Search

When it comes to "bioplastics", we currently notice an immense complexity of this topic, and, most of all, a plethora of contradictory legislations, which confuses or even misleads insufficiently informed consumers. The present article therefore showcases microbial polyhydroxyalkanoate (PHA) biopolyesters as the prime class of "bioplastics" sensu stricto. In particular, biodegradability of PHA as its central benefit in elevating the current plastic waste scenario is elaborated on the biochemical basis: this covers aspects of the enzymatic machinery involved both in intra- and extracellular PHA degradation, and environmental factors impacting biodegradability. Importantly, PHA degradability is contextualized with potential fields of application of these materials. It is further shown how the particularities of PHA in terms of feedstocks, mode of synthesis, degradability, and compostability differ from other polymeric materials sold as "bioplastics", highlighting the unique selling points of PHA as "green" plastic products in the circular economy. Moreover, current standards, norms, and certificates applicable to PHA are presented as basis for a straight-forward, scientifically grounded classification of "bioplastics". [ABSTRACT FROM AUTHOR]

Bioplastics have been created as an eco-efficient alternative to traditional plastic. They are obtained from natural polymers extracted from cellulose or starch, and are 100 % biodegradable. The aim of this research is to analyse the biodegradability of bioplastics made from Mangifera indica and Musa paradisiaca peels for which the research was divided into two parts: preparation of the bioplastic and biodegradability test. In the first stage, a methodology based on the addition of plasticizers such as water and glycerol were used. It is here where bioplastics were elaborated with different volumes of glycerol, to obtain unequal physical characteristics. In the last stage, worm humus was used as a degradation medium, the time range used to estimate the biodegradability of the sheets was 1 to 4 weeks. Finally, it was determined that the bioplastic made from mango peel had a reduction of 93.06 % in its initial weight and the bioplastic made from banana peel had a 73.16 % reduction in its initial weight at the end of the study. Based on the different volumes in the addition of glycerol for the preparation of the bioplastic, it was determined that it has a direct relationship with the biodegradability of the film, since the greater the amount of glycerol, this will increase the biodegradability of the films. [ABSTRACT FROM AUTHOR]

Biodegradable polymers have been developing rapidly in the last years and are widely used today in the fields of pharmacy, ciinical biomedicine, cosmetic, medical, and packing industries, tissue engineering, agriculture and other areas. The interest in biodegradable polymers has been increasing, mainly due to rising oiprices, which is the basic feedstock of plastic derived from petroleum, and also due to the problem of the removal of waste plastics that accumulate in the environment. Biodegradable polymers have many advantages in contrast to synthetic polymers and can be decomposed in the environment to non-hazardous substances. Biodegradable polymers are classified into two classes based on their synthesis, i.e., synthetic and natural polymers. They are derived either from petroleum resources or from biological resources. The following review presents an overview of the different biodegradable polymers andtheir properties, current scientific research, applications, global production of bioplastic and replacement of conventional plastic. [ABSTRACT FROM AUTHOR]

Plastic accumulation has destructive environmental impacts, so the world needs eco-friendly plastic alternatives. Within this context, polyhydroxyalkanoates (PHAs) appear to be real alternatives to the chemical plastics because they are biocompatible and biodegradable. Despite its similar properties to common plastics, PHAs use is still hampered by higher production costs. PHAs are produced by high density fed-batch cultivation, activated sludge, microbial consortia and continuous substrate supply, and a major cost associated with their production is the carbon source used for bacterial fermentation. Therefore, novel carbon sources have been studied for PHA production including, macro algae, peanut oil, crude glycerol and whey. PHAs were applied in myriad fields such as wood production, food packaging, 3D painting, cancer detection, treating ulcers as well as several agricultural and therapeutic applications. In this review, current knowledge of methods and novel carbon sources enhance the sustainability and reliability of PHAs in the prospective future. Unlabelled Image • This review has proposed adverse impact of the chemical plastics on the environmental and human health. • The review illustrates the methods that are considered effective ways for PHA production. • More studies are needed on the discussed carbon sources for attaining a suitable future the biopolymer. • PHAs as biopolymers are promising alternatives for petrochemical plastics in a multitude of applications. [ABSTRACT FROM AUTHOR]

Biobased degradable plastics have received significant attention owing to their potential application as a green alternative to synthetic plastics. A dye-based procedure was used to screen poly-3-hydroxybutyrate (PHB)-producing marine bacteria isolated from the Red Sea, Saudi Arabia. Among the 56 bacterial isolates, Pseudodonghicola xiamenensis, identified using 16S rRNA gene analyses, accumulated the highest amount of PHB. The highest PHB production by P. xiamenensis was achieved after 96 h of incubation at pH 7.5 and 35 °C in the presence of 4% NaCl, and peptone was the preferred nitrogen source. The use of date syrup at 4% (w/v) resulted in a PHB concentration of 15.54 g/L and a PHB yield of 38.85% of the date syrup, with a productivity rate of 0.162 g/L/h, which could substantially improve the production cost. Structural assessment of the bioplastic by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy revealed the presence of methyl, hydroxyl, methine, methylene, and ester carbonyl groups in the extracted polymer. The derivative products of butanoic acid estimated by gas chromatography-mass spectrometry [butanoic acid, 2-amino-4-(methylseleno), hexanoic acid, 4-methyl-, methyl ester, and hexanedioic acid, monomethyl ester] confirmed the structure of PHB. The present results are the first report on the production of a bioplastic by P. xiamenensis, suggesting that Red Sea habitats are a potential biological reservoir for novel bioplastic-producing bacteria. [ABSTRACT FROM AUTHOR]

Research on starch‐based biopolymers has increased because of their potential as environmentally friendly biodegradable substitutes to typical plastics. This study investigates the effect of rye flour as a main reinforcement agent as well as cellulose and citric acid in biocomposite starches on improving their water vapor permeability (WPF) and mechanical properties. The optimum point of the starch biocomposites obtained by Design of Experiments software 7.1.5 is run with 10% cellulose,and 10% rye flour with a WPF value equal to 8.7E‐10 g s−1 m−1 Pa−1, water uptake (WU) of 3.42%, and good mechanical properties. Validation of the optimum point does not show significant difference between the predicted and the actual values. There is some strong hydrogen and physical bonding in the optimized starch biocomposite that changes the intensity of the absorption bands and improves the mechanical properties. [ABSTRACT FROM AUTHOR]

