scholarly journals Siderophores drive invasion dynamics in bacterial communities through their dual role as public good versus public bad

2021 ◽  
Author(s):  
Alexandre R. T. Figueiredo ◽  
Oezhan Oezkaya ◽  
Rolf Kuemmerli ◽  
Jos Kramer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ecosystem Services ◽  
Public Goods ◽  
Public Good ◽  
Bacterial Communities ◽  
Invasion Success ◽  
Invasion Dynamics ◽  
Public Bads ◽  
Invasion Assays

Microbial invasions can compromise ecosystem services and spur dysbiosis and disease in hosts. Nevertheless, the mechanisms determining invasion outcomes often remain unclear. Here, we examine the role of iron-scavenging siderophores in driving invasions of Pseudomonas aeruginosa into resident communities of environmental pseudomonads. Siderophores can be 'public goods' by delivering iron to individuals possessing matching receptors; but they can also be 'public bads' by withholding iron from competitors lacking these receptors. Accordingly, siderophores should either promote or impede invasion, depending on their dual effects on invader and resident growth. Using supernatant feeding and invasion assays, we show that invasion success indeed decreased when the invader was inhibited (public bad) rather than stimulated (public good) by the residents' siderophores. Conversely, invasion success often increased when the invader could use its siderophore to inhibit the residents. Our findings identify siderophores as a major driver of invasion dynamics in bacterial communities.

scholarly journals Heterogeneous groups cooperate in public good problems despite normative disagreements about individual contribution levels

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kasper Otten ◽  
Vincent Buskens ◽  
Wojtek Przepiorka ◽  
Naomi Ellemers
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Individual Contribution ◽  
Public Goods Game ◽  
Homogeneous Groups ◽  
The Public ◽  
Heterogeneous Groups ◽  
Good Provision ◽  
Good Individual

Abstract Norms can promote human cooperation to provide public goods. Yet, the potential of norms to promote cooperation may be limited to homogeneous groups in which all members benefit equally from the public good. Individual heterogeneity in the benefits of public good provision is commonly conjectured to bring about normative disagreements that harm cooperation. However, the role of these normative disagreements remains unclear because they are rarely directly measured or manipulated. In a laboratory experiment, we first measure participants’ views on the appropriate way to contribute to a public good with heterogeneous returns. We then use this information to sort people into groups that either agree or disagree on these views, thereby manipulating group-level disagreement on normative views. Participants subsequently make several incentivized contribution decisions in a public goods game with peer punishment. We find that although there are considerable disagreements about individual contribution levels in heterogeneous groups, these disagreements do not impede cooperation. While cooperation is maintained because low contributors are punished, participants do not use punishment to impose their normative views on others. The contribution levels at which groups cooperate strongly relate to the average normative views of these groups.

scholarly journals Classroom Games: Voluntary Provision of a Public Good

1997 ◽  
Vol 11 (4) ◽  
pp. 209-215 ◽  
Author(s):  
Charles A Holt ◽  
Susan K Laury
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Fund Raising ◽  
Public Goods Game ◽  
Role Of Government ◽  
The Public ◽  
Voluntary Provision ◽  
Good Problem

This paper describes a simple public goods game, implemented with playing cards in a classroom setup. Students choose whether to contribute to the provision of a public good in a situation where it is privately optimal not to contribute, but socially optimal to contribute fully. This exercise motivates discussion of altruism, strategies for private fund-raising, and the role of government in resolving the public good problem.

scholarly journals The role of spatial policy tools protecting the space as a public good

2020 ◽  
Vol 2020 (146) ◽  
pp. 265-274
Author(s):  
Paweł MICKIEWICZ ◽  
◽  
Maciej J. NOWAK ◽  
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Management System ◽  
Design Methodology ◽  
Local Level ◽  
Policy Framework ◽  
Policy Tools ◽  
Spatial Management ◽  
Spatial Policy

