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Waste-centred-bioenergy generation have been garnering interest over the years due to environmental impact presented by fossil fuels. Waste generation is an unavoidable consequence of urbanization and population growth. Sustainable waste management techniques that are long term and environmentally benign are required to achieve sustainable development. Energy recovery from waste biomass via dark fermentative hydrogen production is a sustainable approach to waste management. Vegetable waste is generated in plenty over the food supply chain and being a rich source of carbon and other nutrients it has been studied for production of biohydrogen. This review aims to offer a comprehensive overview on the potential of vegetable waste as a feedstock for dark fermentative biohydrogen production. The hydrogen output from dark fermentative process is lower and additional strategies are required to improve the production. This review addresses the challenges generally encountered during dark fermentative hydrogen production using vegetable waste and the importance of methods such as bioaugmentation and application of extremophiles for process enhancement. The role of machine learning in the field of biohydrogen production is briefly discussed. The application of dark fermentative effluents for secondary valuable product generation and its contribution to the biohydrogen biorefinery is discussed as well. [ABSTRACT FROM AUTHOR]

The Euganean Thermal District, situated in North-East Italy, is one of Europe's largest and oldest thermal centres. The topical application of its therapeutic thermal muds is recognised by the Italian Health System as a beneficial treatment for patients suffering from arthro-rheumatic diseases. Polysaccharides produced by the mud microbiota have been recently identified as anti-inflammatory bioactive molecules. In this paper we analysed the efficacy of Microbial-Polysaccharides (M-PS) derived from mature muds obtained at different maturation temperatures, both within and outside the codified traditional mud maturation range. M-PSs were extracted from six mature muds produced by five spas of the Euganean Thermal District and investigated for their chemical properties, monosaccharide composition and in vivo anti-inflammatory potential, using the zebrafish model organism. Additionally, mature muds were characterized for their microbiota composition using Next-Generation Sequencing. The results showed that all M-PSs exhibit similar anti-inflammatory potential, referable to their comparable chemical composition. This consistency was observed despite changes in cyanobacteria populations, suggesting a possible role of the entire microbial community in shaping the properties of these biomolecules. These findings highlight the importance of scientific research in untangling the origins of the therapeutic efficacy of Euganean Thermal muds in the treatment of chronic inflammatory conditions. [ABSTRACT FROM AUTHOR]

The phycosphere is a unique niche that fosters complex interactions between microalgae and associated bacteria. The formation of this extracellular environment, and the associated bacterial biodiversity, is heavily influenced by the secretion of extracellular polymers, primarily driven by phototrophic organisms. The exopolysaccharides (EPS) represent the largest fraction of the microalgae‐derived exudates, which can be specifically used by heterotrophic bacteria as substrates for metabolic processes. Furthermore, it has been proposed that bacteria and their extracellular factors play a role in both the release and composition of the EPS. In this study, two model microorganisms, the diatom Phaeodactylum tricornutum CCAP 1055/15 and the bacterium Pseudoalteromonas haloplanktis TAC125, were co‐cultured in a dual system to assess how their interactions modify the phycosphere chemical composition by analyzing the EPS monosaccharide profile released in the culture media by the two partners. We demonstrate that microalgal–bacterial interactions in this simplified model significantly influenced the architecture of their extracellular environment. We observed that the composition of the exo‐environment, as described by the EPS monosaccharide profiles, varied under different culture conditions and times of incubation. This study reports an initial characterization of the molecular modifications occurring in the extracellular environment surrounding two relevant representatives of marine systems. [ABSTRACT FROM AUTHOR]

Cyanobacteria are widespread phototrophic microorganisms that represent a promising biotechnological tool to satisfy current sustainability and circularity requirements. They are potential bio-factories of a wide range of compounds that can be exploited in several fields including bioremediation and nanotechnology sectors. This article aims to illustrate the most recent trends in the use of cyanobacteria for the bioremoval (i.e., cyanoremediation) of heavy metals and metal recovery and reuse. Heavy metal biosorption by cyanobacteria can be combined with the consecutive valorization of the obtained metalorganic materials to get added-value compounds, including metal nanoparticles, opening the field of phyconanotechnology. It is thus possible that the use of combined approaches could increase the environmental and economic feasibility of cyanobacteria-based processes, promoting the transition toward a circular economy. [ABSTRACT FROM AUTHOR]