Among many biodegradable and biocompatible biopolymers, polyhydroxyalkanoates (PHAs), generated by microorganisms, have highly attracted attention in various fields due to their unique physicochemical properties. So far, various types of progresses have been made in environmental and engineering fields by employing PHAs. Recently, employing PHAs for nanoarchitecture has become a newly emerging trend among researchers. The intrinsic nature of PHAs has dragged them towards fabrication of nanoparticles and nanocomposites. PHAs integration with nanoparticles has been vastly noted and applied in various areas such as drug delivery, antibacterial agents and bioengineering. Here, a brief review is given to how PHAs act and are produced by microorganisms, demonstrating their properties and finally, their most recent applications are discussed in nanoarchitecture and the ways they are manipulated in the fabrication of nanomaterials. This review can shed light on the exhaustive understanding of PHA capability in nanoarchitectural basics toward the development of advanced nanomaterials in many fields such as medicine, catalysis, sensor, and adsorbents. • Application of polyhydrohxyalkanoates in nanotechnology • Nanoarchitecture of polyhydroxyalkanoates • Coming up with new generation of biopolymers by applying nanotechnology • Bacterial production of polyhydroxyalkanoates using carbohydrates as feedstock • Conversion of carbohydrate based abundant materials to value added nanomaterials [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) form a highly promising class of bioplastics for the transition from fossil fuel-based plastics to bio-renewable and biodegradable plastics. Mixed microbial consortia (MMC)are known to be able to producePHAsfromorganic waste streams. Knowledge of key-microbes and their characteristics in PHA-producing consortia is necessary for further process optimization and direction towards synthesis of specific types of PHAs. In this study, a PHA-producing mixed microbial consortium (MMC) from an industrial pilot plant was characterized and further enriched on acetate in a laboratory-scale selector with a working volume of 5 L. 16S-rDNA microbiological population analysis of both the industrial pilot plant and the 5 L selector revealed that the most dominant species within the population is Thauera aminoaromatica MZ1T, a Gram-negative beta-proteobacterium belonging to the order of the Rhodocyclales. The relative abundance of this Thauera species increased from 24 to 40% after two months of enrichment in the selector-system, indicating a competitive advantage, possibly due to the storage of a reserve material such as PHA. First experiments with T. aminoaromatica MZ1T showed multiple intracellular granules when grown in pure culture on a growth medium with a C:N ratio of 10:1 and acetate as a carbon source. Nuclear magnetic resonance (NMR) analyses upon extraction of PHA from the pure culture confirmed polyhydroxybutyrate production by T. aminoaromatica MZ1T. [ABSTRACT FROM AUTHOR]

This review article critically presents a comprehensive overview of the current advances in the research and development of proteins derived bionanocomposites used in food packaging applications. The recent interest in protein-based biomaterials is due to sustainability, renewability, biodegradability and low carbon footprint. The inherent drawbacks of proteins-based materials for food packaging applications are their low mechanical strength, poor thermal, barrier and inferior physicochemical properties. The nanoreinforced bio-based polymers called bionanocomposites provide an opportunity to overcome these issues and have ability to supersede non-biodegradable food packaging plastics produced from petroleum resources. So far, most studied protein derived bionanocomposites suitable for food packaging are soy protein isolates (SPI) and gelatin proteins. Layered silicates are the most promising nanofillers used to increase strength, improve heat resistance and enhance barrier properties of proteins derived materials while montmorillonites (MMT) is the most commonly used silicate nanofiller. This review emphases on the processing strategies used for proteins-based biomaterials, their mechanical and moisture barrier properties for food packaging applications. Different proteins and nanofillers that have been studied to date in proteins derived food packaging applications are also discussed in detail. [ABSTRACT FROM AUTHOR]

Most of the products used in our everyday life are made of plastics. Even though plastics are very cheap and durable but plastic has a significant problem as due to its non-biodegradable nature plastic causes littering in river and sea, blockage in drains, degradation of landfill and it also causes various other environmental problems when dumped. To find out suitable alternatives of these plastic materials, researchers have preferred starch, an abundantly found and cheapest natural polymer and researchers have found some ways to convert starch in to thermoplastic material. Among these techniques, esterification process has gained most attention. This paper has tried to review some important researchers published on esterifying starch. By analyzing the research results of these researches this paper will try to find out the factors which control the end product properties so that the desired end product can be produced. [ABSTRACT FROM AUTHOR]

Biodegradable polymers is an alternative option to efficient waste management solution as opposed to conventional plastics. The production of biodegradable materials from renewable sources has attracted the interest of the global community, resulting in the examination and increased use of several renewable and sustanble feedstocks. Abundant renewable sources, such as corn, soy beans, sugar cane, wood, agricultural residues, lignocellulosic residues obtained from logging or wood processing etc. could be utilized as raw materials in bioplastics production. In this study, the development of bioplastics from the past to the present is reviewed, as well as a categorization of the existent bioplastics, are implemented based on the raw materials and properties, the main advantages and disadvantages of bioplastics are analyzed. The tendency of recent years on the research field of bioplastics is recorded, while the main current European and International standards referring to the bioplastics production, application and end-of-life management are being presented. [ABSTRACT FROM AUTHOR]

Air-filtration has played an increasingly important role in keeping desired indoor air quality in spite of the heavily polluted air that has worsened by human being's activities. Because the compositions of the pollutants present in the air are so complex and uncontrollable, traditional air-filtering materials produced from non-degradable plastics or glass fibers are facing a big challenge of effectively removing not only the particulate pollutants, such as PM2.5, but also gaseous pollutants, including toxic chemicals, and bacteria and so forth. These materials are also non-degradable and end up in landfills. As a result, development of new multi-functional filtering materials to satisfy the fast-growing community of air-filtration is currently in a critical need. Natural materials that are well known for their richness in functional groups and suitability for many applications represent a promising material solution for high-performance air-filtration. In addition, these materials are sustainable, and their inherent bio-degradability makes them a green solution. In this review, we summarize the significant studies on using polymeric materials for air-filtration with an emphasis on natural biomaterials. In specific, the characteristics of polluted air, the air filter types and filtering materials are briefly summarized. The advantages of developing green air filters from natural polymers as well as the challenges are highlighted. [ABSTRACT FROM AUTHOR]

Bio-based plastics have a huge market and a wide range of applications and then have become increased in economy and research. Due to the environmental hazard on all organisms and the pollution that happens in all natural resources such as air, water, plants and soil pollution and the limitation of quantity of fossil resources on our planet, the future cannot depend on petro-plastics. All fossil products should be replaced by bio-based products. The petro-plastics are one of the fossil products which should be replaced by bio-based plastics. In this study, potato peels were used to produce bioplastics by the extraction of the starch from the peels and adding some ingredients such as water, glycerin, vinegar and industrial colors with different ratios and in biochemical reaction under heating. This process produced a wide range of bioplastics samples with different properties such as texture, hardness and coherence. It was found that when the glycerin ratio increases the produced bioplastic becomes more flexible which withstands compressive stress to 0.5 MP, and vice versa when the glycerin ratio decreases the produced bioplastic becomes hard which withstands compressive stress to 1.1 MP. It was concluded that the bio-based materials can be used effectively to process bioproducts such as bioplastics. [ABSTRACT FROM AUTHOR]

In this work, morphological and mechanical properties of biodegradable Polyamide6/Ethyleneoctene Nanoclay/Proteins nanocomposite were studied. The composites were prepared using a laboratory scale twin screw extruder. Morphology of the blend was determined by SEM images. Mechanical properties in term of tensile tests were performed using Testometric TS2000. Stress at break, strain at break and Young's modulus were also determined. The mechanical results demonstrated that the strain at break of the composite decreases sharply by the presence of protein, whereas the Young's modulus increases with increasing protein content. The blend demonstrated the improvement in both mechanical and thermal properties of the final composition. Nowadays, according to the huge application of plastics in different fields, environmental issues were affected by these kinds of non-degradable materials, while the biodegradability of the plastics is just remains an unsolved flaw. In this study, biodegradable blends were prepared using starch as a natural polymer. The outcome of biological procedure-test indicated sufficient weight loss and biodegradation of these blends. [ABSTRACT FROM AUTHOR]

