Lecture 8 Flashcards
Advantages of genetic manipulation:
- Improved carbohydrate utilization
- Increase ethanol
- Temperature tolerance
- Flocculence changes
Advantages of genetic manipulation (continuation):
- Altered synthesis of organoleptics (changes flavor or aroma)
- Inhibition of contamination
- Novel By-products (yeast producing ethanol and then vitamin B)
- Low ethanol beers
- Post fermentation products (animal feed)
4 ways genetic mutation can occur?
- Mutagenesis (mutation)
- Rare mating
- Protoplast fusion
- Transformation
Types of mutations:
- Spontaneous: single nucleotide change
- Chemical: single nucleotide change
- UV: errors in DNA replication
- Ionizing Radiation: Deletion and translocations
Benefits of mutations?
-Increases the resistance to a toxin
-Enhances the production of substance
Method for improving Beta-pinene bioconversion
Mutagenesis and adaptation of Chrysosporium pannorum
How the solve the problem of yeast being sensitive to antibiotics?
- Spread High No. onto the Agar and antibiotic it will spot spontaneous resistance.
- By treating the cell with UV before spreading, it will increase the chance of selecting.
What is rare mating?
It is a type of yeast sexual reproduction in which high densities of non mating cultures are mixed together until the spontaneously mate and true hybrids are formed.
Way of manipulating brewing strains?
Single chromosome transfer
-one chromosome is transferred from one strain to another
What is a protoplast?
It is a cell that doesn’t have a cell wall material
What is a spheroplast?
It is a membrane that is covered in cell wall fragments
Ways that a protoplast can be isolated?
Mechanically
Metabolically
Enzymatically
Factors affecting protoplast stability?
- Membrane damage
- Isotonic buffer (sugar alcohol or salt)
- Lytic preparations
- pH (if too low lysis will occur)
- Osmotic concentration
- Metabolism
2 types of protoplast reversion?
- Cell wall regeneration
- Reversion to cell cycle
