactone Oxidase Gene Evolution Among Primates, Including H. Neanderthalensis
Mansueto, Alexander; Good, Deborah J. (Springer, 2024-04-29)
Ascorbic acid functions as an antioxidant and facilitates other biochemical processes such as collagen triple helix formation, and iron uptake by cells. Animals which endogenously produce ascorbic acid have a functional gulonolactone oxidase gene (GULO); however, humans have a GULO pseudogene (GULOP) and depend on dietary ascorbic acid. In this study, the conservation of GULOP sequences in the primate haplorhini suborder were investigated and compared to the GULO sequences belonging to the primates strepsirrhini suborder. Phylogenetic analysis suggested that the conserved GULOP exons in the haplorhini primates experienced a high rate of mutations following the haplorhini/strepsirrhini divergence. This high mutation rate has decreased during the evolution of the haplorhini primates. Additionally, indels of the haplorhini GULOP sequences were conserved across the suborder. A separate analysis for GULO sequences and well-conserved GULOP sequences focusing on placental mammals identified an in-frame GULO sequence in the Brazilian guinea pig, and a potential GULOP sequence in the pika. Similar to haplorhini primates, the guinea pig and lagomorph species have experienced a high substitution rate when compared to the mammals used in this study. A shared synteny to examine the conservation of local genes near GULO/GULOP identified a conserved inversion around the GULO/GULOP locus between the haplorhini and strepsirrhini primates. Fischer’s exact test did not support an association between GULOP and the chromosomal inversion. Mauve alignment showed that the inversion of the length of the syntenic block that the GULO/GULOP genes belonged to was variable. However, there were frequent rearrangements around ~ 2 million base pairs adjacent to GULOP involving the KIF13B and MSRA genes. These data may suggest that genes acquiring deleterious mutations in the coding sequence may respond to these deleterious mutations with rapid substitution rates.
404 Not Found: Quantitative Methods in Disability Studies
Blanchard, Aurelian; Blanchard, Enka; Shew, Ashley (SAGE, 2024-11-04)
Disability is sometimes theorised as existing between the world (including social norms and infrastructure) and the person (who gets labelled disabled in a ‘misfit’ between the world and them). Disability is often enacted through data systems and infrastructures and the history of disability studies reflects a fight against such systems. In this paper, we examine the fraught relationships between disability studies and data science — from institutions and historical marginalisation to current practices of policing and surveillance. We critique the resulting preeminence of qualitative methods in disability studies as one impediment to translating disability studies to data scientists and to effective policy-making. We then address hopeful movements to crip data studies, looking at work on AI and disability bias, crip technoscience, counterventional research, and cripped data.
Why pursue a career in teaching agriculture? Application of self-determination theory and the theory of planned behavior
Hur, Gangseok; Barry, Debra M.; Katrina, Alford; Jagger, Carla B.; Roberts, T. Grady (2024-06-30)
Given the shortage of agriculture teachers across the country, understanding individuals’ motivation to pursue a career in teaching agricultural education is critical to developing strategies for teacher recruitment and teacher education. Several studies have investigated factors that motivate preservice and in-service agriculture teachers to pursue a career teaching agricultural education based on the Factors Influencing Teaching Choice (FIT-Choice) model. However, little research investigated the topic using different theoretical lenses or a mixed-methods approach, which could provide new perspectives on individuals’ motivation to teach. To address the knowledge gap, we investigated Florida preservice teacher recruitment program participants’ motivation to teach agricultural education using a mixed-methods approach from the self-determination theory and the theory of planned behavior theoretical lens. We found that individuals’ intention to become agriculture teachers was statistically significantly explained by two predictors: attitude toward behavior and perceived behavioral control regarding a career in teaching agriculture. When choosing a career in teaching agriculture, the score for more self-determined motivation was substantially higher than that for less self-determined motivation. Furthermore, inspiring agriculture teachers, positive experiences with SBAE programs, a passion for teaching and agriculture, and paying it forward to students were the main factors that motivated them to pursue a career in teaching agricultural education. Based on the theoretical frameworks and the results, a model for understanding factors influencing individuals to pursue a career in teaching agriculture was proposed to broaden our understanding of the multidimensional nature of individuals’ motivation to teach agriculture.
Stochastic Boolean model of normal and aberrant cell cycles in budding yeast
Taoma, Kittisak; Tyson, John J.; Laomettachit, Teeraphan; Kraikivski, Pavel (Nature Portfolio, 2024-10-18)
The cell cycle of budding yeast is governed by an intricate protein regulatory network whose dysregulation can lead to lethal mistakes or aberrant cell division cycles. In this work, we model this network in a Boolean framework for stochastic simulations. Our model is sufficiently detailed to account for the phenotypes of 40 mutant yeast strains (83% of the experimentally characterized strains that we simulated) and also to simulate an endoreplicating strain (multiple rounds of DNA synthesis without mitosis) and a strain that exhibits ‘Cdc14 endocycles’ (periodic transitions between metaphase and anaphase). Because our model successfully replicates the observed properties of both wild-type yeast cells and many mutant strains, it provides a reasonable, validated starting point for more comprehensive stochastic-Boolean models of cell cycle controls. Such models may provide a better understanding of cell cycle anomalies in budding yeast and ultimately in mammalian cells.
