Industrial Microbiology

Introduction 

In the early 1800s, N. Appert was known for making practical food preservation processes or ‘canning’. After that, L.Pasteur established the direct relationship between microbial activity and food spoilage. Regarding this aspect, foodborne disease has increased in the mid-1800s as well.  In recent times, the commercialization of food comes under several purification processes.

Overview of methods that are used for purification of microbial products

Microbial and bacterial activities have been used by humans to confront problems in regards to the limited shelf life of plant food and animals. During 5000-10000 years several activities and purification processes emerged empirically, which were able to increase the shelf life of animal and plant food. 

• Crystallisation: It is used to purify solid foods where impure solids dissolve in a hot boiling solvent. After cooling purest form is extracted
• Chromatography: It is mainly used to purify protein products though there are subgroups such as “affinity chromatography”, “Ion exchange chromatography”, “Gel permeation chromatography” and so on. 

• Centrifugation: A process of purification where impure particles are separated based on their shape, size, viscosity, density and rotor speed. 
• Electrophoresis: Here by the use of electric current, molecules are being separated through the gel. 

• Precipitation: Considered as a crude method of purification, quite cheap and easy to perform. pH and temperature act as a moderator in this purification process.

 Definition of microbial product 

Microbial products are derived from different microscopic organisms. Microbial products containing microorganisms, (as per their size) can be categorised into Bacteria, Fungi, Protozoa, Viruses and Yeast and moulds etc. Anti pain, which is produced by “Streptomyces yokosukaensis”, is considered a classic example of the microbial product. 

Examples of microbial products 

In food and beverages, there are three types of microbial products that can be found, which are viruses, bacteria and parasites. In this regard, these microbial organisms create desirable properties related to the organoleptic for instance, taste, odour and texture amongst various foods. These foods such as cheeses, cultured buttermilk, yoghurt, pickles, sour cream, fermented food items resulted in a part of microbial activity by some particular microbial flora. In other cases. Microorganisms can be associated with food in particular, “useful”, “pathogenic” or  “spoilage”. Useful microbial products can produce lactic acid, yeast and bacteria, naturally or artificially. Pathogenic microorganisms render the food harmful for humans in several ways, where food serves as the transportation of gaining infectious organisms into the gastrointestinal tract, which can produce toxins; such as “Clostridium botulinum”, “Salmonella” and “Shigella” etc. Lastly, the Spoilage microbial organisms, which grow in the food can cause negative changes. Consequently, the bacteria enzymes can create slow deterioration among frozen and dried food, which has been stored for a long time. 

 Microbial natural products 

The natural products from various microbes and plants are not only used in food commercialization and beverage making purposes but also used in making several drugs as well. A wide range of microbial genomes is used among secondary metabolites. Some useful products are anticancer agents, antibiotics, immunosuppressants etc. Some natural products can be used for other applications for example anthelmintics, antivirals, enzyme inhibitors, polymers, nutraceuticals, bioherbicides, surfactants and vaccines have also been commercialised. Not only drugs but microorganisms in plant growth as well as agricultural purposes are already used. Some commonly promoted microorganisms are rhizobia, azospirillum, mycorrhizae, pseudomonas etc. Some natural antimicrobials are peptides, polysaccharides, lipids from animals; onion, garlic, Cruciferae, phenolic compounds from plants; bacteriocins, bacteriophages from bacteria; and macro-micro algae, mushrooms etc. 

List of microbial products 

• Bacillus cereus 

• Staphylococcus aureus

• Mycobacterium para tube

• Clostridium perfringens

• Escherichia coli 

• Salmonella Typhimurium

• Campylobacter jejuni

• Yersinia enterocolitica

The above mentioned are the most common foodborne pathogens which cause contamination in food products. Microbial products can be found in a variety of foods, such as Bacillus cereus are found in rice, peas, and potatoes which cause contamination. Staphylococcus aureus causes contamination in cooked meat and poultry products. Mycobacterium para tube generally infects dairy cattle which can lead to Johne’s diseases. Yersinia enterocolitica causes contamination in fish, oysters, raw milk and crab. 

Conclusion 

This can be concluded that the purification of microbial products is commonly used for the fermentation of the food commercialization process, which has been going on for many years. In this regard, natural microbial products are used for making antibiotic and anticancer drugs as well as an agricultural business. Additionally, useful microbial bacteria create or reshape the structure and texture, tastes in foods, whereas the pathogenic bacteria in microbial products can create foodborne diseases such as stomach flu and so on.