Brief History And Developments In Industrial Microbiology

• Industrial Microbiology can define as branch of microbiology which deals with use of microorganisms for commercial and industrial purposes.
• It mainly concern with production of products by microorganisms like enzymes, alcohols, acids, antibiotics, vitamins etc.
• The study mostly focus on fermentation process, which was earlier practiced as an art, later become science after discovery of microorganisms.
• In this field, microbes like bacteria, fungi, yeast, actinomycetes are used to synthesize useful compounds.
• Industrial microbiology is also sometimes called Biotechnological Microbiology, since it overlap with biotechnology field in many processes.
• Large scale fermenters are employed for growth of microorganisms under controlled condition of pH, temperature, aeration etc., though contamination sometimes occur.
• It involves both primary and secondary metabolites production, for example ethanol, citric acid, penicillin are main products.
• The work of Louis Pasteur and Hansen were very important in early development, as they showed fermentation is biological and pure culture could be used for stable product formation.
• Later, techniques like genetic engineering, continuous culture, and immobilization of cells improved productivity.
• Industrial microbiology plays crucial role in food, pharmaceutical, chemical, agriculture and energy sectors for human welfare.
• It has divided historically into different periods: Alcohol fermentation, Antibiotic, Single Cell Protein, Metabolite Production and Biotechnological era.
• Through all these phases, the basic principle remain same—microbes are exploited for making materials of economic value.
• Now-a-days, it also involve recombinant DNA technology and animal cell culture for production of complex therapeutic proteins.
• So, Industrial Microbiology represent an applied science where biological systems used for manufacturing processes that are clean, renewable and often cheaper than chemical method etc.

History and Development in industrial microbiology

The history of Industrial Microbiology is divided into five main phases, each was defined by dominant products and technologies.

• Phase I — Alcohol Fermentation Period (Before 1900) was marked by production of alcohol, vinegar and beer, and fermentation was practiced as an art, not as a controlled science.
  • Pasteur’s work was considered pivotal, fermentation was proved to be biological and pasteurization was introduced to save wine industry.
  • Pure yeast starters (by Emil Hansen) were adopted in brewing, large wooden vats (upto 1500 barrels) were used, process control was minimal.
• Phase II — Antibiotic Period (1900–1940) was ushered in, when penicillin discovery (1929) and later mass-production during WWII transformed the field.
  • Penicillin and other antibiotics were produced by submerged, aseptic fermentations and mechanical stirring, aeration and pH control were developed.
  • Many antibiotics were discovered from Streptomyces species, and they were commercialized for medical use.
• Phase III — Single Cell Protein (SCP) Period (1940–1964) was focused on microbial biomass as protein source, continuous culture techniques were introduced and very large fermenters were built.
  • The ICI Pruteen process (with Methylophilus methylotrophus) was piloted and continuous operation was demonstrated, though economical issues were later faced.
• Phase IV — Metabolite Production Period (1964–1979) was characterized by production of amino acids, enzymes, nucleotides and biopolymers like xanthan and dextran. Enzyme and cell immobilization methods were developed, and computer-linked control loops began to be used for process regulation.
• Phase V — Biotechnological Period (1979 onward) was started with genetic engineering and hybridoma technologies, recombinant proteins were produced (e.g., human insulin).
• Animal cell culture and monoclonal antibodies were introduced for therapeutics and diagnostics, and process sensors/computers became standard.
• Secondary metabolites like Cyclosporine, Lovastatin, Ivermectin and modified antibiotics were commercialized in this era.
• Over the phases, fermenter design, strain selection, quality control and pilot plant facilities were progressively improved, and they were made more aseptic and instrumented.
• The shift from art to science was driven by discoveries of microbiology (yeast, bacteria, anaerobes) and by developments in sterilization, pure culture and process control.
• Genetic engineering and recombinant DNA technology were later applied to improve production of phase-3 type products, and new products were enabled.
• The historical phases are still relevant, because current processes are often described as evolved forms of these earlier categories.
• Some terms were used interchangeably, biotechnology and industrial microbiology are overlapped, and they are now integrated into modern bioprocess industries.

