Biopolymers & Microbial Biotechnology Flashcards
Which of the following statements is FALSE?
a) Polyhydroxyalkonates (PHAs) are common storage polymers in bacteria
b) Polyhydroxybutyrate/polyhydroxyvalerate co-polymers can be used to make biodegradable containers for personal care products
c) Ralstonia eutropha is currently used for the production of a biodegradable thermoplastic called Biopol on an industrial scale
d) Xenobiotics are natually occurring biopolymers that are synthesised by bacteria
e) Highly chlorinated compounds are typically the pesticides which are most resistant to degradation by bacteria
d) Xenobiotics are natually occurring biopolymers that are synthesised by bacteria
Which of the following statements (if any) is TRUE?
a) Primary metabolites are produced during the stationary phase of growth
b) Alcohol is an example of a secondary metabolite
c) Secondary metabolites are typically produced during the exponential phase of growth
d) Penicillin is an example of a primary metabolite
e) None of these statements is true
e) None of these statements is true
Which of the following statements is TRUE?
a) Penicillin is produced by the yeast Saccharomyces cerevisiae
b) Penicillin is produced by the fungus Penicillium chrysogenum
c) Penicillin is produced by the actinomycete Streptomyces penicillica
d) Penicillin is produced by the bacterium Pseudomonas penicillica
e) Secondary metabolites are often large organic molecules that require a very limited number of specific enzymatic steps for production
b) Penicillin is produced by the fungus Penicillium chrysogenum
How much plastic was produced in 2017?
348 million tons
(half of which was not recycled)
Since 2010, how much plastic has entered the oceans?
Between 4.8 and 12.7 M metric tons
Since 2010, how much plastic has entered the oceans?
Between 4.8 and 12.7 M metric tons
Which bacterium produces Bacitracin?
Bacillus licheniformis
Which bacterium produces Streptomycin?
Streptomyces griseus
Which bacterium produces Tetracycline?
Streptomyces rimosus
When is a PRIMARY metabolite produced?
During exponential growth
e.g. alcohol
When is a SECONDARY metabolite produced?
During stationary phase
e.g antibiotics
What are some features 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
Are Secondary metabolites small or large organic molecules?
Large organic molecules
How many enzymatic steps does the synthesis of tetracycline require?
72
What supplies oxygen to fermenters?
Impellers and spargers
What organisms are most antibiotics produced by?
Filamentous fungi or Actinomycetes
What is the Cross-Streak Method in antibiotics?
Used to test new microbial isolates for antibiotic production
What type of antibiotics are Penicillins?
β-lactam antibiotics
What spectrum of activity do Penicillins have?
Broad spectrum
What can repress Penicillin production?
High levels of Glucose
When does Penicillin production begin?
After near-exhaustion of carbon source
What is the structure of basic Penicillin?
- Thiazolidine ring
- β-lactam ring
- Acyl side chain
What are THREE semisynthetic Penicillins?
- Ampicillin
- Amoxycillin
- Methicillin
What are Exoenzymes?
Enzymes that are excreted into the medium instead of being held within the cell
What polymers can Exoenzymes digest?
Insoluble polymers such as cellulose, protein, and starch
Why are enzymes useful as industrial catalysts?
- Produce only one stereoisomer
- High substrate specificity
What type of bacteria are proteases used in laundry detergents isolated from?
Alkaliphillic bacteria
What are Extremozymes?
Enzymes that function at some environmental extreme
What is the optimal growth temperature of Pyrococcus woesei to produce pullanase?
100°C
Denatures at 110°C
What improves the heat stability of Pyrococcus woesei?
Calcium
What are the THREE ways to immobilise an enzyme?
- Bonding of enzyme to a carrier
- Cross-linking of enzyme molecules
- Enzyme inclusion
What TWO examples that Immobilised enzymes are used for?
- Production of lactose free milk
- Glucose testing strips for diabetics
What is Brewing?
The manufacture of alcoholic beverages from malted grains
What type of yeast is Saccharomyces cerevisiae?
- Top fermenting
- Ales
What type of yeasts are S. uvarum and S. carlsbergensis?
- Bottom fermenting
- Lagers
What is Lagering?
A process where lagers are stored at 0-3°C for 4-6 weeks to permit slow secondary fermentation to take place
What type of organism is Brewer’s yeast?
Facultative anaerobes
(can grow in the presence or absence of O2)
At what percentage is glucose repressed?
0.4%
What problems is protein synthesis in a foreign host subject to?
- Degradation by intracellular proteases
- Toxicity to prokaryotic host
- Formation of inclusion bodies
Where do RNA Polymerases bind on an expression vector?
At the Promoter
What gene allows for selection in the host?
Antibiotic Resistance Gene
What part of the expression vector allows the plasmid to replicate?
Origin of Replication (Ori)
What is Somatotropin?
A growth hormone
What does recombinant bovine somatotropin (rBST) do?
Stimulates milk production in cows
