Deciphering the complexity of the chemicals in food packaging materials using molecular networks.

Chemicals from packaging materials might be transferred into food resulting in consumer exposure. Identifying these migrated chemicals is highly challenging and crucial to perform their safety assessment, usually starting by the understanding of the chemical composition of the packaging material itself. This study explores the use of the Molecular Networking (MN) approach to support identification of the extracted chemicals. Two formulations of bioplastics were analyzed using Liquid Chromatography hyphenated to High-Resolution Mass Spectrometry. Data processing and interpretation using a conventional manual method was performed as a point of comparison to understand the power of MN. Interestingly, only the MN approach facilitated the identification of unknown chemicals belonging to a novel oligomer series containing the azelaic acid monomer. The MN approach provided a faster visualization of chemical families in addition to the highlight of unrelated chemicals enabling to prioritize chemicals for further investigation improving the safety assessment of packaging materials.

Aqueous-based assembly of plant-derived proteins yields a crosslinker-free biodegradable bioplastic consistent with green chemistry principles.

Plastics are an indispensable part of modern life. Due to the harmful environmental consequences of petroleum-based plastic usage, there is an urgent need to replace them with biodegradable bioplastics that meet the sustainability standards required for a low environmental footprint. Here, we use plant-derived proteins to produce bioplastics. Since most plant-derived proteins are not water-soluble, there has always been a need to use acidic or basic solutions or organic solvents with plasticizers and crosslinkers to produce bioplastic. Here, we present a counterintuitive approach for using water-insoluble plant-derived soy and pea proteins to manufacture large-scale bioplastics using only water as a solvent without common plasticizers or crosslinkers. We show that bioplastics can form via a self-assembly process initiated by a small molecular initiator while maintaining favourable mechanical properties. The lack of crosslinking and the protein nature of the bioplastic leads to a rapid biodegradation process under various conditions. Overall, the approach we present is highly attractive in terms of cost and time, and most importantly, it obeys all the relevant principles of green chemistry in bioplastics production.

Abiotic degradation and accelerated ageing of microplastics from biodegradable and recycled materials in artificial seawater.

Microplastics (MPs) are considered one of the most widespread pollutants in all ecosystems worldwide. In the environment, MPs can undergo hydrolysis and/or oxidation, resulting in the release of low-molecular weight degradation products, along with additives, and adsorbed organic pollutants. In this study, the morphological, chemical, and thermal changes of microplastics obtained from two biodegradable plastics, polylactic acid and Mater-Bi®, and a recycled plastic, recycled-polyethylene terephthalate, were examined after accelerated ageing under photo-oxidative conditions in synthetic seawater in a Solarbox system, and after thermal treatment in the dark. Thermal properties have been studied by thermogravimetric analysis, differential scanning calorimetry, and evolved gas analysis-mass spectrometry. Compositions and changes of chemical components of the polymers were evaluated by attenuated total reflection-Fourier transform infrared spectroscopy and pyrolysis-gas chromatography-mass spectrometry. The leachable fractions and degradation products released in synthetic seawater by degraded MPs were characterized by gas chromatography-mass spectrometry. This study allowed us to identify hydrolysis as the main degradation pathway of the polymers under analysis, and to characterize not only the oligomers and degradation products released in the water as a consequence of degradation, but also additives used in plastic item formulations. This study improves our understanding of these polymers' behavior under accelerated ageing conditions.

Synergistic effects of starch and carrageenan from Kappaphycus alvarezii in composite film formation: Physicochemical and degradable properties.

Rising concerns around plastic pollution from single-use plastic (SUPs), especially food packaging, have driven interest in sustainable alternatives. As such, algae biomass has gained attention for bioplastic production due to algae's rapid growth and abundant polysaccharides. This research focuses on extracting carrageenan from Kappaphycus alvarezii, extensively cultivated in Sabah, Malaysia, and utilizing it in combination with starch and glycerol to develop algae-based films. The physicochemical properties and degradation rate of these films were evaluated, revealing that the addition of carrageenan enhanced overall thermal stability meanwhile increasing water solubility, water content but reducing the degradation rate and swelling degree. This is primarily due to the crystalline structures of carrageenan, which provide a more rigid arrangement compared to the network of starch polymers. However, the incorporation of starch into the blends has enhanced the elongation and surface morphology, resulting in more balanced properties. Overall, these carrageenan films displayed impressive thermal, mechanical, and biodegradability characteristics, establishing their viability as substitutes for conventional plastics.