A perturbation approach for refining Boolean models of cell cycle regulation
Banerjee, Anand; Rahaman, Asif Iqbal; Mehandale, Alok; Kraikivski, Pavel (PLOS, 2024-09-06)
Considerable effort is required to build mathematical models of large protein regulatory networks. Utilizing computational algorithms that guide model development can significantly streamline the process and enhance the reliability of the resulting models. In this article, we present a perturbation approach for developing data-centric Boolean models of cell cycle regulation. To evaluate networks, we assign a score based on their steady states and the dynamical trajectories corresponding to the initial conditions. Then, perturbation analysis is used to find new networks with lower scores, in which dynamical trajectories traverse through the correct cell cycle path with high frequency. We apply this method to refine Boolean models of cell cycle regulation in budding yeast and mammalian cells.
Subjective Assessments of Arm-Support Exoskeletons During Simulated Static and Dynamic Overhead Tasks
Morris, Wallace; Kim, Sunwook; Ojelade, Aanuoluwapo; Srinivasan, Divya; Smets, Marty; Nussbaum, Maury A. (SAGE Publications, 2022-10-27)
Multimodal Feedback to Improve Performance of Order Picker Truck Drivers Using a Virtual Reality Simulator
Islam, Md Shafiqul; Hsing, Hsiang-Wen; Kim, Sunwook; Lau, Nathan; Nussbaum, Maury A.; Lim, Sol (SAGE Publications, 2024-10-21)
VR technology presents exciting prospects for immersive forklift training environments. VR facilitates hands-on learning without the risks of real world errors. Real-time multimodal feedback (such as visual and haptic) is an effective way to enhance learning outcomes and skill acquisition. However, the efficacy and usability of real-time multimodal feedback provided for VR-based forklift driving needs to be investigated, as its impact on training outcomes remains unexplored. We aim to understand how various feedback modalities influence task performance, perceived workload, and user preferences. Fifteen (3 female, 12 male) individuals participated and completed VR-based forklift driving tasks with four feedback conditions (No feedback, visual, haptic, combined visual and haptic). A significant main effect of Feedback was found for completion time. Mental demand and frustration were affected by the Sex and Feedback interaction. These differences in the perception of feedback modalities underscore the importance of considering diverse user demographics when designing feedback systems.
FaaSr: Cross-Platform Function-as-a-Service Serverless Scientific Workflows in R
Park, Sungjae; Thomas, R. Quinn; Carey, Cayelan C.; Delany, Austin D.; Ku, Yun-Jung; Lofton, Mary E.; Figueiredo, Renato J. (IEEE, 2024-09)
Modern Function-as-a-Service (FaaS) cloud platforms offer great potential for supporting event-driven scientific workflows. Nonetheless, there remain barriers to adoption by the scientific community in domains such as environmental sciences, where R is the focal language used for the development of applications and where users are typically not well-versed with FaaS APIs. This paper describes the design and implementation of FaaSr, a novel middleware system that supports event-driven scientific workflows in R. A key novelty in FaaSr is the ability to deploy workflows across FaaS providers without the need for any managed servers for coordination. With FaaSr: 1) functions are written in R; 2) the runtime environments for their execution are customizable containers; 3) functions access data in cloud storage (S3) with a familiar file-based abstraction supporting both full file put/get primitives and subsetting using the Parquet format; and 4) function invocation and workflow coordination only requires S3 cloud object storage, without relying on any dedicated, active workflow engine server or cloud-specific queues/databases. The paper reports on the functionality and performance of FaaSr for micro-benchmarks and two case studies: event-driven forecast and batch job workflows. These demonstrate the ability to deploy workflows across multiple platforms (GitHub Actions, Amazon Web Services Lambda, and the open-source OpenWhisk), without the need for dedicated coordination servers, across both cloud and edge resources. FaaSr is open-source and available as a CRAN package.
