Recent advances in the microbial synthesis of lactate-based copolymer

Due to the increasing environmental pollution of un-degradable plastics and the consumption of non-renewable resources, more attention has been attracted by new bio-degradable/based polymers produced from renewable resources. Polylactic acid (PLA) is one of the most representative bio-based materials, with obvious advantages and disadvantages, and has a wide range of applications in industry, medicine, and research. By copolymerizing to make up for its deficiencies, the obtained copolymers have more excellent properties. The development of a one-step microbial metabolism production process of the lactate (LA)-based copolymers overcomes the inherent shortcomings in the traditional chemical synthesis process. The most common lactate-based copolymer is poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB)], within which the difference of LA monomer fraction will cause the change in the material properties. It is necessary to regulate LA monomer fraction by appropriate methods. Based on synthetic biology and systems metabolic engineering, this review mainly focus on how did the different production strategies (such as enzyme engineering, fermentation engineering, etc.) of P(LA-co-3HB) optimize the chassis cells to efficiently produce it. In addition, the metabolic engineering strategies of some other lactate-based copolymers are also introduced in this article. These studies would facilitate to expand the application fields of the corresponding materials.

Isolation and Extraction of PHB from Soil Isolate: Determining its Physio- Chemical characteristics with an application study in Biomedical

Biopolymer Poly Hydroxy Butyrate (PHB) is gaining importance based on its physiochemical and biological characteristics. Hence, the characteristics of the PHB extracted from soil bacterial isolate as studied with an aim of developing a 2D films for biomedical applications. The isolates from soil samples were screened for the ability to produce PHB and confirmed using Sudan black staining methods. The physio-chemical characteristics were studied using FTIR, FESEM and GCMS analysis. FTIR spectrum obtained for the extracted polymer shows peaks at 1723.51 cm-1and 1287.63 cm-1 which confirms that the extracted polymer is PHB. FESEM image reveals the presence of pores of different size throughout the sample. The surface consists of multiple pores with different sizes. GC-MS analysis revealed the presence of various compounds attributing for the PHB production from the isolate. As a biological characteristic, a novel wound dressing 2D laminate bio composite films were developed using PHB extracts. The antibacterial activity of the developed film showed significant inhibitory zones against Escherichia coli and Klebsiella pneumoniae. The present research work showed promising results and proved that the PHB obtained from bacterial sp. can be used as an alternative to non-degradable plastics with a wide range of applications in biomedical industries.

Valorization and Application of Fruit and Vegetable Wastes and By-Products for Food Packaging Materials

The important roles of food packaging are food protection and preservation during processing, transportation, and storage. Food can be altered biologically, chemically, and physically if the packaging is unsuitable or mechanically damaged. Furthermore, packaging is an important marketing and communication tool to consumers. Due to the worldwide problem of environmental pollution by microplastics and the large amounts of unused food wastes and by-products from the food industry, it is important to find more environmentally friendly alternatives. Edible and functional food packaging may be a suitable alternative to reduce food waste and avoid the use of non-degradable plastics. In the present review, the production and assessment of edible food packaging from food waste as well as fruit and vegetable by-products and their applications are demonstrated. Innovative food packaging made of biopolymers and biocomposites, as well as active packaging, intelligent packaging, edible films, and coatings are covered.

Research Progress on Degradation and Market Dynamics of PBAT

At present, the massive use of traditional plastics which are very hard to degrade and hereinafter referred to as non-degradable plastics has caused serious pollution problems, which has a harmful effect on the environment and human health. Up to now, many countries have enacted strict policies and regulations to limit the use of non-degradable plastics, polyadipate/butanediol terephthalate (PBAT), as a kind of degradable plastic, has drawn more and more attention. In this paper, research progress on the degradation of PBAT is reviewed and the market dynamics of PBAT are introduced. In the next few years, the global capacity of PBAT is surging and is mainly concentrated in China. The prospect of PBAT is discussed which may provide a reference for PBAT producers.

Degradation of Plastics

The degradation of plastics is most important for the removal and recycling of plastic wastes. The book presents a comprehensive overview of the field. Topics covered include plastic degradation methods, mechanistic actions, biodegradation, involvement of enzymes, photocatalytic degradation and the use of cyanobacteria. Also covered are the market of degradable plastics and the environmental implications. The degradation of plastics is most important for the removal and recycling of plastic wastes. The book presents a comprehensive overview of the field. Topics covered include plastic degradation methods, mechanistic actions, biodegradation, involvement of enzymes, photocatalytic degradation and the use of cyanobacteria. Also covered are the market of degradable plastics and the environmental implications.

Versatile Applications of Degradable Plastic

In the last 50 years, plastics has become a favorite industry for packaging materials for their ease of manufacture and excellent performance. The advancement of food, electronics, automobile, medical and agricultural industries has increased the demand for packaging and casing materials made of large hydrocarbon polymers. Since plastics show resistance to biodegradation, they pose considerable threats to the environment. Degradable plastics and biopolymers offer promising solutions to this problem. Degradable plastics can be easily absorbed in the environment while exhibiting the properties of conventional plastics. There are three types of biopolymers according to their source: biomass extracted polymers, synthesized from microorganisms and produced from bio-derived monomers. Biodegradable plastics are commonly used in one-off packaging such as crockery, food service containers and cutlery. Although biodegradable plastics can replace conventional plastics in a lot of applications, their performance and cost are sometimes problematic. This chapter analyses the growth of the degradable plastic industry and explores their potential applications.

Overview of the Degradable Plastic Market

Degradable plastic manufacturing has emerged as an eminent industry due to multiple range of products it offers to the consumers. The diversity induced by the usage of biomaterials lures the customer, making it even more popular for consumption. Degradable plastic industry is a market of multifarious products. The backlash on the massive plastics consumption is expected to be eradicated in the wake of the large business market of degradable plastics in the coming years. The supremacy of the degradable plastic market is not easy to evade by any means. The degradable plastic market is not a solitary market; instead, it encompasses the production, consumption and recycling industry as well. In order to triumph the status of a flourished market a joint venture by the leading companies need to be in harmony. The circular economy of the world is indispensable without a degradable plastic market in future.

Degradation of Plastics in Simulated Landfill Conditions

Different degradable plastics have been promoted as a solution for the accumulation of waste in landfills and the natural environment; in Mexico, the most popular options are oxo-degradable, which degrade in a sequential abiotic–biotic process, and compostable plastics. In this research, high-density polyethylene, oxo-degradable high-density polyethylene, and certified compostable plastic were exposed to simulated landfill conditions in an 854-day-long experiment to assess their degradation. High-density polyethylene showed limited degradation, due mainly to surface erosion, evidenced by a 13% decrease in elongation at break. The pro-oxidant additive in the oxo-degradable plastic increased this loss of mechanical properties to 27%. However, both plastic films kept their physical integrity and high molecular weight by the end of the experiment, evidencing degradation but no biodegradation. While the compostable film fragmented, had a lower molecular weight at the end of the experiment, and decreased the presence of C=O bonds, this degradation took place remarkably slower than expected from a composting process. Results show that oxo-degradable and compostable plastics will not biodegrade readily in landfills. This fact should be known and understood for decision-makers to match the characteristics of the materials to the features of the waste management systems.