Article
Biochemistry & Molecular Biology
Jesse B. Gordon, Mikaila C. Hoffman, Julianne M. Troiano, Mingshan Li, Gerald L. Hazelbauer, Gabriela S. Schlau-Cohen
Summary: Transmembrane receptors in motile bacteria play a crucial role in detecting and responding to chemical gradients. This study investigated the conformational signaling in Escherichia coli aspartate receptor homodimers and found that ligand binding had asymmetric effects on the two helical pairs, with the scaffold pair compacting further and the dynamic pair increasing in separation and dynamics. The differential alterations to the packing and dynamics of the two helical pairs upon ligand binding reflect a previously unappreciated mode of conformational signaling.
ACS CHEMICAL BIOLOGY
(2021)
Article
Multidisciplinary Sciences
Nicolas Waisbord, Amin Dehkharghani, Jeffrey S. Guasto
Summary: Through microfluidic experiments, it was found that individual magnetotactic bacteria display three distinct regimes when directed upstream through pores, resembling the electrical conductivity of a diode. This diode-like behavior persists at the pore scale, impacting flow conductivity in higher dimensional geometries. The study has implications for magnetotactic bacteria survival strategies in sediments and potential drug delivery applications in vascular networks.
NATURE COMMUNICATIONS
(2021)
Article
Mechanics
Dokyum Kim, Yongsam Kim, Sookkyung Lim
Summary: Environmental conditions can alter the swimming behavior of bacteria, and this behavior depends on the physical and geometrical properties of the bacteria. By considering different environmental conditions, we can observe the different modes of bacterial motility.
Article
Chemistry, Physical
Miru Lee, Christoph Lohrmann, Kai Szuttor, Harold Auradou, Christian Holm
Summary: The study focuses on the transport of bacteria in a porous media modeled by a square channel with a cylindrical obstacle, using molecular dynamics simulations and lattice Boltzmann fluid. By varying the external flow strength, bacterial motility, and channel geometry, the research reveals the crucial interactions between bacteria and confining walls for the accumulation process.
Article
Multidisciplinary Sciences
Jyot D. Antani, Rachit Gupta, Annie H. Lee, Kathy Y. Rhee, Michael D. Manson, Pushkar P. Lele
Summary: The bacterial flagellar motor is able to adapt its switching between clockwise and counterclockwise rotation in response to changes in mechanical load by controlling the binding affinity of the chemotaxis response regulator, CheY-P. This allows the motor to maintain optimal function in environments of varying viscosities. The interplay between mechanical forces and CheY-P binding tunes the chemotactic function to match the load, resembling proprioceptive feedback in neuromuscular systems.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Himanshu Joshi, Meher K. Prakash
Summary: We performed atomistic calculations on the MCP-CheA-CheW complex from Escherichia coli and found that methylation favors an intermediate structure that is more inclined towards a lower state and increases the chance of ATP hydrolysis. This suggests that the model is sensitive to nutrient signal response, encouraging further studies on the thermodynamic quantification of these effects and the identification of signaling networks.
Article
Multidisciplinary Sciences
Avik Mukherjee, Jade Ealy, Yanqing Huang, Nina Catherine Benites, Mark Polk, Markus Basan
Summary: Utilizing a combination of experiments and computer simulations, researchers have found that the emergence and persistence of coexistence of multiple ecotypes in Escherichia coli long-term evolution experiment can be explained by two interacting trade-offs rooted in biochemical constraints. Faster growth enabled by higher fermentation and obligate acetate excretion results in longer lag times when utilizing acetate after glucose is depleted, creating an ecological niche for a slower-growing ecotype specialized in switching to acetate. These findings highlight the importance of trade-offs in the evolution of complex microbial communities.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Oleksandr Chepizhko, Thomas Franosch
Summary: This study investigates the dynamics of a single chiral active particle under an external torque caused by the presence of a gravitational field. Through computer simulations, it is observed that the longtime diffusivity of the gravitactic agent significantly increases when the external torque approaches the intrinsic angular drift. Analytic expressions for the mean-square displacement are provided using eigenfunctions and eigenvalues of the noisy-driven-pendulum problem. The pronounced maximum in the diffusivity is explained by the vanishing of the lowest eigenvalues of the Fokker-Planck equation for the angular motion as the rotational diffusion decreases and the underlying classical bifurcation is approached. A simple harmonic oscillator model accurately describes the onset of resonance during barrier-dominated motion.
