Aug 2026· Journal of Biotechnology· Vol 419, pp. 53-57· 0 citations· 24 references
Medicine
Abstract
The bioplastics field has oriented around industrial compostability as the primary biodegradation target. We argue this constitutes a regime mismatch: most plastic waste enters landfills - anaerobic, ambient-temperature environments in which poly(lactic acid) (PLA) and the majority of certified compostable bioplastics exhibit negligible degradation. Accepting landfill-active biodegradability as the correct constraint immediately reorders the candidate space. We conduct a systematic analysis across molecule class, production organism, processing architecture, and degradation mechanism, identifying three primary microbial production architectures with credible paths to the $1-2/kg commodity cost target: (1) Halomonas bluephagenesis Next-Generation Industrial Biotechnology (NGIB) for polyhydroxyalkanoate (PHA) - the most industrially-validated architecture, with demonstrated 149g/L cell dry weight at 82% PHA in 5,000-L continuous non-sterile fermentation; (2) poly(γ-glutamic acid) (γ-PGA) / chitosan polyelectrolyte composites - extracellular production from Bacillus subtilis, water-phase processing without organic solvents, thermoplastic behavior when dry, and rapid protease-mediated landfill degradation, a combination not previously proposed as an integrated commodity plastic production strategy; and (3) a beetle cuticle-mimetic composite produced entirely from microbial sources - presented as a biomimetic materials hypothesis pending experimental validation. Two orthogonal strategies - bacterial cellulose pellicle production and viral capsid protein nanofillers - are evaluated as secondary approaches. A claim-status framework distinguishing evidence levels across all architectures is provided.
The accumulation of biodegradable plastics (BPs) in wastewater treatment plants (WWTPs) presents a novel environmental concern, while carbon deficiency concurrently limits advanced biological denitrification. Herein, this research explored the fate of BPs and their viability as solid-phase carbon donors for denitrification. Six prevalent BPs were selected; results showed that microbially synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was identified as the optimal solid-phase carbon source with superior DOC bioavailability, achieving a denitrification rate of 0.72 mg/(g·h). Light irradiation and pH variations accelerated DOC release via surface micro-cleavage, predominantly yielding highly active aliphatic oligomers without disrupting the primary polymeric backbone. Furthermore, macromolecular depolymerization genes (cellulase, hexosaminidase) and nitrous oxide reductase genes (nosZ, nosD) were strongly temperature-dependent, which induced the directional enrichment of the core denitrifying genus Thauera and upregulated expression at 25 °C, which promoted NO3− reduction. This research provides the theoretical basis for the in situ resource utilization of BPs for advanced wastewater denitrification.
: The increasing prevalence of plastic pollution demands strategies for sustainable biodegradable plastic production. Marine bacteria can be found on all continents able to survive in a variety of salinity levels and may be used to biosynthesis polyhydroxyalkanoates (PHAs), which can serve as a bioplastic substitute for conventional petroleum-based plastics. This paper presents a literature review and case study examining marine PHAs-producing microorganisms in the context of a circular bioeconomy and waste management. More specifically, it examines the marine PHA-producing bacteria’s ability to utilise varying and renewable carbon substrates for PHA biosynthesis. From prior research studies, it was found that diversity of marine bacteria possesses the ability to produce short-chain length (scl-PHA) and medium-chain length (mcl-PHA) types of PHAs, leading to wide potential applications. The integration of marine bacterial processes not only mitigates waste and pollution in the environment but also contributes to carbon cycling through the conversion of greenhouse gases into valuable biopolymers. This demonstrates the importance of marine microbes for bioplastic production and reinforces the need for the use of marine biota in the management of bioplastics to achieve a sustainable and circular economy.
Nurul Afifah Mohd Kamal Rufadzil, Siti Nor Syairah Anis, S. Vigneswari· Journal of Polymer Materials· 0 citations
Anaerobic biodegradation of bioplastics has gained increasing attention as a sustainable strategy for waste valorization and renewable energy recovery within circular bio-economy systems. The present study investigated the anaerobic biodegradation of Poly lactic acid (PLA) pellet, PLA film, Polybutylene succinate (PBS), and commercially available bioplastics under controlled conditions at different temperatures and incubation periods. Biodegradation behavior was evaluated through cumulative gas production, visual observations, FTIR characterization, kinetic modeling, and microbial analysis. All biopolymer samples exhibited significant cumulative gas production within 20 days before reaching the stationary phase. Among the biopolymer materials, PLA film showed distinct degradation behavior with high total solids (92.5%) and volatile solids (75.4%), along with the highest cumulative gas production. FTIR analysis and observable structural changes further confirmed polymer degradation during anaerobic digestion. Microbial species associated with biodegradation were identified through PCR amplification, 16S rRNA sequencing, and phylogenetic analysis, revealing the involvement of Bacillus sp in the degradation process. The cumulative biogas production profiles of all biopolymers followed the Hill sigmoidal kinetic model with high correlation coefficients (R2: 0.9854, 0.9839, 0.9931, and 0.9772 for PLA pellet, PBS, PLA film, and bioplastic, respectively), indicating excellent model fitting accuracy. Moreover, a generalized anaerobic biodegradation model equation was developed for biopolymers. The findings demonstrated the potential applicability of anaerobic digestion for biopolymer waste valorization through simultaneous biodegradation and biogas generation, supporting sustainable waste management and circular bio-economy approaches.
