Industrial fermentation
| Technology | |
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| Technology details | |
| Name: | Industrial fermentation |
| Category: | Conversion (Biochemical processes and technologies) |
| Feedstock: | Garden and park waste, food waste |
| Product: | Biomass, bioproducts (e.g., enzymes, biopolymers, organic acids, alcohols) |
Industrial fermentation is a biotechnological process which uses microorganisms (genetically modified or not), in particular bacteria, yeasts, fungi or algae, to make useful products. The cells are real "cell factories" for the industrial conversion of a wide range of renewable feedstocks into bulk chemicals, fine chemicals, platform chemicals, pharmaceutical ingredients, bio-fuels, bio-plastics, etc. It is a multidisciplinary technology and includes the integrated application of disciplines such as biochemistry, microbiology, molecular genetics and process technology to develop useful processes and products.
Feedstock
Composition and origin
Depending on the type of microorganisms and its genetic modifications, a various range of feedstocks can be used. The most commonly used feedstocks are listed below:
Lignocellulose and cellulose
Lignocellulose is present in garden and park waste. Cellulose is present in food waste such as fruit and vegetable waste. Via hydrolysis, which is usually performed through enzymatic or thermal treatment, fermentable sugars can be obtained from lignocellulose and cellulose.
Starch
Starch is present in food waste such as potatoes, corn, wheat or cassava. Starch can directly be utilized by amylase-producing microorganisms, particularly filamentous fungi. However, to allow its use in a wider range of fermentations, starch is usually converted into glucose or dextrins by enzymatic hydrolysis.
Oils and Fat
Oils and fats are present in food waste such as gravy, used cooking oil and grease. They can directly be used as fermentation substrate. As they are not water soluble, extensive mixing is required to allow a good contact between the liquid droplets and the fermentation water phase.
Dairy waste
Whey, the liquid by-product of cheese manufacturing, is used as a source of fermentable carbohydrate and nitrogen.
Sugars
Sugar-rich waste streams can be derived from food industry waste, e.g., from the candy industry.
Pre-treatment
Depending on the type of feedstock and its purity, specific pre-treatment technologies are required to provide fermentable substrates to the microorganisms. Generally, this involves a size reduction step, after which the milled biomass can be processed to separate the desired substrate by e.g., centrifugation, filtration, evaporation or crystallization.
In addition, it should be taken into account that some of the above mentioned feedstocks only provide the carbon source (which compose about 50% of the weight of most microorganisms), in that case also other nutrients such as nitrogen, phosphate and potassium need to be added.
Process and technologies
Microorganisms
Microorganisms used in industrial fermentations include: bacteria, yeast, fungi or algae. In practice, these are well-known, productive and harmless (GRAS - Generally Regarded As Safe) production organisms, equipped with the new genetic information, that are used to produce the desired products in high yield and efficiency. A major advantage is that these often genetically modified microorganisms do their work under controlled conditions in a fermenter or bio-reactor, carefully contained and separated from the outside world (contained environment). They cannot escape from the factory so that ecological problems or concerns regarding the release of genetically modified organisms in the environment are avoided.
Equipment
A typical industrial fermenter consists of an CSTR equipped with:
- an aeration and agitation system: to provide good mixing and availability of oxygen for the cell culture
- a temperature and pH control system: to assure optimal conditions for growth or production
- a foam control system: to avoid excessive foam formation
- sampling ports
- addition ports
- a cleaning and sterilization system: to avoid contamination with other, undesired microorganism
Operating conditions
As it involves living organisms, a fermentation process is typically conducted under mild conditions (pH and temperature). As a result, the energy consumption is relatively low as well as the capital and operating costs. However, fermentation technologies are complex and sensitive requiring careful control of quality and safety of the raw materials, process parameters, contamination, etc.
Industrial fermentations may be carried out as batch, fed-batch, or continuous culture systems. Batch and fed-batch operations are quite common, continuous fermentations being relatively rare [1].
