Microbial Ecology/Communities 3 Flashcards
Steps from taking a sample of skin microbes to getting a phylogenetic tree from it
- Collection of skin microbes
- DNA isolation from sample
- PCR amplification of bacterial 16s rRNA gene
- Sequencing of 16s rRNA genes
- Creation of phylogenetic tree
What is single cell sequencing
Isolation of single cells from different environments
What leaves a “fingerprint” behind
A unique community of microbes on the skin of finger
What plays a role in the link between red meat consumption & heart disease
Gut microbes
What to do with our diet can have an immediate & dramatic impact on makeup of microbiome
Fat & fiber intake
What does the compound found in red meat metabolise to become & what does this compound promote
Gut microbiome can metabolise a compound in red meat to form TMAO (trimethylamine -N- oxide).
This has a known role in promoting cardiovascular disease
Monitoring the gut microbiome can be used as an early detection of what disease
Crohn’s disease
When does Crohn’s disease occur
When there is redness, swelling & sores along the digestive tract
Symptoms of crohns disease (9)
- Abdominal pain, often in lower right area
- Diarrhea, sometimes bloody
- Rectal bleeding
- Weight loss
- Fever
- Joint pain
- Nausea / vomiting
- Anal fissure
- Rashes
What is the principal of metagenomics
DNA is cloned from microbial community & sequenced.
Detects as many genes as possible.
Yields picture of gene pool in environment.
Assesses phylogenetic & metabolic diversity of an environment.
2 probiotic bacteria
Lactobacilli & bifidobacteria
What can be said about the microbiota of people in long stay care compared to that of community dwellers
The microbiota of those in long stay care in significantly less diverse
What does the loss of microbiota associated w older people correlate to in terms of their health
Increased frailty
What diet promotes gut bacteria linked to healthy ageing in older people
The Mediterranean diet
Principle of industrial microbiology
Uses microorganisms grown on a large scale to produce products/ carry out chemical transformations
What are the major organisms used in industrial micro
Bacteria & fungi
What is the major bacteria used in industrial micro
Streptomyces
What kind of bacteria are Streptomyces
- gram positive
- aerobic
What do Streptomyces form
A thread like net called a mycelium.
This bears chains of spores at maturity.
What antibiotics do Streptomyces, Streptomyces rimosus in particular, produce
Oxytetracycline
And other Tetracycline antibiotics
What are the properties of a useful industrial microbe (6)
- Produces spores
- Can be easily inoculated
- Grows rapidly on a large scale in inexpensive medium
- Produces product quickly
- Should not be pathogenic
- Amenable to genetic manipulation
What are some microbial products of industrial interest (6)
- Microbial cells
- Enzymes
- Antibiotics
- Steroids
- Food additives e.g: amino acids
- Commodity chemicals e.g: ethanol, citric acid
When is the primary metabolite produced and give an example of one
During exponential growth phase (phase where population doubles every 20 mins)
Alcohol
When is the secondary metabolite produced and give an example of one
Produced during stationary phase (phase when growth stops)
Penicillin
What kind of metabolites are antibiotics
Secondary metabolites
Characteristics of secondary metabolites (5)
- Not essential for growth
- Formation depends on growth conditions
- Produced as a group of related compounds -> tetracyclines/ penicillans
- Significantly overproduced
- Often produced by spore forming microbes during sporulation
Why do Streptomyces produce tetracyclines
For an advantage in environment compared to other bacteria
Where does the micro process take place in industrial micro
Fermenter
Are most large scale processes aerobic or anaerobic
Most are aerobic processes
What supply O2 in large scale fermenters
Impellers & spargers supply O2
Why is steam added in to the fermenters
For sterilisation
Why is sterile air added in to the fermenters
So the bacteria has oxygen for reaction
What environmental factors must be controlled and altered in industrial fermenters
- Temp
- pH
- Cell mass
- Nutrients
- Product concentration
Process of scaling up industrial process
Flask -> lab fermenter -> pilot plant -> commercial fermenter
Overall fermentation process
- Design
- Lab development
- Pilot
- Full scale production
(testing needs to be done to go from design to lab development, redesign for improvement, scale up from lab to pilot, industrial implementation from pilot to full scale production, scale down for troubleshooting if needed)
What can continuous fermentation be used for the production of
Single Cell Protein (SCPs) from yeast & bacteria for use in human & animal feed
What bacteria is used for the production of SCPs
Fusarium venenatum
Why are the fermenters making SCPs heat treated
To reduce nucleic acid content
