1
|
Langeslay B, Fahy W, Juarez G. Stress and alignment response to curved obstacles in growing bacterial monolayers. Phys Rev E 2024; 109:054608. [PMID: 38907398 DOI: 10.1103/physreve.109.054608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 05/09/2024] [Indexed: 06/24/2024]
Abstract
Monolayers of growing bacteria, confined within channel geometries, exhibit self-organization into a highly aligned laminar state along the axis of the channel. Although this phenomenon has been observed in experiments and simulations under various boundary conditions, the underlying physical mechanism driving this alignment remains unclear. In this study, we conduct simulations of growing bacteria in two-dimensional channel geometries perturbed by fixed obstacles, either circular or arc shaped, placed at the channel's center. Our findings reveal that even sizable obstacles cause only short-ranged disruptions to the baseline laminar state. These disruptions arise from a competition between local planar anchoring and bulk laminar alignment. At smaller obstacle sizes, bulk alignment fully dominates, while at larger sizes planar anchoring induces increasing local disruptions. Furthermore, our analysis indicates that the resulting configurations of the bacterial system display a striking resemblance to the arrangement of hard-rod smectic liquid crystals around circular obstacles. This suggests that modeling hard-rod bacterial monolayers as smectic, rather than nematic, liquid crystals may yield successful outcomes. The insights gained from our study contribute to the expanding body of research on bacterial growth in channels. Our work provides perspectives on the stability of the laminar state and extends our understanding to encompass more intricate confinement schemes.
Collapse
|
2
|
Ugolini GS, Wang M, Secchi E, Pioli R, Ackermann M, Stocker R. Microfluidic approaches in microbial ecology. LAB ON A CHIP 2024; 24:1394-1418. [PMID: 38344937 PMCID: PMC10898419 DOI: 10.1039/d3lc00784g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Microbial life is at the heart of many diverse environments and regulates most natural processes, from the functioning of animal organs to the cycling of global carbon. Yet, the study of microbial ecology is often limited by challenges in visualizing microbial processes and replicating the environmental conditions under which they unfold. Microfluidics operates at the characteristic scale at which microorganisms live and perform their functions, thus allowing for the observation and quantification of behaviors such as growth, motility, and responses to external cues, often with greater detail than classical techniques. By enabling a high degree of control in space and time of environmental conditions such as nutrient gradients, pH levels, and fluid flow patterns, microfluidics further provides the opportunity to study microbial processes in conditions that mimic the natural settings harboring microbial life. In this review, we describe how recent applications of microfluidic systems to microbial ecology have enriched our understanding of microbial life and microbial communities. We highlight discoveries enabled by microfluidic approaches ranging from single-cell behaviors to the functioning of multi-cellular communities, and we indicate potential future opportunities to use microfluidics to further advance our understanding of microbial processes and their implications.
Collapse
Affiliation(s)
- Giovanni Stefano Ugolini
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Miaoxiao Wang
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Roberto Pioli
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| | - Martin Ackermann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
- Laboratory of Microbial Systems Ecology, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédéral de Lausanne (EPFL), Lausanne, Switzerland
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Laura-Hezner-Weg 7, 8093 Zurich, Switzerland.
| |
Collapse
|
3
|
Hickl V, Pamu HH, Juarez G. Hydrodynamic Treadmill Reveals Reduced Rising Speeds of Oil Droplets Deformed by Marine Bacteria. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:14082-14089. [PMID: 37675846 DOI: 10.1021/acs.est.3c04902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
In marine environments, microscopic droplets of oil can be transported over large distances in the water column. Bacterial growth on the droplets' surface can deform the oil-water interface to generate complex shapes and significantly enlarge droplets. Understanding the fate of spilled oil droplets requires bridging these length scales and determining how microscale processes affect the large-scale transport of oil. Here, we describe an experimental setup, the hydrodynamic treadmill, developed to keep rising oil droplets stationary in the lab frame for continuous and direct observation. Oil droplets with radii 10 < R < 100 μm were colonized and deformed by bacteria over several days before their effective rising speeds were measured. The rising speeds of deformed droplets were significantly slower than those of droplets without bacteria. This decrease in rising speed is understood by an increase in drag force and a decrease in buoyancy as a result of bio-aggregate formation at the droplet surface. Additionally, we found sinking bio-aggregate particles of oil and bacterial biofilms and quantified their composition using fluorescence microscopy. Our experiments can be adapted to further study the interactions between oil droplets and marine organisms and could significantly improve our understanding of the transport of hydrocarbons and complex aggregates.
