Dual anaerobic reactor model to study biofilm and microbiologically influenced corrosion interactions on carbon steel.

Continual challenges due to microbial corrosion are faced by the maritime, offshore renewable and energy sectors. Understanding the biofilm and microbiologically influenced corrosion interaction is hindered by the lack of robust and reproducible physical models that reflect operating environments. A novel dual anaerobic biofilm reactor, using a complex microbial consortium sampled from marine littoral sediment, allowed the electrochemical performance of UNS G10180 carbon steel to be studied simultaneously in anaerobic abiotic and biotic artificial seawater.

Metal Bionanohybrids against Microbiologically Influenced Corrosion (MIC) Consortia.

In search of new materials that would help to prevent microbiologically influenced corrosion (MIC), we have designed and synthetized six different copper and copper-silver nanoparticle-enzyme hybrids using a mild-conditions method carried out in water and r.t. Characterization analyses exhibited the presence of small crystalline nanoparticles with diameters from 2 to 20 nm.

Sediment-driven plastisphere community assembly on plastic debris in tropical coastal and marine environments.

Coastal habitats have been suggested to serve as a sink for unaccounted plastic debris, i.e., "missing plastic" in the sea, and hence, a hotspot of plastic pollution in the marine and coastal environments.

Early biofilm and streamer formation is mediated by wall shear stress and surface wettability: A multifactorial microfluidic study.

Biofilms are intricate communities of microorganisms encapsulated within a self-produced matrix of extra-polymeric substances (EPS), creating complex three-dimensional structures allowing for liquid and nutrient transport through them. These aggregations offer constituent microorganisms enhanced protection from environmental stimuli-like fluid flow-and are also associated with higher resistance to antimicrobial compounds, providing a persistent cause of concern in numerous sectors like the marine (biofouling and aquaculture), medical (infections and antimicrobial resistance), dentistry (plaque on teeth), food safety, as well as causing energy loss and corrosion. Recent studies have demonstrated that biofilms interact with microplastics, often influencing their pathway to higher trophic levels.

High-throughput method development for quantification of aquatic phototrophic biofilms.

In the maritime field where biofouling has both economic and environmental impacts, quantification methods of biofilm development are of outstanding importance. Indeed, it is challenging to temporally monitor biofilm formation due to the complexity of the marine ecosystem, common inaccessibility of sampling location and lack of standardized techniques. Here, an artificial polymeric surface was tested and against natural phototrophic biofilms and monoculture biofilms using plate reader fluorescence.

Priorities to inform research on marine plastic pollution in Southeast Asia.

Southeast Asia is considered to have some of the highest levels of marine plastic pollution in the world. It is therefore vitally important to increase our understanding of the impacts and risks of plastic pollution to marine ecosystems and the essential services they provide to support the development of mitigation measures in the region. An interdisciplinary, international network of experts (Australia, Indonesia, Ireland, Malaysia, the Philippines, Singapore, Thailand, the United Kingdom, and Vietnam) set a research agenda for marine plastic pollution in the region, synthesizing current knowledge and highlighting areas for further research in Southeast Asia.

Marine biofilms on different fouling control coating types reveal differences in microbial community composition and abundance.

Marine biofouling imposes serious environmental and economic impacts on marine applications, especially in the shipping industry. To combat biofouling, protective coatings are applied on vessel hulls which are divided into two major groups: biocidal and non-toxic fouling release. The current study aimed to explore the effect of coating type on microbial biofilm community profiles to better understand the differences between the communities developed on fouling control biocidal antifouling and biocidal-free coatings.

The oceans are changing: impact of ocean warming and acidification on biofouling communities.

Climate change (CC) is driving modification of the chemical and physical properties of estuaries and oceans with profound consequences for species and ecosystems. Numerous studies investigate CC effects from species to ecosystem levels, but little is known of the impacts on biofilm communities and on bioactive molecules such as cues, adhesives and enzymes. CC is induced by anthropogenic activity increasing greenhouse emissions leading to rises in air and water temperatures, ocean acidification, sea level rise and changes in ocean gyres and rainfall patterns.

Biofilm Inhibition by Novel Natural Product- and Biocide-Containing Coatings Using High-Throughput Screening.

The use of natural products (NPs) as possible alternative biocidal compounds for use in antifouling coatings has been the focus of research over the past decades. Despite the importance of this field, the efficacy of a given NP against biofilm (mainly bacteria and diatoms) formation is tested with the NP being in solution, while almost no studies test the effect of an NP once incorporated into a coating system. The development of a novel bioassay to assess the activity of NP-containing and biocide-containing coatings against marine biofilm formation has been achieved using a high-throughput microplate reader and highly sensitive confocal laser scanning microscopy (CLSM), as well as nucleic acid staining.

Life under flow: A novel microfluidic device for the assessment of anti-biofilm technologies.

In the current study, we have developed and fabricated a novel lab-on-a-chip device for the investigation of biofilm responses, such as attachment kinetics and initial biofilm formation, to different hydrodynamic conditions. The microfluidic flow channels are designed using computational fluid dynamic simulations so as to have a pre-defined, homogeneous wall shear stress in the channels, ranging from 0.03 to 4.

Anti-biofilm performance of three natural products against initial bacterial attachment.

Marine bacteria contribute significantly towards the fouling consortium, both directly (modern foul release coatings fail to prevent "slime" attachment) and indirectly (biofilms often excrete chemical cues that attract macrofouling settlement). This study assessed the natural product anti-biofilm performance of an extract of the seaweed, Chondrus crispus, and two isolated compounds from terrestrial sources, (+)-usnic acid and juglone, against two marine biofilm forming bacteria, Cobetia marina and Marinobacter hydrocarbonoclasticus. Bioassays were developed using quantitative imaging and fluorescent labelling to test the natural products over a range of concentrations against initial bacterial attachment.

Marine biofilms on artificial surfaces: structure and dynamics.

The search for new antifouling (AF) coatings that are environmentally benign has led to renewed interest in the ways that micro-organisms colonize substrates in the marine environment. This review covers recently published research on the global species composition and dynamics of marine biofilms, consisting mainly of bacteria and diatoms found on man-made surfaces including AF coatings. Marine biofilms directly interact with larger organisms (macrofoulers) during colonization processes; hence, recent literature on understanding the basis of the biofilm/macrofouling interactions is essential and will also be reviewed here.

Designing biomimetic antifouling surfaces.

Marine biofouling is the accumulation of biological material on underwater surfaces, which has plagued both commercial and naval fleets. Biomimetic approaches may well provide new insights into designing and developing alternative, non-toxic, surface-active antifouling (AF) technologies. In the marine environment, all submerged surfaces are affected by the attachment of fouling organisms, such as bacteria, diatoms, algae and invertebrates, causing increased hydrodynamic drag, resulting in increased fuel consumption, and decreased speed and operational range.

A galvanic sensor for monitoring the corrosion condition of the concrete reinforcing steel: relationship between the galvanic and the corrosion currents.

This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, I(gal), and the corrosion currents, I(corr), estimated from the polarization resistance, R(p). Sensors have been tested in saturated Ca(OH)(2) aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O(2). For all the conditions, the influence of temperature (20 to 55 °C) has also been considered.