Recent Advances in Biotechnological Itaconic Acid Production, and Application for a Sustainable Approach

Efficient production of itaconic acid from the single-carbon substrate methanol with engineered Komagataella phaffii

BACKGROUND

Amidst the escalating carbon dioxide levels resulting from fossil fuel consumption, there is a pressing need for sustainable, bio-based alternatives to underpin future global economies. Single-carbon feedstocks, derived from CO2, represent promising substrates for biotechnological applications. Especially, methanol is gaining prominence for bio-production of commodity chemicals.

RESULTS

In this study, we show the potential of Komagataella phaffii as a production platform for itaconic acid using methanol as the carbon source. Successful integration of heterologous genes from Aspergillus terreus (cadA, mttA and mfsA) alongside fine-tuning of the mfsA gene expression, led to promising initial itaconic acid titers of 28 g·L-1 after 5 days of fed-batch cultivation. Through the combined efforts of process optimization and strain engineering strategies, we further boosted the itaconic acid production reaching titers of 55 g·L-1 after less than 5 days of methanol feed, while increasing the product yield on methanol from 0.06 g·g-1 to 0.24 g·g-1.

CONCLUSION

Our results highlight the potential of K. phaffii as a methanol-based platform organism for sustainable biochemical production.

A comprehensive review of recent advances in the applications and biosynthesis of oxalic acid from bio-derived substrates

Organic acids are important compounds with numerous applications in different industries. This work presents a comprehensive review of the biological synthesis of oxalic acid, an important organic acid with many industrial applications. Due to its important applications in pharmaceuticals, textiles, metal recovery, and chemical and metallurgical industries, the global demand for oxalic acid has increased. As a result, there is an increasing need to develop more environmentally friendly and economically attractive alternatives to chemical synthesis methods, which has led to an increased focus on microbial fermentation processes. This review discusses the specific strategies for microbial production of oxalic acid, focusing on the benefits of using bio-derived substrates to improve the economics of the process and promote a circular economy in comparison with chemical synthesis. This review provides a comprehensive analysis of the various fermentation methods, fermenting microorganisms, and the biochemistry of oxalic acid production. It also highlights key sustainability challenges and considerations related to oxalic acid biosynthesis, providing important direction for further research. By providing and critically analyzing the most recent information in the literature, this review serves as a comprehensive resource for understanding the biosynthesis of oxalic acid, addressing critical research gaps, and future advances in the field.

Engineering Single-Component Antibacterial Anti-inflammatory Polyitaconate-Based Hydrogel for Promoting Methicillin-Resistant Staphylococcus aureus-Infected Wound Healing and Skin Regeneration

Hydrogel wound dressings play a crucial role in promoting the healing of drug-resistant bacterially infected wounds. However, their clinical application often faces challenges such as the use of numerous components, a complicated preparation process, and insufficient biological activity. Itaconic acid, known for its excellent biological and reaction activities, has not been extensively studied for the preparation of itaconic acid-based hydrogels and their application in infected wound healing. Therefore, there is a need to develop a multifunctional single-component itaconic acid-based hydrogel that is easy to synthesize and holds promising prospects for clinical use in promoting the healing of infected wounds. In this study, we present a single-component polyitaconate-based hydrogel (PICGI) with antibacterial, anti-inflammatory, and biological activity. The PICGI hydrogel demonstrates great potential in promoting healing of infected wounds and skin regeneration. It exhibits desirable thermosensitive, injectable, and adhesive properties, as well as broad-spectrum antibacterial activity and anti-inflammatory effects. Furthermore, the PICGI hydrogel is biocompatible and significantly enhances the migration and tube formation of endothelial cells. In the case of drug-resistant bacterially infected wounds, the PICGI hydrogel effectively inhibits bacterial infection and inflammation, promotes angiogenesis, and facilitates collagen deposition, thereby accelerating the healing and regeneration of the skin. This study highlights the promising application of the PICGI hydrogel as a single-component hydrogel in tissue repair associated with bacterial infection and inflammation. Moreover, the simplicity of its components, convenient preparation process, and sufficient biological activity make the PICGI hydrogel highly suitable for promotion and clinical application.