Purpose: The aim of the paper is to indicate functions that spatial policy tools at local level 10 should fulfill while protecting the space understood as a public good. Design/methodology/approach: The paper is of a review nature, but it refers to results of conducted research, included in the context of public goods. Findings: The area of communes covered by local plans is varied and very often depends on random circumstances from the perspective of the main spatial policy framework. The above illustrates diverse conditions, in which spatial conflicts may occur. Factors that should theoretically play an ordering role actually bring much more chaos. Therefore, the behavior of communal authorities in the implementation of spatial policy is contained in the sphere of impacts difficult to clearly predict, about which E. Ostrom mentioned. Social implications: In the context of current problems occurring in the spatial management system, it is worth developing the approach to space as a public good. This will help to adapt the approaches and characteristics of public goods to the current conditions of spatial management system and optimal role of spatial policy tools. Originality/value: This paper defines the roles of spatial policy tools protecting the space understood as a public good. Space protection in this approach must be implemented through specific spatial policy tools. The paper verifies the real scope of such protection. An attempt was made to translate approaches and dilemmas regarding public goods into conditions related to the spatial management system.

scholarly journals Quorum Sensing Protects Pseudomonas aeruginosa against Cheating by Other Species in a Laboratory Coculture Model

2015 ◽  
Vol 197 (19) ◽  
pp. 3154-3159 ◽  
Author(s):  
Nicole E. Smalley ◽  
Dingding An ◽  
Matthew R. Parsek ◽  
Josephine R. Chandler ◽  
Ajai A. Dandekar
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Public Goods ◽  
Public Good ◽  
Hydrogen Cyanide ◽  
Cooperative Behavior ◽  
Bacterial Species ◽  
Cell Communication ◽  
Content Type ◽  
Burkholderia Multivorans

ABSTRACTMany species of bacteria use a cell-cell communication system called quorum sensing (QS) to coordinate group activities. QS systems frequently regulate the production of exoproducts. Some of these products, such as proteases, are “public goods” that are shared among the population and vulnerable to cheating by nonproducing members of the population. Because the QS system of the opportunistic pathogenPseudomonas aeruginosaregulates several public goods, it can serve as a model for studying cooperation. Bacteria also commonly regulate antimicrobial production through QS. In this study, we focused on the hypothesis that QS-regulated antimicrobials may be important forP. aeruginosato protect against cheating by another bacterial species,Burkholderia multivorans.We assessed laboratory cocultures ofP. aeruginosaandB. multivoransand investigated the importance of threeP. aeruginosaQS-regulated antimicrobials, hydrogen cyanide, rhamnolipids, and phenazines, for competition. We found thatP. aeruginosadominates cocultures withB. multivoransand that the three antimicrobials together promoteP. aeruginosacompetitiveness, with hydrogen cyanide contributing the greatest effect. We show that these QS-regulated antimicrobials are also critical forP. aeruginosato preventB. multivoransfrom cheating under nutrient conditions where both species require aP. aeruginosaquorum-regulated protease for growth. Together our results highlight the importance of antimicrobials in protecting cooperating populations from exploitation by other species that can act as cheaters.IMPORTANCECooperative behaviors are threatened by social cheating, wherein individuals do not produce but nonetheless benefit from shared public goods. Bacteria have been shown to use several genetic mechanisms to restrain the emergence of cheaters from within the population, but public goods might also be used by other bacterial species in the vicinity. We demonstrate that a public good produced byPseudomonas aeruginosacan be used by another species,Burkholderia multivorans, to obtain carbon and energy. We also show thatP. aeruginosaantimicrobials that are coregulated with the public good prevent invasion by the cheating species. Our results demonstrate that cross-species cheating can occur and that coregulation of public goods with antimicrobials may stabilize cooperative behavior in mixed microbial communities.

scholarly journals Enforced specialization fosters mutual cheating and not division of labour in the bacterium Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Subham Mridha ◽  
Rolf Kuemmerli
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Natural Selection ◽  
Public Goods ◽  
Public Good ◽  
Experimental System ◽  
Division Of Labour ◽  
Iron Limitation ◽  
Mixing Ratios ◽  
Negative Frequency Dependent Selection ◽  
Complementary Goods