Cellulose is one of the most abundant biopolymers in nature. It is used in the industry in various ways, in both its original and modified forms and the latter are called cellulose derivatives. These derivatives are used in several industrial such as the pharmaceutical, food, cosmetics and can be used in solid or semi-solid form. An important application that has been currently clarified is the use of some types of cellulose derivatives as adsorbents for both metal ions and other molecules. An example is the decontamination of wastewater, as with the industrial development, some water sources are compromised and decontamination by conventional means is often not enough, hence the need for new techniques. The main advantage of using natural polymers is that they are biodegradable, because it is extremely important that a product disappear after fulfilling its purpose. An example of a natural polymer is cellulose synthesized by bacteria, also known as bacterial cellulose (BC). It has been the subject of several studies in the last decade, mainly due to the fact that it is a highly pure polymer, which makes their physical and chemical properties very different from those of plant cellulose, and also because it is easy to produce, with yields varying from one bacterium to another. The aim of this paper was to gather general information about the structures, production mode, synthesis and industrial applications of bacterial, vegetable and cellulose derivatives. [ABSTRACT FROM AUTHOR]

Cosmetics, personal care and biomedical products obtained by bio-based polymers and natural bioactive compounds are a new growing market. The ecological awareness is changing consumers' demands, causing consumers to look for more sustainable options, with a reduced environmental impact. The innovation of this work was to develop a natural polymer matrix (chitosan) entrapping antioxidant actives compounds such as annatto (Bixa Orellana L.) and vitamin C with potential application as sustainable anti-aging skin mask treatment. Films of chitosan (Ch) and reacetylated chitosan (RCh), exhibiting different degrees of acetylation (DA = 13.3 and 33.9%, respectively), were produced. The formulations of active films of chitosan (BCh) and reacetylated chitosan (BRCh) were 1% (w/w) of chitosan, 1% (w/w) of annatto powder, 5% (w/w) of vitamin C and 1% (w/w) of glycerol (as plasticizer). Reacetylated chitosan films (DA = 33.9%) presented higher water affinity than chitosan films (DA = 13.3%). The elongation of RCh and BRCh increased and the resistance decreased, as compared to Ch and BCh. The antioxidants compounds (annatto and vitamin C) of BRCh films released faster than BCh films. Thus, the BRCh films showed potential application as an anti-aging skin mask. • Reacetylated chitosan films (DA = 33.9%) presented higher water affinity than chitosan films (DA = 13.3%). • Chitosan film entrapping antioxidant compounds: annatto (Bixa Orellana L.) and vitamin C • Reacetylated chitosan films showed potential application as an anti-aging skin mask. [ABSTRACT FROM AUTHOR]

Nonbiodegradable plastics have brought a variety of issues associated with human health and environmental pollution. Thus, biodegradable films have attracted interest to replace plastics because of their good degradability and rich material supplies. Research on deep eutectic solvents (DESs), which falls under the guidelines of the "Twelve Principles of Green Chemistry", has grown exponentially over the past few years. DESs are new green solvents with excellent chemical tunability that can be used as alternatives to ionic liquids (ILs). Recently, using DESs in the preparation of biodegradable food packaging films has become a research focus. In this review, we summarize the application of choline chloride (ChCl)-based DESs in biodegradable films and discuss the link between ChCl and degradable film materials, with a particular focus on recent advances of ChCl-based DESs in improving film performance. In addition, we also summarize the application of DES extracts in packaging films. ChCl is the most commonly used hydrogen bond acceptor (HBA). ChCl-based DESs exhibit superior performance compared to traditional plasticizers in the production of biodegradable films using natural polymers such as chitosan, starch, and cellulose. ChCl-based DESs can improve the physical-mechanical and barrier properties of films. Therefore, DESs present a new option for improving the functional properties of degradable films. [Display omitted] • Choline chloride (ChCl) is the most common hydrogen bond acceptor for deep eutectic solvents (DESs). • ChCl-based DESs improves the physical and mechanical properties of biodegradable films. • The molar ratio of ChCl to the hydrogen bond donor affects the properties of DESs. • H-bonds formed on the basis of ChCl-based DESs changes the linkage of polymers. [ABSTRACT FROM AUTHOR]

Starch is a biodegradable biopolymer, a sustainable material that can replace conventional petrochemical-based plastics. However, starch has some limitations, as it must be processed by heating and treated mechanically with a plasticizer to become thermoplastic starch (TPS). Different variables such as mixing speeds, amount, and kind of plasticizers play a vital role in preparing TPS by melting. Despite this, the properties of the TPS are not comparable with those of traditional plastics. To overcome this limitation, microcellulose or nanocellulose is added to TPS by melt mixing, including the extrusion and internal mixing process, which enables large-scale production. This review aims to compile several studies that evaluate the effect of plasticizers, as well as the relevance of incorporating different cellulosic fillers of different dimensions on the properties of TPS obtained by melt mixing. Potential applications of these materials in food packaging, biomedical applications, and other opportunities are also described. • Recent advances in strategies to enhance TPS properties reinforcing with cellulose are reviewed. • Performance of the last year reported green composites based on TPS and cellulose is described. • Reinforcing TPS with micro- or nano- cellulose enhances its mechanical and water vapor properties. • Future perspectives and challenges for packaging using TPS/cellulose biodegradable composites are discussed. [ABSTRACT FROM AUTHOR]

Petroleum-based polymers have raised significant environmental concerns. It is critical to create compostable, good biocompatibility, and nontoxic polymers to replace petroleum-based polymers. Thus, this research was performed to extract the gelatin from fish waste cartilage and coated it over the surface of spherical shaped pre-synthesized ZnNPs along with a suitable plasticizer to produce the biodegradable film. The presence of gelatin on the surface of ZnNPs was first confirmed using UV–visible spectrophotometers, as well as the characteristic functional groups involved in the coating were investigated using Fourier-Transform Infrared Spectroscopy (FTIR). The morphological appearance of gelatin coated ZnNPs was ranged from 41.43 to 52.31 nm, the shape was found as platonic to pentagonal shape, and the fabricated film was observed through Scanning Electron Microscope (SEM). The thickness, density, and tensile strength of fabricated film were found to be 0.04–0.10 mm, 0.10–0.27 g/cm3, and 31.7 kPa. These results imply that the fish waste cartilage gelatin coated ZnNPs-based nanocomposite can be used for film preparation as well as a wrapper for food and pharmaceutical packaging. • Gelatin has been harvested successfully from fish waste cartilage. • The gelatin effectively coated the ZnNPs, resulting in the formation of a nanocomposite. • The size of the gelatin coated ZnNPs was found as 41.43–52.31 nm & platonic shape. • Thickness & density of the fabricated film were found as 0.10 mm & 0.27 g/cm3. • The tensile strength of the gelatin-coated ZnNPs-based biodegradable film was 31.7 kPa. [ABSTRACT FROM AUTHOR]