Current Insights in Fungal Importance-A Comprehensive Review

Besides plants and animals, the Fungi kingdom describes several species characterized by various forms and applications. They can be found in all habitats and play an essential role in the excellent functioning of the ecosystem, for example, as decomposers of plant material for the cycling of carbon and nutrients or as symbionts of plants. Furthermore, fungi have been used in many sectors for centuries, from producing food, beverages, and medications. Recently, they have gained significant recognition for protecting the environment, agriculture, and several industrial applications. The current article intends to review the beneficial roles of fungi used for a vast range of applications, such as the production of several enzymes and pigments, applications regarding food and pharmaceutical industries, the environment, and research domains, as well as the negative impacts of fungi (secondary metabolites production, etiological agents of diseases in plants, animals, and humans, as well as deteriogenic agents).

Filamentous fungi for sustainable remediation of pharmaceutical compounds, heavy metal and oil hydrocarbons

This review presents a comprehensive summary of the latest research in the field of bioremediation with filamentous fungi. The main focus is on the issue of recent progress in remediation of pharmaceutical compounds, heavy metal treatment and oil hydrocarbons mycoremediation that are usually insufficiently represented in other reviews. It encompasses a variety of cellular mechanisms involved in bioremediation used by filamentous fungi, including bio-adsorption, bio-surfactant production, bio-mineralization, bio-precipitation, as well as extracellular and intracellular enzymatic processes. Processes for wastewater treatment accomplished through physical, biological, and chemical processes are briefly described. The species diversity of filamentous fungi used in pollutant removal, including widely studied species of Aspergillus, Penicillium, Fusarium, Verticillium, Phanerochaete and other species of Basidiomycota and Zygomycota are summarized. The removal efficiency of filamentous fungi and time of elimination of a wide variety of pollutant compounds and their easy handling make them excellent tools for the bioremediation of emerging contaminants. Various types of beneficial byproducts made by filamentous fungi, such as raw material for feed and food production, chitosan, ethanol, lignocellulolytic enzymes, organic acids, as well as nanoparticles, are discussed. Finally, challenges faced, future prospects, and how innovative technologies can be used to further exploit and enhance the abilities of fungi in wastewater remediation, are mentioned.

Renewable carbon sources to biochemicals and -fuels: contributions of the smut fungi Ustilaginaceae

The global demand for food, fuels, and chemicals increases annually. Using renewable C-sources (i.e. biomass, CO₂, and organic waste) is a prerequisite for a future free of fossil carbon. The smut fungi Ustilaginaceae naturally produce a versatile spectrum of valuable products, such as organic acids, polyols, and glycolipids, applicable in the food, energy, chemistry, and pharmaceutical sector. Combined with the use of alternative (co-)substrates (e.g. acetate, butanediol, formate, and glycerol), these microorganisms offer excellent potential for industrial biotechnology, thereby overcoming central challenges humankind faces, including CO₂ release and land use. Here, we provide insight into fundamental production capacities, present genetic modifications that improve the biotechnical application, and review recent high-performance engineering of Ustilaginaceae toward relevant platform chemicals.

The monitoring of oil production process by deep learning based on morphology in oleaginous yeasts

BACKGROUND

Monitoring jar fermenter-cultured microorganisms in real time is important for controlling productivity of bioproducts in large-scale cultivation settings. Morphological data is used to understand the growth and fermentation states of these microorganisms during monitoring. Oleaginous yeasts are used for their high productivity of single-cell oils but the relationship between lipid productivity and morphology has not been elucidated in these organisms.

RESULTS

In this study, we investigated the relationship between the morphology of oleaginous yeasts (Lipomyces starkeyi and Rhodosporidium toruloides were used) and their cultivation state in a large-scale cultivation setting using a real-time monitoring system. We combined this with deep learning by feeding a large amount of high-definition cell images obtained from the monitoring system to a deep learning algorithm. Our results showed that the cell images could be grouped into 7 distinct groups and that a strong correlation existed between each group and its biochemical activity (growth and oil-productivity).

CONCLUSIONS

This is the first report describing the morphological variations of oleaginous yeasts in a large-scale cultivation, and describes a promising new avenue for improving productivity of microorganisms in large-scale cultivation through the use of a real-time monitoring system combined with deep learning.

KEY POINTS

• A real-time monitoring system followed the morphological change of oleaginous yeasts. • Deep learning grouped them into 7 distinct groups based on their morphology. • A correlation between the cultivation state and the shape of the yeast was observed.

