Flashcards
What is a biorefinery?
It’s a refinery that converts biomass to energy and other beneficial byproducts (such as chemicals).
Biorefinery is the sustainable processing of biomass into a spectrum of bio-based products (food, feed, chemicals, materials) and bioenergy (biofuels, power and/or heat)
What’s the difference between 1st and 2nd generation ethanol production?
1st generation ethanol production refers to the process of producing ethanol from food crops such as corn, sugarcane, and wheat. In this process, the starch or sugar in the crops is converted into ethanol through fermentation. This process is commonly used for producing ethanol for use as a fuel additive.
2nd generation ethanol production refers to the process of producing ethanol from non-food sources such as agricultural waste, wood chips, and other types of biomass. The process of producing 2nd generation ethanol involves breaking down the cellulose and lignin present in the non-food sources into simple sugars (using enzymes!), which are then fermented to produce ethanol. This process is seen as a more sustainable and environmentally-friendly way of producing ethanol as it does not rely on food crops and makes use of waste materials. However, the technology for producing 2nd generation ethanol is still developing and has not yet reached commercial scale.
What are some strategies for a more robust bioconversion process?
- Less inhibitors (high levels of inhibitory compounds are a problem in both enzymatic hydrolysis and in fermentation)
- Optimized fermentation conditions (is glucose being repressed? are the cells dying?)
- Better strain performance
- Process design
What are some characteristics of an ideal microorganism for industrial bioproduction?
- Broad substrate range
- Robust
- Tolerant to inhibitors
- Efficient producer (TRY)
- Tolerant to high conc. of end product
- Non-pathogenic
- Easy to cultivate
- Easy to recycle
What is bioprospecting?
Biological prospecting (bioprospecting) is the exploration of natural areas in search of native organisms that can be used in commercial products ranging from pharmaceutical and medical technologies to cosmetics and personal care.
Normal workflow: Sample collection -> isolation of microbes -> species identification -> enzyme activity assays/growth characterisation
Pros and cons of classic strain development for
microbial strain improvement
+ Useful for complex, multifactorial traits
+ Useful for non-model organisms (lack of
knowledge on genomics and physiology and/or
genome editing tools)
+ Developed strains are not considered as GMO
(no negative associations, less rigid regulations
for use and disposal)
- Time consuming, labour intensive
- The microorganism must have the prerequisite
genes for developing a specific trait
What is ALE?
“Adaptive Laboratory Evolution”
Experimental improvement of cellular properties exploiting genetic variation in large microbial populations and selection through under a controlled selection pressure for predetermined functions
What are some selection pressures that can be used in ALE?
- Increased temp
- Tolerance to inhibitors, low pH
- Growth on a specific carbon source or nutrient
What are some risks with ALE?
- Contaminations
- Losing traits not selected for
Pros and cons with metabolic engineering
+ Precise, directed changes to the genome:
* Heterologous gene expression
* Homologous gene (up)regulation
* Mutant gene expression
* Gene deletions
- Time consuming, labour intensive
- Creates GMOs
- Requires a lot of information about the organism’s genome
Definition GMO
An organism whose genome has been genetically engineered in the laboratory in order to favour the expression of desired physiological traits or the
production of desired biological products.
If your strain will be used IN food or feed in Europe –
FORGET about metabolic engineering
For production of biofuels, biochemicals or even a food
ingredient – the microorganism is not part of the final product and hence less of a problem
What are some markers that can be used in metabolic engineering?
- Auxotrophic markers (usually mutants in amino acid or nucleotide pathways)
- Dominant markers (e.g., drug resistance - can be recycled)
What are filamentous fungi good for?
They are excellent producers of antibiotics, organic acids and enzymes
Three types of macroscopic morphology of filamentous fungi
- Freely dispersed
- Clumps
- Pellets
Two types of microscopic morphology of filamentous fungi
- Hyphal dimensions
- Segregation
Some problems that filamentous fungi’s morphology can cause
- Wall growth and sporulation
- Growth on internal parts
- Excessive hyphal growth leading to oxygen depletion (can increase agitation!)
Protein synthesis in filamentous fungi
After protein synthesis in the ER and modifications in the golgi, the proteins are transported in vesicles to the cell wall at the hyphal tip where they are secreted through pores
How does enzyme regulation work in filamentous fungi?
Two major events:
- Glucose repression - if glucose is present in the medium, no enzymes will be produced
- Induction from a carbon source related compound - if there is no glucose present and an inducing compound present enzymes can be produces
Which fungal species produce most industrial enzymes?
The Aspergillus and Trichoderma species predominate
What is solid-state fermentation?
It is a cultivation process in which microorganisms grow on solid materials without the presence of free liquid. It is economical! Cannot be used for bacteria since they require high water activity.
What’s the most important factors for a successful cultivation of filamentous fungi?
- inoculum procedure
- medium
- growth conditions
- morphology
Microorganism for plant health
Bacillus spp.
