Mass Production: Industrial Fermentation Explained

If oxygen is poorly soluble in water, Then it must be forced into the liquid. If a sparger has tiny holes to create a "fizz" of small bubbles, Then it maximizes the surface area for oxygen to dissolve into the fermentation broth.

If penicillin requires oxygen to be made, Then it is an aerobic process. If ethanol is made without oxygen, Then it is an anaerobic process. Since both are done in factories, Then industrial fermentation covers both metabolic types.

If the goal of industrial fermentation is mass production, Then success is defined by keeping the cells healthy and productive at a large scale (e.g., 200,000 liters) just as they were in the lab.

If a cell naturally spends energy on things the scientist doesn't want, Then the yield is low. If the scientist uses CRISPR or other tools to redirect the cell's energy toward the product, Then they are engineering the metabolism.

If upstream includes everything before the actual large-scale run, Then engineering the cells, picking the food (media), and growing the "starter" cells are all upstream; packaging happens at the very end of downstream.

If a single wild bacteria cell enters the tank, Then it will compete with the expensive industrial strain for food. If the wild strain grows faster, Then the industrial fermentation run will be contaminated and the batch must be destroyed.

If bacteria produce organic acids or ammonia as they eat, Then the pH will drift away from the ideal level. If the pH goes outside the survival range, Then the enzymes will stop working and the microbes will die.

If a process is "batch" style, Then it is a closed system. If it is a closed system, Then only the air and pH control chemicals are added during the run, meaning all main nutrients must be present at the beginning.

If the growth phase is "upstream," Then the cleanup and isolation phase is logically named downstream processing. This is where most of the cost of industrial fermentation occurs.

If the surface-area-to-volume ratio changes drastically as a tank gets larger, Then the physics of heating and oxygen transfer also change. If these physics change, Then the industrial fermentation parameters must be completely redesigned.

If a microbe finishes its main growth (primary phase) and begins to produce defense chemicals, Then those are secondary metabolites. If these chemicals kill other bacteria, Then they are used by humans as antibiotics.

If a microbe is sensitive to high sugar levels, Then adding all the food at once will slow it down. If nutrients are added slowly (fed-batch), Then the cell density can reach much higher levels without inhibiting growth.

If downstream processing is the recovery of the product after growth is done, Then you must separate the cells (centrifugation), break them open if needed (lysis), and purify the drug (chromatography).

If aerobic microbes require oxygen to survive, Then that oxygen must reach every part of the large tank. If the impeller spins the liquid, Then it maintains a uniform environment for the cells.

If a microbe is expected to produce a high yield of a specific medicine, Then its genetic profile and metabolic pathways must match the target product. If the wrong strain is chosen, Then the entire industrial fermentation process will fail to be profitable.

If scientists inserted the human gene for insulin into E. coli, Then the bacteria became a factory for the human protein. If this product was released in the 1980s, Then it was the first "biotech" drug produced via large-scale fermentation.

If microbes need energy and carbon to build their bodies and products, Then they require a concentrated sugar source. If molasses is a cheap byproduct of the sugar industry, Then it is the most economical choice for industrial fermentation.

If an organism grows well in tanks and can be genetically modified, Then it is a good host. While bacteria, yeast, and mammal cells (CHO) are standard, sharks cannot be used in industrial fermentation tanks.

If yeast perform alcoholic fermentation on corn or sugarcane sugars, Then they produce ethanol. If this ethanol is harvested for use in car engines, Then it is the primary product of biofuel industrial fermentation.

If a specific fungus is known for producing the first mass-produced antibiotic, Then it is Penicillium. This mold is grown in massive tanks to provide medicine for the world.