Recent Advances on the Production of Itaconic Acid via the Fermentation and Metabolic Engineering

Itaconic acid (ITA) is one of the top 12 platform chemicals. The global ITA market is expanding due to the rising demand for bio-based unsaturated polyester resin and its non-toxic qualities. Although bioconversion using microbes is the main approach in the current industrial production of ITA, ecological production of bio-based ITA faces several issues due to: low production efficiency, the difficulty to employ inexpensive raw materials, and high manufacturing costs. As metabolic engineering advances, the engineering of microorganisms offers a novel strategy for the promotion of ITA bio-production. In this review, the most recent developments in the production of ITA through fermentation and metabolic engineering are compiled from a variety of perspectives, including the identification of the ITA synthesis pathway, the metabolic engineering of natural ITA producers, the design and construction of the ITA synthesis pathway in model chassis, and the creation, as well as application, of new metabolic engineering strategies in ITA production. The challenges encountered in the bio-production of ITA in microbial cell factories are discussed, and some suggestions for future study are also proposed, which it is hoped offers insightful views to promote the cost-efficient and sustainable industrial production of ITA.

Recent advances and perspectives on production of value-added organic acids through metabolic engineering

Organic acids are important consumable materials with a wide range of applications in the food, biopolymer and chemical industries. The global consumer organic acids market is estimated to increase to $36.86 billion by 2026. Conventionally, organic acids are produced from the chemical catalysis process with petrochemicals as raw materials, which posts severe environmental concerns and conflicts with our sustainable development goals. Most of the commonly used organic acids can be produced from various organisms. As a state-of-the-art technology, large-scale fermentative production of important organic acids with genetically-modified microbes has become an alternative to the chemical route to meet the market demand. Despite the fact that bio-based organic acid production from renewable cheap feedstock provides a viable solution, low productivity has impeded their industrial-scale application. With our deeper understanding of strain genetics, physiology and the availability of strain engineering tools, new technologies including synthetic biology, various metabolic engineering strategies, omics-based system biology tools, and high throughput screening methods are gradually established to bridge our knowledge gap. And they were further applied to modify the cellular reaction networks of potential microbial hosts and improve the strain performance, which facilitated the commercialization of consumable organic acids. Here we present the recent advances of metabolic engineering strategies to improve the production of important organic acids including fumaric acid, citric acid, itaconic acid, adipic acid, muconic acid, and we also discuss the current challenges and future perspectives on how we can develop a cost-efficient, green and sustainable process to produce these important chemicals from low-cost feedstocks.

Alleviating glucose repression and enhancing respiratory capacity to increase itaconic acid production

The Crabtree effect products ethanol and acetic acid can be used for itaconic acid (IA) production in Saccharomyces cerevisiae. However, both the IA synthesis and oxidative phosphorylation pathways were hampered by glucose repression when glucose was used as the substrate. This study aimed to improve IA titer by increasing gene expressions related to glucose derepression without impairing yeast growth on glucose. Engineering the acetyl-CoA synthesis pathway increased the titer of IA to 257 mg/L in a urea-based medium. Instead of entire pathway overexpression, we found that some signaling pathways regulating glucose repression were effective targets to improve IA production and respiratory capacity. As a consequence of the reduced inhibition, IA titer was further increased by knocking out a negative regulator of the mitochondrial retrograde signaling MKS1. SNF1/MIG1 signaling was disturbed by deleting the hexokinase HXK2 or an endoplasmic reticulum membrane protein GSF2. The shaking results showed that XYY286 (BY4741, HO::cadA, Y::Dz.ada, 208a::Mt.acs, Δhxk2, pRS415-cadA, pRS423-aac2) accumulated 535 mg/L IA in 168 h in the YSCGLU medium. qRT-PCR results verified that deletion of MKS1 or HXK2 upregulated the gene expressions of the IA synthesis and respiratory pathways during the growth on glucose.

Metabolic engineering of Corynebacterium glutamicum for acetate-based itaconic acid production

BACKGROUND

Itaconic acid is a promising platform chemical for a bio-based polymer industry. Today, itaconic acid is biotechnologically produced with Aspergillus terreus at industrial scale from sugars. The production of fuels but also of chemicals from food substrates is a dilemma since future processes should rely on carbon sources which do not compete for food or feed. Therefore, the production of chemicals from alternative substrates such as acetate is desirable to develop novel value chains in the bioeconomy.

