FERMENTATION

Aerobic Anaerobic

FERMENTATION

Adequate aeration

In addition, these fermenters may have a mechanism for stirring and mixing of the medium and cells

Eg: Antibiotics, enzymes, vitamins

Aerobic fermentation

In anaerobic fermentation, a provision for aeration is usually not needed.

Eg: Lactic acid, ethanol, wine

Anaerobic fermentation

Fermentation could be: Batch Continuous

Fermentation

Most fermentations are batch processes.

Nutrients and the inoculum are added to the sterile fermenter and left to get on with it.

Anti-foaming agent may be added.

Once the desired amount of product is present in the fermenter the contents are drained off and the product is extracted.

After emptying, the tank is cleaned & prepared for a new batch.

Batch fermentation

Some products are made by a continuous culture system.

Sterile medium is added to the fermentation with a balancing withdrawal of broth for product extraction.

Continuous fermentation

Fed-batch fermentation is a production technique in between batch and continuous fermentation.

A proper feed rate, with the right component constitution is required during the process.

Fed-batch offers many advantages over batch and continuous cultures.

Fed-batch fermentation

What it is?

In contrast to Submerged (liquid state) Fermentation, Solid State Fermentation (SSF) is the cultivation of micro organisms under controlled conditions in the absence of free water.

Examples of products of Solid State Fermentation include industrial enzymes, fuels and nutrient enriched animal feeds. The application of modern biotechnical knowledge and process control technologies can lead to significant productivity increases from this ancient process.

Solid state fermentation

Higher volumetric productivity Usually simpler with lower energy

requirements Might be easier to meet aeration

requirements Resembles the natural habitat of some fungi

and bacteria Easier downstream processing

Advantages of solid state fermentation

Techniques for large-scale production of microbial products. It must both provide an optimum environment for the microbial synthesis of the desired product and be economically feasible on a large scale. They can be divided into surface (emersion) and submersion techniques. The latter may be run in batch, fed batch, continuous reactors.

In the surface techniques, the microorganisms are cultivated on the surface of a liquid or solid substrate. These techniques are very complicated and rarely used in industry.

What are fermentation techniques?

Upstream processing encompasses any technology that leads to the synthesis of a product. Upstream includes the exploration, development and production.

UPSTREAM PROCESSING

• The media is the feed solution◦ It must contain the essential nutrients needed

for the microbe to grow• Factors of consideration when choosing

media-Quality consistence and availability-Ensure there are no problems with Media Prep or other aspects of production process

Ex. Cane molasses, beet molasses, cereal grains

Media for Industrial Fermentations

• The type: complex and synthetic medium (mineral medium)

• Even small modifications in the medium could change cell line stability, product quality, yield, operational parameters, and downstream processing.

Fermentation medium

Fermentation medium consists of:

• Macronutrients (C, H, N, S, P, Mg sources water, sugars, lipid, amino acids, salt minerals)

• Micronutrients (trace elements/ metals, vitamins)

• Additional factors: growth factors, attachment proteins, transport proteins, etc)

For aerobic culture, oxygen is sparged.

Medium composition

• CARBON SOURCES:Lactose, glucose & sucrose may be used.

NITROGEN SOURCES:• Corn steep liquor (CSL), ammonium sulphate and

ammonium acetate can be used as nitrogenous sources.

MINERAL SOURCES:Elements namely potassium, phosphorus, magnesium, sulphur, zinc and copper are essential for penicillin production. Some of these are applied by corn steep liquor.

• Calcium can be added in the form of chalk to counter the natural acidity of some media.

RAW MATERIALS

Incoculum is the substance/ cell culture that is introduced to the medium. The cell then grow in the medium, conducting metabolisms.

Inoculum is prepared for the inoculation before the fermentation starts.

It needs to be optimized for better performance

Inoculum

• The inoculum is the starter culture that is injected into the fermenter◦ It must be of sufficient size for optimal growth

kinetics• Since the production fermenter in

industrial fermentations is so large, the inoculum volume has to be quite large

- A seed fermenter is usually required to produce the inoculum volume

-The seed fermenter’s purpose is not to produce product but to prepare inoculum

The Development of Inocula for Industrial Fermentations