A common way for bacteria to cooperate is via the secretion of beneficial public goods (proteases, siderophores, biosurfactants) that can be shared among individuals in a group. Bacteria often simultaneously deploy multiple public goods with complementary functions. This raises the question whether natural selection could favour division of labour where subpopulations or species specialise in the production of a single public good, whilst sharing the complementary goods at the group level. Here we use an experimental system, where we genetically enforce specialization in the bacterium Pseudomonas aeruginosa with regard to the production of its two siderophores, pyochelin and pyoverdine, and explore the conditions under which specialization can lead to division of labour. When growing pyochelin and pyoverdine specialists at different mixing ratios in various iron limited environments, we found that specialists could only successfully complement each other in environments with moderate iron limitation and grow as good as the generalist wildtype but not better. Under more stringent iron limitation, the dynamics in specialist communities was characterized by mutual cheating and with higher proportions of pyochelin producers greatly compromising group productivity. Nonetheless, specialist communities remained stable through negative frequency-dependent selection. Our work shows that specialization in a bacterial community can be spurred by mutual cheating and does not necessarily result in beneficial division of labour. We propose that natural selection might favour fine-tuned regulatory mechanisms in generalists over division of labour because the former enables generalists to remain flexible and adequately adjust public good investments in fluctuating environments.

scholarly journals Ecosystem Services Valuation for the Sustainable Land Use Management by Nature-Based Solution (NbS) in the Common Agricultural Policy Actions: A Case Study on the Foglia River Basin (Marche Region, Italy)

Land ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Elisa Morri ◽  
Riccardo Santolini
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Public Goods ◽  
River Basin ◽  
Agricultural Land ◽  
Agricultural Practices ◽  
Land Use Management ◽  
Positive Effects ◽  
Human Wellbeing

Agricultural land is a very important ecosystem that provides a range of services like food, maintenance of soil structure, and hydrological services with high ecological value to human wellbeing Ecosystem Services (ESs). Understanding the contribution of different agricultural practices to supply ESs would help inform choices about the most beneficial land use management. Nature-based Solutions (NbS) are defined by IUCN (International Union for Conservation of Nature) as actions to protect, sustainably manage and restore natural or modified ecosystems, which address societal challenges (e.g., climate change, food and water security, or natural disasters) effectively and adaptively, while simultaneously providing human wellbeing and biodiversity benefits. Some actions farmers can implement in the new Rural Development Programs (RDP 2021–2022 and 2023–2027) can be considered as NbS and could affect the quantity, quality, and time of some ESs related to water regulation and supply, N adsorption and erosion protection. This study aims to evaluate these ESs in different scenarios in the upper Foglia river basin (Italy) and at a local scale (farming), and to highlight the issue to compensate farmers for the production of public goods which benefit the whole society (ESs) by the implementation of RDP’s actions. These scenarios highlight how actions have positive effects on ecosystem services and their economic value related to land use management, on maintaining agricultural practices by integrating Water Frame Directive (2000/60/EC), Directive 2007/60/EC on the management of flood risks and highlighting the potential role of farmers in a high diversity landscape. This study highlights a new way to evaluate the processes of natural capital in the production of public goods, which benefits the whole society (ESs), by emphasizing the economic and environmental role of farmers in producing them and putting on the table data to trigger a PES (Payment for Ecosystem Services) mechanism. To facilitate decision making, robust decision support tools are needed, underpinned by comprehensive cost-benefit analyses and spatially modeling in which agriculture can be a strategic sector to optimize food production and environmental protection in harmony with the Farm to Fork (F2F) strategy.

scholarly journals Siderophores drive invasion dynamics in bacterial communities through their dual role as public good versus public bad

2021 ◽  
Author(s):  
Alexandre R. T. Figueiredo ◽  
Özhan Özkaya ◽  
Rolf Kümmerli ◽  
Jos Kramer
Keyword(s):  
Public Good ◽  
Bacterial Communities ◽  
Dual Role ◽  
Invasion Dynamics

scholarly journals Adaptation to public goods cheats in Pseudomonas aeruginosa

2017 ◽  
Vol 284 (1859) ◽  
pp. 20171089 ◽  
Author(s):  
Siobhán O'Brien ◽  
Adela M. Luján ◽  
Steve Paterson ◽  
Michael A. Cant ◽  
Angus Buckling
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Public Goods ◽  
Public Good ◽  
High Frequency ◽  
Iron Acquisition ◽  
Siderophore Production ◽  
Fitness Costs ◽  
Negative Effects ◽  
Evolutionary Response ◽  
Selection For