Ancient Origins and Pre-Scientific Use

• The Ancient Origins of Industrial Microbiology were grounded in everyday fermentation practices that were used long before microbes were seen.
• Around 7000 BCE in Neolithic China, rice mead production was recorded and alcoholic fermentation was being practiced, though the cause was unknown.
• In Sumeria and Babylonia (7000 BC), beer was produced by natural fermentation and these beverages were integrated into social and ritual life.
• By about 4000 BC, in ancient Egypt, carbon dioxide from brewer’s yeast was observed to leaven bread, and leavened bread was thus produced.
• Wine production was being carried out in Assyria by 3500 BC, and it was considered an established fermented product.
• Vinegar was used medicinally by 400 BC in Assyria, and Hippocrates applied it for wound and ear treatments, showing early applied uses.
• By 100 BC, more than 250 bakeries were functioning in Ancient Rome, where leavened bread was being baked daily, indicating widespread yeast use.
• Milk preservation was achieved by lactic fermentation, and products like yogurt, kefyr and koumiss were produced in Asia using microbes (for example Kluyveromyces species).
• The Koji process (a solid-state fermentation) was originated by 2500 BC in China and the technique was transferred to Japan in 7th century, where molds were used to saccharify rice.
• By 700 AD, molds were in routine use to convert rice starch into sugars for brewing and sauce making, an early enzymatic biotechnology.
• During the Middle Ages, methods for beer and wine production were refined and fermentation was used widely as a method of food preservation.
• In the 14th century AD, distillation of alcoholic spirits from fermented grains became common, a practice thought to have roots in China or the Middle East.
• Vinegar manufacture was established in Orleans, France, at the end of the 14th century, and shallow-tray methods were used to increase aeration.
• All these techniques were developed empirically, the underlying microbial agents were not known, yet processes were standardized by craft and tradition.
• Practical knowledge was accumulated, starter cultures/techniques were transmitted, and many fermentations were operated by observation and experience, rather than theory.
• In the 17th century, Antonie van Leeuwenhoek made simple microscopes and observed tiny “animalcules”, and letters describing these findings were sent to the Royal Society (1673–1723).
• Leeuwenhoek’s observations were communicated widely, and although direct linkage to fermentation was not immediately made, the invisible agents were thus revealed.
• The pre-scientific era was therefore closed gradually, empirical fermentation practices were retained, but they were soon to be explained by microbiology.
• Many preservation benefits were obtained by these early fermentations, and spoilage was attempted to be prevail by salting, acidifying and fermenting, (an ironic malapropism used here).

Phase I — Alcohol Fermentation Period (Before 1900)

• Phase I – Alcohol Fermentation Period (Before 1900) is known as the earliest stage in the history of Industrial Microbiology, marked mainly by production of alcohol, beer, and vinegar.
• The biochemical process was not understood at that time, fermentation was considered more as an art than as science.
• Beer, which represent first phase of fermentation process, was produced by ancient Egyptians on small scale, but large scale brewing began in the early 1700s.
• Big wooden vats of about 1500-barrel capacity were used for brewing, and thermometers / heat exchangers were introduced to control temperature during fermentation.
• In mid-18th century, Justus von Liebig described fermentation as a chemical disintegration process of starch or sugar, leading to alcohol formation.
• This view was also supported by other chemists like Berzelius (1779–1848) and Bertholet (1827–1907) who thought life was not necessary for fermentation.
• However, scientists Cagniard Latour, Schwann, and Kutzing independently observed that yeast (a unicellular fungus) was actually responsible for the process.
• The debate continued until Louis Pasteur finally proved through experiments that fermentation was biological and not just chemical.
• In 1857, Pasteur found that other organisms, not yeasts, could convert sugars into lactic acid, meaning that different fermentations were done by different organisms.
• Later, while studying butyric acid fermentation (1861), he discovered that some microorganisms can survive and work without oxygen, introducing concept of anaerobic life.
• The organism causing butyric fermentation was later identified as Clostridium butyricum, an anaerobic bacterium.
• Pasteur’s discovery led to the division of microorganisms broadly into aerobic and anaerobic types, which became fundamental concept in microbiology.
• Around this time, the wine industry in France suffered due to spoilage called “souring.”
• The French Government requested Pasteur to investigate the problem, and he found that unwanted microorganisms were contaminating wine and changing its taste.
• He recommended heating the juice below boiling point to kill spoilage microbes but keep desirable ones alive; this process was called Pasteurization.
• Pasteurization saved the French wine industry from major economic losses, and later was used for milk and other beverages also.
• Pasteur also disproved the chemical theory of fermentation by showing that living microorganisms are essential for it.
• In late 19th century, Emil Christian Hansen at Carlsberg Brewery developed method for producing pure yeast cultures, and starter techniques for stable brewing.
• These pure-culture methods eliminated mixed fermentation problems and standardized beer quality, marking true industrial control of microbiological processes.
• By the end of nineteenth century, the understanding of microbial involvement in fermentation and process control became well established, transforming brewing into an applied science.

