Lecture 20 Symbiosis and Intercellular Interactions Flashcards
Definition of Biofilm
Aggregates of microbiomes adherent to each other or surfaces, embedded in extracellular polymeric substances (EPS)
Importance of Biofilms
Primary mode of microbial life ~ 80% of microbes reside in biofilms
Characteristics of Biofilm
-Multispecies
-complex interactions (intercellular) can be positive or negative
-emergent properties:
(antibiotic resistance, quorum sensing, dessication)
Can be advantageous or detrimental…
* Wastewater treatment
* Ship hulls
* Drinking water pipes or oil pipelines
* Medical implants
* Human/ animal skin
What are the types of interactions that occur in biofilm?
- Symbiosis: stable association between two different species
- Variation: Beneficial, antagonistic, one way/two way, obligate/facultative
- Endosymbiont: Organism living inside another organism
Define Syntrophy
Mutualistic interaction
involving hydrogen producers (fermenters) and hydrogen consumers (methanogens).
Rumen Microbiome consist of?
Bacteria, archaea, fungi, protists – esp. fermenters, methanogens, acetogens
What enzymes are first encountered in the abomasum?
Ruminant enzymes
Which symbiont do corals obtain food from?
obligate phototrophic zooxanthellae symbionts
Explain the significance of corals and their microbiota.
Corals obtain food from obligate phototrophic zooxanthellae symbionts and have additional symbiotic relationships with bacteria, especially nitrogen fixers.
Under stress, corals produce antimicrobial compounds and may eject their symbionts, leading to bleaching.
Bleaching is a result of algal symbiont loss, containing their pigment.
Info on Bdellovibrio
Predator of gram-negative bacteria
alternates between a predatory phase and an intracellular reproductive phase.
It utilizes host contents for carbon, nitrogen, and energy sources
growing into a filament that undergoes multiple fission.
Describe the role of LAB (Lactobacillus, Leuconostoc spp.) in the food and beverage industry.
LAB is involved in homo and heterolactic fermentation, normal in the human gut, and crucial in the food industry for fermented products.
Lactobacillus (kimchi, yogurt) Leuco (wine and kombucha)
What is a holobiont?
A host organism and its microbes forming a single functional unit.
What functions does the human microbiota perform?
The human microbiota, estimated to be as abundant as 10x more than human cells
Contributes to functions such as immune system development, digestion, gut physiology, and brain health.
What factors prevent infection by microbiota?
The delicate homeostasis between humans and their microbia is controlled by their host genotype, microbiome composition, and environmental factors (diet,antibiotics, etc)
The transition from commensal/mutualist to a pathogen is limited by host immunity and a limited number of genetic changes to the microbe
How is synotrophy related to rumen microbiome?
Syntrophy takes place in the rumen biome to degrade organic matter.
In the rumen microbiome, it is the mutualistic interaction between hydrogen producers (fermenters) and hydrogen scavengers (methanogens) to continue fermentation.
