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The microplastic that pollutes the ocean is a serious problem around the world. The bioplastic consisting of biopolymers which is degraded in nature, is one of the strategies to solve this problem. Although the bioplastics consisting of protein, polysaccharide, polylactic acid, etc., have been reported, which consist of DNA, one of the most important materials in the genetic process, have not been reported to the best of our knowledge. In addition, a large amount of DNA-containing materials, such as salmon milts, is discarded as industrial waste around the world. Therefore, we demonstrated the preparation of a bioplastic consisting of salmon milt DNA. The DNA plastic was prepared by the immersion of a DNA pellet in a formaldehyde (HCHO) solution and heating. As a result, the water-stable DNA plastics were obtained at the HCHO concentration of 20% or more. Particularly, the DNA plastic with a 25% HCHO treatment showed water-insoluble, thermally stable, and highly mechanical properties. These are due to the formation of a three-dimensional network via the crosslinking reaction between the DNA chains. In addition, since DNA in plastic possesses the double-stranded structure, these plastics effectively accumulated the DNA intercalator, such as ethidium bromide. Furthermore, the DNA plastics indicated a biodegradable property in a nuclease-containing aqueous solution and the biodegradable stability was able to be controlled by the HCHO concentration. Therefore, salmon milt DNA has shown the potential to be a biodegradable plastic. [ABSTRACT FROM AUTHOR]

For many decades, global efforts have been attempted to replace the petrochemical plastics with biodegradable and environment friendly plastics. The petrochemical plastics that require many years to decompose have profound consequences on the environment. A natural, biodegradable, and plastic‐like polymer, polyhydroxyalkanoate (PHA), has been extracted from and synthesized by microbes, particularly bacteria. However, the prospective large‐scale production of PHA faced an economic bottleneck for less production costs. Research has thus shifted to one of the most common alternatives, which is the utilization of less costly raw materials or carbon sources that include industrial by‐products and wastes, such as glycerine pitch and glycerol. This review elucidates the discovery, basic mechanisms, and applications of PHA, as well as provides insights regarding the importance of PHA conversion from glycerine pitch and glycerol. This review also summarizes some possible future modifications to improve the efficiency of glycerine pitch and glycerol as carbon sources in PHA production. The conversion endeavors of wastes to a valuable product, PHA, that not only reduces petrochemical plastic pollution, waste generation, and PHA production costs but also supports economic and resource sustainability, which ultimately further progress towards the cradle‐to‐cradle design and circular bioeconomy concept. [ABSTRACT FROM AUTHOR]

Bioplastics are currently and increasingly used as substitutes of conventional plastics; furthermore, they are mainly utilised in order to cope with problems related to plastic-based pollution. Certified international standard methods identify the criteria a bioplastic must comply with in order to be labelled as compostable and/or biodegradable. In addition, this is particularly the case when operating under the conditions that are expected in full-scale waste facilities. However, biodegradation in natural environments occurs under a manifold of different conditions, such that the aim of research studies is to estimate the extent to which a bioplastic can biodegrade under simulated natural conditions. For this reason, specific indexes are used to quantitatively estimate the degree of degradation. In the present paper, a description of the standard methods, research methods, and the indexes used to assess the biodegradability of bioplastics under different environmental conditions is provided. By summarising the results obtained by this study, it can be concluded that: (i) biopolymers claimed as biodegradable bioplastics may not degrade in full-scale plants due to the fact that the process conditions present in industrial waste treatment plants cannot completely reproduced at lab-scale; (ii) the static conditions set by the standard methods are not representative of the dynamic processes that occur in natural or industrial environments; and (iii) experimental tests are difficult to compare to one other due to the differences in the multitude of matrixes that can be used (i.e., inocula, soils, and biopolymers). [Display omitted] • Different standards (STDs) are used for testing bioplastics (BPs) biodegradability. • STDs should reflect more natural and industrial environments conditions. • The effects of microBPs on environment and human health need to be studied. • Results are not comparable due to the difference of procedures and materials used. • Research methods need to be more standardised to deliver comparable results. [ABSTRACT FROM AUTHOR]