Cyanobacteria can cope with various environmental stressors, due to the excretion of exopolysaccharides (EPS). However, little is known about how the composition of these polymers may change according to water availability. This work aimed at characterizing the EPS of Phormidium ambiguum (Oscillatoriales; Oscillatoriaceae) and Leptolyngbya ohadii (Pseudanabaenales; Leptolyngbyaceae), when grown as biocrusts and biofilms, subject to water deprivation. The following EPS fractions were quantified and characterized: soluble (loosely bound, LB) and condensed (tightly bound, TB) for biocrusts, released (RPS), and sheathed in P. ambiguum and glycocalyx (G-EPS) in L. ohadii for biofilms. For both cyanobacteria upon water deprivation, glucose was the main monosaccharide present and the amount of TB-EPS resulted was significantly higher, confirming its importance in these soil-based formations. Different profiles of monosaccharides composing the EPSs were observed, as for example the higher concentration of deoxysugars observed in biocrusts compared to biofilms, demonstrating the plasticity of the cells to modify EPS composition as a response to different stresses. For both cyanobacteria, both in biofilms and biocrusts, water deprivation induced the production of simpler carbohydrates, with an increased dominance index of the composing monosaccharides. The results obtained are useful in understanding how these very relevant cyanobacterial species are sensitively modifying the EPS secreted when subject to water deprivation and could lead to consider them as suitable inoculants in degraded soils. [ABSTRACT FROM AUTHOR]

Cancer is a leading cause of death worldwide with a huge societal and economic impact. Clinically effective and less expensive anticancer agents derived from natural sources can help to overcome limitations and negative side effects of chemotherapy and radiotherapy. Previously, we showed that the extracellular carbohydrate polymer of a Synechocystis ΔsigF overproducing mutant displayed a strong antitumor activity towards several human tumor cell lines, by inducing high levels of apoptosis through p53 and caspase-3 activation. Here, the ΔsigF polymer was manipulated to obtain variants that were tested in a human melanoma (Mewo) cell line. Our results demonstrated that high molecular mass fractions were important for the polymer bioactivity, and that the reduction of the peptide content generated a variant with enhanced in vitro antitumor activity. This variant, and the original ΔsigF polymer, were further tested in vivo using the chick chorioallantoic membrane (CAM) assay. Both polymers significantly decreased xenografted CAM tumor growth and affected tumor morphology, by promoting less compact tumors, validating their antitumor potential in vivo. This work contributes with strategies for the design and testing tailored cyanobacterial extracellular polymers and further strengths the relevance of evaluating this type of polymers for biotechnological/biomedical applications. [ABSTRACT FROM AUTHOR]

In the scenario of alarming increase in greenhouse and toxic gas emissions from the burning of conventional fuels, it is high time that the population drifts towards alternative fuel usage to obviate pollution. Hydrogen is an environment-friendly biofuel with high energy content. Several production methods exist to produce hydrogen, but the least energy intensive processes are the fermentative biohydrogen techniques. Dark fermentative biohydrogen production (DFBHP) is a value-added, less energy-consuming process to generate biohydrogen. In this process, biohydrogen can be produced from sugars as well as complex substrates that are generally considered as organic waste. Yet, the process is constrained by many factors such as low hydrogen yield, incomplete conversion of substrates, accumulation of volatile fatty acids which lead to the drop of the system pH resulting in hindered growth and hydrogen production by the bacteria. To circumvent these drawbacks, researchers have come up with several strategies that improve the yield of DFBHP process. These strategies can be classified as preliminary methodologies concerned with the process optimization and the latter that deals with pretreatment of substrate and seed sludge, bioaugmentation, co-culture of bacteria, supplementation of additives, bioreactor design considerations, metabolic engineering, nanotechnology, immobilization of bacteria, etc. This review sums up some of the improvement techniques that profoundly enhance the biohydrogen productivity in a DFBHP process. [ABSTRACT FROM AUTHOR]

