Fermentation, types of fermentatins pptx

Fermentation is a metabolic process in which microorganisms such as bacteria, yeast, or fungi convert sugars and other organic compounds into alcohol, gases, or acids. This biological process occurs in the absence of oxygen (anaerobic conditions) and is widely used in both food production and industrial applications.

Key Points About Fermentation:
Types of Fermentation:

Alcoholic Fermentation: Yeast or certain bacteria convert sugars (like glucose) into alcohol (ethanol) and carbon dioxide. This process is used in the production of beer, wine, and bread.
Lactic Acid Fermentation: Lactic acid bacteria (e.g., Lactobacillus) convert sugars into lactic acid. This method is used in yogurt, sauerkraut, pickles, and other fermented foods.
Acetic Acid Fermentation: Involves the conversion of alcohol into acetic acid by acetic acid bacteria. It's used to make vinegar.
Stages of Fermentation:

Initiation: Microorganisms are introduced or naturally present in the food begin to metabolize sugars.
Primary Fermentation: Rapid microbial activity leads to the production of primary metabolites like alcohol, lactic acid, or gases.
Secondary Fermentation (optional): Slower phase where additional compounds, such as complex flavors, are formed.
Applications:

Food Preservation: Fermentation can help preserve food by producing acids or alcohol that inhibit the growth of spoilage-causing organisms.
Flavor and Texture Development: It enhances the taste, aroma, and texture of foods. For example, the tangy flavor of yogurt and the bubbly texture of bread are due to fermentation.
Nutritional Enhancement: Some fermented foods are richer in vitamins (like B vitamins) and may aid in digestion, improving gut health.
Industrial Uses: Beyond food, fermentation is used in industries for the production of biofuels (ethanol), pharmaceuticals (antibiotics, insulin), and biodegradable plastics.

Fermentation has been used for centuries, playing a crucial role in food safety, flavor development, and nutrition.Fermentation is an ancient process with broad applications across various sectors. Let's dive deeper into the different aspects of fermentation:

1. Microorganisms Involved in Fermentation
Yeasts: Yeast species like Saccharomyces cerevisiae are essential for alcoholic fermentation. They break down sugars into ethanol and carbon dioxide, which is critical for brewing beer, fermenting wine, and baking bread.
Lactic Acid Bacteria (LAB): These bacteria, such as Lactobacillus, Leuconostoc, and Streptococcus thermophilus, are involved in lactic acid fermentation. They convert carbohydrates into lactic acid, contributing to the sourness in yogurt, kefir, and sauerkraut.
Acetic Acid Bacteria: Genera like Acetobacter and Gluconobacter convert ethanol to acetic acid, crucial for vinegar production.
Molds and Fungi: Certain molds, such as Aspergillus oryzae (used in soy sauce and sake), and fungi like Rhizopus (used in tempeh production) are also key players in fermentation.Fermentation

1. Fermentation •Fermentation is a metabolic process that converts sugar to acids, gases or alcohol. • It occurs in yeast and bacteria, but also in oxygen- starved muscle cells, as in the case of lactic acid fermentation. • Fermentation is also used more broadly to refer to the bulk growth of microorganisms on a growth medium, often with the goal of producing a specific chemical product. • The science of fermentation is known as zymology.

2. Range of Fermentation Processes To Produce Microbial cells or Biomass To Produce Microbial Enzymes To Produce Microbial Metabolites To Produce Recombinant Products To modify a compound which is added to the fermentation (Transformation)

3. Steps to carry out a Fermentation The formulation of media to be used in culturing the process organism during the development of the inoculum and in the production fermenter . The sterilization of the medium, fermenters and ancillary equipment. The production of an active, pure culture in sufficient quantity to inoculate the production vessel. The growth of the organism in the production fermenter under optimum conditions for product formation. The extraction of the product and its purification. The disposal of effluents produced by the process

4. Basic Functions of a Fermenter • The vessel should be capable of being operated aseptically for a number of days and should be reliable in long-term operation and meet the requirements of containment regulations. • Adequate aeration and agitation should be provided to meet the metabolic requirements of the micro-organism. However, the mixing should not cause damage to the organism. • Power consumption should be as low as possible. • A system of temperature control should be provided

5. • A system of pH control should be provided. • Sampling facilities should be provided. • Evaporation losses from the fermenter should not be excessive. • The vessel should be designed to require the minimal use of labour in operation, harvesting, cleaning and maintenance. • Ideally the vessel should be suitable for a range of processes, but this may be restricted because of containment regulations.

