Module 7: Microbial Ecology and Microbial Communities

Microbial Ecology

1. Autecological Investigation:

Key Divisions of Microbial Ecology

1. _________________:

   • Focuses on the life history and behavior of individual microbial populations within an ecosystem.

2. Synecological Investigation:

   • Examines the interactions and relationships among different microbial populations within a community.

1. Synecological Investigation

Key Divisions of Microbial Ecology

1. Autecological Investigation:

   • Focuses on the life history and behavior of individual microbial populations within an ecosystem.

2. _________________:

   • Examines the interactions and relationships among different microbial populations within a community.

• Community

Microbial Communities and Assemblages

• _____________:

  • The highest unit in an ecological hierarchy, composed of various populations interacting within a habitat.

  • Represents the totality of microbial populations in a specific location.

• Guild:

  • A subset of the community, where populations share similar resource utilization strategies.

• Guild

Microbial Communities and Assemblages

• Community:

  • The highest unit in an ecological hierarchy, composed of various populations interacting within a habitat.

  • Represents the totality of microbial populations in a specific location.

• _____________:

  • A subset of the community, where populations share similar resource utilization strategies.

• Autochthonous

Microbial Population Types

• _____________:

  • Indigenous microorganisms that are well-adapted to their habitat and can grow, survive, and metabolize within their environmental niches.

• Allochthonous:

  • Transient microorganisms introduced from external sources; they typically do not establish long-term populations.

• Allochthonous

Microbial Population Types

• Autochthonous:

  • Indigenous microorganisms that are well-adapted to their habitat and can grow, survive, and metabolize within their environmental niches.

• ____________:

  • Transient microorganisms introduced from external sources; they typically do not establish long-term populations.

Population Selection and Strategies

___________________

Microorganisms employ two primary strategies for survival and reproduction:

1. r-Strategists:

   • Reproduce rapidly with high population growth rates.

   • Adapted to unstable environments with abundant resources.

   • Examples: Opportunistic microorganisms that colonize new or disturbed habitats.

2. K-Strategists:

   • Adapt physiologically to stable environments with limited resources.

   • Focus on survival and efficiency over rapid reproduction.

   • Examples: Microorganisms that degrade humus in soil.

   • Winogradsky's Contribution:

     • Zygomenous (opportunistic) soil populations align with r-strategists.

     • Autochthonous (humus-degrading) populations align with K-strategists.

1. r-Strategists

Population Selection and Strategies

Microorganisms employ two primary strategies for survival and reproduction:

1. _____________:

   • Reproduce rapidly with high population growth rates.

   • Adapted to unstable environments with abundant resources.

   • Examples: Opportunistic microorganisms that colonize new or disturbed habitats.

2. K-Strategists:

   • Adapt physiologically to stable environments with limited resources.

   • Focus on survival and efficiency over rapid reproduction.

   • Examples: Microorganisms that degrade humus in soil.

   • Winogradsky's Contribution:

     • Zygomenous (opportunistic) soil populations align with r-strategists.

     • Autochthonous (humus-degrading) populations align with K-strategists.

1. K-Strategists

Population Selection and Strategies

Microorganisms employ two primary strategies for survival and reproduction:

1. r-Strategists:

   • Reproduce rapidly with high population growth rates.

   • Adapted to unstable environments with abundant resources.

   • Examples: Opportunistic microorganisms that colonize new or disturbed habitats.

2. ________________:

   • Adapt physiologically to stable environments with limited resources.

   • Focus on survival and efficiency over rapid reproduction.

   • Examples: Microorganisms that degrade humus in soil.

   • Winogradsky's Contribution:

     • Zygomenous (opportunistic) soil populations align with r-strategists.

     • Autochthonous (humus-degrading) populations align with K-strategists.

• Colonization

Colonization and Succession in Microbial Communities

Microbial communities undergo changes over time, influenced by environmental factors and interactions:

• _____________:

  • Microbial populations occupy niches within the ecosystem.