Plastics have become an integral part of human life. Single-use plastics (SUPs) are disposable plastics designed to be used once then promptly discarded or recycled. This SUPs range from packaging and takeaway containers to disposable razors and hotel toiletries. Synthetic plastics, which are made of non-renewable petroleum and natural gas resources, require decades to perpetually disintegrate in nature thus contribute to plastic pollution worldwide, especially in marine environments. In response to these problems, bioplastics or bio-based and biodegradable polymers from renewable sources has been considered as an alternative. Understanding the mechanisms behind the degradation of conventional SUPs and biodegradability of their greener counterpart, bioplastics, is crucial for appropriate material selection in the future. This review aims to provide insights into the degradation or disintegration of conventional single-use plastics and the biodegradability of the different types of greener-counterparts, bioplastics, their mechanisms, and conditions. This review highlights on the biodegradation in the environments including composting systems. Here, the various types of alternative biodegradable polymers, such as bacterially biosynthesised bioplastics, natural fibre-reinforced plastics, starch-, cellulose-, lignin-, and soy-based polymers were explored. Review of past literature revealed that although bioplastics are relatively eco-friendly, their natural compositions and properties are inconsistent. Furthermore, the global plastic market for biodegradable plastics remains relatively small and require further research and commercialization efforts, especially considering the urgency of plastic and microplastic pollution as currently critical global issue. Biodegradable plastics have potential to replace conventional plastics as they show biodegradation ability under real environments, and thus intensive research on the various biodegradable plastics is needed to inform stakeholders and policy makers on the appropriate response to the gradually emerging biodegradable plastics. • Some bioplastics can biodegrade in real environments. • Global plastic market for bioplastics remains relatively small. • Compositions and properties of natural polymers are inconsistent and need research. [ABSTRACT FROM AUTHOR]

The potential use of agro-waste in food packaging applications is receiving remarkable attention due to its sustainable approach and biodegradable properties. As typical lignocellulosic biomass, rice straw (RS) is widely produced but is usually abandoned and burned, causing tremendous environmental concerns. The exploration of using RS as the source of biodegradable packaging materials is promising for economically converting this agricultural waste into packaging material, thereby providing a considerable solution for RS disposal and an alternative solution to synthetic plastic waste. Polymers have been infused with nanoparticles, fibers, and whiskers, along with plasticizers and cross-linkers, and fillers like nanoparticles and fibers. They have also been blended with natural extracts, essential oils, and other synthetic and natural polymers to improve RS properties. There is still much research to be done before this biopolymer can be applied at an industrial level in food packaging. In this respect, RS can be valued for packaging to add value to these underutilized residues. This review article focuses on the extraction methods and functionality of cellulose fibers and their nanostructured forms from RS and their utilization in packaging applications. [Display omitted] • Valorization of rice straw (RS) is a sustainable approach to utilizing agricultural waste. • Various techniques of extracting cellulose and nanocellulose from RS to fabricate biocomposites are addressed. • Functionality of RS cellulose and its derivatives has been discussed. • RS-based packaging application has been outlined. [ABSTRACT FROM AUTHOR]

This editorial considers biosynthesis of polyhydroxyalkanoates (PHA), polymer processing of PHA, and the use of PHA in production of bioplastics or biocomposites. The views come from a workshop aimed to join students and experts working with PHA or those interested in the application of biopolymers. The goals are 1) to synchronize their opinions with up-to-date knowledge published in the literature within the last 10 years, and 2) to formulate perspectives and conclusions. [ABSTRACT FROM AUTHOR]

Highlights • Bioplastic-based electromechanical actuators. • Poly(3-hydroxybutirate) and ionic liquid-based ionogels using solvent casting from acetic acid. • Fabrication of compliant cluster-assembled gold electrodes. • Natural-derived, soft, durable and water-resistant electromechanical actuators. Abstract We present the fabrication and characterization of electroactive actuators based on natural-derived bioplastic able to display reversible bending deformations in response to low intensity electric fields. We used biodegradable poly(3-hydroxybutyrate) (PHB) blended with a suitable ionic liquid to produce freestanding electroactive ionogel layers through a solvent casting process employing non-toxic solvents. The ionogels were provided with compliant cluster-assembled gold electrodes fabricated by means of supersonic cluster beam deposition (SCBD). These metal layers exhibit tailored electrical properties, large surface areas and mechanical resiliency against deformations. The manufactured actuators were characterized in terms of mechanical, morphological, electrochemical and electromechanical properties. We show that the mechanical properties of the ionogels are similar to those of low density polyethylene, while the actuators demonstrated large bending displacement and stable operational durability. Furthermore, due to the use of PHB in combination with a hydrophobic ionic liquid, the actuators did not exhibit hygroscopic behaviour. [ABSTRACT FROM AUTHOR]

Abstract Petrochemical plastics are generally recalcitrant to microbial degradation and accumulate in the environment. Biodegradable polymers obtained synthetically like poly(ε -caprolactone) (PCL) or polyhydroxyalkanoates (PHA), obtained biotechnologically, have shown great potential as a replacement for petroleum-based plastics. Nevertheless, their biodegradation and environmental faith have been less examined. In this study, thin films of PCL (200 μm) and medium chain length PHA (mcl-PHA, 70 M fraction of 3-hydroxyoctanoate and 30 M fraction of 3-hydroxydecanoate, 600 μm) were exposed to total protein preparations (extracellular proteins combined with a crude cell extract) of soil isolates Pseudomonas chlororaphis B-561 and Streptomyces sp. BV315 that had been grown on waste cooking oil as a sole carbon source. Biodegradation potential of two polyesters was evaluated in buffer with total protein preparations and in a laboratory compost model system augmented with selected bacteria. Overall, PCL showed better biodegradation properties in comparison to mcl-PHA. Both materials showed surface erosion after 4-weeks of exposure to total protein preparations of both strains, with a moderate weight loss of 1.3% when P. chlororaphis B-561 was utilized. In laboratory compost model system PCL and mcl-PHA showed significant weight loss ranging from 13 to 17% when Streptomyces sp. BV315 culture was used. Similar weight loss of PCL and mcl-PHA was achieved for 4 and 8 weeks, respectively indicating slower degradation of mcl-PHA. Growth on waste cooking oil as a sole carbon source increased the potential of both tested strains to degrade PCL and mcl-PHA, making them good candidates for augmentation of compost cultures in waste management of both waste cooking oils and biodegradable polymers. Graphical abstract Image 1 Highlights • Pseudomonas and Streptomyces grown on waste cooking oil for biopolymers degradation. • Enzymes from Pseudomonas chlororaphis B-561 hydrolyzed PCL better than mcl-PHA. • Mcl-PHA degraded more efficiently in model compost with Streptomyces sp. BV315. [ABSTRACT FROM AUTHOR]