6. The vessel should be constructed to ensure smooth internal surfaces, using welds instead of flange joints whenever possible. The vessel should be of similar geometry to both smaller and larger vessels in the pilot plant or plant to facilitate scale-up. The cheapest materials which enable satisfactory results to be achieved should be used. There should be adequate service provisions for individual plants.

7. Hazard Assessment Systems • Once the organism has been allocated to a hazard group, the appropriate containment requirements can be applied. • Hazard group 1 organisms used on a large scale only require Good Industrial Large Scale Practice (GILSP). • Processes in this category need to be operated aseptically but no containment steps are necessary, including prevention of escape of organisms. • If the organism is placed in Hazard group 4 the stringent requirements of level 3 will have to be met before the process can be operated

8. Materials for Body Construction of a Fermenter • In fermentations with strict aseptic requirements it is important to select materials that can withstand repeated steam sterilization cycles. • On a small scale (1 to 30 dm3) it is possible to use glass and/or stainless steel. • Glass is useful because it gives smooth surfaces, is non-toxic, corrosion proof and it is usually easy to examine the interior of the vessel

9. Two basic types of Fermenters • A glass vessel with a round or flat bottom and a top flanged carrying plate. • All vessels of this type have to be sterilized by autoclaving

10. A glass cylinder with stainless-steel top and bottom plates. • Vessels with two stainless steel plates cost approximately 50% more than those with just a top plate. • At pilot and large scale, when all fermenters are sterilized in situ, any materials used will have to be assessed on their ability to withstand pressure sterilization and corrosion and on their potential toxicity and cost

11. Pilot scale and Industrial scale vessels are normally constructed of stainless steel or at least have a stainless-steel cladding to limit corrosion. • The American Iron and Steel Institute (AISI) states that steels containing less than 4% chromium are classified as steel alloys and those containing more than 4% are classified as stainless steels. • Mild steel coated with glass or phenolic epoxy materials has occasionally been used.

12. The corrosion resistance of stainless steel is thought to depend on the existence of a thin hydrous oxide film on the surface of the metal. • The composition of this film varies with different steel alloys and different manufacturing process treatments such as rolling, pickling or heat treatment. • The film is stabilized by chromium and is considered to be continuous, non-porous, insoluble and self healing. • If damaged, the film will repair itself when exposed to air or an oxidizing agent.

13. Wine/Beverage fermenters

14. • The minimum amount of chromium needed to resist corrosion will depend on the corroding agent in a particular environment, such as acids, alkalis, gases, soil, salt or fresh water. • Increasing the chromium content enhances resistance to corrosion, but only grades of steel containing at least 10 to 13% chromium develop an effective film. The inclusion of nickel in high percent chromium steels enhances their resistance and improves their engineering properties.

15. • The presence of molybdenum improves the resistance of stainless steels to solutions of halogen salts and pitting by chloride ions in brine or sea water. • Corrosion resistance can also be improved by tungsten, silicone and other elements. • At this stage it is important to consider the ways in which a reliable aseptic seal is made between glass and glass, glass and metal or metal and metal joints such as between a fermenter vessel and a detachable top or base plate.

16. With glass and metal, a seal can be made with a compressible gasket, a lip seal or an '0' ring. • With metal to metal joints only an '0' ring is suitable. • Nitryl or butyl rubbers are normally used for these seals as they will withstand fermentation process conditions. • A single '0' ring seal is adequate for GILSP and levels 1 and B2, a double '0' ring seal is required for levels 2 and B3 and a double '0' ring seal with steam between the seals (steam tracing) is necessary for levels 3 and B4.

17. Aeration and Agitation • Primary purpose of aeration is to provide microorganisms in submerged culture with sufficient oxygen for metabolic requirements. • While agitation should ensure that a uniform suspension of microbial cells is achieved in a homogenous nutrient medium

18. Agitator (Impellers) • The agitator is required to achieve a number of mixing objectives, e.g. bulk fluid and gas- phase mixing, air dispersion, oxygen transfer, heat transfer, suspension of solid particles and maintaining a uniform environment throughout the vessel contents. • Agitators may be classified as disc turbines, vaned discs, open turbines of variable pitch and propellers.

19. The disc turbine consists of a disc with a series of rectangular vanes set in a vertical plane around the circumference. • The vaned disc has a series of rectangular vanes attached vertically to the underside. • Air from the sparger hits the underside of the disc and is displaced towards the vanes where the air bubbles are broken up into smaller bubbles