Jesus Manuel Antúnez Domínguez

Latent space-driven quantification of biofilm formation using time-resolved droplet microfluidics published in Microchemical Journal

Automated segnmentation of bacterial structures within a droplet. The image shows a bright-field microscopy view where a large biofilm region (green, outlined in blue) has been segmented from surrounding features. Small aggregates (yellow contours) are also highlighted. This segmentation enables structural differentiation of biofilm components for downstream quantitative analysis. *(Image by D. Pérez Guerrero.)*

Latent space-driven quantification of biofilm formation using time-resolved droplet microfluidics
Daniela Pérez Guerrero, Jesús Manuel Antúnez Domínguez, Aurélie Vigne, Daniel Midtvedt, Wylie Ahmed, Lisa D. Muiznieks, Giovanni Volpe, Caroline Beck Adiels
Microchemical Journal 225, 117685 (2026)
arXiv: 2507.07632
DOI: 10.1016/j.microc.2026.117685

Bacterial biofilms play crucial roles across diverse contexts, from public health risks to beneficial applications in bioremediation, biodegradation, and wastewater treatment. However, tools that enable high-resolution, dynamic analysis of their responses to environmental cues and collective cellular behaviors remain limited. Here, we present a droplet-based microfluidic platform that combines continuous in situ microscopy with subsequent unsupervised deep learning for quantitative analysis of biofilm development. In our setup, Bacillus subtilis cells are encapsulated in monodisperse aqueous microdroplets containing Lysogeny Broth, suspended in an oil phase and immobilized within microfabricated traps, providing continuous optical access throughout biofilm formation at the water–oil interface. The platform supports both fluorescence and bright-field imaging, enabling high-throughput, time-resolved monitoring of thousands of droplets under controlled conditions. To extract quantitative information from these large datasets, we developed an automated analysis pipeline based on a Variational Autoencoder (VAE) trained directly on microscopy images from our experiments. This unsupervised model enables segmentation and latent-space representation of bacterial structures without manual annotation or synthetic training data. Post-segmentation size thresholding enables classification of bacterial aggregates and larger biofilm-like clusters, including quantification of biofilm porosity, thereby supporting detailed morphological and temporal analyses across droplets and conditions. By integrating droplet microfluidics with unsupervised deep learning, our platform provides a scalable, robust, and rapid approach for high-throughput quantitative studies of biofilm behavior. It resolves complex structural biofilm patterns, bypasses the need for manual annotation, and opens new opportunities to probe environmental determinants of biofilm formation. Departing from earlier methods, our framework fuses biological training data with unsupervised models to quantify microbial community dynamics across scales, offering a generalizable platform for future high-resolution microbiology.

Poster by J. Dominguez at the Protein Folding in Real Time conference, Stockholm, 11 March 2026

Brightfield image of biofilm inside the droplet where motile aggregates are highlighted in yellow, biofilm mass in blue, and open patches in the structures due to dispersal in orange. *(Image from D. Pérez and J. Domínguez)*

Quantitative Analysis of Dynamic Biofilm Structures via Time-Resolved Droplet Microfluidics and Artificial Intelligence
Daniela Pérez Guerrero, Jesús Manuel Antúnez Domínguez, Aurélie Vigne, Daniel Midtvedt, Wylie Ahmed, Lisa Muiznieks, Giovanni Volpe and Caroline Beck Adiels
Date: 11th March 2026
Time: 18:00 – 20:00
Place: Aula Medica, Karolinska Institute, Solna
Conference Protein Folding in Real Time, 11-13 March 2026, Stockholm, Sweden

Droplet Microfluidics offers a powerful approach to study the spatiotemporal dynamics of biofilm formation at high resolution and throughput. By encapsulating microbial communities within controlled microenvironments, it becomes possible to monitor biofilm development continuously using time-lapse imaging, capturing transitions from initial attachment to maturation and dispersal. To make sense of these complex, high-dimensional datasets, we are developing an unsupervised variational autoencoder framework that can automatically identify and separate distinct stages of biofilm growth without prior labeling. This approach enables the extraction of latent features that characterize structural and behavioral shifts within the biofilm over time. In this context, protein folding may play a critical role in regulating both the establishment and dispersal of biofilms, as the conformational states of key structural and regulatory proteins can influence adhesion, matrix production, and the transition back to planktonic states.

