Niche partitioning and plastisphere core microbiomes in the two most plastic polluted zones of the world ocean.

Plastics are offering a new niche for microorganisms colonizing their surface, the so-called "plastisphere," in which diversity and community structure remain to be characterized and compared across ocean pelagic regions. Here, we compared the bacterial diversity of microorganisms living on plastic marine debris (PMD) and the surrounding free-living (FL) and organic particle-attached (PA) lifestyles sampled during the Tara expeditions in two of the most plastic polluted zones in the world ocean, i.e.

Generation of synthetic FTIR spectra to facilitate chemical identification of microplastics.

In a context where learning databases of microplastic FTIR spectra are often incomplete, the objective of our work was to test whether a synthetic data generation method could be relevant to fill the gaps. To this end, synthetic spectra were generated to create new databases. The effectiveness of machine learning from these databases was then tested and compared with previous results.

First national reference of microplastic contamination of French soils.

The recent emergence of studies on plastic contamination of terrestrial environments has revealed the presence of microplastics (MP) in a variety of soil types, from the most densely populated areas to the most remote ones. However, the concentrations and chemical natures of MP in soils vary between studies, and only a few ones have focused on this issue in France. The MICROSOF project aimed to establish the first national references for French soil contamination by microplastics.

Bioplastic degradation and assimilation processes by a novel bacterium isolated from the marine plastisphere.

Biosourced and biodegradable plastics offer a promising solution to reduce environmental impacts of plastics for specific applications. Here, we report a novel bacterium named Alteromonas plasticoclasticus MED1 isolated from the marine plastisphere that forms biofilms on foils of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Experiments of degradation halo, plastic matrix weight loss, bacterial oxygen consumption and heterotrophic biosynthetic activity showed that the bacterial isolate MED1 is able to degrade PHBV and to use it as carbon and energy source.

Sunlight and marine weathering of poly(oxymethylene): Evolution of the physico-chemical properties.

Plastic pollution is now an environmental problem that affects all environmental compartments. The study of plastic degradation in terrestrial, marine and other freshwater environments is emerging. Research is mainly focused on plastic fragmentation into microplastics.

Mission Tara Microplastics: a holistic set of protocols and data resources for the field investigation of plastic pollution along the land-sea continuum in Europe.

The Tara Microplastics mission was conducted for 7 months to investigate plastic pollution along nine major rivers in Europe-Thames, Elbe, Rhine, Seine, Loire, Garonne, Ebro, Rhone, and Tiber. An extensive suite of sampling protocols was applied at four to five sites on each river along a salinity gradient from the sea and the outer estuary to downstream and upstream of the first heavily populated city. Biophysicochemical parameters including salinity, temperature, irradiance, particulate matter, large and small microplastics (MPs) concentration and composition, prokaryote and microeukaryote richness, and diversity on MPs and in the surrounding waters were routinely measured onboard the French research vessel Tara or from a semi-rigid boat in shallow waters.

Continents of plastics: An estimate of the stock of microplastics in agricultural soils.

While there are estimates of the stock of microplastics in the marine environment, there are no estimates for soils. The main objective of this work is to estimate the total mass of microplastics in global agricultural soils. Microplastic abundance data from 442 sampling sites were collected from 43 articles.

A bionanocomposite of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/ZnO-nanoparticles intended for food packaging.

Films-based bionanocomposites have gained a great importance in food plastic packaging because they are eco-friendly materials and have the potential to improve food protection, while limiting the accumulation of synthetic plastics on the planet. In this paper, biofilms were prepared using poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) reinforced with Zinc oxide nanoparticles (ZnO-NPs) to develop new bionanocomposite materials intended for food packaging. The samples were fabricated using first solvent casting method followed by melt compounding at various loading rates, i.

Discussion about suitable applications for biodegradable plastics regarding their sources, uses and end of life.

This opinion paper offers a scientific view on the current debate of the place of biodegradable plastics as part of the solution to deal with the growing plastic pollution in the world's soil, aquatic, and marine compartments. Based on the current scientific literature, we focus on the current limits to prove plastic biodegradability and to assess the toxicity of commercially used biobased and biodegradable plastics in natural environments. We also discuss the relevance of biodegradable plastics for selected applications with respect to their use and end of life.

Microplastic fouling: A gap in knowledge and a research imperative to improve their study by infrared characterization spectroscopy.

The marine weathering of microplastics is spectrally characterized by the appearance of new bands that disturb our understanding of the information carried by the spectra. Yet, no explanation has been provided on the chemical origin of these new bands. Thus, the main objective of this work was to identify the origins of these additional bands.

Seasonal patterns of microplastics in surface sediments of a Mediterranean lagoon heavily impacted by human activities (Bizerte lagoon, Northern Tunisia).

In this paper, we investigated seasonal variations in concentrations of microplastics (MPs) in surface sediments of a lagoon heavily impacted by human activities, located in northern Tunisia (the Bizerte lagoon, southern Mediterranean Sea). Analyses of 112 sediment samples collected from 28 stations between May 2019 and February 2020 revealed significant seasonal variation in concentrations of total MPs, with the highest levels recorded in August 2019 (109.6 ± 59.

Chemical composition of microplastics floating on the surface of the Mediterranean Sea.