RESULTS

In this study, Corynebacterium glutamicum ATCC 13032 was engineered to efficiently produce itaconic acid from the non-food substrate acetate. Therefore, we rewired the central carbon and nitrogen metabolism by inactivating the transcriptional regulator RamB, reducing the activity of isocitrate dehydrogenase, deletion of the gdh gene encoding glutamate dehydrogenase and overexpression of cis-aconitate decarboxylase (CAD) from A. terreus optimized for expression in C. glutamicum. The final strain C. glutamicum ΔramB Δgdh IDH^R453C (pEKEx2-malEcad_opt) produced 3.43 ± 0.59 g itaconic acid L^-1 with a product yield of 81 ± 9 mmol mol^-1 during small-scale cultivations in nitrogen-limited minimal medium containing acetate as sole carbon and energy source. Lowering the cultivation temperature from 30 °C to 25 °C improved CAD activity and further increased the titer and product yield to 5.01 ± 0.67 g L^-1 and 116 ± 15 mmol mol^-1, respectively. The latter corresponds to 35% of the theoretical maximum and so far represents the highest product yield for acetate-based itaconic acid production. Further, the optimized strain C. glutamicum ΔramB Δgdh IDH^R453C (pEKEx2-malEcad_opt), produced 3.38 ± 0.28 g itaconic acid L^-1 at 25 °C from an acetate-containing aqueous side-stream of fast pyrolysis.

CONCLUSION

As shown in this study, acetate represents a suitable non-food carbon source for itaconic acid production with C. glutamicum. Tailoring the central carbon and nitrogen metabolism enabled the efficient production of itaconic acid from acetate and therefore this study offers useful design principles to genetically engineer C. glutamicum for other products from acetate.

Novel Approach in Biodegradation of Synthetic Thermoplastic Polymers: An Overview

Biodegradation is necessary for water-soluble or water-immiscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. Low/high-density polyethylene is a vital cause of environmental pollution. It occurs by choking the sewer line through mishandling, thus posing an everlasting ecological threat. Environmental pollution due to the unscrupulous consumption of synthetic polymers derived from petroleum has an adverse impact on the environment since the majority of plastics do not degrade, and the further incineration of synthetic plastics generates CO2 and dioxin. This requires understanding the interactions between materials and microorganisms and the biochemical changes involved. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers through microbes viz., bacteria, fungi, and actinomycetes. The microbial degradation of plastics is caused by certain enzymatic activities that lead to a chain cleavage of polymers into oligomers and monomers. This review focuses on the biodegradation rate of plastics by fungal and bacterial communities and the mode of action of biodegradation.

Development of Pectin and Poly(vinyl alcohol)-Based Active Packaging Enriched with Itaconic Acid and Apple Pomace-Derived Antioxidants

The production of active and biodegradable packaging materials is an emerging and efficient alternative to plastic packaging materials. By combining poly(vinyl alcohol) (PVA), pectin, and itaconic acid (IA), biodegradable and water-soluble packaging materials can be obtained that can also increase the shelf-life and quality of foodstuff. In the present study, the generated film-forming solutions were enriched with organic or phenolic extracts from apple by-products (apple pomace). These extracts possess an efficient antioxidant activity of 9.70 ± 0.08, and 78.61 ± 0.24 μM Trolox/100 g fresh weight, respectively. Furthermore, the lyophilization of these by-products increased the extract’s organic and phenolic content and the antioxidant activity to 67.45 ± 0.28 and 166.69 ± 0.47 μM Trolox/100 g fresh weight, respectively. These extracts influence the physical-chemical properties of the biofilm solutions by facilitating the polymerization process and thus positively influencing their viscosity. The resulting biofilms presented low water vapor permeability and reduced solubility in water. Adding IA and organic/phenolic compounds facilitates the resistance against intrinsic and extrinsic factors; therefore, they might be applicable in the food industry.