Pollution is a global problem and the increased use non-biodegradable plastic packaging films have caused environmental concerns. Thus, there is a tendency to use natural polymer materials, such as biodegradable films. This paper aims to prepare and characterize novel collagen hydrolysate/carboxymethyl cellulose/nano-SiO2 films for packaging/coating applications. The results indicate that the incorporation of nano-SiO2 in films from 1% to 4% caused significant increase (p<0.05) in thickness and tensile strength but significantly decreased the elongation at break. Nano-SiO2 drastically reduced the water vapor permeability and water solubility values of films. Furthermore, the increments in nano-SiO2 proportion in films increased the values of transparency and provided a reduction in the light transmission in the ultraviolet and visible range. This study demonstrates that nano-SiO2 addition to collagen hydrolysate/carboxymethyl cellulose films gives significantly effects on properties of film produced. The enhancement of film properties shows the potential for using collagen hydrolysate/carboxymethyl cellulose films for coating/packaging purposes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlight • A low-cost and eco-friendly semi-IPN hydrogels of CSt-g-PAA/NR/PVA was prepared. • CSt, AA, APS and MBA contents were optimized. • The highest water absorbency was 794% in distilled water and 244% in 0.9 wt% NaCl solution. • Hydrogel was highly sensitive to the salt concentration, cation type, pH and reswelling time. • The hydrogel showed a good biodegradation. Abstract In order to reduce the production costs of hydrogel and decrease the negative impact on the environment, a new low-cost and eco-friendly semi-interpenetrating polymer network (semi-IPN) hydrogels of cassava starch-g-polyacrylic acid/natural rubber/polyvinyl alcohol blends (CSt-g-PAA/NR/PVA) was prepared. The hydrogel was synthesized by aqueous solution polymerization method in the presence of initiator ammonium persulfate (APS) and N,N' -methylene-bis-acrylamide (MBA) as a crosslinker. A reaction mechanism for synthesis of CSt-g-PAA/NR/PVA semi-IPN hydrogels was proposed. Factors affecting the swelling capacity, such as CSt, AA, APS and MBA contents were evaluated and optimized. The sample prepared under optimized conditions had a water absorbency of 794% in distilled water and 244% in 0.9 wt% NaCl solution. It also exhibited an excellent water retention with lower decreasing rate and were highly sensitive to the salt concentration, cation type, pH and reswelling time. The semi-IPN hydrogel demonstrated a good biodegradation with a rate of 0.626 wt%/day. It is believed that the obtained CSt-g-PAA/NR/PVA could have potential applications in agricultural areas because of their good water absorption, excellent retention capacities, high reswelling capability, and cost-effective and ecofriendly preparation. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by a wide range of bacteria, which serve as a promising candidate in replacing some conventional petrochemical-based plastics. PHA synthase (PhaC) is the key enzyme in the polymerization of PHA, and the crystal structures were successfully determined using the catalytic domain of PhaC from Cupriavidus necator (PhaCCn-CAT) and Chromobacterium sp. USM2 (PhaCCs-CAT). Here, we review the beneficial mutations discovered in PhaCs from a structural perspective. The structural comparison of the residues involved in beneficial mutation reveals that the residues are near to the catalytic triad, but not inside the catalytic pocket. For instance, Ala510 of PhaCCn is near catalytic His508 and may be involved in the open-close regulation, which presumably play an important role in substrate specificity and activity. In the class II PhaC1 from Pseudomonas sp. 61-3 (PhaC1Ps), Ser325 stabilizes the catalytic cysteine through hydrogen bonding. Another residue, Gln508 of PhaC1Ps is located in a conserved hydrophobic pocket which is next to the catalytic Asp and His. A class I, II-conserved Phe420 of PhaCCn is one of the residues involved in dimerization and its mutation to serine greatly reduced the lag phase. The current structural analysis shows that the Phe362 and Phe518 of PhaC from Aeromonas caviae (PhaCAc) are assisting the dimer formation and maintaining the integrity of the core beta-sheet, respectively. The structure-function relationship of PhaCs discussed in this review will serve as valuable reference for future protein engineering works to enhance the performance of PhaCs and to produce novel biopolymers. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is one of the most versatile biopolymers, being available in large quantities produced by industrial fabrication in a wide range of grades. PLA is aliphatic polyester of lactic acid (2-hydroxypropanoic). Lactic acid can be obtained from the microbial fermentation of carbohydrate or chemical synthesis from the petrochemical. There are many ways to obtain PLA from lactic acid. The main methods are: direct condensation of lactic acid, azeotropic dehydration polymerization, and ring opening polymerization. PLA it is a relatively cheap polymer and has some remarkable properties, being suitable for different applications such as automotive, packaging, consumer goods, building and construction, consumer electronics, sportswear, biomedical. Nowadays, biopolymers such as starch, protein, cellulose, chitosan, PLA, and their derivatives are used in food packaging. These biopolymers are used as edible film or coating on the food with the aim of reducing the loss of moisture, prevention of oxidation, decreasing the migration of lipids, and so on. According to the latest market data, global bioplastics production capacity is set to increase from around 2.05 million tons in 2017 to approximately 2.44 million tons in 2022. Innovative biopolymers such as PLA and PHAs (polyhydroxyalkanoates) are the main drivers of this growth in the field of bio-based, biodegradable plastics. The development of packaging materials based on PLA polymers is expected to grow in the future with major focuses on enhancing food safety and quality and concurrently exploring alternatives to synthetic polymers made from petrochemicals that are less environment friendly. [ABSTRACT FROM AUTHOR]

During the last decades, biopolymers experienced a renaissance. The increasing limitation of fossil resources in combination with a public demand for environmental-friendly and sustainable processes has led to the formation of a market for biobased plastics. Especially non-biodegradable bioplastics are very interesting materials, as they combine the benefits of reduced carbon footprint during production and increased resource efficiency with the persistence to microbial degradation. Consequently, persistent biomass-derived plastic materials are highly promising to substitute conventional fossil-based plastics in applications, which require durability and longevity. Non-biodegradable bioplastics derived from renewable resources represent 57% of all bioplastics with partially biobased polyethylene terephthalate currently leading the market, followed by biobased polyamides and fully biomass-derived polyethylene. An exceptional biopolymer with thermoplastic properties was discovered only two decades ago, when—for the first time—polythioesters were synthesized by microbial fermentation. Though synthesized by bacteria, it turned out that polythioesters are non-biodegradable by microorganisms in contrast to all other biopolymers and thus, represent a novel non-biodegradable bioplastic material. This review gives an overview about the recent development and progress regarding bioplastics with special focus on persistent bioplastics. We describe the generation of the respective monomers from biomass-derived substrates and summarize the current status of production, which range from the laboratory-scale up to large-scale industrial processes. [ABSTRACT FROM AUTHOR]

Abstract Biodegradable plastic composites were produced from mixtures of polyvinyl alcohol (PVA) and starch, which were mixed with different natural fillers [sugarcane bagasse (SB), oat hulls (OH) or silkworm exuvia (SE)] and nutrients to stimulate the biodegrading microbiota. The physicochemical and biodegradability characteristics of the produced materials were studied, in addition to their influence over the microbiota involved in biodegradation. The SB-composite showed reduced solubility in water, a lower water absorption capacity and a slower mineralization rate when buried in a commercial substrate for seedlings production, as compared with those of the OH- and SE-composites. Scanning electron micrographs demonstrated the increased colonization of materials by the biodegrading microbiota over time, which were predominated by filamentous fungi in OH- and SE-composites, while the SB-composite was predominantly colonized by bacteria. A Fourier transform-infrared spectroscopy (FT-IR) analysis of the biodegraded materials highlighted the chemical differences in the protein and carbohydrate content between formulations, corroborating the activity of different microbial groups on their mineralization. Regardless of its composition, the mineralization rate of the materials was positively correlated with the microbial biomass carbon (C mic) and basal respiration (R B) of the substrate. However, the correlation between the mineralization rate and the metabolic quotient of the substrate (qCO 2) was negative for the OH- and SE-composites, while the SB-composite showed no significant correlation among these variables. The differences observed in the formulations indicated that biodegradable plastics can be designed for a given goal by selecting the most appropriate formulation. Highlights • Injection-mold biodegradable materials were produced from composites with PVA, starch, natural fillers and nutrients. • Different natural fillers produced materials with different physicochemical and biodegradation characteristics. • The C/N ratio of fillers guided the activity and composition of microbial communities involved in biodegradation. • The findings indicate that biodegradable plastics can be designed to perform as conditioner of microbial communities. [ABSTRACT FROM AUTHOR]