Scale-up of industrial fermentations
Typically, a pure starter culture (or seed), maintained under carefully controlled conditions, is used to inoculate sterile petri dishes or liquid medium in the shake flasks. After sufficient growth, the preculture is used to inoculate the seed fermenter. Because industrial fermentations tend to be large (typically 1–250 m3), the inoculum is built up through several successively larger stages, to 5–10% of the working volume of the production fermenter. However, scale-up of a fermentation process is not straightforward as an increase in fermenter size affects the various process parameters in different ways. Therefore, ample expertise is required to find a compromise between all process parameters.
Products
Depending on the type of microorganisms and its genetic modifications, a range of products can be synthesized. The most common products are listed and divided over two categories: (1) biomass, (2) bioproducts. In case of the latter, some products require complex genetic modifications.
Biomass
- Single Cell Protein
- Single Cell Oil
- Baker's yeast
- Lactic acid bacteria
Bioproducts
Enzymes
- Proteases
- Lipases
- Amylases
- Cellulases
- Peroxidases
Biopolymers
- Poly-hydroxyalkanoates (PHA)
- Polysaccharides: xanthan gum, dextran
Organic acids
- Acetic acid
- Lactic acid
- Citric acid
- Tartaric acid
- Fumaric acid
Alcohols
- Ethanol
- Butanol
- Glycerol
- Butanediol
Solvents
- Acetone
Pharmaceuticals
- Vitamins: vitamin C, B2, B12 ...
- Antibiotics: aminoglycosides, penicillins, cephalosporins, tetracyclines ...
- Hormones
Biocolorants
- cartenoids
- astaxanthins
Biosurfactants and bioemulsifiers
- glycolipids
- rhamnolipids
Amino-acids
- monosodium glutamate (MSG)
- Lysine
- Tryptophan
- Phenylalanine
Post-treatment
The first step in the post-treatment of fermentation broth cultures, also known as downstream processing (DSP), is to remove the cells from the medium. This is typically performed by a solid-liquid separation technology, such, as centrifugation or membrane filtration. Each fraction can then undergo further processing, depending on whether the product is the biomass itself or an intra- or extracellular product. While intracellular products require cell disruption to release the products, extracellular products are solubilized in the depleted fermentation medium. Cell disruption techniques can be divided into mechanical methods (f.e. homogenisation, grinding, sonication, microwave treatment, steam explosion) and non-mechanical methods (f.e. osmotic or temperature shock, enzymatic destruction). To further purify and concentrate the products several methods can be used including chromatography, solvent extraction, crystallization, distillation, drying etc. The choice of purification technology is depending on the characteristics of the desired products.
Technology providers
| Company name | Country | Technology category | Technology name | TRL | Capacity [kg/h] | Feedstock: Food waste | Feedstock: Garden & park waste |
|---|---|---|---|---|---|---|---|
| Company 1 | [Country HQ location] | [Technology category (if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)] | [Technology name (the "branded name" or the usual naming from company side)] | [4-9] | [numeric value] | ● | ● |
| Company 2 | [Country HQ location] | [(if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)] | [Technology name (the "branded name" or the usual naming from company side)] | [4-9] | [numeric value] | ● | ● |
Amphi-Star
| General information | |||
| Company: | AmphiStar |
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| Country: | Belgium | ||
| Contact: | info@amphistar.be | ||
| Webpage: | www.amphi-star.be | ||
| Technology and process details | |||
| Technology name: | BioSurf Biosurfactant Technology Platform | Technology category: | Conversion (Biochemical processes and technologies) |
| TRL: | 1-7 | Capacity: | kg·h-1 |
| Aeration: | Yes | Agitator: | |
| Biosafety level: | 1 | Controlled parameters: | Temperature, pH, Oxygen, Stirring speed, feed rates, etc. |
| Microorganism: | Starmerella bombicola, Candida kuoi, Rhodotorula bogoriensis, etc. Open for collaboration on any BSL-1 biosurfactant producing strain |
Reactor material: | Glass or stainless steel |
| Other: | |||
| Feedstock and product details | |||
| Feedstock: | Vegetable oils and sugars from biomass | Product: | Biosurfactants e.g. glycolipids such as sophorolipids |
AmphiStar has developed a proprietary technology platform for the cost-efficient and ecological production of biosurfactants. We are a founders-led spin-off company established in July 2021 that is the result of 15 years joint development between Ghent University (Inbio.be) and the Bio Base Europe Pilot Plant. We derisk the early development stage for biosurfactant production, guide and support technology transfer to industrial manufacturers and collaborate intensely for further development and improvement of the licensed technology.
