Fermentation for Biopolymers

Plastic materials derived from non-renewable raw materials such as petroleum have a critical role in our daily lives. However, the chemically engineered durability and the slow biodegradation rates of most of the exclusively fossil-based plastics such as polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC) allow these synthetic polymers to endure for years in marine environments and terrestrial ecosystems, thus affecting organisms at multiple trophic levels. Chemical synthesis often involves the application of toxic reagents and solvents as well as high energy consumption, which is conflict with the sustainable handling of energy and raw material resources. At the same time, a large number of chemicals can be efficiently produced by microbial fermentation. Biopolymers are new environmentally friendly compounds obtained from a wide range of microorganisms and plants. Thus, complex biopolymers have the potential to replace fossil-derived plastics in the future, and have a very wide range of applications in the food industry, cosmetics, pharmaceuticals. Nowadays, research is focused on developing techniques to produce biodegradable biomaterials. By introducing safe and inexpensive fermentation techniques that do not use toxic and hazardous chemicals, as well as integrating monitoring and automation tools, the production of biopolymers can be more efficient, and the investment and operational costs is reduced significantly.

Fig 1. Various methods employed in the production of biopolymers. (Vigneswari, S.; et al. 2021)

Common Types of Biopolymers

• Hyaluronic acid (HA) is an industrially produced polymer used in various biomedical applications and cosmetics.
• Itaconate is used as a building block for the production of pharmaceuticals and adhesives, as a copolymer for synthetic resins, and as a promising starting material for biofuel production.
• Polyhydroxypropionates (PHAs) are linear polyesters produced by aerobic fermentation of bacteria from many carbon sources, and are fully biodegradable and biocompatible.
• Polylactic acid (PLA) is one of the most promising biodegradable and biocompatible aliphatic thermoplastic with extensive mechanical property profile. PLA is obtained from lactic acid (LA), a naturally occurring organic acid produced by microbial fermentation from renewable resources such as sugars obtained from corn, cane sugar, and sugar beets.

Fig 2. Biopolymer poly-hydroxyalkanoates (PHA) production from apple industrial waste residues. (Liu, H.; et al. 2021)

Fermentation Techniques Applied in Biopolymer Production

• Anaerobic-aerobic Fermentation

Production of PHA from organic waste can be obtained using an anaerobic-aerobic fermentation system with mixed microbial cultures. Palm oil mill effluent (POME) was used as an organic source and cultivated in a two-step-process of acidogenesis and acid polymerization to obtain volatile fatty acids (VFAs) for PHAs production.

• Syngas Fermentation

Modern processing technologies are applied to combine biopolymer production with bacterial fermentation of syngas and pyrolysis of highly complex biological wastes (e.g. municipal, commercial, sludge, agricultural). Efficient integration of physicochemical, biochemical, downstream and synthetic technologies is able to produce a wide range of new biopolymers. Chemical and enzymatic catalysis can be used to synthesize novel bio-based plastic prototype, and this innovative biofermentation technology not only facilitates the environmental management of terrestrial waste, but also reduces the harmful environmental impact of petrochemical plastics.

• Solid-state Fermentation (SSF)

SSF offers desirable biotechnological advantages, such as higher fermentation productivity and higher product concentration.

• Electro-Fermentation

Aiming to meet the needs of biopolymerization, the electro-oxidation process (i.e. electro-fermentation) is used to obtain biofuels and biopolymers. Electro-fermentation systems with major bio-product production have been designed to develop a model of an anaerobic fermentation process for the production of organic acids for biopolymerization.

Fig 3. Microbial production, ultrasound-assisted extraction and characterization of biopolymer polyhydroxybutyrate (PHB). (Pradhan, S.; et al. 2017)

Fermentation Process in Biopolymers Production

• Strain and Process Characterization

Process development is a key factor in creating faster and more cost effective methods of producing target products. By optimizing process parameters, bioprocess engineers are able to ensure realistic fermentation conditions on a small scale, making it possible to mimic production conditions.

• Process Automation

Through automation, bioprocess equipment can be used more efficiently, as the process becomes independent of laboratory operating time. At the same time, it reduces the risk of human error.

• Scale-up

The scale-up of fermentation processes is critical to the success of industrial fermentation for the production of biopolymers. In order to determine the appropriate parameters, key engineering parameters related to scale-up need to be considered. Computer fluid dynamics (CFD) simulations can help predict power numbers and fluid flow conditions.

• Scale-down

In large-scale industrial bioprocesses, the presence of gradients in key process parameters such as dissolved oxygen (DO), pH and substrate concentration can be observed. They lead to inhomogeneous growth conditions within the bioreactor/fermenter and may affect cell yield and/or productivity. Laboratory scale-down methods are useful tools to analyze the effects of the inhomogeneities.

Our Services for Fermentation Production of Biopolymers

• Fermentation CDMO Service
• Strain Development Service
• Fermentation Process Optimization
• Fermentation for Special Small Molecules
• GRAS Services

BOC Sciences provides fermentation CDMO service for biopolymers. With our advanced equipment and extensive expertise, we are able to perform microbial production of biopolymers and their monomer molecules, providing a full range of services from fermentation to synthesis.

Workflow of Our Service

References

1. Vigneswari, S.; et al. Recent Advances in the Biosynthesis of Polyhydroxyalkanoates from Lignocellulosic Feedstocks. Life (Basel, Switzerland). 2021. 11(8).
2. Liu, H.; et al. Biopolymer poly-hydroxyalkanoates (PHA) production from apple industrial waste residues: A review. Chemosphere. 2021. 284:131427.
3. Pradhan, S.; et al. Microbial production, ultrasound-assisted extraction and characterization of biopolymer polyhydroxybutyrate (PHB) from terrestrial (P. hysterophorus) and aquatic (E. crassipes) invasive weeds. Bioresource Technology. 2017. 242: 304-310.