scholarly journals A light tunable differentiation system for the creation and control of consortia in yeast

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chetan Aditya ◽  
François Bertaux ◽  
Gregory Batt ◽  
Jakob Ruess
Keyword(s):  
Dynamic Control ◽  
Division Of Labour ◽  
Microbial Consortia ◽  
Continuous Cultures ◽  
Straightforward Manner ◽  
Single Strain ◽  
Differentiation Strategy ◽  
The Creation ◽  
And Control ◽  
Immense Potential

AbstractArtificial microbial consortia seek to leverage division-of-labour to optimize function and possess immense potential for bioproduction. Co-culturing approaches, the preferred mode of generating a consortium, remain limited in their ability to give rise to stable consortia having finely tuned compositions. Here, we present an artificial differentiation system in budding yeast capable of generating stable microbial consortia with custom functionalities from a single strain at user-defined composition in space and in time based on optogenetically-driven genetic rewiring. Owing to fast, reproducible, and light-tunable dynamics, our system enables dynamic control of consortia composition in continuous cultures for extended periods. We further demonstrate that our system can be extended in a straightforward manner to give rise to consortia with multiple subpopulations. Our artificial differentiation strategy establishes a novel paradigm for the creation of complex microbial consortia that are simple to implement, precisely controllable, and versatile to use.

scholarly journals A light tunable differentiation system for the creation and control of consortia in yeast

2021 ◽  
Author(s):  
Chetan Aditya ◽  
François Bertaux ◽  
Gregory Batt ◽  
Jakob Ruess
Keyword(s):  
Dynamic Control ◽  
Division Of Labour ◽  
Microbial Consortia ◽  
Continuous Cultures ◽  
Straightforward Manner ◽  
Single Strain ◽  
Differentiation Strategy ◽  
The Creation ◽  
And Control ◽  
Immense Potential

Artificial microbial consortia seek to leverage division-of-labour to optimize function and possess immense potential for bioproduction. Co-culturing approaches, the preferred mode of generating a consortium, remain limited in their ability to give rise to stable consortia having finely tuned compositions. Here, we present an artificial differentiation system in budding yeast capable of generating stable microbial consortia with custom functionalities from a single strain at user-defined composition in space and in time based on optogenetically-driven genetic rewiring. Owing to fast, reproducible, and light-tunable dynamics, our system enables dynamic control of consortia composition in continuous cultures for extended periods. We further demonstrate that our system can be extended in a straightforward manner to give rise to consortia with multiple subpopulations. Our artificial differentiation strategy establishes a novel paradigm for the creation of complex microbial consortia that are simple to implement, precisely controllable, and versatile to use.

scholarly journals Emergent spatiotemporal population dynamics with cell-length control of synthetic microbial consortia

2021 ◽  
Vol 17 (9) ◽  
pp. e1009381
Author(s):  
James J. Winkle ◽  
Bhargav R. Karamched ◽  
Matthew R. Bennett ◽  
William Ott ◽  
Krešimir Josić
Keyword(s):  
Population Dynamics ◽  
Population Control ◽  
Dynamic Control ◽  
Cell Length ◽  
Microbial Consortia ◽  
Cell Alignment ◽  
Rotational Parameter ◽  
Single Strain ◽  
Bacterial Consortia ◽  
Spatiotemporal Population Dynamics

The increased complexity of synthetic microbial biocircuits highlights the need for distributed cell functionality due to concomitant increases in metabolic and regulatory burdens imposed on single-strain topologies. Distributed systems, however, introduce additional challenges since consortium composition and spatiotemporal dynamics of constituent strains must be robustly controlled to achieve desired circuit behaviors. Here, we address these challenges with a modeling-based investigation of emergent spatiotemporal population dynamics using cell-length control in monolayer, two-strain bacterial consortia. We demonstrate that with dynamic control of a strain’s division length, nematic cell alignment in close-packed monolayers can be destabilized. We find that this destabilization confers an emergent, competitive advantage to smaller-length strains—but by mechanisms that differ depending on the spatial patterns of the population. We used complementary modeling approaches to elucidate underlying mechanisms: an agent-based model to simulate detailed mechanical and signaling interactions between the competing strains, and a reductive, stochastic lattice model to represent cell-cell interactions with a single rotational parameter. Our modeling suggests that spatial strain-fraction oscillations can be generated when cell-length control is coupled to quorum-sensing signaling in negative feedback topologies. Our research employs novel methods of population control and points the way to programming strain fraction dynamics in consortial synthetic biology.

