Fermentation Flashcards
What is fermentation
Fermentation is any process catalyzed by microorganisms to produce a product.
What are some examples of food products produced through fermentation?
belacan, budu, pekasam, yogurt
What role do microorganisms play in fermentation?
Microorganisms produce primary and secondary metabolites like industrial chemicals, antibiotics, pigments, enzymes, and amino acids.
What is subtilisin, and what is its industrial application?
Subtilisin is a protease enzyme derived from Bacillus subtilis, used in laundry detergents to break down and remove protein stains from clothing.
Differentiate between aerobic and anaerobic fermentation.
Aerobic fermentation, oxygen is supplied, the contents are agitated using an impeller and sterilized air, to maintain oxygen levels.
Anaerobic fermentation operates without oxygen, using milder aeration only for initial growth phases and requiring sufficient agitation for mixing and maintenance of temperature.
What are some industrial applications of amylase?
used in the corn syrup industry to prepare high-maltose syrup, extract juices in the food industry, act as a detergent in laundry and leather industries, and improve fermentation rates in baking.
What enzyme is used to produce high-fructose corn syrup (HFCS), and how does it work?
Glucose isomerase (also called xylose isomerase) converts glucose into fructose, creating high-fructose corn syrup. It also helps remove oxygen from soft drinks, stabilizes flavors, and controls color in wines.
How does lactase benefit lactose-intolerant individuals?
Antifrozen
breaks down lactose into glucose and galactose,
Used in produce ice cream and frozen desserts.
What is the main advantage of using enzymes in industrial processes?
Enzymes provide high selectivity, allowing for precise targeting of specific substrates. They are non-toxic and non-corrosive, function well at ambient temperatures, and significantly lower energy requirements.
What are the most important industrial products made from primary metabolites in fermentation?
Key primary metabolites include amino acids, nucleotides, vitamins, solvents, and organic acids. These are often made by microbial fermentation because it is cost-effective and produces active biological isomers.
What are lipases, and what is their role in industrial applications?
Lipases catalyze the creation and breakdown of ester bonds, acting at oil-water interfaces.
Use as catalyst in production of fine chemicals
Use as detergent in laundries and leather industry.
What is medium-chain triglyceride (MCT), and where is it commonly used?
MCTs are flavorless, stable fats with quick metabolism,
used as an energy source for athletes, in low-calorie foods, and as carriers in food, cosmetic, and pharmaceutical industries.
How is the enzyme response surface methodology (RSM) used in fermentation?
RSM is a statistical method for optimizing fermentation conditions by evaluating interactive effects between variables,
which reduces the number of experiments needed and helps find optimal conditions efficiently.
What are the advantages of enzymes in green environmental reactions?
Enzymes are environmentally friendly, non-toxic, reduce energy use by working under mild conditions, and show high selectivity, making them ideal for sustainable industrial applications.
What is kojic acid, and what are its uses?
Kojic acid has antibacterial, antifungal,
and skin-lightening properties used in cosmetics
and as an anti-browning agent in food. Its derivatives are formulated to increase stability of products.
What are chiral drugs, and why are they significant in fermentation?
Chiral drugs are compounds with two mirror-image forms, where only one is often effective. Using specific enzymes in fermentation allows for selective production of the desired, non-toxic isomer, enhancing drug safety.
How does aerobic fermentation differ from anaerobic fermentation in terms of oxygen requirements and equipment used?
Aerobic fermentation requires oxygen, so air is continuously supplied through an impeller in a closed fermenter.
Anaerobic fermentation does not require oxygen, although mild aeration may be needed initially for microbial growth. Anaerobic fermenters do not need intense agitation or aeration once the initial phase is complete.
Why is agitation important in aerobic fermentation, and how is it achieved?
To maintain a uniform environment and ensure oxygen is distributed throughout the medium.
This is achieved through the use of an impeller, which stirs the contents and facilitates the even mixing of oxygen, nutrients, and microbes.
What are the conditions needed for anaerobic fermentation, and how are they maintained?
Anaerobic fermentation requires a low-oxygen or oxygen-free environment. This is maintained by limiting aeration and reducing agitation after the initial growth phase
What are the primary factors that affect microbial growth in fermentation processes?
Microbial growth in fermentation is influenced by factors such as temperature, pH, nutrient availability, oxygen levels (for aerobic fermentation), and agitation speed.
What are the main types of fermenters used in industrial applications?
Batch
Continuous
Fed-Batch
Air-Lift
Tower
fed-batch fermenter
A fed-batch fermenter allows for substrates to be added gradually throughout the fermentation process. This helps control microbial growth rates and product formation.
air-lift fermenters
Air-lift fermenters are useful because they provide an efficient way to aerate the culture without using propeller, which can be too harsh for some organisms. They operate by introducing air bubbles at the bottom, which bubbles do the agitation, enhancing oxygen transfer.