Indiscriminate usage, disposal and recalcitrance of petroleum-based plastics have led to its accumulation leaving a negative impact on the environment. Bioplastics, particularly microbial bioplastics serve as an ecologically sustainable solution to nullify the negative impacts of plastics. Microbial production of biopolymers like Polyhydroxyalkanoates, Polyhydroxybutyrates and Polylactic acid using renewable feedstocks as well as industrial wastes have gained momentum in the recent years. The current study outlays types of bioplastics, their microbial sources and applications in various fields. Scientific evidence on bioplastics has suggested a unique range of applications such as industrial, agricultural and medical applications. Though diverse microorganisms such as Alcaligenes latus, Burkholderia sacchari, Micrococcus species , Lactobacillus pentosus, Bacillus sp., Pseudomonas sp., Klebsiella sp., Rhizobium sp., Enterobacter sp., Escherichia sp., Azototobacter sp., Protomonas sp., Cupriavidus sp., Halomonas sp., Saccharomyces sp., Kluyveromyces sp., and Ralstonia sp. are known to produce bioplastics, the industrial production of bioplastics is still challenging. Thus this paper also provides deep insights on the advancements made to maximise production of bioplastics using different approaches such as metabolic engineering, rDNA technologies and multitude of cultivation strategies. Finally, the constraints to microbial bioplastic production and the future directions of research are briefed. Hence the present review emphasizes on the importance of using bioplastics as a sustainable alternative to petroleum based plastic products to diminish environmental pollution. [Display omitted] • Overview of microbial bioplastics. • Leads and hurdles of microbial bioplastics were discussed. • Diverse applications were discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT This research study focuses on the thermomechanical polymerization of microalgae protein biomass such as Chlorella and Spirulina to develop algal-based bioplastics and thermoplastic blends. The algal protein biomass can grow on nutrient-rich wastewater from livestock farms, municipal or industrial effluent sources, remediating the excess nitrogen and phosphorus. The algal bioplastics provide biodegradability that can be tailored to have a wide range of material properties suitable for various applications-consumable and disposable plastic products, agricultural plastic products, and horticultural planting containers. According to experimental results, pressure, temperature, content of plasticizer, and processing time are major variables in polymerization and structure stabilization during the compression molding process of both algal protein biomass and thermoplastic blends containing polyethylene polymer. Chlorella showed better bioplastic behavior than Spirulina microalgae, whereas Spirulina showed better blend performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3263-3275, 2013 [ABSTRACT FROM AUTHOR]

The present study aimed to the investigation of the feasibility of the combined biohydrogen and biopolymers production from OMW (Olive oil Mill Wastewater), using a two stage system. H2 and volatile fatty acids (VFAs) were produced via anaerobic fermentation and subsequently the acidified wastewater was used as substrate for aerobic biodegradable polymer production. Two different bioreactors, one of CSTR type and a SBR were used for the anaerobic and the aerobic process respectively. The anaerobic reactor was operated at different hydraulic retention times (HRTs) with OMW, diluted 1:4 (v/v) with tap water, as feed. The main VFAs produced were acetate, butyrate and propionate, in different ratios depending on the HRT. Valerate, isovalerate and isobutyrate were also detected in small quantities. Selective effluents of the acidogenic/hydrogen producing reactor were subsequently used as feed for the aerobic reactor. The aerobic reactor was inoculated with an enriched PHAs producing bacteria culture, and was operated in sequential cycles of nitrogen offer (growth phase) and nitrogen limitation (PHAs accumulation phase). The operational program of the SBR was determined according to the results from batch test, and its performance was evaluated for a period of 100 days. During the accumulation phase butyrate was consumed preferably, indicating that the dominant PHA produced is polyhydroxybutyrate. The higher yield of PHAs observed was 8.94% (w/w) of dry biomass weight. [Copyright &y& Elsevier]

Apple pomace, the residue which is left out after processing of apple serves as a potential carbon source for the production of biopolymer, PHA (poly-hydroxyalkanoates). It is rich in carbohydrates, fibers and polyphenols. Utilization of these waste resources has dual societal benefit-waste management and conversion of waste to an eco-friendly biopolymer. This will lower the overall economics of the process. A major limitation for the commercialization of biopolymer in comparison with petroleum derived polymer is the high cost. This article gives an overview of valorization of apple pomace for the production of biopolymer, various strategies adopted, limitations as well as future perspectives. [Display omitted] • Potential of apple waste residues (apple pomace etc.) for PHA production is studied. • Biopolymer (PHA) production from apple industrial waste residues using microbes is investigated. • Importance of biotechnology sector for PHA production was reviewed. • Life cycle assessment during the PHA production has great advantages. • Limitations and future outlook for PHA production from apple industrial wastes was reviewed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recovery of bioplastics, gels, and fibers from wastes. • Production of biopolymers from wastes by selected microorganisms. • Hybrid biopolymeric structures for the development of high-added value products. • Biomedical applications of hybrid biomaterials: nanoparticles, microparticles, and scaffolds. • Biopolymer blends for drug delivery, tissue engineering, and theragnostic. Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms. However, the use of biopolymers at industrial scale for the development of products with high added value, such as food or biomedical products, not only can compensate the primary costs of biopolymer production, but also improve local economies and environmental sustainability. The present review describes some of the most relevant aspects related to the synthesis of hybrid materials and nanocomposites based on biopolymers for the development of products with high-added value. [ABSTRACT FROM AUTHOR]

Abstract: Waste activated sludge generated from a combined dairy and food processing industry wastewater treatment plant was evaluated for its potential to produce biodegradable plastic, poly β-hydroxybutyric acid (PHB). Deproteinized jowar grain-based distillery spentwash yielded 42.3% PHB production (w/w), followed by filtered rice grain-based distillery spentwash (40% PHB) when used as substrates. Addition of di-ammonium hydrogen phosphate (DAHP) resulted in an increase in PHB production to 67% when raw rice grain-based spentwash was used. Same wastewater, after removal of suspended solids by filtration and with DAHP supplementation resulted in lower PHB production (57.9%). However, supplementing other wastes with DAHP led to a substantial decrease in PHB content in comparison to what was observed in the absence of DAHP. [Copyright &y& Elsevier]