Abstract Biodegradable plastics have emerged as an encouraging alternative to reduce the production of plastic waste, especially for agricultural mulches. However, degradation of these plastics in the field may involve the release of products from the mulch into the soil, before and during the in-soil biodegradation. The present work aims to assess the potential effects on two agricultural plant species (Lactuca sativa L. –lettuce-, and Lycopersicon esculentum Mill. -tomato) of extracts from biodegradable (BDMs: Mater-Bi, Bioplast-SP4 and SP-6, BioFilm, BioFlex, Ecovio, Mirel, Paper) and Polyethylene mulch films. A previously designed highly sensitive in vitro ecotoxicity test was used. Some of the extracts from the biodegradable plastics had effects on plant development. Germination was reduced by Bioplast films treatments, both in lettuce (B-SP4) and in tomato (B-SP4 and B-SP-6). In lettuce, root development was notably reduced by all treatments except for Paper and Polyethylene. Plant aerial growth was also limited with Bioplast and BioFlex, but enhanced with Paper extracts. At a whole, tomato plants showed higher sensitivity than lettuce in the test. Tomato aerial plant part and root growth were reduced by all treatments with the exception of BioFlex and Polyethylene. For both plant species, inhibitory effects on development were associated to proline increases, a physiological marker for some plant stresses. It can be concluded that the contact of unused biodegradable films with a water solution may result in changes in plant development that depend on the nature of the biodegradable film. The in vitro used test revealed to be a highly sensitive tool for ecotoxicity studies. These results are to contribute to design safe materials for agricultural applications. Highlights • An in vitro test for ecotoxicity in cultivated plants has been developed. • Lettuce and tomato are sensitive to compounds released from biodegradable mulches. • Germination and plant growth do not equally respond to the test. • Compounds released from biodegradable plastic mulches may have strong inhibitory effects on plant root development. • Proline is proposed as stress marker for compounds released from biodegradable plastic mulches. [ABSTRACT FROM AUTHOR]

This work aimed to develop green biodegradable film using red seaweed ( Kappaphycus alvarezii ) as a base matrix and calcium carbonate (CaCO 3 ) as a filler to enhance the properties of the red seaweed material for plasticulture purpose. CaCO 3 which was produced by microbially induced precipitation (MB-CaCO 3 ) using Bacillus sphaericus , was characterized and compared with the commercial CaCO 3 (C CaCO 3 ). FESEM image revealed that the size of MB-CaCO 3 was smaller and more uniform compared to C CaCO 3 . FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO 3 , which contained a higher percentage of calcite than C CaCO 3 . However, the crystallinity and thermal stability of MB-CaCO 3 was lower than C CaCO 3 . From the results of physical, mechanical and thermal properties of composite films filled with C CaCO 3 and MB-CaCO 3 fillers, the optimum loading of C CaCO 3 and MB-CaCO 3 was found at 0.1% and 0.15%, respectively. Composite films filled with MB-CaCO 3 promote brighter film, better water barrier, hydrophobicity and biodegradability compared to C CaCO 3 . Since the effect of MB-CaCO 3 on film functional properties was comparable to C CaCO 3 , it can be used as an alternative to C CaCO 3 as inorganic filler for composite films in agriculture applications. [ABSTRACT FROM AUTHOR]

Protein-based bioplastics may be regarded as novel biopolymer matrices based on renewable natural components. Due to technological, economic and environmental benefits, these biopolymer matrices are highly attractive for the incorporation and subsequent release of micronutrients that are essential for the development and health of plants, avoiding the typical excesses of conventional fertilizers. In addition, soy protein isolate (SPI) seems to be an adequate resource for the manufacture of natural-based superabsorbent materials due to its hydrophilic character and excellent processability when combined with a plasticizer. The objective of this work is to develop soy protein-based bioplastic matrices loaded zinc sulphate monohydrate with potential applications in horticulture. With this aim, the micronutrient loading level and water absorption are the most important properties to assess. The effect of the presence of a selected micronutrient (zinc) at different concentrations in the soy protein-based matrix was assessed, evaluating the mechanical properties, water uptake capacity, microstructure and loading level of zinc. The results confirm that important amounts of an essential micronutrient for a plant (Zn) can be incorporated into bioplastic matrices, modifying water absorption, mechanical and microstructural properties. In any case, the results obtained in this work open up a great potential for the use of this matrices as a supplying source of micronutrients for horticultural crop applications. [ABSTRACT FROM AUTHOR]

Bioactive films from hydroxypropyl methylcellulose (HPMC), nisin (N), and different percentage (5% to 75%) of TEMPO-oxidized nanofibrillated cellulose (NFC) isolated from rice straw pulp were prepared by solution casting technique and their properties were studied. Scanning electron microscope images (SEM) of films showed homogeneous surface with absence of nanofibers agglomeration. The mechanical and barrier properties were evaluated by measuring their tensile strength, tensile modulus, strain at maximum load, dynamic mechanical thermal properties (DMTA), and water vapor permeability (WVP). In all films, there was an improvement in the mechanical, thermomechanical, and moisture barrier properties as a result of presence of NFC. The molecular structure of the films was studied by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction patterns (XRD). Presence of NFC in HPMC films affected crystallinity of the later. The prepared HPMC/N, NFC/N, and HPMC/N/NFC films exhibited significant antimicrobial activities against Gram-positive bacteria Staphylococcus aureus with noticeable controlled release of nisin in case of films containing HPMC/NFC. [ABSTRACT FROM AUTHOR]

Abstract: Functional bionanocomposites are developed from the assembly of naturally occurring polymers and inorganic solids that show at least one dimension at the nanoscale. Our research group focused on the development of bionanocomposites based on clay minerals, including smectites and fibrous silicates, as well as layered double hydroxides. The resulting materials show interesting properties regarding biocompatibility and biodegradability, together with improved mechanical and thermal properties in comparison to the pristine biopolymer. Besides these characteristics, they offer also other interesting functional properties that allow their potential use in a wide range of applications, including sensors, drug delivery and other health care applications, bioplastics and environmental remediation. For these materials, nature provides not only the components but also the inspiration to develop new combinations that may give rise to nanostructured biomaterials with exceptional features. [ABSTRACT FROM AUTHOR]

[Display omitted] Polymers with biodegradable properties are termed as the future "green materials" possessing a shorter lifetime compared to synthetic polymeric materials. Though naturally available biopolymers are the most abundant, synthetic biodegradable polymers have been designed and synthesized to get the required physical and chemical properties finding varied applications in cosmetics, coatings, wound dressings, enzyme immobilization, gene delivery, and tissue engineering scaffolds. Further, structurally-modified biopolymers are more prescribed and suggested for their usage in nanotechnology, augmentation, cryopreservation, prosthetics, medical implants, devices, and sanitation products including surgical sutures. It is important to understand the structural properties of various biodegradable polymers for their applications. In this regard, the present review article describes the classification of bio-degradable polymers as natural (polysaccharides and proteins) and synthetic (esters, amides, ethers, urethanes, or hybrid systems) biodegradable polymers by describing their structural properties suitable to the biomedical applications. The development of new hybrid biodegradable polymers with flexibility and long-term biocompatibility leads to the flow of numerous non-toxic biomaterials appropriate to biomedical fields like orthopedics, long-term implants, regenerative medicine, and controlled drug delivery experiencing vital contributions. The enormous efforts and investigations made by these biodegradable polymers facilitate the significant expansion of the development of new viable products for clinical trials. [ABSTRACT FROM AUTHOR]

