Biodegradability and methane fermentability of polylactic acid by thermophilic methane fermentation

Draft genome sequence and morphological data of Planifilum fimeticola PLACP1, a thermophilic chloramphenicol-resistant bacterium isolated from thermophilic sludge

Planifilum is a thermophilic aerobic Actinomyces often found in compost that is suggested to play a primary role in the degradation of organic matter and is a potential antibiotic-resistance gene (ARG)-hosting bacterium during the composting process. Planifilum fimeticola PLACP1 was isolated from thermophilic sludge on a Columbia plate supplemented with chloramphenicol. PLACP1 was Gram-stain-positive with cells longer than 20 μm that branched and intertwined with each other. A draft genome sequence of P. fimeticola PLACP1 was generated using the Illumina NovaSeq system and deposited in the National Center for Biotechnology Information database under the BioProject accession numbers PRJDB17484 and SAMD00736731. The genome sequence comprised 3,395,140 bp, with 57.97 % GC content and 3,368 genes, including 3,267 protein-coding, 6 rRNA, and 56 tRNA genes. Based on the Comprehensive Antibiotic Resistance Database, 237 predicted gene products were related to ARGs, including 44 macrolide antibiotic-related genes (19 %) as the largest group. This dataset will be beneficial for the morphological identification, comparative genomic analyses, and ARG research in the genus Planifilum.

Anaerobic Biodegradability of Commercial Bioplastic Products: Systematic Bibliographic Analysis and Critical Assessment of the Latest Advances

Bioplastics have entered everyday life as a potential sustainable substitute for commodity plastics. However, still further progress should be made to clarify their degradation behavior under controlled and uncontrolled conditions. The wide array of biopolymers and commercial blends available make predicting the biodegradation degree and kinetics quite a complex issue that requires specific knowledge of the multiple factors affecting the degradation process. This paper summarizes the main scientific literature on anaerobic digestion of biodegradable plastics through a general bibliographic analysis and a more detailed discussion of specific results from relevant experimental studies. The critical analysis of literature data initially included 275 scientific references, which were then screened for duplication/pertinence/relevance. The screened references were analyzed to derive some general features of the research profile, trends, and evolution in the field of anaerobic biodegradation of bioplastics. The second stage of the analysis involved extracting detailed results about bioplastic degradability under anaerobic conditions by screening analytical and performance data on biodegradation performance for different types of bioplastic products and different anaerobic biodegradation conditions, with a particular emphasis on the most recent data. A critical overview of existing biopolymers is presented, along with their properties and degradation mechanisms and the operating parameters influencing/enhancing the degradation process under anaerobic conditions.

The role of waste management in reducing bioplastics' leakage into the environment: A review

Bioplastics are becoming more and more widespread as substitutes for petroleum-derived plastics due to their biodegradability. Bioplastics degradation under different environments has been described and reported to depend mainly on bioplastics' compositions and the environmental conditions. Incomplete degradation during waste management processes and leakage of bioplastics into the environment are becoming major concerns that need to be further investigated. In this context, the present paper aimed to review recent literature dealing with biodegradation of bioplastics under industrial (e.g. anaerobic digestion and composting) and natural (e.g. soil and water) environments, and to link it to the potential bioplastics' leakage into the environment. Reviewed data were used to estimate the potential role of waste management processes in decreasing the potential leakage of bioplastics. Depending on bioplastics' type and processing conditions, waste management can effectively reduce bioplastics' potential leakage, decreasing the concentration of these materials that can reach the natural environments.

Inspired by nature: Microbial production, degradation and valorization of biodegradable bioplastics for life-cycle-engineered products

The global environmental pollution by micro- and macro-plastics reveals the consequences of an extensive use of recalcitrant plastic products together with inappropriate waste management practices that fail to sufficiently recycle the broad types of conventional plastic waste. Biobased and biodegradable plastics are experiencing an uprising as their properties offer alternative waste management solutions for a more circular material economy. However, although the production of such bioplastics has advanced on scale, the end-of-life (EOL) (bio)technologies to promote circularity are lacking behind. While composting and biogas plants are the only managed EOL options today, advanced biotechnological recycling technologies for biodegradable bioplastics are still in an embryonic stage. Thus, developing efficient biotechnologies capable of transforming bioplastic waste into high-value chemical building blocks or into the constituents of the original polymer offers promising routes towards life-cycle-engineered products. This review aims at providing a comprehensive state-of-the-art overview of microbial-based processes involved in the complete lifecycle of bioplastics. The current trends in the bioplastic market, the beginning and EOL scenarios of bioplastics, and a critical discussion on the key factors and mechanisms governing microbial degradation are systematically presented. Also, a critical evaluation of terminology and international standards to quantify polymer biodegradability is provided together with the latest biotechnological recycling strategies, including the use of different pre-treatments for (bio)plastic waste. Finally, the challenges and future perspectives for the development of life-cycle-engineered biobased and biodegradable plastic products are discussed.