Production of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by Haloferax mediterranei Using Candy Industry Waste as Raw Materials.

The haloarchaeon Haloferax mediterranei synthesizes poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under unfavorable nutritional conditions without the addition of any precursor to the culture, which is an advantage compared to other microbial counterparts able to synthesize polyhydroxyalkanoates (PHA). PHBV is a biodegradable polymer showing physiochemical properties of biotechnological and biomedical interest and can be used as an alternative to plastics made from chemical synthesis (which are not environmentally friendly). The versatile metabolism of H. mediterranei makes the use of waste as a carbon source for cellular growth and PHA synthesis possible. In this work, cellular growth and the production and characterization of PHBV using two different types of confectionery waste were analyzed and compared with cellular growth and PHBV synthesis in a standard culture media with glucose of analytical grade as a carbon source. The PHBV granules produced were analyzed by TEM and the biopolymer was isolated and characterized by GC-MS, FTIR NMR, and DSC. The results reveal that H. mediterranei can use these two residues (R1 and R2) for pure PHBV production, achieving 0.256 and 0.983 g PHBV/L, respectively, which are among the highest yields so far described using for the first-time waste from the candy industry. Thus, a circular economy-based process has been designed to optimize the upscaling of PHBV production by using haloarchaea as cell factories and valorizing confectionery waste.

Ageing behavior of starch-based food packaging bioplastics in riparian sediments and sediment-derived dissolved organic matter in the soil environment.

Riparian sediment (RS) is a translational zone separating aquatic and terrestrial ecosystems. To this date, the bioplastic's UV ageing and biodegradation features in these contaminated sediments remain unknown. It is a considerable concern to investigate whether a food packaging film can interact with RS and riparian sediment-derived Dissolved Organic Matter (RS-DOM) during biodegradation and UV ageing respectively, after disposal in a natural environmental setting. To address this research gap, for the first time, this study investigates the biodegradation and UV ageing of starch/PPst/GTR films intended for food packaging applications in RS and RS-DOM respectively. The findings revealed that RS comprises major fulvic acid DOM components. Remarkably, research demonstrates the leaching of humic acid-like DOM from the film promotes aromaticity and humification as UV ageing progresses from the third to the tenth day. Comparable DOM samples were darkly analysed, revealing aromatic proteins I and II. Furthermore, an elevated carbonyl carboxyl index confirmed significant degradation of films during UV ageing. Lesser humification, aromaticity, and higher biological activity were confirmed by a HI < 10 and BIX > 0.6 respectively. In comprehension, these findings reveal that the starch/PPst/GTR food packaging film will have a lesser adverse environmental impact after disposal, offering a hopeful outlook for the future of bioplastics.

Recent Advances in Food Waste Transformations into Essential Bioplastic Materials.

Lignocellulose is a major biopolymer in plant biomass with a complex structure and composition. It consists of a significant amount of high molecular aromatic compounds, particularly vanillin, syringeal, ferulic acid, and muconic acid, that could be converted into intracellular metabolites such as polyhydroxyalkanoates (PHA) and hydroxybutyrate (PHB), a key component of bioplastic production. Several pre-treatment methods were utilized to release monosaccharides, which are the precursors of the relevant pathway. The consolidated bioprocessing of lignocellulose-capable microbes for biomass depolymerization was discussed in this study. Carbon can be stored in a variety of forms, including PHAs, PHBs, wax esters, and triacylglycerides. From a biotechnology standpoint, these compounds are quite adaptable due to their precursors' utilization of hydrogen energy. This study lays the groundwork for the idea of lignocellulose valorization into value-added products through several significant dominant pathways.