Our technology platform is initially based on the fermentative production with the yeast Starmerella bombicola, producing many different biosurfactants at a high volumetric productivity. Our biosurfactants are made from sustainable, renewable feedstocks and waste streams. Microbial fermentation is a clean production technology that is safe for people and the environment. Our biosurfactants are environmentally friendly, palm oil-free, sulfate-free, mild, non-toxic and non-irritant.
Avecom
| General information | |||
| Company: | Avecom | 
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| Country: | Belgium | ||
| Contact: | sales@avecom.be | ||
| Webpage: | https://www.avecom.be | ||
| Technology and process details | |||
| Technology name: | PROMIC | Technology category: | Conversion (Biochemical processes and technologies) |
| TRL: | 4-7 | Capacity: | kg·h-1 |
| Aeration: | Agitator: | ||
| Biosafety level: | Controlled parameters: | ||
| Microorganism: | Reactor material: | ||
| Other: | |||
| Feedstock and product details | |||
| Feedstock: | Residual side streams and co-products from the food industry | Product: | Single Cell Protein, PHB-rich biomass |
Avecom has developed its PROMIC biomass fermentation platform for the efficient conversion of industrial and agricultural residual side streams and co-products towards high-value single cell proteins.
Dranco
| General information | |||
| Company: | Dranco |
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| Country: | |||
| Contact: | |||
| Webpage: | |||
| Technology and process details | |||
| Technology name: | Technology category: | Conversion (Biochemical processes and technologies) | |
| TRL: | Capacity: | kg·h-1 | |
| Aeration: | Agitator: | ||
| Biosafety level: | Controlled parameters: | ||
| Microorganism: | Reactor material: | ||
| Other: | |||
| Feedstock and product details | |||
| Feedstock: | Product: | ||
NovelYeast bv
| General information | |||
| Company: | NovelYeast bv |
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| Country: | Belgium | ||
| Contact: | johan.thevelein@novelyeast.com | ||
| Webpage: | https://www.linkedin.com/in/johan-thevelein-aab60a10/ | ||
| Technology and process details | |||
| Technology name: | Yeast fermentation to biofuels and bio-based chemicals. Protein production | Technology category: | Conversion (Biochemical processes and technologies) |
| TRL: | 3-5 | Capacity: | Lab-scale kg·h-1 |
| Aeration: | Aerobic, semi-anaerobic | Agitator: | |
| Biosafety level: | BSL-1 | Controlled parameters: | Standard parameters |
| Microorganism: | Saccharomyces cerevisiae, other yeast species, Trichoderma | Reactor material: | Glass |
| Other: | Construction of cell factories with recombinant DNA technology | ||
| Feedstock and product details | |||
| Feedstock: | 1G and 2G feedstocks | Product: | Biofuels and bio-based chemicals, proteins, specialty sugars, specialty chemicals |
NovelYeast bv was founded in 2019 by Prof. Johan Thevelein (KU Leuven and VIB) to continue his R&D activities after his retirement in 2020 as emeritus. The company focusses on the development and industrial implementation of yeast cell factories for the production of biofuels, bio-based chemicals as well as specialty sugars and ingredients with first- and second-generation feedstocks. It also develops cell factories for the production of specific proteins for food applications and enzymes for saccharification of lignocellulosic biomass. In addition, it uses yeast as a tool for biomedical and agroindustrial applications, including yeast probiotics and anti-cancer drugs selected by screening in yeast. NovelYeast has several R&D service collaborations with companies world-wide.
Open access pilot and demo facility providers
Patents
Currently no patents have been identified.
References
- ↑ Y. Chisti, 2014: Encyclopedia of Food Microbiology (Second Edition). Science Direct, {{{place}}}.