Lecture 3 Flashcards
3 methods of sequencing uncultivated bacteria?
Environmental samples -> bacteria -> i)Community DNA ii) Single cell isolation
i) a) 16S rRNA gene PCR
i) b) Metagenomics
ii) c) Single-cell sequencing
LOOK AT DIAGRAM
What is the HMP and what did they identify?
The Human Microbiome Project identified the sequencing of uncultivated bacteria as a crucial unmet goal
Single-cell sequencing allows genome recovery from species that are distantly related to current isolates and provides new key reference genomes to help characterise healthy and disease states
(Compare single cell genome w reference genome)
What leaves a fingerprint?
The unique community of microbes on the skin
Gut microbiome and red meat
The gut microbiome can metabolize a compaound in red meat resulting in the formation of a diff compound, TMAO (trimethylamine-N-oxide) which has a known role in promoting cardiovascular disease
In our diet what impacts the makeup of our microbiome immediately and dramatrically?
Fat and fiber
Alterations in the gut microbiome?
Can have a direct effect on colon cancer
What affect does the gut microbiomes own circadian rhythm have on us?
A metabolite produced by these bacteria can influence our own circadian rhythms
A high fat diet can alter the microbiome circadian rhythm, suggesting a link between our diet, the gut microbiome and our circadian clocks
What can monitoring the gut microbiome be used to detect early?
Crohns disease and can also be used to monitor effectiveness of various treatments
What is Crohns disease?
Occurs when there is redness and swelling inflammation and sores along your digestive tract
Part of diseases known as inflammatory bowel disease
What is environmental genomics (metagenomics)?
-DNA is cloned from microbial community and sequenced
-Detects as many genes as possible
-Yields picture of gene pool in environment
-Can detect genes that are not amplified by current PCR primers
-Powerful tool for assessing the phylogenetic and metabolic diversity of an environment
Examples of probiotic bacteria?
Lactobacilli and bifidobacteria
Look at intestinal microflora diagram
Elderly people gut microbiota findings?
-The individual microbiota of people in long stay care was significantly less diverse tha´n that of community dwellers
-Loss of microbiota normally associated with older people living in the general community and in those in long-term residential care - correlated with increased fragility
-Results support a relationship between diet, microbiota and health status and indicate a role for diet-driven microbiota alterations in varying rates of health decline upon aging
Mediterranean diet……….
Promotes gut bacteria linked to ‘healthy ageing’ in older people
What is industrial microbiology?
Uses mo typically grown on a large scale, to produce products or carry out chemical transformations
Originated with alcoholic fermentation processes
Used to select for high-yielding microbial variants
What are major organisms used in industrial microbiology?
Bacteria, fungi, streptomyces
What are Streptomyces?
-Gram positive aerobic bacteria
-Form a thread like net called a mycelium that bears chains of spores at maturity
-Branching strands are 0.5 to 1.0 micrometre in diameter
-Produces Oxytetracycline and other tetracycline antibiotics
What are the properties of a useful industrial microbe?
-Produces spores or can be easily inoculated
-Grows rapidly on a large scale in inexpensive medium
-Produces desired product quickly
-Should not be pathogenic
-Amenable to genetic manipulation
What microbe produces the antibiotic Bacitracin?
Bacillus licheniformis
What microbe produces the antibiotic Streptomycin?
Streptomyces griseus
What microbe produces the antibiotic Tetracycline?
Streptomyces rimosus
What microbe produces the antibiotic Penicillin?
Penicillium chryosgenum
What are commodity chemicals?
Inexpensive chemicals produced in bulk e.g ethanol, citric acid etc
What are examples of microbial products of industrial interest?
Microbial cells, enzymes, antibiotics, steroids, food additives (amino acids), commodity chemicals
When are i) Primary metabolite and ii) Secondary metabolite produced and what is an example of each?
-Primary metabolit is produced during exponential growth e.g alcohol
-Secondary metabolite is produced during stationary phase e.g penicillin
Properties of secondary metabolites
-Not essential for growth
-Formation depends on growth conditions
-Produced as a group of related compounds
-often significantly overproduced
-Often produced by spore-forming microbes during sporulation
-Often large organic molecules that require a large no. of specific enzymatic steps for production
How many separate enzymatic steps does it take for the synthesis of tetracycline?
Atleast 72
What is a fermenter?
Where the microbiology process takes place
Any large scale reaction is called a fermentation
Vary in size from 5-500,000L - aerobic and anaerobic fermenters
Large scale fermenters are almost always stainless steel
What supplies oxygen in fermenters?
Impellers(mixer) and spargers - look at image on slides
What is the route of scaling up?
Flask -> laboratory fermenter -> pilot plant -> commercial fermenter
What can continuous fermentation be used for?
The production of Single Cell Protein (SCP) from yeast and bacteria for use as human and animal feed - Mycoprotein
What is used in quorn?
Fusarium venenatum - high protein content - 43-85%