Partha Kundu, Mariyam Muhammed, Ananthakrishnan G et al.· Preparative Biochemistry & B...· 1 citation
Polyhydroxyalkanoates (PHAs) are a promising class of bio-based, biodegradable polymers that offer a sustainable alternative to conventional fossil-based plastics. However, their commercialization is hindered by high production costs, primarily due to expensive feedstock and complex downstream processing. While valorizing organic waste is a clear path to economic viability, recent research has shown that the two primary feedstocks, food waste (FW) and lipid-rich waste (LRW), demand fundamentally divergent bioprocessing strategies rooted in their distinct biochemical composition and microbial utilization pathways. This review provides a critical, mechanism-based comparative analysis of these two waste-derived PHA platforms: the multi-stage FW-to-volatile fatty acids (VFA) and sugar platform, which is limited by costly pretreatment and mixed culture challenges, and the LRW-to-PHA platform, which offers a high-yield pathway constrained by mass transfer and the need for sterile fermentation. This review further examines advances in microbial metabolism and bioprocess design, highlighting how strain selection and fermentation strategies align with feedstock-specific challenges. It also evaluates modern downstream extraction and purification methods for their impact on polymer quality, cost, and scalability, demonstrating the potential of waste-derived PHAs for applications in packaging, biomedical devices, and agriculture. Finally, the review proposes an evidence-based, application-driven decision-support framework to guide platform selection based on feedstock composition and target polymer specifications.
Lijun Luo, P. Dessì, R. Tyagi et al.· Bioresource Technology· 0 citations
The increasing accumulation of petroleum-based plastic waste and wastewater has intensified the need for sustainable waste management and biodegradable alternatives. Poly(3-hydroxybutyrate) (P3HB), a microbial biopolymer, has emerged as a promising substitute for conventional plastics. This article reviews the potential of wastewater as a renewable substrate for P3HB production, with emphasis on microbial pathways, production strategies, and sustainability aspects. It discusses different wastewater sources, P3HB-producing microorganisms, metabolic engineering approaches, production processes, and polymer recovery techniques, highlighting the factors that influence productivity and product quality. The integration of P3HB production into biorefinery systems and its contribution to resource recovery, greenhouse gas mitigation, and the circular bioeconomy are also addressed. Overall, wastewater-based P3HB production represents a sustainable and economically attractive approach for biodegradable polymer production, although further technological advances are required to support large-scale industrial implementation.
Gul Ahmad Fazli, Fariba Fazli, Omid Fazli· International Journal of Cur...· 0 citations
The production and utilization of petroleum‐based plastics cause severe environmental degradation and climate alteration. These conventional plastics release greenhouse gases and hazardous chemicals during production, and their resistance to degradation—persisting undamaged for over 60 years—fuels critical marine pollution. To mitigate these issues, research is shifting toward biobased plastics as sustainable, biocompatible, and biodegradable alternatives. Derived from renewable biomass or microbes, these materials include starches, cellulose, casein, and diverse polysaccharides sourced from red (
Rhodophyta
), green (
Chlorophyta
), and brown (
Phaeophyta
) algae. Aligning with the principles of a circular bioeconomy, this approach maximizes resource efficiency and minimizes waste. Furthermore, innovative materials like Bio‐PET, polybutylene succinate (PBS), polylactic acid (PLA), and polyhydroxyalkanoates (PHAs) are increasingly deployed to replace traditional plastics. Beyond offering excellent preservation against oxidation and microbial decomposition in food packaging, these bioplastics show immense promise in medicine, nutraceuticals, and pharmaceuticals. This review article evaluates the diverse natural sources of bioplastics, analyzes their mechanical, thermal, and physical properties, and highlights their most promising future applications.