scholarly journals Single strain control of microbial consortia

2019 ◽  
Author(s):  
Alex J.H. Fedorec ◽  
Behzad D. Karkaria ◽  
Michael Sulu ◽  
Chris P Barnes
Keyword(s):  
Escherichia Coli ◽  
Competitive Exclusion ◽  
Division Of Labour ◽  
Host Cells ◽  
Microbial Consortia ◽  
Community Members ◽  
Strain Control ◽  
Single Strain ◽  
Stable Populations ◽  
Over Time

AbstractThe scale of the biological systems we can engineer is limited by the burden that host cells can bear. Division-of-labour can spread that burden across a community of cells but competitive exclusion inevitably leads to the removal of less fit community members over time. Here, we leverage amensalism and competitive exclusion to stabilise multi-species communities by engineering a strain of Escherichia coli which secretes a toxin in response to competition. We show mathematically and experimentally that such a system can produce stable populations with a composition that is tunable by easily controllable parameters. This is the first system to use competitive exclusion to create a stable two-species consortia and the first to only require the engineering of a single strain.

scholarly journals Emergent spatiotemporal population dynamics with cell-length control of synthetic microbial consortia

2021 ◽  
Author(s):  
James J Winkle ◽  
Bhargav R Karamched ◽  
Matthew R Bennett ◽  
William Ott ◽  
Kresimir Josić
Keyword(s):  
Population Dynamics ◽  
Population Control ◽  
Dynamic Control ◽  
Cell Length ◽  
Microbial Consortia ◽  
Cell Alignment ◽  
Rotational Parameter ◽  
Single Strain ◽  
Bacterial Consortia ◽  
Spatiotemporal Population Dynamics

Increased complexity of engineered microbial biocircuits highlights the need for distributed cell functionality due to concomitant increases of metabolic and regulatory burdens imposed on single-strain topologies. Distributed systems, however, introduce additional challenges since consortium composition and spatiotemporal dynamics of constituent strains must be robustly controlled to achieve desired circuit behaviors. Here, we address these challenges with a modeling-based investigation of emergent spatiotemporal population dynamics that result from cell-length control of monolayer, two-strain bacterial consortia. We demonstrate that with dynamic control of a strain's division length, nematic cell alignment in close-packed monolayers can be destabilized. We found this destabilization conferred an emergent, competitive advantage on smaller-length strains---but by mechanisms that differed depending on the spatial patterns of the population. We used complementary modeling approaches to elucidate underlying mechanisms: an agent-based model to simulate detailed mechanical and signaling interactions between the competing strains and a reductive, stochastic lattice model to represent cell-cell interactions with a single rotational parameter. Our modeling suggests that spatial strain-fraction oscillations can be generated when cell-length control is coupled to quorum-sensing signaling in negative feedback topologies. Our research employs novel methods of population control and points the way to programming strain fraction dynamics in consortial synthetic biology.

scholarly journals Single strain control of microbial consortia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alex J. H. Fedorec ◽  
Behzad D. Karkaria ◽  
Michael Sulu ◽  
Chris P. Barnes
Keyword(s):  
Escherichia Coli ◽  
Microbial Communities ◽  
Competitive Exclusion ◽  
Division Of Labour ◽  
Microbial Consortia ◽  
Community Members ◽  
Strain Control ◽  
Single Strain ◽  
Stable Populations ◽  
Over Time