Collapse
Affiliation(s)
- Vincent Hickl
- Department of Physics, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Hima Hrithik Pamu
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Gabriel Juarez
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
4
|
Prasad M, Obana N, Lin SZ, Zhao S, Sakai K, Blanch-Mercader C, Prost J, Nomura N, Rupprecht JF, Fattaccioli J, Utada AS. Alcanivorax borkumensis biofilms enhance oil degradation by interfacial tubulation. Science 2023; 381:748-753. [PMID: 37590351 DOI: 10.1126/science.adf3345] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 06/21/2023] [Indexed: 08/19/2023]
Abstract
During the consumption of alkanes, Alcanivorax borkumensis will form a biofilm around an oil droplet, but the role this plays during degradation remains unclear. We identified a shift in biofilm morphology that depends on adaptation to oil consumption: Longer exposure leads to the appearance of dendritic biofilms optimized for oil consumption effected through tubulation of the interface. In situ microfluidic tracking enabled us to correlate tubulation to localized defects in the interfacial cell ordering. We demonstrate control over droplet deformation by using confinement to position defects, inducing dimpling in the droplets. We developed a model that elucidates biofilm morphology, linking tubulation to decreased interfacial tension and increased cell hydrophobicity.
Collapse
Affiliation(s)
- M Prasad
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - N Obana
- Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - S-Z Lin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT (UMR 7332), Turing Centre for Living systems, Marseille, France
| | - S Zhao
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - K Sakai
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Université, Sorbonne Université, CNRS, 75005 Paris, France
- Institut Pierre-Gilles de Gennes pour la Microfluidique, 75005 Paris, France
| | - C Blanch-Mercader
- Laboratoire Physico-Chimie Curie UMR168, Institut Curie, Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Sorbonne Université, 75248 Paris, France
| | - J Prost
- Laboratoire Physico-Chimie Curie UMR168, Institut Curie, Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Sorbonne Université, 75248 Paris, France
- Mechanobiology Institute, National University of Singapore, 117411 Singapore
| | - N Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- TARA center, Univeristy of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - J-F Rupprecht
- Aix Marseille Univ, Université de Toulon, CNRS, CPT (UMR 7332), Turing Centre for Living systems, Marseille, France
| | - J Fattaccioli
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Université, Sorbonne Université, CNRS, 75005 Paris, France
- Institut Pierre-Gilles de Gennes pour la Microfluidique, 75005 Paris, France
| | - A S Utada
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
- Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| |
Collapse
|
5
|
Langeslay B, Juarez G. Microdomains and stress distributions in bacterial monolayers on curved interfaces. SOFT MATTER 2023; 19:3605-3613. [PMID: 37161525 DOI: 10.1039/d2sm01498j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Monolayers of growing non-motile rod-shaped bacteria act as active nematic materials composed of hard particles rather than the flexible components of other commonly studied active nematics. The organization of these granular monolayers has been studied on flat surfaces but not on curved surfaces, which are known to change the behavior of other active nematics. We use molecular dynamics simulations to track alignment and stress in growing monolayers fixed to curved surfaces, and investigate how these vary with changing surface curvature and cell aspect ratio. We find that the length scale of alignment (measured by average microdomain size) increases with cell aspect ratio and decreases with curvature. Additionally, we find that alignment controls the distribution of extensile stresses in the monolayer by concentrating stress in negative-order regions. These results connect active nematic physics to bacterial monolayers and can be applied to model bacteria growing on droplets, such as oil-degrading marine bacteria.
Collapse
Affiliation(s)
- Blake Langeslay
- Department of Physics, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gabriel Juarez
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.
| |
Collapse
|
6
|
Dong R, Wan Z, Wang X, Bai Y, Bao M, Li H. The Role of Bacteria in the Formation and Migration of Oil-Particle Aggregates (OPAs) after Marine Oil Spills and the Associated Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7018-7028. [PMID: 37083415 DOI: 10.1021/acs.est.3c00647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Oil spills interact with mineral particles to form oil-particle aggregates (OPAs), which promotes the oil's natural diffusion and biodegradation. We investigated the effect of bacteria on the formation and vertical migration of OPAs under different concentrations and types of particles and proposed and elucidated an oil-particle-bacteria coupling mechanism. The depth of particle penetration into oil droplets (13-17 μm) was more than twice that of the nonbacterial group. Oil that remained in the water column and deposited to the bottom decreased from 87% to 49% and increased from 14% to 15% at high/low concentration, respectively. Interestingly, the median droplet diameter showed a negative correlation (R2 = 0.83) and positive correlation (R2 = 0.60) at high/low concentration, respectively, with the relative penetration depth first proposed. We further demonstrated that bacteria increased the penetrating depth by a combination of reducing/increasing the interfacial tension, reducing the oil amount (C17-C38) in the OPAs, and increasing the particle width. These effects reduced the droplet size and ultimately changed the vertical migration of OPAs. Finally, we provided a simple assessment of the vertical distribution of OPAs in nearshore environments based on experimental data and suggested that the role of bacteria in increasing the depth of particles penetrating into the oil droplets should not be ignored. These findings will broaden the research perspective of marine oil spill migration.
Collapse
Affiliation(s)
- Ranran Dong
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
| | - Zhifeng Wan
- School of Marine Sciences, Sun Yat-sen University/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, People's Republic of China
| | - Xinping Wang
- North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266033, People's Republic of China
| | - Yan Bai
- School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China
| | - Mutai Bao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
| | - Haoshuai Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
| |
Collapse
|