An in vitro evaluation of intravenous lipid emulsion on three common canine toxicants
Jones, Emery; Walton, Stuart A.; Davis, Jennifer; Council-Troche, McAlister (Frontiers, 2024-09-25)
Objective: To determine whether intravenous lipid emulsion (ILE) therapy significantly reduces the concentration of baclofen, ibuprofen, and/or bromethalin in canine whole blood over time. Animals: Seven 500 mL bags of canine DEA 1.1 negative blood were divided into aliquots of 125 mL and randomly assigned to one of three treatment groups (baclofen, ibuprofen, bromethalin) or four control groups (a positive control for each treatment group and a negative control group). Procedures: Injectable ibuprofen (200 mg/kg), baclofen (8 mg/kg), or bromethalin (3 mg/kg) was apportioned into 125 mL aliquots of canine whole blood and incubated for 30 min at 38.5°C. ILE (12.4 mL, Intralipid®) was added to each sample and the solution vortexed [215 rpm for 15 min at 37°C (98.6°F)]. Samples were obtained at designated time points (0, 15, 30, 60, 180, 360 min), centrifuged, and separated into serum and RBC fractions. Serum samples were ultracentrifuged (22,000 g for 10 min at 37°C) to separate lipid rich and poor fractions. Samples were stored at −80°C prior to analysis. Results: A significant decrease in total drug concentration was established for bromethalin and its metabolite desmethylbromethalin compared to positive controls. ILE significantly reduced desmethylbromethalin at the 30-and 360-min time points. The remainder of the desmethylbromethalin time points did not reach significance. Bromethalin concentration was significantly reduced at all time points compared to positive controls. Neither baclofen nor ibuprofen had significant changes in concentration. Conclusion: ILE therapy was effective at reducing the total drug concentration of bromethalin and its metabolite desmethylbromethalin supporting the lipid sink theory. As a single compartment in vitro study, this study does not evaluate other proposed mechanisms of action of ILE therapy. ILE therapy may have other means of significantly decreasing lipophilic drug concentration in cases of toxicosis.
The Chemistry of the Defensive Secretions of Three Species of Millipedes in the Genus Brachycybe
Banks, Paige; Funkhouser, Emma M.; Macias, Angie M.; Lovett, Brian; Meador, Shelby; Hatch, Arden; Garraffo, H. Martin; Cartwright, Kaitie C.; Kasson, Matt T.; Marek, Paul E.; Jones, Tappey H.; Mevers, Emily (Springer, 2024-06-10)
Millipedes have long been known to produce a diverse array of chemical defense agents that deter predation. These compounds, or their precursors, are stored in high concentration within glands (ozadenes) and are released upon disturbance. The subterclass Colobognatha contains four orders of millipedes, all of which are known to produce terpenoid alkaloids—spare the Siphonophorida that produce terpenes. Although these compounds represent some of the most structurally-intriguing millipede-derived natural products, they are the least studied class of millipede defensive secretions. Here, we describe the chemistry of millipede defensive secretions from three species of Brachycybe: Brachycybe producta, Brachycybe petasata, and Brachycybe rosea. Chemical investigations using mass spectrometry-based metabolomics, chemical synthesis, and 2D NMR led to the identification of five alkaloids, three of which are new to the literature. All identified compounds are monoterpene alkaloids with the new compounds representing indolizidine (i.e. hydrogosodesmine) and quinolizidine alkaloids (i.e. homogosodesmine and homo-hydrogosodesmine). The chemical diversity of these compounds tracks the known species phylogeny of this genus, rather than the geographical proximity of the species. The indolizidines and quinolizidines are produced by non-sympatric sister species, B. producta and B. petasata, while deoxybuzonamine is produced by another set of non-sympatric sister species, B. rosea and Brachycybe lecontii. The fidelity between the chemical diversity and phylogeny strongly suggests that millipedes generate these complex defensive agents de novo and begins to provide insights into the evolution of their biochemical pathways.
Discovery of Biofilm Inhibitors from the Microbiota of Marine Egg Masses
Kyei, Lois; Piedl, Karla; Miller, Eleanor M.; Mevers, Emily (American Chemical Society, 2024-05-30)
Biofilms commonly develop in immunocompromised patients, which leads to persistent infections that are difficult to treat. In the biofilm state, bacteria are protected against both antibiotics and the host’s immune system; currently, there are no therapeutics that target biofilms. In this study, we screened a chemical fraction library representing the natural product capacity of the microbiota of marine egg masses, namely, the moon snail egg collars. This led to the identification of active fractions targeting both Pseudomonas aeruginosa and Staphylococcus aureus biofilms. Subsequent analysis revealed that a subset of these fractions were capable of eradicating preformed biofilms, all against S. aureus. Bioassay-guided isolation led us to identify pseudochelin A, a known siderophore, as a S. aureus biofilm inhibitor with an IC50 of 88.5 μM. Mass spectrometry-based metabolomic analyses revealed widespread production of pseudochelin A among fractions possessing S. aureus antibiofilm properties. In addition, a key biosynthetic gene involved in producing pseudochelin A was detected on 30% of the moon snail egg collars and pseudochelin A is capable of inhibiting the formation of biofilms (IC50 50.6 μM) produced by ecologically relevant bacterial strains. We propose that pseudochelin A may have a role in shaping the microbiome or protecting the egg collars from microbiofouling.

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