Advances in Microbial Biotechnology for Sustainable Alternatives to Petroleum-Based Plastics: A Comprehensive Review of Polyhydroxyalkanoate Production.

The industrial production of polyhydroxyalkanoates (PHAs) faces several limitations that hinder their competitiveness against traditional plastics, mainly due to high production costs and complex recovery processes. Innovations in microbial biotechnology offer promising solutions to overcome these challenges. The modification of the biosynthetic pathways is one of the main tactics; allowing for direct carbon flux toward PHA formation, increasing polymer accumulation and improving polymer properties. Additionally, techniques have been implemented to expand the range of renewable substrates used in PHA production. These feedstocks are inexpensive and plentiful but require costly and energy-intensive pretreatment. By removing the need for pretreatment and enabling the direct use of these raw materials, microbial biotechnology aims to reduce production costs. Furthermore, improving downstream processes to facilitate the separation of biomass from culture broth and the recovery of PHAs is critical. Genetic modifications that alter cell morphology and allow PHA secretion directly into the culture medium simplify the extraction and purification process, significantly reducing operating costs. These advances in microbial biotechnology not only enhance the efficient and sustainable production of PHAs, but also position these biopolymers as a viable and competitive alternative to petroleum-based plastics, contributing to a circular economy and reducing the dependence on fossil resources.

Integrated assessment of the chemical, microbiological and ecotoxicological effects of a bio-packaging end-of-life in compost.

The present study aimed to i) assess the disintegration of a novel bio-packaging during aerobic composting (2 and 6 % tested concentrations) and evaluate the resulting compost ii) analyse the ecotoxicity of bioplastics residues on earthworms; iii) study the microbial communities during composting and in 'earthworms' gut after their exposure to bioplastic residues; iv) correlate gut microbiota with ecotoxicity analyses; v) evaluate the chemico-physical characterisation of bio-packaging after composting and earthworms' exposure. Both tested concentrations showed disintegration of bio-packaging close to 90 % from the first sampling time, and compost chemical analyses identified its maturity and stability at the end of the process. Ecotoxicological assessments were then conducted on Eisenia fetida regarding fertility, growth, genotoxic damage, and impacts on the gut microbiome. The bioplastic residues did not influence the earthworms' fertility, but DNA damages were measured at the highest bioplastic dose tested. Furthermore bioplastic residues did not significantly affect the bacterial community during composting, but compost treated with 2 % bio-packaging exhibited greater variability in the fungal communities, including Mortierella, Mucor, and Alternaria genera, which can use bioplastics as a carbon source. Moreover, bioplastic residues influenced gut bacterial communities, with Paenibacillus, Bacillus, Rhizobium, Legionella, and Saccharimonadales genera being particularly abundant at 2 % bioplastic concentration. Higher concentrations affected microbial composition by favouring different genera such as Pseudomonas, Ureibacillus, and Streptococcus. For fungal communities, Pestalotiopsis sp. was found predominantly in earthworms exposed to 2 % bioplastic residues and is potentially linked to its role as a microplastics degrader. After composting, Attenuated Total Reflection analysis on bioplastic residues displayed evidence of ageing with the formation of hydroxyl groups and amidic groups after earthworm exposure.

Green composites for sustainable food packaging: Exploring the influence of lignin-TiO2 nanoparticles on poly(butylene adipate-co-terephthalate).