Interactions amongst marine microalgae and heterotrophic bacteria drive processes underlying major biogeochemical cycles and are important for many artificial systems. These dynamic and complex interactions span the range from cooperative to competitive, and it is the diverse and intricate networks of metabolites and chemical mediators that are predicted to principally dictate the nature of the relationship at any point in time. Recent advances in technologies to identify, analyze, and quantify metabolites have allowed for a comprehensive view of the molecules available for exchange and/or reflective of organismal interactions, setting the stage for development of mechanistic understanding of these systems. Here, we (i) review the current knowledge landscape of microalgal–bacterial interactions by focusing on metabolomic studies of selected, simplified model systems; (ii) describe the state of the field of metabolomics, with specific focus on techniques and approaches developed for microalga–bacterial interaction studies; and (iii) outline the main approaches for development of mathematical models of these interacting systems, which collectively have the power to enhance interpretation of experimental data and generate novel testable hypotheses. We share the viewpoint that a comprehensive and integrated series of -omics approaches that include theoretical formulations are necessary to develop predictive and mechanistic understanding of these biological entities. [ABSTRACT FROM AUTHOR]

Simple Summary: Microalgae-based biorefineries allow the simultaneous production of microalgae biomass enriched in a particular macromolecule and high-added and low-value products if a proper selection of the microalgae species and the cultivation conditions are adequate for the purpose. This review discusses the challenges and future trends related to microalgae-based biorefineries stressing the multi-product approach and the use of raw wastewater or pretreated wastewater to improve the cost-benefit ratio of biomass and products. Emphasis is given to the production of biomass enriched in carbohydrates. Microalgae-bioactive compounds as potential therapeutical and health promoters are also discussed. Future and novel trends following the circular economy strategy are also discussed. Microalgae have demonstrated a large potential in biotechnology as a source of various macromolecules (proteins, carbohydrates, and lipids) and high-added value products (pigments, poly-unsaturated fatty acids, peptides, exo-polysaccharides, etc.). The production of biomass at a large scale becomes more economically feasible when it is part of a biorefinery designed within the circular economy concept. Thus, the aim of this critical review is to highlight and discuss challenges and future trends related to the multi-product microalgae-based biorefineries, including both phototrophic and mixotrophic cultures treating wastewater and the recovery of biomass as a source of valuable macromolecules and high-added and low-value products (biofertilizers and biostimulants). The therapeutic properties of some microalgae-bioactive compounds are also discussed. Novel trends such as the screening of species for antimicrobial compounds, the production of bioplastics using wastewater, the circular economy strategy, and the need for more Life Cycle Assessment studies (LCA) are suggested as some of the future research lines. [ABSTRACT FROM AUTHOR]

Summary: Biocrusts provide numerous ecological functions in drylands. Recovering biocrusts via cyanobacterial inoculation recently gathered interest for ecological restoration, yet it still lacks long‐term experiments to unravel biocrust community dynamics. To examine how cyanobacterial inoculants influenced local microbial community and biocrust development, we observed a 2 km2 (Qubqi Desert, China) inoculation experiment after 10 and 15 years, following biocrust formation. Our results revealed that biocrust development was in line with ecological regime shift, providing evidence for biocrust community succession, from cyanobacteria‐ to moss‐dominated types. Associated with biocrust development, microbial communities differed significantly with less specialists compared to shifting sands. Cyanobacterial community analysis showed that Microcoleus vaginatus and Scytonema javanicum are an ideal inoculating model, as they were still dominating the community after 15 years since inoculation, while other nitrogen‐fixing cyanobacteria occurred profusely with biocrust development. Biocrust community composition combined with thickness, Chl‐a and exopolysaccharide measurements revealed the large variation of cyanobacterial ecological functions along biocrust development, suggesting a main function shift: from carbon fixation associated with exopolysaccharide secretion in bare sandy soils to nitrogen fixation in developed biocrusts. This large‐scale field study verifies that cyanobacterial inoculation accelerates biocrust development and forwards succession, shaping the biocrust community composition over a long time. [ABSTRACT FROM AUTHOR]

Summary: An intricate set of interactions characterizes marine ecosystems. One of the most important is represented by the microbial loop, which includes the exchange of dissolved organic matter (DOM) from phototrophic organisms to heterotrophic bacteria. Here, it can be used as the major carbon and energy source. This interaction is one of the foundations of the entire ocean food‐web. The carbon fixed by phytoplankton can be redirected to bacteria in two main ways; either (i) bacteria feed on dead phytoplankton cells or (ii) DOM is actively released by phytoplankton (a process resulting in up to 50% of the fixed carbon leaving the cell). Here, we have set up a co‐culture of the diatom Phaeodactylum tricornutum and the chemoheterotrophic bacterium Pseudoalteromonas haloplanktis TAC125 and used this system to study the interactions between these two representatives of the microbial loop. We show that the bacterium can thrive on diatom‐derived carbon and that this growth can be sustained by both diatom dead cells and diatom‐released compounds. These observations were formalized in a network of putative interactions between P. tricornutum and P. haloplanktis and implemented in a model that reproduces the observed co‐culture dynamics, revealing an overall accuracy of our hypotheses in explaining the experimental data. [ABSTRACT FROM AUTHOR]