Cooperation in nature is ubiquitous, but is susceptible to social cheats who pay little or no cost of cooperation yet reap the benefits. The effect such cheats have on reducing population productivity suggests that there is selection for cooperators to mitigate the adverse effects of cheats. While mechanisms have been elucidated for scenarios involving a direct association between producer and cooperative product, it is less clear how cooperators may suppress cheating in an anonymous public goods scenario, where cheats cannot be directly identified. Here, we investigate the real-time evolutionary response of cooperators to cheats when cooperation is mediated by a diffusible public good: the production of iron-scavenging siderophores by Pseudomonas aeruginosa . We find that siderophore producers evolved in the presence of a high frequency of non-producing cheats were fitter in the presence of cheats, at no obvious cost to population productivity. A novel morphotype independently evolved and reached higher frequencies in cheat-adapted versus control populations, exhibiting reduced siderophore production but increased production of pyocyanin—an extracellular toxin that can also increase the availability of soluble iron. This suggests that cooperators may have mitigated the negative effects of cheats by downregulating siderophore production and upregulating an alternative iron-acquisition public good. More generally, the study emphasizes that cooperating organisms can rapidly adapt to the presence of anonymous cheats without necessarily incurring fitness costs in the environment they evolve in.

scholarly journals The contribution of prosecutors to the failure of damage claims of victims in war crimes trials at the Court of Bosnia and Herzegovina

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Dr.Sc. Goran Šimić ◽  
MA. Ena Kazić
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Bosnia And Herzegovina ◽  
War Crimes ◽  
Limited Resources ◽  
Criminal Prosecution ◽  
Procedure Code ◽  
War Crimes Trials ◽  
Damage Claims

According to definition and laws, the role of the prosecutor is to represent public goods. In the cases of war crimes, that public good is not exhausted with criminal prosecution of the perpetrators of the criminal offences, but it also covers reparation of the damage to the victims. This is not part of the judiciary praxis of Bosnia and Herzegovina. Although there is a clear obligation to collect evidence that would support damage claims of the victims as prescribed in the Criminal Procedure Code of Bosnia and Herzegovina (CPCBH), in reality prosecutors fail to fulfill this obligation. In few cases, settled before the Court of Bosnia and Herzegovina, where the court had awarded compensation to the victims of war crimes, merits for that are to be given to the victims who have, on their own initiative and with their own limited resources, hired attorneys and other experts who acted as prosecutors. To prevent this from happening in the future, having in mind hundreds of potential pending cases (with thousands of victims) waiting for trial, this practice needs to be changed. In that way, although mostly only declaratory in nature in criminal codes and during war crimes trials, more “realistic” and “humane” justice could be achieved for those directly affected by these crimes.

scholarly journals Inequality, role reversal and cooperation in multiple group membership settings

2021 ◽  
Author(s):  
Andreas Lange ◽  
Jan Schmitz ◽  
Claudia Schwirplies
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Group Membership ◽  
Role Reversal ◽  
Global Public Good ◽  
Local Public Good ◽  
The Public ◽  
Multiple Group ◽  
Income Disparities

AbstractWe investigate the role of endowment inequality in a local and global public goods setting with multiple group membership and examine the effect of temporal role reversal on cooperation decisions. Subjects can contribute to a global public good which benefits all subjects and two local public goods which benefit only subjects of either their own group or the group of the other endowment type. Endowment inequality per-se decreases contributions of subjects with a high endowment to the global public good, but increases cooperation of subjects with a low endowment on their local public good, thereby aggravating income disparities. Exogenously induced role reversal for several periods affects cooperation behavior of subjects with a high endowment positively and induces them to contribute more to the global good. Cooperation in unequal environments thus appears to be more stable when all parties have experienced the public goods game from the disadvantageous perspective.

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