Phase II — Antibiotic Period (1900–1940)

• During Phase II – Antibiotic Period (1900–1940), many great advancements were developed in industrial microbiology, especially about fermentation and antibiotics production.
• Techniques for large-scale production of baker’s yeast was improved, where growth of yeast cells in alcoholic fermentation controlled by adding wort slowly in small amount. This method called as fed-batch culture and widely used to avoid oxygen-limiting condition.
• Aeration of yeast culture was enhanced by using air sparging tubes, which allowed more oxygen reach into medium, it made culture more efficient.
• Development of acetone–butanol fermentation by Weisman was considered one of the truly aseptic and anaerobic fermentations, which marked major step forward in fermentation industry.
• From this technology, later the production of organic solvents like glycerol, citric acid, lactic acid, etc. was facilitated and those processes also shifted to aseptic aerobic systems.
• A remarkable achievement during this time was discovery and large-scale production of the antibiotic Penicillin by Alexander Fleming (1929), which saved many soldiers’ lives in World War–II.
• Production of Penicillin is an aerobic process, carried by submerged culture under aseptic condition, it involved sparging sterile air in viscous broth and mixing large volume of medium which was quite problematic initially.
• After solving contamination issues and aeration problems, technology of penicillin fermentation opened way for new processes like vitamins, amino acids, enzymes and steroid transformations production.
• About same time, Dubos from Rockefeller Institute found several microbial products with antimicrobial properties which helpful in human disease treatments.
• Later S.A. Waksman and team, soil microbiologists, discovered many antibiotics produced by Streptomyces species, that inhabit soil, e.g., St. griseus, St. fradiae, St. rimosus, etc.
• The list of antibiotics discovered during this period includes Penicillin (1929) by Fleming, Tyrothricin (1939) from Bacillus, and Griseofulvin (1939) from Penicillium griseofulvum. After that, others followed soon in 1940s–1950s.
• These discoveries together changed industrial microbiology completely, leading from solvent fermentations to therapeutic drug manufacturing on industrial scale.
• This period sometimes also called as the Golden beginning of antibiotic age, since microbial products started to be seen as lifesaving medicines.

Phase III — Single Cell Protein (SCP) Period (1940–1964)

• Phase III – Single Cell Protein (SCP) Period (1940–1964) was marked by development of microbial biomass used as protein food material, which later called as SCP.
• During this time, large-scale production of microbial protein was started because cost of resultant product was very low, so industrial interest was grown rapidly.
• Production of proteinaceous food from microorganisms was considered as efficient way to overcome shortage of protein food, especially for animal feed and sometimes for human use too.
• To produce huge biomass, large fermenters were developed – mechanically stirred type ranging from 80,000 – 1,50,000 liters capacity, sometimes even more, which had to operate continuously for many days to remain economical.
• For that purpose, continuous culture fermentation process came into existence, where culture was maintained in steady condition and fresh medium continuously supplied.
• In this system, cells continuously harvested while maintaining balanced growth – it allowed very high productivity compared to batch or fed-batch system used earlier.
• The most successful and long-lived continuous culture system known as ICI Pruteen Process, which employed Methylophillus methylotrophus, a methylotrophic bacterium growing on methanol as carbon source.
• This process was used mainly for animal feed production and became model for future SCP programs, though later replaced by cheaper substrates and new organisms.
• During this period, single-cell proteins became important research field, combining microbiology, fermentation engineering, and nutritional sciences together.
• Thus, this phase represented the shift of industrial microbiology toward food biotechnology and large-scale biomass utilization rather than only metabolite production.