A novel method was developed for virus-like particle (VLP) extraction and characterization from biological soil crust (BSC) after microbial community reactivation. The method consisted of a single cell analysis by flow cytometry to monitor viable cells in BSC reactivated under controlled hydration, temperature, and light/dark exposure. Then, VLPs were extracted from reactivated BSCs, followed by viral DNA extraction and shotgun metagenomic analysis. The hydrated BSC under light/dark conditions showed the highest number of viable cells, and this condition was optimal for VLPs isolation. Taxonomic composition showed that families of the order of Caudovirales (Podoviridae, Myoviridae and Syphoviridiae) were the most abundant double strand DNA phages while Microviridiae were the most abundant single strand DNA phages. The isolated VLPs also carried sequences of relevant bacterial inhabiting soil. The functional categories of "phages, prophages, transposable elements, plasmids" and "clustering-base subsystem" were abundant (38 and 12%, respectively). All these data suggest viral predation as a key factor in shaping and maintaining bacterial diversity in the BSCs. [ABSTRACT FROM AUTHOR]

The induction of biocrusts through inoculation-based techniques has gained increasing scientific attention in the last 2 decades due to its potential to address issues related to soil degradation and desertification. The technology has shown the most rapid advances in the use of biocrust organisms, particularly cyanobacteria and mosses, as inoculants and biocrust initiators. Cyanobacteria and mosses are poikilohydric organisms – i.e., desiccation-tolerant organisms capable of reactivating their metabolism upon rehydration – that can settle on bare soils in abiotically stressing habitats, provided that selected species are used and an appropriate and customized protocol is applied. The success of inoculation of cyanobacteria and mosses depends on the inoculant's physiology, but also on the ability of the practitioner to identify and control, with appropriate technical approaches in each case study, those environmental factors that most influence the inoculant settlement and its ability to develop biocrusts. This review illustrates the current knowledge and results of biocrust induction biotechnologies that use cyanobacteria or mosses as inoculants. At the same time, this review's purpose is to highlight the current technological gaps that hinder an efficient application of the technology in the field. [ABSTRACT FROM AUTHOR]

Land degradation in drylands is a drawback of the combined action of climate change and human activities. New techniques have been developed to induce artificial biocrusts formation as a tool for restoration of degraded drylands, and among them soils inoculation with cyanobacteria adapted to environmental stress. Improvement of soil properties by cyanobacteria inoculation is largely related to their ability to synthesize exopolysaccharides (EPS). However, cyanobacterial EPS features [amount, molecular weight (MW), composition] can change from one species to another or when grown in different conditions. We investigated the differences in growth and polysaccharidic matrix features among three common biocrust-forming cyanobacteria (Nostoc commune, Scytonema javanicum , and Phormidium ambiguum), when grown in liquid media and on sandy soil microcosms under optimal nutrient and water, in controlled laboratory conditions. We extracted and analyzed the released EPS (RPS) and sheath for the liquid cultures, and the more soluble or loosely-bound (LB) and the more condensed or tightly-bound (TB) soil EPS fractions for the sandy soil microcosms. In liquid culture, P. ambiguum showed the greatest growth and EPS release. In contrast, on the sandy soil, S. javanicum showed the highest growth and highest LB-EPS content. N. commune showed no relevant growth after its inoculation of the sandy soil. A difference was observed in terms of MW distribution, showing that the higher MW of the polymers produced by P. ambiguum and S. javanicum compared to the polymers produced by N. commune , could have had a positive effect on growth for the first two organisms when inoculated on the sandy soil. We also observed how both RPS and sheath fractions reflected in the composition of the soil TB-EPS fraction, indicating the role in soil stabilization of both the released and the cell attached EPS. Our results indicate that the features of the polysaccharidic matrix produced by different cyanobacteria can influence their growth success in soil. These results are of great relevance when selecting suitable candidates for large-scale cyanobacteria applications in soil restoration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Purple Queen® is an early ripening pomegranate cultivar growing well in soilless cultivation. Substrates have direct effects on plant development and, due to progressive peatland exhaustion, the request for new materials for plant growth is high. OBJECTIVE: The objective of this work was to verify the effects of a new potential substrate obtained from the remediation of marine port sediments on the nutraceutical profile of Purple Queen® fruits, using 50% and 100% of reclaimed sediment. METHODS: The study was carried out determining ellagitannins and polysaccharides obtained from peel after decoction, and anthocyanins in aril juice on fruits from two agronomic seasons. RESULTS: The presence of 100% of the sediment had a partial detrimental effect on fruits size and weight. Compared to a peat-based commercial substrate (control), remediated sediment preserved ellagitannin content and increased the anthocyanin amount (up to 40% higher) and polysaccharide content up to 34% on dry fruit. High molecular weight polysaccharides (>2000 kDa) were identified in all the fruits with glucose and galacturonic acid as the major sugars. CONCLUSIONS: Fruits from plants cultivated only on sediment or in a mixture with 50% of peat showed significant increases of bioactive compounds as stress response in two consecutive seasons. [ABSTRACT FROM AUTHOR]