Polysaccharide-Based Edible Gels as Functional Ingredients: Characterization, Applicability, and Human Health Benefits

Nowadays, edible materials such as polysaccharides have gained attention due to their valuable attributes, especially gelling property. Polysaccharide-based edible gels (PEGs) can be classified as (i) hydrogels, (ii) oleogels and bigels, (iii) and aerogels, cryogels and xerogels, respectively. PEGs have different characteristics and benefits depending on the functional groups of polysaccharide chains (e.g., carboxylic, sulphonic, amino, methoxyl) and on the preparation method. However, PEGs are found in the incipient phase of research and most studies are related to their preparation, characterization, sustainable raw materials, and applicability. Furthermore, all these aspects are treated separately for each class of PEG, without offering an overview of those already obtained PEGs. The novelty of this manuscript is to offer an overview of the classification, definition, formulation, and characterization of PEGs. Furthermore, the applicability of PEGs in the food sector (e.g., food packaging, improving food profile agent, delivery systems) and in the medical/pharmaceutical sector is also critically discussed. Ultimately, the correlation between PEG consumption and polysaccharides properties for human health (e.g., intestinal microecology, "bridge effect" in obesity, gut microbiota) are critically discussed for the first time. Bigels may be valuable for use as ink for 3D food printing in personalized diets for human health treatment. PEGs have a significant role in developing smart materials as both ingredients and coatings and methods, and techniques for exploring PEGs are essential. PEGs as carriers of bioactive compounds have a demonstrated effect on obesity. All the physical, chemical, and biological interactions among PEGs and other organic and inorganic structures should be investigated.

Carotenoid Recovery from Tomato Processing By-Products through Green Chemistry

The recovery of bioactive compounds from agro-industry-derived by-products sustains circular economy principles by encouraging maximized recycling and minimized waste. Tomato processing by-products are abundant in carotenoids, which have several health-promoting properties, and their reintegration into functional food products represents a major interest for scientists and manufacturers. In the present study, carotenoids were recovered from tomato processing by-products based on the principles of green chemistry by using generally recognized as safe (GRAS) solvents, freeze-drying as pretreatment, and ultrasound in the recovery procedure. Spectrophotometric measurements and HPLC were used to identify and quantify total and individual carotenoids from the extracts. The highest values for lycopene (1324.89 µg/g dw) were obtained when ethyl lactate was applied as a solvent, followed by ethyl acetate with slightly smaller differences (1313.54 µg/g dw). The extracts obtained from freeze-dried samples presented significantly lower amounts of lycopene, indicating that carotenoids are highly susceptible to degradation during lyophilization. Flaxseed, grape seed, and hempseed oils were enriched with carotenoids and their rheological measurements showed favorable viscoelastic properties, especially hempseed and flaxseed oil, with viscosity under 50 mPa·s. Considering the results and the economic perspective of carotenoid recovery from tomato processing by-products, ethyl acetate is suitable, sustainable, and environmentally friendly for carotenoid extraction.

A real-time monitoring system for automatic morphology analysis of yeast cultivation in a jar fermenter

The monitoring of microbial cultivation in real time and controlling their cultivation aid in increasing the production yield of useful material in a jar fermenter. Common sensors such as dissolved oxygen (DO) and pH can easily provide general-purpose indexes but do not reveal the physiological states of microbes because of the complexity of measuring them in culture conditions. It is well known from microscopic observations that the microbial morphology changes in response to the intracellular state or extracellular environment. Recently, studies have focused on rapid and quantitative image analysis techniques using machine learning or deep learning for gleaning insights into the morphological, physiological or gene expression information in microbes. During image analysis, it is necessary to retrieve high-definition images to analyze the microbial morphology in detail. In this study, we have developed a microfluidic device with a high-speed camera for the microscopic observation of yeast, and have constructed a system capable of generating their morphological information in real-time and at high definition. This system was connected to a jar fermenter, which enabled the automatic sampling for monitoring the cultivation. We successfully acquired high-definition images of over 10,000 yeast cells in about 2.2 s during ethanol fermentation automatically for over 168 h. We recorded 33,600 captures containing over 1,680,000 cell images. By analyzing these images, the morphological changes of yeast cells through ethanol fermentation could be captured, suggesting the expansion of the application of this system in controlling microbial fermentation using the morphological information generated. KEY POINTS: • Enables real-time visualization of microbes in a jar fermenter using microscopy. • Microfluidic device for acquiring high-definition images. • Generates a large amount of image data by using a high-speed camera.

