Article
Environmental Sciences
Yang Yue, Jingru Cheng, Kang Soo Lee, Roman Stocker, Xu He, Maosheng Yao, Jing Wang
Summary: This study investigated the formation mechanism and influencing factors of sulfate in fine particles during haze episodes in different city environments through experiments and collected samples. The results revealed that relative humidity significantly affects the formation of new CaSO4.2H2O crystals.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Biophysics
Noele Norris, Uria Alcolombri, Johannes M. Keegstra, Yutaka Yawata, Filippo Menolascina, Emilio Frazzoli, Naomi M. Levine, Vicente Fernandez, Roman Stocker
Summary: This study investigates how E. coli senses and responds to gradients of maltose. The researchers found that the abundance of a specific porin protein limits the uptake of maltose into the periplasm, allowing E. coli to sense micromolar gradients of maltose despite having a high-affinity ABC transport system that is saturated at these levels. The study suggests a trade-off between uptake and sensing, with high-affinity transport enabling higher uptake rates but severely limiting the range of dynamic sensing.
BIOPHYSICAL JOURNAL
(2022)
Article
Multidisciplinary Sciences
Jean-Baptiste Raina, Bennett S. Lambert, Donovan H. Parks, Christian Rinke, Nachshon Siboni, Anna Bramucci, Martin Ostrowski, Brandon Signal, Adrian Lutz, Himasha Mendis, Francesco Rubino, Vicente I. Fernandez, Roman Stocker, Philip Hugenholtz, Gene W. Tyson, Justin R. Seymour
Summary: This study demonstrates the chemotactic responses of marine bacteria and archaea towards microscale hotspots of phytoplankton-derived dissolved organic matter (DOM). The specific chemical cues attract different prokaryotic populations, which play important roles in biogeochemical processes and ecological interactions in the marine food web.
Review
Microbiology
Johannes M. Keegstra, Francesco Carrara, Roman Stocker
Summary: The mechanism of bacterial chemotaxis is well understood, but the reasons and consequences behind it are still puzzling. Besides foraging, bacterial chemotaxis also plays alternative ecological roles such as navigation, localization, and promoting microbial diversity. Most insights on chemotaxis are obtained from laboratory studies, and observing individual and collective migratory behavior of bacteria in different environments can provide a better understanding of the trade-offs between chemotaxis and growth. Further research using in situ approaches and transgenerational tracking is needed to explore the role of chemotaxis in microbial life.
NATURE REVIEWS MICROBIOLOGY
(2022)
Article
Multidisciplinary Sciences
Eleonora Secchi, Giovanni Savorana, Alessandra Vitale, Leo Eberl, Roman Stocker, Roberto Rusconi
Summary: It has been found that the mechanical stability of Pseudomonas aeruginosa streamers mainly relies on the presence of extracellular DNA (eDNA) and the exopolysaccharide Pel. Controlling the composition of streamers can effectively control the formation of biofilm structures.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Engineering, Environmental
Dorothee L. Kurz, Eleonora Secchi, Roman Stocker, Joaquin Jimenez-Martinez
Summary: The functioning of natural and engineered porous media relies on the interplay between biochemical processes and hydrodynamics. In such environments, biofilms often form, altering the distribution of fluid flow velocities and affecting their permeability. However, the control of biofilm clustering and resulting permeability heterogeneity is not well understood, limiting predictive abilities for biofilm-porous medium systems.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Sang Hyun Lee, Eleonora Secchi, Peter K. Kang
Summary: Bioaggregates are dense porous materials consisting of microorganisms, organic and inorganic matters, and water, which are commonly found in natural and engineered porous media and often cause clogging. The formation mechanism of bioaggregates in porous media systems is largely unknown, but this study shows that it is driven by the interplay of biomass viscoelasticity and hydrodynamic conditions at pore throats. The study also reveals that shear stress triggers morphological changes in bioaggregates, leading to disruptions in flow.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Alon Nissan, Uria Alcolombri, Nadav Peleg, Nir Galili, Joaquin Jimenez-Martinez, Peter Molnar, Markus Holzner
Summary: The role of soil in Earth's carbon budget is uncertain. A new model shows that soil temperature and moisture are linked to global soil respiration. Heterotrophic respiration has been increasing by 2% per decade since the 1980s, and it is projected to increase by 40% by the end of the century. Soil carbon efflux is the largest terrestrial carbon source to the atmosphere, but it remains one of the most uncertain fluxes in the global carbon budget.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Samuel G. V. Charlton, Amber N. Bible, Eleonora Secchi, Jennifer L. Morrell-Falvey, Scott T. Retterer, Thomas P. Curtis, Jinju Chen, Saikat Jana
Summary: Biofilms are bacterial communities structured within an extracellular matrix, which plays a role in controlling their architecture and mechanical resistance. The research investigates the correlation between biofilm structure and viscoelastic response by comparing biofilms of Pantoea sp. (WT) and a mutant (& UDelta;UDP) with reduced exopolysaccharide production.