Titanium dioxide (TiO2) is a common pigment used in food packaging to provide a transparent appearance to plastic packaging materials. In the present study, poly(butylene adipate-co-terephthalate) (PBAT) incorporated with lignin-TiO2 nanoparticles (L-TiO2) eco-friendly composite films was prepared by employing an inexpensive melting and hot-pressing technique. The P-L-TiO2 composite films have been studied using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), Thermogravimetric analysis (TGA), and Differential scanning calorimetry (DSC) analysis. The FTIR results and homogeneous, dense SEM images confirm the interaction of L-TiO2 with the PBAT matrix. It has also been found that the addition of L-TiO2 nanoparticles can increase the crystallinity, tensile strength, and thermal stability of PBAT. The addition of L-TiO2 increased the tensile strength and decreased the elongation at break of films. The maximum tensile strength of the film, achieved with 5 wt% L-TiO2, was 47.0 MPa, compared with 24.3 MPa for pure PBAT film. The composite film with 5 wt% L-TiO2 has outstanding oxygen and water vapor barrier properties. As the content of lignin-TiO2 increases, the antimicrobial activity of the composite films also increases; the percentage of growth of all the tested bacteria Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) is significantly reduced. Strawberries were packed to evaluate the suitability of produced composite films as packaging materials, as they effectively preserved pigments from accumulation and extended the shelf-life as compared to commercial polyethylene packaging film.

Microbial Biosynthesis of Medium-Chain-Length Polyhydroxyalkanoate (mcl-PHA) from Waste Cooking Oil.

Waste cooking oil is a common byproduct in the culinary industry, often posing disposal challenges. This study explores its conversion into the valuable bioplastic material, medium-chain-length polyhydroxyalkanoate (mcl-PHA), through microbial biosynthesis in controlled bioreactor conditions. Twenty-four bacterial isolates were obtained from oil-contaminated soil and waste materials in Mahd Ad-Dahab, Saudi Arabia. The best PHA-producing isolates were identified via 16S rDNA analysis as Neobacillus niacini and Metabacillus niabensis, with the sequences deposited in GenBank (accession numbers: PP346270 and PP346271). This study evaluated the effects of various carbon and nitrogen sources, as well as environmental factors, such as pH, temperature, and shaking speed, on the PHA production titer. Neobacillus niacini favored waste cooking oil and yeast extract, achieving a PHA production titer of 1.13 g/L, while Metabacillus niabensis preferred waste olive oil and urea, with a PHA production titer of 0.85 g/L. Both strains exhibited optimal growth at a neutral pH of 7, under optimal shaking -flask conditions. The bioreactor performance showed improved PHA production under controlled pH conditions, with a final titer of 9.75 g/L for Neobacillus niacini and 4.78 g/L for Metabacillus niabensis. Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) confirmed the biosynthesized polymer as mcl-PHA. This research not only offers a sustainable method for transforming waste into valuable materials, but also provides insights into the optimal conditions for microbial PHA production, advancing environmental science and materials engineering.

Biomethanization of rigid packaging made entirely of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate): Mono- and co-digestion tests and microbial insights.

This study evaluates the anaerobic mesophilic mono- and co-digestion of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) plastic bottles as a proxy for rigid packaging materials. Initial tests showed a 97.3 ± 0.2 % reduction in weight and an observable alteration in the surface (thinning, color fading and pitting) of the PHBH bottles after eight weeks. Subsequent tests showed that PHBH squares (3 × 3 cm) produced 400 NmL-CH4/g-VSfed, at a slower rate compared to powdered PHBH but with similar methane yield. Co-digestion experiments with food waste, swine manure, or sewage sludge showed successful digestion of PHBH alongside organic waste (even at a high bioplastic loading of 20 % volatile solids basis), with methane production comparable to or slightly higher than that observed in mono-digestion. Molecular analyses suggested that the type of co-substrate influenced microbial activity and that methane production was mainly driven by hydrogenotrophic methanogenesis. These results suggest the potential for integrating rigid PHBH packaging into anaerobic digesters.

Overexpression of RuBisCO form I and II genes in Rhodopseudomonas palustris TIE-1 augments polyhydroxyalkanoate production heterotrophically and autotrophically.