Towards a Circular Economy of Plastics: An Evaluation of the Systematic Transition to a New Generation of Bioplastics

Plastics have become an essential part of the modern world thanks to their appealing physical and chemical properties as well as their low production cost. The most common type of polymers used for plastic account for 90% of the total production and are made from petroleum-based nonrenewable resources. Concerns over the sustainability of the current production model and the environmental implications of traditional plastics have fueled the demand for greener formulations and alternatives. In the last decade, new plastics manufactured from renewable sources and biological processes have emerged from research and have been established as a commercially viable solution with less adverse effects. Nevertheless, economic and legislative challenges for biobased plastics hinder their widespread implementation. This review summarizes the history of plastics over the last century, including the most relevant bioplastics and production methods, the environmental impact and mitigation of the adverse effects of conventional and emerging plastics, and the regulatory landscape that renewable and recyclable bioplastics face to reach a sustainable future.

Development and Characterization of Gentamicin-Loaded Arabinoxylan-Sodium Alginate Films as Antibacterial Wound Dressing

Biopolymer-based antibacterial films are attractive materials for wound dressing application because they possess chemical, mechanical, exudate absorption, drug delivery, antibacterial, and biocompatible properties required to support wound healing. Herein, we fabricated and characterized films composed of arabinoxylan (AX) and sodium alginate (SA) loaded with gentamicin sulfate (GS) for application as a wound dressing. The FTIR, XRD, and thermal analyses show that AX, SA, and GS interacted through hydrogen bonding and were thermally stable. The AXSA film displays desirable wound dressing characteristics: transparency, uniform thickness, smooth surface morphology, tensile strength similar to human skin, mild water/exudate uptake capacity, water transmission rate suitable for wound dressing, and excellent cytocompatibility. In Franz diffusion release studies, >80% GS was released from AXSA films in two phases in 24 h following the Fickian diffusion mechanism. In disk diffusion assay, the AXSA films demonstrated excellent antibacterial effect against E.coli, S. aureus, and P. aeruginosa. Overall, the findings suggest that GS-loaded AXSA films hold potential for further development as antibacterial wound dressing material.

Larvicidal activity against Aedes aegypti and molecular docking studies of compounds extracted from the endophytic fungus Aspergillus sp. isolated from Bertholletia excelsa Humn. & Bonpl

Endophytic fungi are microorganisms capable of colonizing the interior of plant tissues without causing damage to them. The study of the secondary metabolites produced by their vast biodiversity fungal is relevant for the discovery of new products for biotechnological and agrochemical applications. In addition, extract of the endophytic fungus Aspergillus sp., isolated from the almonds of Bertholletia excelsa Humn & Bonlp collected in the Brazilian Amazon, oviposition deterrent, and larvicidal activity of against Aedes aegypti. In the oviposition deterrence test was observed that females able to lay eggs preferred the control oviposition sites (46.6%). Furthermore, the extract showed larvicidal activity with LC50 26.86 µg/mL at 24 h and 18.75 µg/mL at 48 h. Molecular docking studies showed the compound Aspergillol B a potent larvicide by to inhibit the acetylcholinesterase enzyme (- 7.74 kcal/mol). These results indicate that compounds from secondary metabolites of Aspergillus sp., isolated from almonds of B. excelsa, are useful biological potential against vectors A. aegypti.

Contribution of Fermentation Technology to Building Blocks for Renewable Plastics

Large-scale worldwide production of plastics requires the use of large quantities of fossil fuels, leading to a negative impact on the environment. If the production of plastic continues to increase at the current rate, the industry will account for one fifth of global oil use by 2050. Bioplastics currently represent less than one percent of total plastic produced, but they are expected to increase in the coming years, due to rising demand. The usage of bioplastics would allow the dependence on fossil fuels to be reduced and could represent an opportunity to add some interesting functionalities to the materials. Moreover, the plastics derived from bio-based resources are more carbon-neutral and their manufacture generates a lower amount of greenhouse gasses. The substitution of conventional plastic with renewable plastic will therefore promote a more sustainable economy, society, and environment. Consequently, more and more studies have been focusing on the production of interesting bio-based building blocks for bioplastics. However, a coherent review of the contribution of fermentation technology to a more sustainable plastic production is yet to be carried out. Here, we present the recent advancement in bioplastic production and describe the possible integration of bio-based monomers as renewable precursors. Representative examples of both published and commercial fermentation processes are discussed.