Green and environmentally friendly approaches are increasingly necessary when developing new analytical methodologies. Electromembrane extraction (EME) has contributed to this by offering new alternatives to the traditional and widely used plastic materials. Specially, those derived from biopolymers (such as agarose or chitosan) have recently gained a great importance in EME as they are biodegradable and sustainable, which constitutes a major advantage in the environmental impact of these processes. This review is intended to cover the recent advances made on EME procedures based on the use of sustainable biopolymer-based materials by addressing the properties and synthesis of these materials as well as their analytical application. Extraction devices and EME methods will be extensively discussed, highlighting their strengths and weaknesses, aiming at improving analytical methodologies for sample processing, while contributing to their sustainability. • Biopolymers are introduced as sustainable materials for sample preparation. • EME procedures based on the use of biopolymers are reviewed. • Synthesis, characteristics, extraction devices and applications are described. • Advantages and limitations of these materials compared to plastic ones are discussed. [ABSTRACT FROM AUTHOR]

Due to its low carbon footprint and environmental friendliness, polylactic acid (PLA) is one of the most widely produced bioplastics in the world. Manufacturing attempts to partially replace petrochemical plastics with PLA are growing year over year. Although this polymer is typically used in high-end applications, its use will increase only if it can be produced at the lowest cost. As a result, food wastes rich in carbohydrates can be used as the primary raw material for the production of PLA. Lactic acid (LA) is typically produced through biological fermentation, but a suitable downstream separation process with low production costs and high product purity is also essential. The global PLA market has been steadily expanding with the increased demand, and PLA has now become the most widely used biopolymer across a range of industries, including packaging, agriculture, and transportation. Therefore, the necessity for an efficient manufacturing method with reduced production costs and a vital separation method is paramount. The primary goal of this study is to examine the various methods of lactic acid synthesis, together with their characteristics and the metabolic processes involved in producing lactic acid from food waste. In addition, the synthesis of PLA, possible difficulties in its biodegradation, and its application in diverse industries have also been discussed. [Display omitted] • Food waste is a favored carbohydrate-rich substrate for lactic acid generation. • Optically pure lactic acid is used as the monomer for polylactic acid (PLA) production. • The process of polymerization is used to convert lactic acid into PLA. • Due to its biodegradability and biocompatibility, PLA has found several uses in a variety of fields. • Degradation of polylactic acid (PLA) occurs through hydrolytic, microbial, enzymatic, and photodegradation. [ABSTRACT FROM AUTHOR]

Since the last two decades, the use of synthetic materials has increased and become more frequent in this capitalist system. Polymers used as raw materials are usually disposed very rapidly and considered serious damages when they return to the environment. Because of this behaviour, there was an increasing in the global awareness by minimizing the waste generated, in addition to the scientific community concern for technological alternatives to solve this problem. Alternatively, biodegradable polymers are attracting special interest due to their inherent properties, which are similar to the ones of the conventional plastics. Bioplastics covers plastics made from renewable resources, including plastics that biodegrade under controlled conditions at the end of their use phase. Polyhydroxyalkanoates (PHAs) are polyesters composed of hydroxy acids, synthesized by a variety of microorganisms as intracellular carbon and energy storage. These environmentally friendly biopolymers have excellent potential in domestic, agricultural, industrial and medical field, however their production on a large scale is still limited. This review considered the most recent scientific publications on the production of bioplastics based on PHAs, their structural characteristics and the exploitation of different renewable sources of raw materials. In addition, there were also considered the main biotechnological applications of these biopolymers. [ABSTRACT FROM AUTHOR]

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based 'green' polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20-30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering. [ABSTRACT FROM AUTHOR]

The polyhydroxyalkanoates (PHAs) are microbially-produced biopolymers that could potentially be used as sustainable alternatives to oil-derived plastics. However, PHAs are currently more expensive to produce than oil-derived plastics. Therefore, more efficient production processes would be desirable. Cell-free metabolic engineering strategies have already been used to optimize several biosynthetic pathways and we envisioned that cell-free strategies could be used for optimizing PHAs biosynthetic pathways. To this end, we developed several Escherichia coli cell-free systems for in vitro prototyping PHAs biosynthetic operons, and also for screening relevant metabolite recycling enzymes. Furthermore, we customized our cell-free reactions through the addition of whey permeate, an industrial waste that has been previously used to optimize in vivo PHAs production. We found that the inclusion of an optimal concentration of whey permeate enhanced relative cell-free GFPmut3b production by approximately 50%. In cell-free transcription-translation prototyping reactions, gas chromatography-mass spectrometry quantification of cell-free 3-hydroxybutyrate (3HB) production revealed differences between the activities of the Native DPhaC_C319A (1.18±0.39 μM), C104 DPhaC_C319A (4.62±1.31 μM) and C101 DPhaC_C319A (2.65±1.27 μM) phaCAB operons that were tested. Interestingly, the most active operon, C104 produced higher levels of PHAs (or PHAs monomers) than the Native phaCAB operon in both in vitro and in vivo assays. Coupled cell-free biotransformation/ transcription-translation reactions produced greater yields of 3HB (32.87±6.58 μM), and these reactions were also used to characterize a Clostridium propionicum Acetyl-CoA recycling enzyme. Together, these data demonstrate that cell-free approaches complement in vivo workflows for identifying additional strategies for optimizing PHAs production. [ABSTRACT FROM AUTHOR]

The search for new materials that replace fossil fuel-based plastics has been focused on biopolymers with similar physicochemical properties to fossil fuel-based plastics, such as Polyhydroxyalkanoates (PHA). The present paper reviews the challenges of scaling-up PHA production from waste streams during the period from 2014 to 2016, focusing on the feasibility of the alternatives and the most promising alternatives to its scaling-up. The reviewed research studies mainly focus on reducing costs or obtaining more valuable polymers. In the future, the integration of PHA production into processes such as wastewater treatment plants, hydrogen production or biodiesel factories could enhance its implementation at industrial scale. [ABSTRACT FROM AUTHOR]

The utilization of industrial waste streams as input materials for bio-mediated production processes constitutes a current R&D objective not only to reduce process costs at the input side but in parallel, to minimize hazardous environmental emissions. In this context, the EU-funded project ANIMPOL elaborated a process for the production of polyhydroxyalkanoate (PHA) biopolymers starting from diverse waste streams of the animal processing industry. This article provides a detailed economic analysis of PHA production from this waste biorefinery concept, encompassing the utilization of low-quality biodiesel, offal material and meat and bone meal (MBM). Techno-economic analysis reveals that PHA production cost varies from 1.41 €/kg to 1.64 €/kg when considering offal on the one hand as waste, or, on the other hand, accounting its market price, while calculating with fixed costs for the co-products biodiesel (0.97 €/L) and MBM (350 €/t), respectively. The effect of fluctuating market prices for offal materials, biodiesel, and MBM on the final PHA production cost as well as the investment payback time have been evaluated. Depending on the current market situation, the calculated investment payback time varies from 3.25 to 4.5 years. [ABSTRACT FROM AUTHOR]