• Succession:

  • Sequential replacement of microbial populations over time, driven by adaptation and ecological interactions.

  • Types of Succession:

    • Primary Succession:

      • Occurs in previously uninhabited habitats.

    • Secondary Succession:

      • Follows a disturbance or catastrophic event in an already colonized habitat.

• Stable Community:

  • The endpoint of succession, characterized by a balanced and persistent assemblage of populations.

• Succession

Colonization and Succession in Microbial Communities

Microbial communities undergo changes over time, influenced by environmental factors and interactions:

• Colonization:

  • Microbial populations occupy niches within the ecosystem.

• ______________:

  • Sequential replacement of microbial populations over time, driven by adaptation and ecological interactions.

  • Types of Succession:

    • Primary Succession:

      • Occurs in previously uninhabited habitats.

    • Secondary Succession:

      • Follows a disturbance or catastrophic event in an already colonized habitat.

• Stable Community:

  • The endpoint of succession, characterized by a balanced and persistent assemblage of populations.

• Stable Community

Colonization and Succession in Microbial Communities

Microbial communities undergo changes over time, influenced by environmental factors and interactions:

• Colonization:

  • Microbial populations occupy niches within the ecosystem.

• Succession:

  • Sequential replacement of microbial populations over time, driven by adaptation and ecological interactions.

  • Types of Succession:

    • Primary Succession:

      • Occurs in previously uninhabited habitats.

    • Secondary Succession:

      • Follows a disturbance or catastrophic event in an already colonized habitat.

• _____________:

  • The endpoint of succession, characterized by a balanced and persistent assemblage of populations.

• Secondary Succession

• Succession:

  • Sequential replacement of microbial populations over time, driven by adaptation and ecological interactions.

  • Types of Succession:

    • Primary Succession:

      • Occurs in previously uninhabited habitats.

    • ______________:

      • Follows a disturbance or catastrophic event in an already colonized habitat.

• Primary Succession

• Succession:

  • Sequential replacement of microbial populations over time, driven by adaptation and ecological interactions.

  • Types of Succession:

    • _________________:

      • Occurs in previously uninhabited habitats.

    • Secondary Succession:

      • Follows a disturbance or catastrophic event in an already colonized habitat.

1. Allogenic Succession

Mechanisms of Succession

1. Autogenic Succession:

   • Microorganisms modify their habitat, creating conditions for new populations to establish.

2. _____________:

   • Changes driven by external environmental factors rather than microbial activity.

1. Autogenic Succession

Mechanisms of Succession

1. ________________:

   • Microorganisms modify their habitat, creating conditions for new populations to establish.

2. Allogenic Succession:

   • Changes driven by external environmental factors rather than microbial activity.

• Autotrophic Succession

Autotrophic vs. Heterotrophic Succession

• ______________________:

  • Driven by energy from sunlight.

  • Occurs in ecosystems where gross photosynthesis (P) exceeds community respiration (R) initially.

  • As succession progresses, the P/R ratio approaches 1, indicating stabilization.

  • Example: Young pioneer communities.

• Heterotrophic Succession:

  • Energy flow decreases over time due to insufficient organic matter input.

  • Often temporary, as stored energy becomes depleted, leading to community extinction.

  • Can lead to a stable community if there is a continuous external input of organic matter (allochthonous material).

  • Example: Decomposition processes.

• Heterotrophic Succession

Autotrophic vs. Heterotrophic Succession

• Autotrophic Succession:

  • Driven by energy from sunlight.

  • Occurs in ecosystems where gross photosynthesis (P) exceeds community respiration (R) initially.

  • As succession progresses, the P/R ratio approaches 1, indicating stabilization.

  • Example: Young pioneer communities.

• __________________:

  • Energy flow decreases over time due to insufficient organic matter input.

  • Often temporary, as stored energy becomes depleted, leading to community extinction.

  • Can lead to a stable community if there is a continuous external input of organic matter (allochthonous material).

  • Example: Decomposition processes.