The practice of "cyanobacterization" (soil inoculation with cyanobacteria) has been shown to be effective in increasing soil fertility and physical stability in natural and agricultural soils, but little is known about its utility for the recovery of burned soils. To partly fill this knowledge gap, we inoculated two cyanobacterial species, Phormidium ambiguum and Scytonema javanicum, in two burned sterilized soils having contrasting properties, and incubated them under laboratory conditions for 45 days. The development of a cyanobacterial biocrust induced by the inoculum was evident and confirmed by the significant increase in chlorophyll a content compared to control soils. Hydrophobicity, surface penetration resistance, and exopolysaccharide content of the two soils were also evaluated. Cyanobacteria inoculation significantly decreased soil hydrophobicity, as assessed by the lower repellency index 15 days after the inoculation compared to the control soils. A significant increase in penetration resistance was recorded in the inoculated samples compared to control ones after 45 days of soil incubation. The effect of cyanobacteria inoculation depended on the characteristics of the burned soil, being more marked in the soil finer in texture, richer in organic carbon and nitrogen, and with lower initial soil hydrophobicity. In conclusion, this study points to the potential of cyanobacterization for the stabilization and recovery of soils in burned areas, which is one of the major concerns in postfire management to avoid net soil loss and major hydrogeological issues. [ABSTRACT FROM AUTHOR]

One third of the World's entire food production is lost or wasted every year. Biohydrogen production offers a possibility to re-use this resource; in particular, bread and bakery products wastes, due to their composition (up to 70% of carbohydrates, mostly starch), represent an appropriate source of nutrients for microorganisms. The aim of this work was to convert bread wastes into hydrogen with a sequential system composed of lactic fermentation and photofermentation, with a minimum number of treatments to the substrate. The best results were provided by Lactobacillus amylovorus DSM 20532, followed by photofermentation by Rhodopseudomonas palustris 42OL, supplemented with ferric citrate and magnesium sulfate. The process led to 3.1 mol H 2 mol −1 glucose, among the highest yields obtained on starch containing substrates, with an energy recovery of 54 MJ t −1 dry waste. This study promotes the re-use of energy-containing food wastes for improving circular economy. [ABSTRACT FROM AUTHOR]

Rhodopseudomonas palustris strain 42OL was isolated in 1973 from a sugar refinery waste treatment pond. The strain has been prevalently used for hydrogen production processes using a wide variety of waste-derived substrates, and cultured both indoors and outdoors, either freely suspended or immobilized. R. palustris 42OL was suitable for many other applications and capable of growing in very different culturing conditions, revealing a wide metabolic versatility. The analysis of the genome sequence allowed to identify the metabolic pathways for hydrogen and poly-β-hydroxy-butyrate production, and confirmed the ability of using a wide range of organic acids as substrates. [ABSTRACT FROM AUTHOR]

Biological Soil Crusts (BSCs) represent an important part of the living cover in drylands worldwide. BCSs change soil hydrology due to extracellular polymeric substances (EPS)-excreting species of cyanobacteria, dominant members of dryland-BSCs. The presence of EPS allowed matric potential (Ψ m ) to remain unchanged down to 20% water content, whereas, without EPS, Ψ m started decreasing at 80% water content. The EPS matrix improved the water retaining capacity of soil, suggesting that BSCs would delay onset of restrictive matric potential values due to its larger water holding capacity. [ABSTRACT FROM AUTHOR]

