Stéphane Bruzaud

• Dr.
• Professor (Full) at University of South Brittany

The effects of gamma irradiation on the morphology and physical properties of various blends based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polylactide (PLA): 50/50 w/w were studied with and without PHBV-g-MA and organomodified montmorillonite used as the compatibilizer and reinforcement agent, respectively. The different blend co...

The expansion of polyhydroxyalkanoates (PHAs) into the biodegradable polymers market is mainly prevented by their production process which is still complicated with a low efficiency, resulting in relatively expensive products. In this study, we developed a method that used the lipophilic fluorescent probe Nile Red (1 mg l(-1) solution in DMSO) dire...

A microalgae cultivation process was developed in order to produce starch-rich biomass, which can be converted into glucose after starch extraction and hydrolysis. Associated to levulinic acid, biosynthesis processes were carried out with microalgae-derived starch glucose, resulting in the production of poly (3-hydroxybutyrate-co-3-hydroxyvalerate)...

Plastic biodegradation in natural environments is performed by the microbial biofilm living on its surface. This study identifies for the first time plastic degraders in marine environment, by using stable isotope tracers. Polyhydroxybutyrate (PHB) biodegradation was proved by monitoring microbial cell growth (via scanning electron microscopy and f...

Le chapitre décrit l’influence des facteurs intrinsèques (relatifs au polymère) et extrinsèques (liés au milieu) sur la dégradation des polyesters susceptible de se manifester aux différentes échelles (macroscopique, microscopique et moléculaire). Il se focalise essentiellement sur deux types de polyesters : les polyhydroxyalcanoates (PHA) et les p...

The present research investigates the influence of chemical modifications on the surface of Diss fibers ( Ampelodesmos mauritanicus ) as an effective reinforcing agent for biocomposites based on poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV). The Diss fiber surface underwent three different chemical treatments: alkaline, alkaline/peroxide, an...

Chemical treatments are used to remove hydrophilic OH groups and surface particles from the fiber surface for increasing aspect ratio of fibers and subsequently, mechanical properties. In this paper, the effect of two eco-friendly chemical treatments on morphology, chemical structure, and thermal stability of Agave Americana fibers (AAFs) is invest...

This work aims at investigating the effect of two eco-friendly chemical treatments of Agave Americana fibers (AAFs) on morphology and mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) biocomposites prepared by melt compounding. Acid citric and sodium bicarbonate treatments are used separately to modify the fiber surfac...

Understanding the fates and impacts of microplastics requires information on their sizes, polymer types, concentrations, and spatial and temporal distributions. Here, we focused on large (LMPs, 500 µm to 5 mm) and small (SMPs, 25 to 500 µm) microplastics sampled with the exact same protocol in nine of the major European rivers during the seven mont...

This study investigates the morphology and properties of biocomposites based on a blend of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly (lactic acid) (PLA) 50/50 (w/w) reinforced with untreated (UNDF) and alkali-treated (ATDF) Diss (Ampelodesmos mauritanicus) fibers at 20 wt. %. Moreover, PHBV-g-MA used as the compatibilizer was add...

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-livin...

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 teste...

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 d...

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...

Au niveau international, la présence de microplastiques dans la matrice sol a été suggérée dès 2012. Il a cependant fallu attendre la période 2015-2020 pour que les premières études mettent effectivement en évidence leur existence. La recherche française sur cette problématique s’est quant à elle développée et structurée à partir de 2020. Cette pre...

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. In this contribution, an engineering polymer, poly(oxy-methylene) (POM), was stu...

Two series of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) and poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) with different amounts of hydroxyvalerate (HV) and hydroxyhexanoate (HHx) units are compared. The infuence of chemical composition on the molecular mobility in quenched samples is discussed, as well as the consequences on...

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 down...

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. From these, the median of the abundance...

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) rein...

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...