The Mediterranean Sea is one of the most studied regions in the world in terms of microplastic (MP) contamination. However, only a few studies have analysed the chemical composition of MPs at the Mediterranean Sea surface. In this context, this study aims to describe the chemical composition as a function of particle size, mass and number concentrations of MPs collected in the surface waters of the Mediterranean Sea.

Bacterial Abundance, Diversity and Activity During Long-Term Colonization of Non-biodegradable and Biodegradable Plastics in Seawater.

The microorganisms living on plastics called "plastisphere" have been classically described as very abundant, highly diverse, and very specific when compared to the surrounding environments, but their potential ability to biodegrade various plastic types in natural conditions have been poorly investigated. Here, we follow the successive phases of biofilm development and maturation after long-term immersion in seawater (7 months) on conventional [fossil-based polyethylene (PE) and polystyrene (PS)] and biodegradable plastics [biobased polylactic acid (PLA) and polyhydroxybutyrate-co-hydroxyvalerate (PHBV), or fossil-based polycaprolactone (PCL)], as well as on artificially aged or non-aged PE without or with prooxidant additives [oxobiodegradable (OXO)]. First, we confirmed that the classical primo-colonization and growth phases of the biofilms that occurred during the first 10 days of immersion in seawater were more or less independent of the plastic type.

Microbial Diversity and Activity During the Biodegradation in Seawater of Various Substitutes to Conventional Plastic Cotton Swab Sticks.

The European Parliament recently approved a new law banning single-use plastic items for 2021 such as plastic plates, cutlery, straws, cotton swabs, and balloon sticks. Transition to a bioeconomy involves the substitution of these banned products with biodegradable materials. Several materials such as polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), poly(butylene succinate) (PBS), polyhydroxybutyrate-valerate (PHBV), Bioplast, and Mater-Bi could be good candidates to substitute cotton swabs, but their biodegradability needs to be tested under marine conditions.

Characterization of microplastics in the surface waters of an urban lagoon (Bizerte lagoon, Southern Mediterranean Sea): Composition, density, distribution, and influence of environmental factors.

Compared to open sea environments, there is still limited knowledge about microplastic levels in semi-enclosed systems such as coastal lagoons. This work aims to assess the levels of MPs in the waters of an urban lagoon (Bizerte lagoon, northern Tunisia) and to study the effects of environmental factors on their distribution and abundance. Average concentration of total MPs was found to be 453.

Pre-detection of microplastics using active thermography.

Spectrometric analysis is one of the most widely used approaches to characterize the chemical nature of microplastics. Despite recent developments, this key step remains time consuming. The aim of this paper is to propose a new method for the pre-detection of microplastics based on mid-infrared imaging.

Microplastics in edible mussels from a southern Mediterranean lagoon: Preliminary results on seawater-mussel transfer and implications for environmental protection and seafood safety.

This study assesses the microplastics (MPs) levels in mussels (Mytilus galloprovincialis) and seawater from a southern Mediterranean lagoon (Bizerte lagoon, Northern Tunisia) and discusses the potential effects of its consumption on human health. Polyethylene was the most abundant in mussels and seawater, followed by polypropylene and cellophane. The lowest and highest average MPs concentrations were recorded in the lagoon channel and southern area of the lagoon, respectively, for both mussels (2.

Why is there plastic packaging in the natural environment? Understanding the roots of our individual plastic waste management behaviours.

Plastic waste is now a classic contaminant of the natural environment and the origins of the contamination need to be well understood. The transition from a useful object to a waste product is a fundamental moment that, from the point of view of the scientific literature, remains poorly understood. This review therefore aims to highlight some factors controlling this intentionality, but also those that influence individual waste management behaviours.

PHA Production and PHA Synthases of the Halophilic Bacterium sp. SF2003.

Among the different tools which can be studied and managed to tailor-make polyhydroxyalkanoates (PHAs) and enhance their production, bacterial strain and carbon substrates are essential. The assimilation of carbon sources is dependent on bacterial strain's metabolism and consequently cannot be dissociated. Both must wisely be studied and well selected to ensure the highest production yield of PHAs.

A machine learning algorithm for high throughput identification of FTIR spectra: Application on microplastics collected in the Mediterranean Sea.

The development of methods to automatically determine the chemical nature of microplastics by FTIR-ATR spectra is an important challenge. A machine learning method, named k-nearest neighbors classification, has been applied on spectra of microplastics collected during Tara Expedition in the Mediterranean Sea (2014). To realize these tests, a learning database composed of 969 microplastic spectra has been created.

Complete genome sequence of the halophilic PHA-producing bacterium Halomonas sp. SF2003: insights into its biotechnological potential.

A halophilic Gram-negative eubacterium was isolated from the Iroise Sea and identified as an efficient producer of polyhydroxyalkanoates (PHA). The strain, designated SF2003, was found to belong to the Halomonas genus on the basis of 16S rRNA gene sequence similarity. Previous biochemical tests indicated that the Halomonas sp.

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) using agro-industrial effluents with tunable proportion of 3-hydroxyvalerate monomer units.

With increasing concerns about future oil depletion and plastic pollution, bioplastics saw an increasing interest from scientists and industrials. Among bioplastics, the polyhydroxyalkanoates (PHA) are a promising family of polyester which are both biosourced and biodegradable. Biosynthesized by microorganisms, especially bacteria, control of their monomeric composition, and thus their thermal and mechanical properties, is still a challenge to really make tailor-made syntheses.