With the rising demand for sustainable renewable resources, microorganisms capable of producing bioproducts such as bioplastics are attractive. While many bioproduction systems are well-studied in model organisms, investigating non-model organisms is essential to expand the field and utilize metabolically versatile strains. This investigation centers on Rhodopseudomonas palustris TIE-1, a purple non-sulfur bacterium capable of producing bioplastics. To increase bioplastic production, genes encoding the putative regulatory protein PhaR and the depolymerase PhaZ of the polyhydroxyalkanoate (PHA) biosynthesis pathway were deleted. Genes associated with pathways that might compete with PHA production, specifically those linked to glycogen production and nitrogen fixation, were deleted. Additionally, RuBisCO form I and II genes were integrated into TIE-1's genome by a phage integration system, developed in this study. Our results show that deletion of phaR increases PHA production when TIE-1 is grown photoheterotrophically with butyrate and ammonium chloride (NH4Cl). Mutants unable to produce glycogen or fix nitrogen show increased PHA production under photoautotrophic growth with hydrogen and NH4Cl. The most significant increase in PHA production was observed when RuBisCO form I and form I & II genes were overexpressed, five times under photoheterotrophy with butyrate, two times with hydrogen and NH4Cl, and two times under photoelectrotrophic growth with N2 . In summary, inserting copies of RuBisCO genes into the TIE-1 genome is a more effective strategy than deleting competing pathways to increase PHA production in TIE-1. The successful use of the phage integration system opens numerous opportunities for synthetic biology in TIE-1.IMPORTANCEOur planet has been burdened by pollution resulting from the extensive use of petroleum-derived plastics for the last few decades. Since the discovery of biodegradable plastic alternatives, concerted efforts have been made to enhance their bioproduction. The versatile microorganism Rhodopseudomonas palustris TIE-1 (TIE-1) stands out as a promising candidate for bioplastic synthesis, owing to its ability to use multiple electron sources, fix the greenhouse gas CO2, and use light as an energy source. Two categories of strains were meticulously designed from the TIE-1 wild-type to augment the production of polyhydroxyalkanoate (PHA), one such bioplastic produced. The first group includes mutants carrying a deletion of the phaR or phaZ genes in the PHA pathway, and those lacking potential competitive carbon and energy sinks to the PHA pathway (namely, glycogen biosynthesis and nitrogen fixation). The second group comprises TIE-1 strains that overexpress RuBisCO form I or form I & II genes inserted via a phage integration system. By studying numerous metabolic mutants and overexpression strains, we conclude that genetic modifications in the environmental microbe TIE-1 can improve PHA production. When combined with other approaches (such as reactor design, use of microbial consortia, and different feedstocks), genetic and metabolic manipulations of purple nonsulfur bacteria like TIE-1 are essential for replacing petroleum-derived plastics with biodegradable plastics like PHA.

The Development of Biocomposite Filaments for 3D Printing by Utilizing a Polylactic Acid (PLA) Polymer Matrix Reinforced with Cocoa Husk Cellulose Fibers.

Vegetable fibers are increasingly used in biocomposites, but there is a need for further development in utilizing by-products like cocoa husks. Three-dimensional printing, through Fused Filament Fabrication (FFF), is advancing rapidly and may be of great interest for applying biocomposite materials. This study focuses on developing innovative and fully biodegradable filaments for the FFF process. PLA filaments were prepared using cellulose fibers derived from cocoa husks (5% mass ratio). One set of filaments incorporated fibers from untreated husks (UCFFs), while another set utilized fibers from chemically treated husks (TCFFs). The fabricated materials were analyzed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) techniques, and they were also tested for tensile strength. ANOVA reveals that both UCFFs and TCFFs significantly predict tensile strength, with the UCFFs demonstrating an impressive R2 value of 0.9981. The optimal tensile strength for the filament test specimens was 16.05 MPa for TCFF8 and 13.58 MPa for UCFF8, utilizing the same printing parameters: 70% infill and a layer thickness of 0.10 mm. Additionally, there was an 18% improvement in the tensile strength of the printed specimens using the filaments filled with chemically treated cocoa husk fibers compared to the filaments with untreated fibers.

Development of Polymeric Films Based on Sunflower Seed Proteins and Locust Bean Gum.