Abstract: H2 is a clean, renewable and energy-efficient fuel. However, in order for it to be a fuel effectively utilizable at an industrial level, key issues about its economically and environmentally sustainable production have still to be solved. Microbial hydrogen production is a process with a low environmental impact and, among microbial processes, photofermentation is considered a promising and sustainable solution. However, the energy input for the biological processes is still higher than the energy output in the form of H2 gas. One possibility for improving this ratio is to increase the efficiency of the process while at the same time reducing electricity consumption, both of which relate to the issue of an optimal photobioreactor design. This review focuses on recent advances made in photobioreactor design towards higher light conversion efficiency, a greater hydrogen production rate and substrate conversion in hydrogen production processes carried out with purple non sulfur bacteria, giving particular attention to the light source and to illumination protocols. Recent achievements in outdoor hydrogen production in large scale photobioreactors are also reviewed. [Copyright &y& Elsevier]

Abstract: Research on photobiological H2 production processes is pointing towards the use of low cost substrates as sources of reduced carbon for H2 generation. Those substrates (either wastewaters or effluents derived from other fermentation processes) are often rich not only in carbon, but also in fixed nitrogen. is an inhibitor of nitrogenase-mediated H2 production in purple non sulfur bacteria. A Rhodopseudomonas palustris mutant strain (NifA*), which constitutively expresses nitrogenase genes, was utilized in order to test the use of containing fermentation products for photobiological production of H2. The strain was grown on both synthetic and waste-derived containing media. The nifA* mutant produced H2 in the presence of high concentrations of , both in a synthetic medium and in a real vegetable waste-derived medium resulting in higher H2 levels than the wild-type strain. Thus, this study demonstrates that the NifA* strain is well suited to overcome the effects of inhibitory naturally occurring as it converts agricultural waste into biofuel. [Copyright &y& Elsevier]

Abstract: Sunlight represents an important choice for low cost photosynthetic cultures irradiation, especially in up-scaled processes. The aim of this study was the assessment of the hydrogen production performances of Rhodopseudomonas palustris strain 42OL cultivated outdoors, under sunlight, in a 50L tubular photobioreactor. Moreover, bacteriochlorophyll a fluorescence was used for the first time as a tool for monitoring the physiological status of Rp. palustris mass cultures. The maximum H2 production rate of 27.2mlL−1 h−1, and the mean rate per illuminated surface of 3.54±1.53Lm−2 d−1 obtained resulted the highest so far reported for outdoor experiments carried out with purple bacteria in tubular photobioreactors of comparable dimensions. The in-situ measurement of bacteriochlorophyll a fluorescence (F v/F m) showed that the photosystem was unaffected by changing light irradiance during the day and remained fully active over the whole period of hydrogen production. [Copyright &y& Elsevier]

Nowadays commercial preparations of yeast polysaccharides (PSs), in particular mannoproteins, are widely used for wine colloidal and tartrate salt stabilization. In this context, the industry has developed different processes for the isolation and purification of PSs from the cell wall of Saccharomyces cerevisiae. This yeast releases limited amounts of mannoproteins in the growth medium, thus making their direct isolation from the culture broth not economically feasible. On the contrary, Schizosaccharomyces japonicus, a non-Saccharomyces yeast isolated from wine, releases significant amounts of PSs during the alcoholic fermentation. In the present work, PSs released by Sch. japonicus were recovered from the growth medium by ultrafiltration and their impact on the wine colloidal stability was evaluated. Interestingly, these PSs contribute positively to the wine protein stability. The visible haziness of the heat-treated wine decreases as the concentration of added PSs increases. Gel electrophoresis results of the haze and of the supernatant after the heat stability test are consistent with the turbidity measurements. Moreover, particle size distributions of the heat-treated wines, as obtained by Dynamic Light Scattering (DLS), show a reduction in the average dimension of the protein aggregates as the concentration of added PSs increases. [ABSTRACT FROM AUTHOR]

