Related Experiment Video
Updated: May 14, 2026
08:14
Scalable Step-by-Step Approach of Sustainable Bioplastic Production from Food Waste
Published on: July 18, 2025
High-load terephthalic acid degradation and diverse bioproduct formation by novel Rhodococcus strains
Caio Issamu Somiza1, Nívea Moreira Vieira2, Alex Gazolla de Castro2
1Department of Microbiology, Federal University of Viçosa, Viçosa, Brazil. caio.somiza@gmail.com.
Biotechnology Letters
|May 13, 2026
Summary
Seven Rhodococcus bacteria strains were discovered that can completely degrade high concentrations of terephthalic acid (TPA), a PET plastic component. These robust microbes offer new possibilities for microbial plastic upcycling.
Area of Science:
- Microbiology
- Biotechnology
- Environmental Science
Background:
- Terephthalic acid (TPA) from poly(ethylene terephthalate) (PET) depolymerization is a key target for microbial upcycling.
- Previous studies reported limitations in complete TPA degradation at concentrations above 120 mM.
Purpose of the Study:
- To isolate and characterize robust Rhodococcus strains capable of degrading high concentrations of TPA.
- To explore the microbial products generated from TPA assimilation by these strains.
Main Methods:
- Isolation of bacteria from compost enrichment cultures using TPA as the sole carbon source.
- Cultivation of isolates in minimal medium under high osmolarity to assess TPA degradation.
- Analysis of microbial products, including exopolysaccharides, polyhydroxyalkanoates, and fatty acids.
Main Results:
- Seven Rhodococcus strains were isolated, with three completely consuming 240 mM TPA, exceeding the previously reported threshold.
- Strain TA18 produced novel β-linked exopolysaccharides and a polyhydroxyalkanoate (PHA) rich in 3-hydroxyvalerate from TPA.
- C16 and C18 fatty acids were also identified as metabolic products in strain TA18.
Conclusions:
- The identified Rhodococcus strains demonstrate enhanced TPA assimilation capabilities, expanding the toolkit for PET upcycling.
- These findings provide a foundation for developing microbial routes to convert plastic waste into valuable products like PHAs and exopolysaccharides.
Related Concept Videos
01:28Microbial Bioremediation of Plastics
Polyethylene terephthalate (PET) is a synthetic polymer widely utilized in the packaging industry, particularly for bottles and containers. Due to its chemical stability and durability, PET accumulates in the environment, contributing significantly to plastic pollution. It comprises repeating units of terephthalic acid and ethylene glycol, resulting in a semi-crystalline structure that is resistant to natural degradation processes.A notable breakthrough in plastic biodegradation came with the...
01:27Bioplastics
Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrates (PHBs), have emerged as prominent candidates due to their biodegradability and biocompatibility. These polymers are synthesized by a variety of bacteria, such as Cupriavidus necator and Pseudomonas putida, which naturally accumulate PHAs as intracellular carbon and energy reserves, especially under...
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:25Lipid Catabolism
Triglycerides serve as crucial long-term energy storage molecules in microorganisms, providing a dense source of metabolic energy. Their breakdown is mediated by lipases, which hydrolyze triglycerides into glycerol and free fatty acids. Each of these components follows distinct metabolic pathways, ultimately contributing to ATP synthesis and cellular energy homeostasis.Glycerol MetabolismGlycerol, released from triglyceride hydrolysis, is phosphorylated by glycerol kinase to form...
01:27Production of Antibiotics
Penicillin, one of the earliest and most widely used antibiotics, is produced industrially by the filamentous fungus Penicillium chrysogenum. Large stirred-tank bioreactors ranging from tens to hundreds of thousands of liters maintain tightly controlled temperature, pH, and dissolved oxygen conditions to support fungal metabolism and maximize antibiotic yield. Penicillin is a secondary metabolite, synthesized primarily during the stationary growth phase, which requires a carefully managed...
01:20Types of Step-Growth Polymers: Polyesters
The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...