This article provides an overall review of the plastic pollution in solid terrestrial environments. The first part describes the main routes of entry of plastics into soils, in particular those associated with certain agricultural uses. Then, the different degradation mechanisms of plastics in these environments and their transport are discussed. T...

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. To t...

Soils, especially agricultural soils, are thought to be the main reservoir of microplastics in Europe (Lofty et al., 2022). One significant source of MP entering in soils are the plastic mulching on agricultural land. Traditionally, mulches are made of PE, whose particles can contaminate the soil for a long time if the film is not completely remove...

The latest literature suggests that organic fertilizers are one of the first sources of contamination of agricultural soils. Indeed, organic materials for intended soil amendments (e.g. composts, green waste, manure, sewage sludge) are the result of various processes and can be contaminated by microplastics (MP), such as packaging residues. In orde...

To date, the majority of the research on microplastics (MP) has focused on the marine environment. The pollution of continental ecosystems is comparatively little studied, even though the majority of all plastics is used and disposed on land. The main sources of plastic in soils include land application of contaminated sewage sludge and compost, pl...

Tensile and viscoelastic properties of poly(3‐hydroxybutyrate‐co‐ 3‐hydroxyhexanoate) (PHBHHx)/zinc oxide nanoparticles (ZnO‐NP) bionanocomposites prepared by melt compounding at various ZnO‐NP content ratios, i.e., 1.5, 3, and 6 wt% are investigated. The study of the comprehension of structure‐properties relationships with respect to filler conten...

The development of new bio‐based and biodegradable composites with enhanced performances is an efficient route to achieve a sustainable materials production. In this work, biocomposites materials based on PHBHHx reinforced with Agave leaves fibers (ALF) are elaborated by melt compounding at various filler content ratios, i.e., 10, 20, and 30 wt%. T...

Plastic microbeads have been produced at very large scales since several decades for cosmetics and personal care products, a large amount of which is being directly transported in the oceans. To better understand their biodegradability in marine environment and evaluate their possible replacement by biodegradable polymers, seven polymer types were...

Green biocomposites based on poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) (PHBHHx) reinforced with Agave Americana fibers (AAF) were elaborated by melt compounding at various fiber content ratios, i.e., 10, 20 and 30 wt.%. Morphology before and after tensile testing, rheological, viscoelastic, mechanical and thermal properties of the biocomposite...

In this work, the main objective is to investigate the effect of olive husk flour (OHF) used as a biofiller on the marine degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites up to 6 months of immersion in sea water at 25°C and 40°C. Film samples based on neat PHBV and PHBV are filled with 20 wt.% OHF is prepared by melt...

Unfortunately, our publication was not accepted. We are thinking about re-submitting it

Le polyoxyméthylène (POM) est un polymère technique souvent utilisé dans des assemblages de précision nécessitant une grande résistance aux sollicitations mécaniques et à l’abrasion [1]. Certains déchets plastiques retrouvés dans l’environnement en sont constitués, et leur vieillissement est méconnu en milieu naturel. Ainsi, les phénomènes de dégra...

Microplastics (MP) in marine ecosystems is a global pollution of increasing scientific and societal concern. With the majority of plastics found in these ecosystems coming from land-based sources [1], through rivers and run-off, studies on MP has recently shifted focus toward freshwater ecosystems. The Tara Microplastics 2019 mission aims to invest...

Le polyoxyméthylène (POM) est un polymère technique souvent utilisé dans des assemblages de précision nécessitant une grande résistance aux sollicitations mécaniques et à l’abrasion [1]. Certains déchets plastiques retrouvés dans l’environnement en sont constitués, et leur vieillissement est méconnu en milieu naturel. Ainsi, les phénomènes de dégra...

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 signi...

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) were used to prepare microbeads, with diameter ranging from 50 to 100 µm, by an emulsion-evaporation process. The emulsification-evaporation process enables the formation of spherical polyhydroxyalcanoate beads, with crystalline rates similar to the ones...

