AND SOLUTIONS RATED A+
✔✔Anoxic zone (bottom) - ✔✔No oxygen;
sulfate-reducing bacteria and photosynthetic sulfur bacteria.
✔✔Microbial Ecology as a Discipline (Biodiversity) - ✔✔• Identify
• Quantify
• Isolate
✔✔Microbial Ecology as a Discipline (Microbial Activity) - ✔✔• Measure metabolic
processes of microbes in their habitats
✔✔Microbial Ecology as a Discipline (Culture Dependent) - ✔✔• Only way to fully
characterize a microbe
• Enrichment approach
✔✔Microbial Ecology as a Discipline (Culture Independent) - ✔✔• 99% of all microbes
can't be cultured
• Alternative methods of characterization
✔✔Culture Independent Analysis: - ✔✔DNA: Genomics
RNA: Transcriptomics
Protein: Proteomics
Small Molecules: Metabolomics
✔✔Culture based methods -Enrichment - ✔✔-Mimic organisms environmental
conditions
-Consider factors such as what you want to exclude (PH, temp., etc)
✔✔Genomics: - ✔✔What the cells have the potential to do
✔✔Transcriptomics: - ✔✔What the cells are trying to do
✔✔Proteomics: - ✔✔What the cells are doing
✔✔Metabolomics: - ✔✔Current state of the cell
✔✔Microbial Interactions: (2) - ✔✔-microbe-invertebrate
-microbe-microbe
✔✔Euprymna scolopes: - ✔✔-cephalopod
-mature in 80 days
-nocturnal
, -camouflage mechanisms
(Ink, burying,bioluminescence)
✔✔Euprymna scolopes: Predator? - ✔✔Hawaiian Monk Seal
✔✔Euprymna—Aliivibrio symbiosis - ✔✔-Mutualistic relationship
-Horizontally transmitted between generations
✔✔Challenges to horizontal transmission? Scolopes - ✔✔-Host must be able to recruit,
enrich, and harvest its microbial partner
-Stability
✔✔Role of immune system-symbiosis (scolopes) - ✔✔Partner must be able to tolerate
multiple environments
(Niche switch)
✔✔Benefits of symbiosis for Euprymna scolopes: - ✔✔-Animal host (E.scolopes)
-Counter illumination during nocturnal activity
-Control intensity-resemble moonlight
Bacterial Symbiont (A. Fischeri)
-Nutrient rich environment
✔✔Diel Cycle: Euprymna scolopes: - ✔✔Dawn: squid bury themselves in sand
Expel-95% of all symbionts
Night: Active with peak population
✔✔What is the benefit of expulsion in Euprymna scolopes? - ✔✔-Flushes out bacteria
each morning
-keeps the light-organ bacteria balanced
-maintains strong,efficient light-producing bacteria
-prevents buildup of harmful bacterial waste
Protects squid tissues/ keeps symbiosis stable
✔✔Establishing the population of scolopes: - ✔✔-Symbionts enter through pores and
move into crypts to colonize the light organ
-Cilia facilitate movement from pores to crypts
-Peptidoglycan detection triggers mucus production
✔✔Symbiont Specificity (Euprymna - Aliivibrio) - ✔✔-Only A. fischeri colonize light
organ
-All bacteria can trigger mucus production
•Only G- cells can accumulate in the mucus