Phase IV — Metabolite Production Period (1964–1979)

• Phase IV – Metabolite Production Period (1964–1979) was characterized by new and advanced microbial processes for production of various metabolites, especially amino acids and nucleosides.
• In Japan, new fermentations were developed for synthesis of amino acids and 5′-nucleosides, which used as flavour augmenters in food industries.
• These microbial processes became highly significant since chemical synthesis of such compounds was expensive and less eco–friendly.
• During this time, numerous enzyme production processes were perfected for industrial, analytical and medical purposes.
• Techniques for enzyme immobilization and cell immobilization were also developed, that allowed reuse of enzymes and long operational stability of biocatalysts.
• This development reduced production cost and made enzymatic processes more suitable for continuous operations.
• Commercial production of microbial biopolymers like Xanthan and Dextran was initiated, these compounds used as food additives and stabilizers, etc.
• The large-scale production of Xanthan gum from Xanthomonas campestris and Dextran from Leuconostoc mesenteroides shown potential for food and pharmaceutical application.
• Also in this period, microorganisms were utilized for tertiary oil recovery, where microbial metabolites like surfactants enhanced oil extraction from old wells.
• Thus, the phase represented transition of industrial microbiology toward production of high-value metabolites and specialty chemicals, beyond only bulk biomass or antibiotics.

Phase V — Biotechnological Period (1979 onward)

• Phase V – Biotechnological Period (1979 onward) was the era where huge and fast progress in industrial microbiology took place, mainly by inventions of genetic engineering / hybridoma technique.
• By genetic engineering, manipulation of genes done in-vitro, and expression of human/ mammalian genes in microorganisms became possible, which was a big breakthrough.
• So large-scale production of human proteins was achieved – first product was Human Insulin, it used for curing the ever-growing disease, diabetes.
• After that, many more proteins produced, like Human Growth Hormone (HGH), Erythropoietin (EPO) and Colony Stimulating Factors (CSFs), which control blood cell formation & proliferation.
• Erythropoietin used in treatment of renal failure, anemia, platelet deficiency in cancer, while G-CSF used for cancer therapy also in recovery after chemotherapy, etc.
• The hybridoma technique, which employed for making monoclonal antibodies (mAbs), developed during this time too – these antibodies aid diagnosis and therapeutics both.
• Monoclonal antibodies found major use in medical field for disease detection and also as targeted drugs for tumor cells, that’s why they became very important tools.
• Beside recombinant DNA works, fermentation of secondary metabolites perfected further, which led to wide industrial production of new microbial compounds.
• Examples of such metabolites released into market were:
  • Cyclosporine – immunoregulant drug that control rejection of transplanted organs.
  • Imipenem – modified carbapenem having wide antibacterial range.
  • Lovastatin – drug used to reduce cholesterol levels.
  • Ivermectin – antiparasitic drug preventing African River Blindness (caused by Onchocerca volvulus).
• These developments showed how biotechnology turned microbiology into multi-disciplinary science, joining genetics/medicine/fermentation together for human benefit.
• Truly, the statement of Foster (1949) “Never underestimate the power of microbes” got justified again during this remarkable period.

Importance of Industrial Microbiology

• Industrial Microbiology is concerned mainly with large-scale production of microbial products, which can used for benefit of humankind.
• Many microorganisms are utilized for production of useful substances like enzymes, antibiotics, organic acids etc.
• By use of fermentation technology, large quantity of products are obtained, even from cheap raw materials.
• It has helped in development of pharmaceutical industries, where drugs and vaccines are produced by microbes.
• Various antibiotics (like penicillin, streptomycin) are obtained from species of Penicillium and Streptomyces, which revolutionized medical treatments.
• In food sector, microbes are used for production of fermented foods like yogurt, vinegar, cheese, and alcoholic beverages.
• Industrial microbiology also support environmental management, like waste-water treatment, composting, and biogas production.
• Some microorganisms are applied for bioremediation, which help to remove pollutants or toxic chemicals from environment.
• Enzymes produced by microbes are applied in many industries – for example, amylase, protease, lipase, used in detergent, paper, and textile industries.
• Production cost is reduced because microbes can grow on low-cost substrates, which make process economically sustainable.
• As a result of continuous research, genetic engineering is now combined with industrial microbiology, which enhance yield and purity of products.
• It also contribute in biofuel generation, where organisms like Saccharomyces cerevisiae used for ethanol production.
• The role of industrial microbiology is very significant in modern world – it connects science with industry, creating both economic and social value.
• However, contamination during production process can cause major losses, so sterile conditions are always maintained.
• Overall, this field has changed industrial processes totally, making them more eco-friendly, productive and sustainable.