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)/ZnO-NP nanoparticles bionanocomposites were elaborated by melt compounding in a twin-screw extruder at content ratio of 1.5, 3 and 6 wt.%. Morphology, crystallinity and thermal stability of the PHBHHx-based bionanocomposite samples were investigated by scanning electron microscopy (SEM), wide a...

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 concentra...

Melt blending of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) and poly(butylene‐co‐succinate‐co‐adipate) (PBSA) was investigated by means of batch mixing at different weight ratios (100:0, 70:30, 50:50, 30:70, and 0:100). PHBV and PBSA were immiscible. PBSA formed small nodules in PHBV, while PHBV formed large inclusions in PBSA. In 50/50 wt...

In this paper, biocomposites samples based on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)/cellulose microcrystalline (MCC) extracted from olive husk flour were prepared in a twin-screw extruder at loading rates of 10, 20 and 30 wt%. Morphology, thermal stability and water uptake of PHBHHx biocomposites were investigated with respect with...

The Tara Microplastics 2019 mission aimed to investigate plastic pollution in rivers across different scientific fields of study: plastic chemistry, physical oceanography and marine biology. From May to November 2019, the Tara schooner collected samples from 9 of the main European rivers: Thames, Elbe, Rhine, Seine, Ebro, Rhone, Tiber, Garonne, Loi...

The ninth International Symposium Monitoring of Mediterranean Coastal Areas: Problems and Measurements Techniques was organized by CNR-IBE in collaboration with Italian Society of Silviculture and Forest Ecology, and Natural History Museum of the Mediterranean and under the patronage of University of Florence, Accademia dei Lincei, Accademia dei Ge...

Bio-based biodegradable plastics offer a valuable alternative to non-biodegradable, petroleum-based plastics. Polyhydroxyalkanoates (PHA) are natural polymers used in the production of bioplastics, have been reported to degrade in oceanic conditions [1] and can be obtained by a purely biotechnological route starting from a variety of carbon-rich bi...

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 bi...

L’article présente les différentes étapes clés du cycle de vie des polyesters biosourcés et/ou biodégradables. Il décrit les modes d’élaboration de chacun de ces polyesters en remontant jusqu’aux matières premières utilisées, en particulier lorsque celles-ci sont végétales. Les principales propriétés fonctionnelles et les applications sont détaillé...

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 ter...

Commercial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were used to prepare microbeads, with diameter ranging from 50 to 100 µm, by an emulsion-evaporation process. The properties of the beads reveal that the elaboration process enables the formation of spherical particles, that th...

In this study, biocomposites of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHHx)/cellulose microcrystalline (MCC) extracted from olive husk flour are prepared by melt compounding at various filler content ratios, i.e., 10, 20, and 30 wt%. The effect of the MCC content on the morphology, thermal stability, crystallinity, and water uptake of th...

Le littoral et la mer sont des ressources naturelles environnementales. C’est-à-dire des ressources qui, sans être un produit de l’activité humaine, influent ou pourraient influer sur l’économie des pays ou le bien-être de leurs habitants. Partout dans le monde, ces zones concentrent des populations croissantes et des activités multiples. Les impac...

Les polyhydroxyalcanoates (PHA) sont des polyesters d'origine bactérienne, qui constituent une famille de polymères très prometteuse tant du point de vue de leurs propriétés d'usage que celui de leur impact environnemental. La production de PHA est particulièrement pertinente puisqu'elle s'affranchit des procédés chimiques traditionnels, faisant ap...

The thin film of life that inhabits all plastics in the oceans, so-called “plastisphere,” has multiple effects on the fate and impacts of plastic in the marine environment. Here, we aimed to evaluate the relative influence of the plastic size, shape, chemical composition, and environmental changes such as a phytoplankton bloom in shaping the plasti...

The OceanWise project aims to propose solutions to reduce pollution of the marine environment by foamed polystyrene (EPS or XPS). Within this framework, EPS/XPS and the most promising alternative materials selected by the consortium were studied. Their mechanical properties and durability, their ageing in the marine and air environment, as well as...