Awareness, Knowledge, and Interest about Prebiotics-A Study among Romanian Consumers

The consumer awareness towards healthier diets and the impact of nutrition on health has triggered an increase in the production and commercialization of foods with health claims. The scientific literature classifies these food products as functional foods, with a role in promoting health and preventing diseases, and they had a market share of almost 200 million EUR in 2019. Prebiotics are considered functional foods, referring to substrates that are selectively utilized by host microorganisms conferring a health benefit, as defined by the International Scientific Association for Probiotics and Prebiotics. Several health benefits are associated with the consumption of prebiotics; however, specific requirements must demonstrate the causality between the specific ingredient and the claimed effect. Health claims associated with food products are assessed in the European Union and need to be supported by rigorous scientific evidence before being authorized and permitted on the market. Consumers’ perception of this topic is influenced by the various stakeholders involved. The current work aimed to study the consumers’ perception and interest and to assess the knowledge on the prebiotic concept in Romania. The consumer interest level was quantified by using the web-based data tool Google Trends, and a questionnaire-based investigation was designed. The collected data were analyzed with the help of the SPSS program, and crosstabulation was used to identify the influence of socio-demographic characteristics on diet choice and awareness of prebiotics. A total of 303 persons answered the online applied questionnaire, grouped as young consumers (15–24 years old) and adults (25–64 years old). Even if most responders were familiar with the term of prebiotics (74% of total responders), some results were contradictory regarding their knowledge. The work emphasized the need to carry out educational campaigns and inform consumers on the relationship between certain food ingredients and health outcomes in a clear way and based on a rigorous assessment of the scientific evidence.

Nanocarriers for Sustainable Active Packaging: An Overview during and Post COVID-19

Lockdown has been installed due to the fast spread of COVID-19, and several challenges have occurred. Active packaging was considered a sustainable option for mitigating risks to food systems during COVID-19. Biopolymeric-based active packaging incorporating the release of active compounds with antimicrobial and antioxidant activity represents an innovative solution for increasing shelf life and maintaining food quality during transportation from producers to consumers. However, food packaging requires certain physical, chemical, and mechanical performances, which biopolymers such as proteins, polysaccharides, and lipids have not satisfied. In addition, active compounds have low stability and can easily burst when added directly into biopolymeric materials. Due to these drawbacks, encapsulation into lipid-based, polymeric-based, and nanoclay-based nanocarriers has currently captured increased interest. Nanocarriers can protect and control the release of active compounds and can enhance the performance of biopolymeric matrices. The aim of this manuscript is to provide an overview regarding the benefits of released active compound-loaded nanocarriers in developing sustainable biopolymeric-based active packaging with antimicrobial and antioxidant properties. Nanocarriers improve physical, chemical, and mechanical properties of the biopolymeric matrix and increase the bioactivity of released active compounds. Furthermore, challenges during the COVID-19 pandemic and a brief post-COVID-19 scenario were also mentioned.

Composite Polyvinylpyrrolidone-Sodium Alginate-Hydroxyapatite Hydrogel Films for Bone Repair and Wound Dressings Applications

Today, the synthesis of biocompatible and bioresorbable composite materials such as “polymer matrix-mineral constituent,” which stimulate the natural growth of living tissues and the restoration of damaged parts of the body, is one of the challenging problems in regenerative medicine. In this study, composite films of bioresorbable polymers of polyvinylpyrrolidone (PVP) and sodium alginate (SA) with hydroxyapatite (HA) were obtained. HA was introduced by two different methods. In one of them, it was synthesized in situ in a solution of polymer mixture, and in another one, it was added ex situ. Phase composition, microstructure, swelling properties and biocompatibility of films were investigated. The crosslinked composite PVP-SA-HA films exhibit hydrogel swelling characteristics, increasing three times in mass after immersion in a saline solution. It was found that composite PVP-SA-HA hydrogel films containing HA synthesized in situ exhibited acute cytotoxicity, associated with the presence of HA synthesis reaction byproducts—ammonia and ammonium nitrate. On the other hand, the films with HA added ex situ promoted the viability of dental pulp stem cells compared to the films containing only a polymer PVP-SA blend. The developed composite hydrogel films are recommended for such applications, such as membranes in osteoplastic surgery and wound dressing.