Cutin is the main component of plant cuticles constituting the framework that supports the rest of the cuticle components. This biopolymer is composed of esterified bi- and trifunctional fatty acids. Despite its ubiquity in terrestrial plants, it has been underutilized as raw material due to its insolubility and lack of melting point. However, in recent years, a few technologies have been developed to obtain cutin monomers from several agro-wastes at an industrial scale. This review is focused on the description of cutin properties, biodegradability, chemical composition, processability, abundance, and the state of art of the fabrication of cutin-based materials in order to evaluate whether this biopolymer can be considered a source for the production of renewable materials. [ABSTRACT FROM AUTHOR]

Over the last decade, biopolymers have seen a sharp increase in their market share as an alternative to conventional oil-based plastic materials. Among them, degradable biopolymers are rarely employed, especially in the field of durable end-goods, because of their often limited chemical, mechanical and thermal behaviours. In contrast, stringent international regulations encourage the employment of low-impact materials in several manufacturing domains, with degradable polymers considered par excellence. In the present work, an innovative route to control the final properties of an extrusion-compounded, high-performance biocomposite composed of polylactic acid (PLA) reinforced with micro-lamellar talc is proposed. For this purpose, talc was first modified via surface reaction with organic (i.e., belonging to the class of polyisocyanates) or hybrid organic-inorganic (i.e., belonging to the class of organosilanes) compatibilizers, respectively. Custom-built formulations were then achieved by the dispersion of the pretreated micro-lamellar talc in commercial-grade PLA. The resulting compounds were analysed by differential scanning calorimetry (DSC) and attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy. The experimental findings show that PLAs with different properties can be achieved as a result of chemical and physical interactions among the functional groups on the surface of the pretreated talc and the terminal groups of the PLA chains. These results are extremely promising for the achievement of innovative grades of PLAs suitable for melt processing and to ensure the greatly improved chemical inertness, thermal stability and mechanical strength of the resulting end-goods. [ABSTRACT FROM AUTHOR]

The emerging bio-based economy is initiating a shift from fossil-based resources towards renewable resources. The use of biopolymers is seen as being a key component in sustainable product development. Research on biopolymers for bioplastics production mainly focuses on product development, environmental performance and cost-related aspects, and neglects the issue of bioplastic market diffusion. This paper aims at identifying the factors influencing the market diffusion of bioplastic by considering the four biopolymers: polylactic acid (PLA), polyhydroxyalkanoate (PHA), lignin and cashew nut shell liquid (CNSL). Scenario techniques employing effects analysis and cross impact analysis are applied in the assessment. The effects analysis shows that the price of PLA and PHA is influenced by the process costs, whereas the prices of CNSL and lignin based novel bio-based plastic materials, are influenced by further technological innovations. The sales volume of all four biopolymers largely depends on the price as well as on marketing activities. The cross impact analysis identifies a range of possible outcomes. While a further price reduction and an increasing sales volume can be assumed likely in the case of PHA and lignin, the scenarios for PLA and CNSL are rather uncertain. The results provide insight into the possible impact of further price and sales volume developments in the bio-based plastic market. [ABSTRACT FROM AUTHOR]

Background: Poly(γ-glutamic acid) (γ-PGA) is a biopolymer with many useful properties making it applicable for instance in food and skin care industries, in wastewater treatment, in biodegradable plastics or in the pharmaceutical industry. γ-PGA is usually produced microbially by different Bacillus spp. The produced γ-PGA increases the viscosity of the fermentation broth. In case of shake flask fermentations, this results in an increase of the volumetric power input. The power input in shake flasks can be determined by measuring the torque of an orbitally rotating lab shaker. The online measurement of the volumetric power input enables to continuously monitor the formation or degradation of viscous products like γ-PGA. Combined with the online measurement of the oxygen transfer rate (OTR), the respiration activity of the organisms can be observed at the same time. Results: Two different Bacillus licheniformis strains and three medium compositions were investigated using online volumetric power input and OTR measurements as well as thorough offline analysis. The online volumetric power input measurement clearly depicted changes in γ-PGA formation due to different medium compositions as well as differences in the production behavior of the two investigated strains. A higher citric acid concentration and the addition of trace elements to the standard medium showed a positive influence on γ-PGA production. The online power input signal was used to derive an online viscosity signal which was validated with offline determined viscosity values. The online measurement of the OTR proved to be a valuable tool to follow the respiration activity of the cultivated strains and to determine its reproducibility under different cultivation conditions. Conclusions: The combination of the volumetric power input and the OTR allows for an easy and reliable investigation of new strains, cultivation conditions and medium compositions for their potential in γ-PGA production. The power input signal and the derived online viscosity directly reflect changes in γ-PGA molecular weight and concentration, respectively, due to different cultivation conditions or production strains. [ABSTRACT FROM AUTHOR]

The increasing amount of plastic waste causes significant environmental pollution. In this study, screening of Arctic microorganisms which are able to degrade bioplastics was performed. In total, 313 microorganisms were isolated from 52 soil samples from the Arctic region (Spitsbergen). Among the isolated microorganisms, 121 (38.66%) showed biodegradation activity. The ability of clear zone formation on emulsified poly(butylene succinate-co-adipate) (PBSA) was observed for 116 microorganisms (95.87%), on poly(butylene succinate) (PBS) for 73 microorganisms (60.33%), and on poly(ɛ-caprolactone) (PCL) for 102 microorganisms (84.3%). Moreover, the growth of microorganisms on poly(lactic acid) (PLA) agar plates was observed for 56 microorganisms (46.28%). Based on the 16S rRNA sequence, 10 bacterial strains which showed the highest ability for biodegradation were identified as species belonging to Pseudomonas sp. and Rhodococcus sp. The isolated fungal strains were tested for polycaprolactone films and commercial corn and potato starch bags degradation under laboratory conditions. Strains 16G (based on the analysis of a partial 18S rRNA sequence, identified as Clonostachys rosea) and 16H (identified as Trichoderma sp.) showed the highest capability for biodegradation. A particularly high capability for biodegradation was observed for the strain Clonostachys rosea, which showed 100% degradation of starch films and 52.91% degradation of PCL films in a 30-day shake flask experiment. The main advantage of the microorganisms isolated from Arctic environment is the ability to grow at low temperature and efficient biodegradation under this condition. The data suggest that C. rosea can be used in natural and laboratory conditions for degradations of bioplastics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimization steps increased by 85% the attained PHB production. • High PHB accumulation (70 %), production (14 g.L−1) and productivity (0.197 g.Lh−1). • Recovered biopolymer with high purity (>99 %). • Generation of a corn biorefinery system producing biofuels and PHB opportunity. The high costs of bioplastics' production may hinder their commercialization. Development of new processes with high yields and in biorefineries can enhance diffusion of these materials. This work evaluated the production of polyhydroxybutyrate (PHB) from the combination of milled corn starchy fraction hydrolysate and crude glycerol as substrates by the strain Cupriavidus necator LPB 1421. After optimization steps, maximum accumulation of 62 % of PHB was obtained, which represents 11.64 g.L−1 and productivity of 0.162 g.Lh−1. In a stirred tank bioreactor system with 8 L of operational volume, 70 % of PHB accumulation was reported, representing 14.17 g.L−1 of the biopolymer with 0.197 g.Lh−1 productivity. PHB recovery was conducted using a chemical digestion method, reaching >99 % purity. Therefore, the potential application of milled corn as substrate for PHB production was confirmed. The developed bioplastic process could be coupled to a bioethanol producing unit creating the opportunity of a sustainable and economic biorefinery. [ABSTRACT FROM AUTHOR]