Dès les années 1970, la présence de plastiques dans l’environnement est observée et l’identification de leurs impacts sur l’environnement étudiée. Aujourd’hui, la pollution par les plastiques est présente aussi bien en zones continentales que marines et peut induire différents risques pour l’homme et l’environnement (toxicité intrinsèque du polymèr...

This paper aims to investigate the effect of different chemical modifications of biocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) and aloe vera bio-fibers incorporated at 20 wt%. The fiber surface was modified with alkaline, organosilanes, and combined alkaline/organosilanes. Surface morphology, thermal stability, water a...

The aim of this work is to prepare and characterize a series of bio-polyurethane foams (Bio-PUFs) based on renewably sourced polyols in order to increase their ecological potential, while maintaining their properties. Polyurethane foams (PUFs) were obtained using two sunflower based-polyols (SF-P1 and SF-P2) with different hydroxyl numbers synthesi...

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...

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. Plastic particles were mixed with sand partic...

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. T...

The article reports some experimental data on the effects of three types of clay: organo-modified montmorillonite (cloisite 30B (C30B)), sepiolite (SP9), and halloysite nanotubes (HNT) on the morphology and physicomechanical properties of polycaprolactone (PCL)/clays bionanocomposites prepared by melt compounding. The clays were incorporated separa...

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 facto...

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 selec...

The aim of this study was to assess the effect of various surface treatments on Aloe Vera fibers (AVF) used as reinforcement in PHBHHx biocomposites prepared by melt compounding. AVF were subjected to various surface treatments including alkaline, organo-silanes and combined alkaline/organo-silanes treatments. Both untreated and treated AVF were ad...

Food trays are often made from extruded polystyrene (XPS), and quantities of millimetre-sized particles of this material are trapped between the meat they contain and the sealing film. The purpose of this study is to identify the chemical nature of these particles and quantify them. Furthermore, the quantification of synthetic or organic fibres was...

Les plastiques sont des matériaux obtenus par l’association de polymères synthétiques ou naturels, généralement chimiquement modifiés, et de divers additifs. Le développement des matières plastiques dans des secteurs aussi diversifiés que l’emballage, la construction, l’automobile, l’électronique ou le médical, est lié à la palette considérable de...

The presence and consequences of plastic waste in the environment have been the subject of intensive researches in recent years. While the state of contamination and the impact of this plastic waste on the environment and ecosystems is beginning to be better understood, the fundamental reasons why we throw away our plastic items, and the reasons th...

Les polyhydroxyalcanoates (PHA) sont des polymères issus de ressources renouvelables, obtenus par fermentation en présence de certaines espèces de bactéries. Ils forment une famille de polyesters thermoplastiques biodégradables fournissant une alternative prometteuse aux polymères issus de la pétrochimie, tant du point de vue de leur mode de synthè...

Halomonas sp. SF2003 is a halophilic Gram-negative eubacterium isolated from the Iroise sea (Brittany, France) which already demonstrated its capacity to produce and accumulate polyhydroxyalkanoates (PHA) up to 78% of the cell dry weight. PHA are biocompatible and completely biodegradable bacterial polyesters exposing thermal, mechanical and physic...

Polyhydroxylalkanoates (PHA) have been studied extensively for some years as replacements or substitutes for current mainstream petrochemical plastics. PHA produced by the fermentation of bacteria or other microorganisms as intracellular reserve of carbon or energy are also fully biodegradable polyesters with a wide array of properties that range f...

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 learni...

INTRODUCTION Polyhydroxylalkanoates (PHA) have been studied extensively for some years as replacements or substitutes for current mainstream petrochemical plastics. PHA produced by the fermentation of bacteria or other microorganisms as intracellular reserve of carbon or energy are also fully biodegradable polyesters with a wide array of properties...