Article
Microbiology
Daniele Marra, Thodoris Karapantsios, Sergio Caserta, Eleonora Secchi, Malgorzata Holynska, Simon Labarthe, Bastien Polizzi, Sandra Ortega, Margaritis Kostoglou, Christophe Lasseur, Ioannis Karapanagiotis, Sigolene Lecuyer, Arnaud Bridier, Romain Briandet, Marie-Francoise Noirot-Gros
Summary: Astronauts are spending longer periods in space for scientific missions, which could lead to increased risk of exposure to pathogenic microorganisms in space habitats. These microbial communities, often associated with biofilm formation on surfaces, have been found to degrade equipment functionality and pose a threat to the health of astronauts. Recent research suggests that microgravity could enhance the persistence, resistance, and virulence of these microorganisms. Efforts are being made to understand the installation and propagation of these microbial communities and to develop control measures to ensure cohabitation between microorganisms and astronauts.
Review
Biology
Jonasz Slomka, Uria Alcolombri, Francesco Carrara, Riccardo Foffi, Francois J. Peaudecerf, Matti Zbinden, Roman Stocker
Summary: Properties of microbial communities emerge from interactions between microorganisms and between microorganisms and their environment. To quantify and design these interactions, it is necessary to quantify encounter rates, which can often be done through encounter kernels. However, encounter kernels are often overlooked in descriptions of microbial populations, and the formulae for kernels are known in only a few encounter scenarios. Despite this, encounter kernels can guide experimental efforts and provide estimates for parameters in ecological models. This review focuses on encounter kernels describing interactions in aquatic systems.
Article
Biochemical Research Methods
Cameron Boggon, Srikanth Mairpady Shambat, Annelies S. Zinkernagel, Eleonora Secchi, Lucio Isa
Summary: Accessing single-cell information within large populations is crucial in microbiology. Bio-sCAPA is introduced as a technique to pattern bacterial cells in defined arrangements and monitor their growth in different nutrient environments. Using this method, the phenotypic characteristics of antibiotic-tolerant bacteria are analyzed, revealing prolonged lag-time as the main characteristic.
Article
Multidisciplinary Sciences
Dorothee L. Kurz, Eleonora Secchi, Roman Stocker, Joaquin Jimenez-Martinez
Summary: Bacterial biofilms are present in various environmental and industrial porous media, affecting permeability and mass flow. A microfluidic platform is developed to visualize biofilm development under controlled physical conditions and measure biofilm-induced pressure buildup.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2022)
Article
Biology
Samuel G. V. Charlton, Dorothee L. Kurz, Steffen Geisel, Joaquin Jimenez-Martinez, Eleonora Secchi
Summary: The study reveals that the viscoelasticity and expansion of biofilms depend on ECM components. The phase angle phi is identified as the best viscoelastic parameter correlating to biofilm expansion dynamics. Deletion of ECM components significantly increases the coherence of micro-scale colony expansion patterns.