Most polymeric food packaging materials are non-biodegradable and derived from petroleum, thus recent studies have focused on evaluating alternative biodegradable materials from renewable sources, with polysaccharides and proteins as the main types of employed biopolymers. Therefore, this study aimed to develop biopolymeric films based on sunflower proteins and galactomannans from locust bean gum. The influence of the galactomannan amount (0.10%, 0.30%, 0.50%, and 0.75% w/v) on the physicochemical, thermal, and mechanical properties of cast sunflower protein-based films was studied. Sunflower proteins gave rise to yellowish, shining, and translucid films. With the incorporation of locust bean gum-derived galactomannans, the films became more brown and opaque, although they still maintained some translucency. Galactomannans significantly changed the proteins' secondary structures, giving rise to films with increased tensile resistance and stretchability. Nevertheless, the increase in the galactomannan amount did not have a significant effect on the film's thermal stability. The protein/galactomannan-based films showed values of water vapor and oxygen permeability that were slightly higher than those of the pristine materials. Overall, blending locust bean gum galactomannans with sunflower proteins was revealed to be a promising strategy to develop naturally colored and translucid films with enhanced mechanical resistance while maintaining flexibility, fitting the desired properties for biodegradable food packaging materials.

Development of Biodegradable Bioplastics with Sericin and Gelatin from Silk Cocoons and Fish Waste.

The bioplastics sector promotes environmentally friendly means of cutting down on the usage of fossil fuels, plastic waste, and environmental pollution. Plastic contamination has detrimental effects on both ecological systems and the global food supply. The approach we present here to resolve this issue involves the integration of sericin and gelatin, obtained from cocoon and fish waste, respectively, with nano-reinforced cellulose crystals, to develop a biodegradable and compostable plastic material. The use of cocoon and fish wastes for the extraction of sericin and gelatin presents an environmentally beneficial approach since it contributes to waste reduction. The sericin level found in silk cocoon waste was determined to be 28.08%, and the gelatin amount in fish waste was measured to be 58.25%. The inclusion of sericin and gelatin in bioplastics was accompanied by the incorporation of glycerol, vinegar, starch, sodium hydroxide, and other coloring agents. Fourier transform infrared (FTIR) examination of bioplastics revealed the presence of functional groups that corresponded to the sericin and gelatin components. The tensile strength of the bioplastic material was measured to be 27.64 MPa/psi, while its thickness varied between 0.072 and 0.316 mm. The results of burial experiments indicated that the bioplastic material had a degradation rate of 85% after 14 days. The invention exhibits potential as a viable alternative for packaging, containment, and disposable plastic materials. The use of this sustainable approach is recommended for the extraction of sericin and gelatin from silk cocoons and fish waste, with the intention of using them as raw materials for bioplastic production.

Molecular changes and interactions of wheat flour biopolymers during bread-making: Implications to upcycle bread waste into bioplastics.

This study aims to understand the molecular and supramolecular transformations of wheat endosperm biopolymers during bread-making, and their implications to fabricate self-standing films from stale white bread. A reduction in the Mw of amylopectin (51.8 × 106 vs 425.1 × 106 g/mol) and water extractable arabinoxylans WEAX (1.79 × 105 vs 7.63 × 105 g/mol), and a decrease in amylose length (245 vs 748 glucose units) was observed after bread-baking. The chain length distribution of amylopectin and the arabinose-to-xylose (A/X) ratio of WEAX remained unaffected during bread-making, suggesting that heat- or/and shear-induced chain scission is the mechanism responsible for molecular fragmentation. Bread-making also resulted in more insoluble cell wall residue, featured by water unextractable arabinoxylan of lower A/X and Mw, along with the formation of a gluten network. Flexible and transparent films with good light-blocking performance (<30 % transmittance) and DPPH-radical scavenging capacity (~8.5 %) were successfully developed from bread and flour. Bread films exhibited lower hygroscopicity, tensile strength (2.7 vs 8.5 MPa) and elastic modulus (67 vs 501 MPa) than flour films, while having a 6-fold higher elongation at break (10.0 vs 61.2 %). This study provides insights into the changes in wheat biopolymers during bread-making and sets a precedent for using stale bread as composite polymeric materials.