PHYSICAL REVIEW LETTERS
(2022)
Review
Microbiology
Remy Colin, Bin Ni, Leanid Laganenka, Victor Sourjik
Summary: Swimming bacteria can follow gradients of nutrients and signaling molecules for optimal growth, with chemotaxis enhancing efficiency in environmental colonization. The balance between individual and collective behaviors is crucial, with multiple roles of motility and chemotaxis in bacterial swarming, biofilm formation, and interactions with hosts.
FEMS MICROBIOLOGY REVIEWS
(2021)
Article
Physics, Fluids & Plasmas
Mohammad Nabil, Andrew Frankowski, Ashton Orosa, Andrew Fuller, Amir Nourhani
Summary: We proposed a method to modulate the drifting motion of overdamped circle swimmers in steady fluid flows by static sinusoidal potentials, and quantified the drift velocity as a function of potential strength and wavelength with and without diffusional motion. The results show that drift velocity is essentially quantized without diffusion but has a continuous range with noise, and different regimes can be observed based on the dimensionless potential wave number in the drift velocity diagram. This method can help differentiate biological and artificial circle swimmers based on their dynamical properties.
Article
Microbiology
Sooyeon Song, Thomas K. Wood
Summary: AI-2, a ubiquitous metabolite, has been shown to influence biofilm formation and motility in Escherichia coli, establishing it as a true signal with important physiological roles. Additionally, AI-2 signaling in E. coli is compared to indole signaling, showing opposite effects on biofilm formation and virulence.
Article
Physics, Fluids & Plasmas
Shobhan Dev Mandal, Sakuntala Chatterjee
Summary: The competition between sensing and adaptation in Escherichia coli chemotaxis can lead to a performance peak, as shown in extensive numerical simulations using a detailed theoretical model. Receptor clustering amplifies the input signal from ligand binding to enhance chemotactic efficiency, but large clusters also introduce fluctuations in total activity. Additionally, the activity and run-tumble motility are controlled by methylation levels in the adaptation module rather than by ligand binding, resulting in reduced chemotactic efficiency.
Article
Multidisciplinary Sciences
Hiroto Tanaka, Yasuaki Kazuta, Yasushi Naruse, Yukihiro Tominari, Hiroaki Umehara, Yoshiyuki Sowa, Takashi Sagawa, Kazuhiro Oiwa, Masato Okada, Ikuro Kawagishi, Hiroaki Kojima
Summary: Chemical sensing is crucial for the survival of organisms. Bacterial chemotaxis regulates flagellar rotation direction based on chemical signals, and can determine the favorability of chemicals. An experimental setup and statistical framework were used to monitor and extract information on chemical stimuli from the responses of bacteria. This research provides a basis for developing novel bio-inspired sensors to detect a wider range of chemicals.
SCIENTIFIC REPORTS
(2022)
Article
Mechanics
A. R. Galaly, O. B. Ahmed, Atif H. Asghar
Summary: The research shows that increasing the concentration of the TiO2 precursor can enhance the deactivation rate of E. coli, due to the photocatalytic disinfection performance. This is because the increase in TiO2 precursor concentration enhances the effect of the non-thermal jet, leading to the generation of more active substances that can be absorbed by the cells, thereby accelerating the sterilization efficiency.
Article
Chemistry, Physical
Elena Sese-Sansa, Demian Levis, Ignacio Pagonabarraga
Summary: This article discusses a dynamical field theory for self-propelled particles subjected to generic torques and forces. By coarse-graining their microscopic dynamics, the study investigates the instabilities of macroscopic and finite structures, and the influence of intrinsic torques on phase separation and non-equilibrium patterns.
JOURNAL OF CHEMICAL PHYSICS
(2022)