AbstractThe scope of bioengineering is expanding from the creation of single strains to the design of microbial communities, allowing for division-of-labour, specialised sub-populations and interaction with “wild” microbiomes. However, in the absence of stabilising interactions, competition between microbes inevitably leads to the removal of less fit community members over time. Here, we leverage amensalism and competitive exclusion to stabilise a two-strain community by engineering a strain of Escherichia coli which secretes a toxin in response to competition. We show experimentally and mathematically that such a system can produce stable populations with a composition that is tunable by easily controllable parameters. This system creates a tunable, stable two-strain consortia while only requiring the engineering of a single strain.

scholarly journals Creating and Maintaining Structural Hindrances to Criminal Justice Control – A Policy Analysis on the Normalisation of Parental Violence as a Crime in Finland

2021 ◽  
pp. 096466392110208
Author(s):  
Riikka Kotanen
Keyword(s):  
Criminal Justice ◽  
Criminal Law ◽  
Interpersonal Violence ◽  
Legal Regulation ◽  
Division Of Labour ◽  
Legal Form ◽  
Parental Violence ◽  
Control Policies ◽  
And Control

In the context of home, violence remains more accepted when committed against children than adults. Normalisation of parental violence has been documented in attitudinal surveys, professional practices, and legal regulation. For example, in many countries violent disciplining of children is the only legal form of interpersonal violence. This study explores the societal invisibility and normalisation of parental violence as a crime by analysing legislation and control policies regulating the division of labour and involvement between social welfare and criminal justice authorities. An empirical case study from Finland, where all forms of parental violence were legally prohibited in 1983, is used to elucidate the divergence between (criminal) law and control policies. The analysis demonstrates how normalisation operates at the policy-level where, within the same system of control that criminalised these acts, structural hindrances are built to prevent criminal justice interventions.

Regulating Religious Broadcasting

1992 ◽  
Vol 2 (10) ◽  
pp. 287-304
Author(s):  
Ian Leigh
Keyword(s):  
New Technologies ◽  
Technological Advance ◽  
Regulatory Framework ◽  
Religious Expression ◽  
Satellite Broadcasting ◽  
Religious Broadcasting ◽  
The Creation ◽  
The Uk ◽  
A Minor ◽  
And Control

The broadcasting world is currently undergoing a revolution. The new technologies of cable and, more importantly, satellite broadcasting have brought within reach an enormous potential expansion and diversity in broadcasting. The Broadcasting Act 1990 is the government's response to the challenge, creating a mostly new regulatory framework. Alongside technological advance there has been a growing concern with regulating programme quality, as the creation of the Broadcasting Standards Commission (placed by Pt. V of the Act on a statutory footing) bears witness. A minor, but not insignificant, place in these cross-currents of ferment is occupied by religious broadcasting. This article seeks to place the controls and duties relating to religious broadcasting under the new regime within the context of its history in the UK and to consider the extent to which the new legal and administrative controls achieve an acceptable balance between religious expression and control of standards.

Effects of Community Versus Single Strain Inoculants on the Biocontrol of Salmonella and Microbial Community Dynamics in Alfalfa Sprouts†

2005 ◽  
Vol 68 (1) ◽  
pp. 40-48 ◽  
Author(s):  
ANABELLE MATOS ◽  
JAY L. GARLAND
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Dynamics ◽  
Community Level ◽  
Microbial Consortia ◽  
Single Strain ◽  
Acridine Orange Staining ◽  
Physiological Profiles ◽  
Alfalfa Sprouts ◽  
Alfalfa Seeds