Myxococcus xanthus for active matter studies: a tutorial for its growth and potential applications published in Soft Matter

*Myxococcus xanthus* colonies develop different strategies to adapt to their environment, leading to the formation of macroscopic patterns from microscopic entities. *(Image by the Authors of the manuscript.)*

Tutorial for the growth and development of Myxococcus xanthus as a Model System at the Intersection of Biology and Physics
Jesus Manuel Antúnez Domínguez, Laura Pérez García, Natsuko Rivera-Yoshida, Jasmin Di Franco, David Steiner, Alejandro V. Arzola, Mariana Benítez, Charlotte Hamngren Blomqvist, Roberto Cerbino, Caroline Beck Adiels, Giovanni Volpe
Soft Matter 21, 8602-8623 (2025)
arXiv: 2407.18714
doi: 10.1063/5.0235449

Myxococcus xanthus is a unicellular organism known for its capacity to move and communicate, giving rise to complex collective properties, structures and behaviors. These characteristics have contributed to position M. xanthus as a valuable model organism for exploring emergent collective phenomena at the interface of biology and physics, particularly within the growing domain of active matter research. Yet, researchers frequently encounter difficulties in establishing reproducible and reliable culturing protocols. This tutorial provides a detailed and accessible guide to the culture, growth, development, and experimental sample preparation of M. xanthus. In addition, it presents several exemplary experiments that can be conducted using these samples, including motility assays, fruiting body formation, predation, and elasticotaxis—phenomena of direct relevance for active matter studies.

Jesús Domínguez defended his PhD thesis on 6 September 2024. Congrats!

The three platforms developed to observe and characterise bacterial collective behaviour in different conditions. *(Image by J. Dominguez.)*

Jesús Manuel Antúnez Domínguez defended his PhD thesis on 6 September 2024. Congrats!
The defense took place in PJ, Institutionen för fysik, Origovägen 6b, Göteborg.

Title: Microscopic approaches for bacterial collective behaviour studies.

Abstract: Bacteria significantly impact our lives, from their beneficial role as probiotics to their involvement in infection environments. Their widespread presence is largely due to their ability to adapt to diverse conditions through collective behavior, which enables the development of complex strategies from the contributions of simple individual entities. However the understanding of these systems is limited by the reach of current study techniques. This work presents the development of three platforms designed to perform microscopic studies and characterise bacterial collective behaviors in situ, profiting the advantages of microfluidics over traditional culture techniques.

The first platform integrates bacterial culture on solid agar directly on the microscope stage, allowing for extended observation periods of up to a week. The agar is housed within an elastomer structure sealed with glass, ensuring environmental isolation while maintaining optical accessibility. This platform was used to document the complex social strategies of Myxococcus xanthus, including motility mechanisms, predation organisation, and fruiting body formation.

The second platform is an automated testing system for quantifying bacterial viability under various conditions. Using microfluidic technology, this platform streamlines and parallelise the process. It adapts the Ames genotoxicity test to a miniaturized version, using microscopy imaging as the readout. This approach reduces experimental turnaround time and minimizes the handling of hazardous substances.

The third platform is a microfluidic system designed for the microscopy observation of bacteria within stabilised droplets. This approach enhances throughput and allows for the production of various types of droplets on the same chip. Bacillus subtilis bacteria were encapsulated in these droplets, and their entire biofilm formation life cycle was observed in detail. Parallel to this, custom software was developed specifically for analysing microscopy images to automatically quantify biofilm formation.

Each of these platforms provides a unique perspectives in the study of bacterial collective behavior to offer a comprehensive toolkit for researchers. complementing one another. This work will equip researchers with the tools to address the mysteries of bacterial collective behavior and opens up new possibilities for application and investigation.

Thesis: https://hdl.handle.net/2077/81543

Supervisor: Caroline Beck Adiels
Examiner: Raimund Feifel
Opponent: Jana Jass
Committee: Edith Hammer, Per Augustsson, Johan Bengtsson-Palme
Alternate board member: Mattias Marklund