From raw microalgae to bioplastics: Conversion of Chlorella vulgaris starch granules into thermoplastic starch.

Microalgae are emerging as a promising feedstock for bioplastics, with Chlorella vulgaris yielding significant amounts of starch. This polysaccharide is convertible into thermoplastic starch (TPS), a biodegradable plastic of industrial relevance. In this study, we developed a pilot-scale protocol for extracting and purifying starch from 430 g (dry weight - DW) of starch-enriched Chlorella vulgaris biomass. More than 200 gDW of starch were recovered, with an extraction yield and starch purity degree reaching 98 and 87 %, respectively. We have characterized this extracted starch and processed it into TPS using twin-screw extrusion and injection molding. Microalgal starch showed similar properties to those of native plant starch, but with smaller granules. We compared the mechanical properties of microalgal TPS with two controls, namely a commercial TPS and a TPS prepared from commercial potato starch granules. TPS prepared from microalgal starch showed a softer and more ductile behavior compared to the reference materials. This study demonstrates the feasibility of recovering high-purity microalgal starch at pilot scale with high yields, and highlights the potential of microalgal starch for the production of TPS using industrially relevant processes.

Key challenges in the advancement and industrialization of biobased and biodegradable plastics: a value chain overarching perspective.

At the International Symposium on Biodegradable Polymers (ISBP2022) in Sion, Switzerland, experts from academia and industry underscored the remarkable progress in biobased and biodegradable polymers (BBPs) since their initial commercialization around 50 years ago. Despite significant advancements, the technology readiness level (TRL), market adoption, and industrialization of BBPs is not yet competitive to conventional plastics. In this perspective, we summarize the challenges and requirements for advancing the development and industrialization of BBPs, drawing insights from international experts coming from academia and industry, who had participated in the survey and podium discussion during the ISBP2022. In fact, BBPs grapple with persistent and emerging challenges throughout the value chain. These challenges can be grouped into four areas and involve i) the pursuit of sustainable feedstocks together with efficient production and downstream processes as well as recycling technologies and infrastructure; ii) meeting or revisiting product requirements by industry, markets, and consumers; iii) navigating a non-level playing field in their sustainability assessment (LCA) compared to conventional plastics; and iv) struggling with underdeveloped and partially biased policy and financial frameworks as well as lacking clear definitions, terminologies and communication.

Electrochemical detection of poly(3-hydroxybutyrate) production from Burkholderia glumae MA13 using a molecularly imprinted polymer-reduced graphene oxide modified electrode.

The development and application of an electrochemical sensor is reported for detection of poly(3-hydroxybutyrate) (P3HB) - a bioplastic derived from agro-industrial residues. To overcome the challenges of molecular imprinting of macromolecules such as P3HB, this study employed methanolysis reaction to break down the P3HB biopolymer chains into methyl 3-hydroxybutyrate (M3HB) monomers. Thereafter, M3HB were employed as the target molecules in the construction of molecularly imprinted sensors. The electrochemical device was then prepared by electropolymerizing a molecularly imprinted poly (indole-3-acetic acid) thin film on a glassy carbon electrode surface modified with reduced graphene oxide (GCE/rGO-MIP) in the presence of M3HB. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy with field emission gun (SEM-FEG), Raman spectroscopy, attenuated total reflection Fourier-transform infrared (ATR-FTIR) and X-ray Photoelectron Spectroscopy (XPS) were employed to characterize the electrode surface. Under ideal conditions, the MIP sensor exhibited a wide linear working range of 0.1 - 10 nM and a detection limit of 0.3 pM (n = 3). The sensor showed good repeatability, selectivity, and stability over time. For the sensor application, the bioproduction of P3HB was carried out in a bioreactor containing the Burkholderia glumae MA13 strain and sugarcane byproducts as a supplementary carbon source. The analyses were validated through recovery assays, yielding recovery values between 102 and 104%. These results indicate that this MIP sensor can present advantages in the monitoring of P3HB during the bioconversion process.