Potential biological control inoculants, Pseudomonas fluorescens 2-79 and microbial communities derived from market sprouts or laboratory-grown alfalfa sprouts, were introduced into alfalfa seeds with and without a Salmonella inoculum. We examined their ability to inhibit the growth of this foodborne pathogen and assess the relative effects of the inoculants on the alfalfa microbial community structure and function. Alfalfa seeds contaminated with a Salmonella cocktail were soaked for 2 h in bacterial suspensions from each inoculant tested. Inoculated alfalfa seeds were grown for 7 days and sampled during days 1, 3, and 7. At each sampling, alfalfa sprouts were sonicated for 7 min to recover microflora from the surface, and the resulting suspensions were diluted and plated on selective and nonselective media. Total bacterial counts were obtained using acridine orange staining, and the percentage culturability was calculated. Phenotypic potential of sprout-associated microbial communities inoculated with biocontrol treatments was assessed using community-level physiological profiles based on patterns of use of 95 separate carbon sources in Biolog plates. Community-level physiological profiles were also determined using oxygen-sensitive fluorophore in BD microtiter plates to examine functional patterns in these communities. No significant differences in total and mesophilic aerobe microbial cell density or microbial richness resulting from the introduction of inoculants on alfalfa seeds with and without Salmonella were observed. P. fluorescens 2-79 exhibited the greatest reduction in the growth of Salmonella early during alfalfa growth (4.22 log at day 1), while the market sprout inoculum had the reverse effect, resulting in a maximum log reduction (5.48) of Salmonella on day 7. Community-level physiological profiles analyses revealed that market sprout communities peaked higher and faster compared with the other inoculants tested. These results suggest that different modes of actions of single versus microbial consortia biocontrol treatments may be involved.

Intact Priming for Novel Perceptual Representations in Amnesia

1997 ◽  
Vol 9 (6) ◽  
pp. 699-713 ◽  
Author(s):  
Stephan B. Hamann ◽  
Larry R. Squire
Keyword(s):  
Recognition Memory ◽  
Declarative Memory ◽  
Brain Structures ◽  
Perceptual Identification ◽  
Single Exposure ◽  
Memory Representations ◽  
Perceptual Representations ◽  
The Creation ◽  
And Control ◽  
The Brain

Recent studies have challenged the notion that priming for ostensibly novel stimuli such as pseudowords (REAB) reflects the creation of new representations. Priming for such stimuli could instead reflect the activation of familiar memory representations that are orthographically similar (READ) and/or the activation of subparts of stimuli (RE, EX, AR), which are familar because they occur commonly in English. We addressed this issue in three experiments that assessed perceptual identification priming and recognition memory for novel and familiar letter strings in amnesic patients and control subjects. Priming for words, pseudowords, and orthographically illegal nonwords was fully intact in the amnesic patients following a single exposure, whereas recognition memory was impaired for the same items. Thus, priming can occur for stimuli that are unlikely to have preexisting representations. Words and pseudowords exhibited twice as much priming as illegal nonwords, suggesting that activation may contribute to priming for words and wordlike stimuli. Additional results showed that priming for illegal nonwords resulted from the formation of new perceptual associations among the component letters of each nonword rather than the activation of individual letter representations. In summary, the results demonstrate that priming following a single exposure can depend on the creation of new perceptual representations and that such priming is independent of the brain structures essential for declarative memory.

scholarly journals A Modular Digital Twinning Framework for Safety Assurance of Collaborative Robotics

2021 ◽  
Vol 8 ◽  
Author(s):  
J.A. Douthwaite ◽  
B. Lesage ◽  
M. Gleirscher ◽  
R. Calinescu ◽  
J. M. Aitken ◽  
...  
Keyword(s):  
Testing Strategy ◽  
Modular Architecture ◽  
Industrial Case Study ◽  
Safety Assurance ◽  
Physical Environments ◽  
Digital Twins ◽  
The Creation ◽  
Hardware Platforms ◽  
And Control

Digital twins offer a unique opportunity to design, test, deploy, monitor, and control real-world robotic processes. In this paper we present a novel, modular digital twinning framework developed for the investigation of safety within collaborative robotic manufacturing processes. The modular architecture supports scalable representations of user-defined cyber-physical environments, and tools for safety analysis and control. This versatile research tool facilitates the creation of mixed environments of Digital Models, Digital Shadows, and Digital Twins, whilst standardising communication and physical system representation across different hardware platforms. The framework is demonstrated as applied to an industrial case-study focused on the safety assurance of a collaborative robotic manufacturing process. We describe the creation of a digital twin scenario, consisting of individual digital twins of entities in the manufacturing case study, and the application of a synthesised safety controller from our wider work. We show how the framework is able to provide adequate evidence to virtually assess safety claims made against the safety controller using a supporting validation module and testing strategy. The implementation, evidence and safety investigation is presented and discussed, raising exciting possibilities for the use of digital twins in robotic safety assurance.

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