Microbial Symbioses

These flashcards cover key concepts from the lecture on microbial symbioses, including definitions, relationships, and examples.

Symbioses

Close long-term relationships between organisms.

Mutualism

A type of symbiotic relationship where both species benefit.

Parasitism

A type of symbiotic relationship where one species benefits at the expense of another.

Commensalism

A type of symbiotic relationship where one species benefits and the other is neither helped nor harmed.

Antagonism

A type of relationship where one organism is harmed by the presence of another.

Biofilms

Assemblages of bacterial cells adhered to a surface and enclosed in an adhesive matrix.

Extracellular polymeric substance (EPS)

Long-chain sugar macromolecules that form a gel-like layer in biofilms.

Transparent exopolymer particles (TEP)

Gel-like particles of acidic polysaccharides found in aquatic environments.

Quorum sensing (QS)

A process of communication between bacterial cells that coordinates behavior based on population density.

Legionnaires' disease

A waterborne bacterial infection often associated with biofilm formation.

Rhizobia

N2-fixing bacteria that establish symbiotic relationships with leguminous plants.

N2 fixation

Biological conversion of atmospheric nitrogen (N2) into ammonia (NH3).

Lichens

Symbiotic associations formed between fungi and algae or cyanobacteria.

Endosymbionts

Microorganisms that live inside another organism, forming a symbiotic relationship.

Foregut fermentation

A digestive process where fermentation occurs in a chamber before the small intestine.

Hindgut fermentation

A digestive process that occurs in the cecum or large intestine.

Termite endosymbionts

Microbial symbionts allowing termites to digest cellulose.

Buchnera aphidicola

Endosymbiotic bacteria of pea aphids that synthesize essential amino acids.

Aliivibrio fischeri

Marine bacterium involved in mutualistic symbiosis with Hawaiian bobtail squid.

Symbiodinium

Dinoflagellate that forms a symbiotic relationship with reef-building corals.

Mycorrhizae

Mutualistic associations between plant roots and fungi.

Ectomycorrhizae

Mycorrhizae where fungal cells form a sheath around root tips.

Endomycorrhizae

Mycorrhizae where fungal hyphae penetrate root cells.

Foregut

A digestive chamber in certain herbivorous animals for fermentation before the stomach.

Rumen

A part of the digestive system in ruminants where fermentation of plant material occurs.

Cellulose

A polysaccharide that serves as a structural component in plant cell walls.

Fermentation

Metabolic process converting sugars to acids, gases, or alcohol in anaerobic conditions.

Ruminants

Herbivorous mammals with specialized stomachs for digesting fibrous plant materials.

Volatile fatty acids (VFAs)

Short-chain fatty acids produced by microbial fermentation, serving as an energy source.

Hawaiian bobtail squid

Example of an aquatic invertebrate that forms a mutualistic relationship with A. fischeri.

Defense symbiosis

Symbiotic relationships that provide organisms with protection from predators or pathogens.

Trophic relationships

Connections among organisms based on food sources and energy transfer.

Cellulose breakdown

The process in which microbes degrade cellulose to release glucose.

Nutritional symbionts

Microbial partners in symbiosis that provide nutritional benefits to the host.

Symbiotic associations

Types of interactions between organisms that include mutualism, commensalism, and parasitism.

Aggressive symbiosis

A type of relationship where one organism actively harms another for its benefit.

Microhabitats

Specific environments where organisms live and interact, often influenced by symbiotic relationships.

Obligate symbionts

Symbiotic organisms that cannot survive without their partner.

Facultative symbionts

Symbiotic organisms that can live independently, but benefit from the relationship.

Mycorrhizal networks

Interconnected fungal networks that facilitate nutrient exchange among plants.

Symbiotic interactions

Dynamic relationships among different species, impacting their survival and reproduction.