The Euganean Thermal District (Italy) represents the oldest and largest thermal center in Europe, and its therapeutic mud is considered a unique product whose beneficial effects have been documented since Ancient Roman times. Mud properties depend on the heat and electrolytes of the thermal water, as well as on the bioactive molecules produced by its biotic component, mainly represented by cyanobacteria. The investigation of the healing effects of compounds produced by the Euganean cyanobacteria represents an important goal for scientific validation of Euganean mud therapies and for the discovering of new health beneficial biomolecules. In this work, we evaluated the therapeutic potential of exopolysaccharides (EPS) produced by Phormidium sp. ETS05, the most abundant cyanobacterium of the Euganean mud. Specifically, Phormidium EPS resulted in exerting anti-inflammatory and pro-resolution activities in chemical and injury-induced zebrafish inflammation models as demonstrated using specific transgenic zebrafish lines and morphometric and expression analyses. Moreover, in vivo and in vitro tests showed no toxicity at all for the EPS concentrations tested. The results suggest that these EPS, with their combined anti-inflammatory and pro-resolution activities, could be one of the most important therapeutic molecules present in the Euganean mud and confirm the potential of these treatments for chronic inflammatory disease recovery. [ABSTRACT FROM AUTHOR]

Given the necessity for bioprocesses scaling-up, the present study aims to explore the potential of three marine cyanobacteria and a consortium, cultivated in semi-continuous mode, as a green approach for i) continuous exopolysaccharide-rich biomass production and ii) removal of positively charged metals (Cu, Ni, Zn) from mono and multi-metallic solutions. To ensure the effectiveness of both cellular and released exopolysaccharides, weekly harvested whole cultures were confined in dialysis tubings. The results revealed that all the tested cyanobacteria have a stronger affinity towards Cu in mono and three-metal systems. Despite the amount of metals removed per gram of biomass decreased with higher biosorbent dosage, the more soluble carbohydrates were produced, the greater was the metal uptake, underscoring the pivotal role of released exopolysaccharides in metal biosorption. According to this, Dactylococcopsis salina 16Som2 showed the highest carbohydrate productivity (142 mg L−1 d−1) and metal uptake (84 mg Cu g−1 biomass) representing a promising candidate for further studies. The semi-continuous cultivation of marine cyanobacteria here reported assures a schedulable production of exopolysaccharide-rich biosorbents with high metal removal and recovery potential, even from multi-metallic solutions, as a step forward in the industrial application of cyanobacteria. [Display omitted] • Semi-continuous cultivation ensures consistent, schedulable biosorbent production. • Marine cyanobacteria show higher affinity to Cu than Ni and Zn dissolved in water. • Up to 84 mg Cu per gram of dry weight were removed by D. salina 16Som2. • The presence of soluble EPS improves metal uptake. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), a bioplastic synthesized from lactic acid, has a broad range of applications owing to its excellent proprieties such as a high melting point, good mechanical strength, transparency, and ease of fabrication. However, the safe disposal of PLA is an emerging environmental problem: it resists microbial attack in environmental conditions, and the frequency of PLA-degrading microorganisms in soil is very low. To date, a limited number of PLA-degrading bacteria have been isolated, and most are actinomycetes. In this work, a method for the selection of rare actinomycetes with extracellular proteolytic activity was established, and the technique was used to isolate four mesophilic actinomycetes with the ability to degrade emulsified PLA in agar plates. All four strains—designated SO1.1, SO1.2, SNC, and SST—belong to the genus Amycolatopsis. The PLA-degrading capability of the four strains was investigated by testing their ability to assimilate lactic acid, fragment PLA polymers, and deteriorate PLA films. The strain SNC was the best PLA degrader—it was able to assimilate lactic acid, constitutively cleave PLA, and form a thick and widespread biofilm on PLA film. The activity of this strain extensively eroded the polymer, leading to a weight loss of 36% in one month in mesophilic conditions. [ABSTRACT FROM AUTHOR]

Cyanobacteria have been used as inoculants in dryland soils to promote biological soilcrust (or biocrust) recovery and restore vital soil functions. Their viability obeys totheir high resilience to stressful conditions and their reported beneficial effectson soil properties. Cyanobacteria from dry environments are characterized by ahigh capacity to synthesize large amounts of exopolysaccharides (EPS) that play afundamental role in the survival of cyanobacteria in these extreme habitats and areresponsible of many soil functions. Cyanobacterial EPS increase soil organic matter andnutrient content, thus improving soil fertility, and greatly enhance soil stability, thusconferring a high resistance to soils to erosive forces by water and wind. CyanobacterialEPS are characterized by a different degree of condensation, molecular weight(MW) distribution and monosaccharidic composition, which condition the role ofthe cyanobacterial polysaccharidic matrix in the soil. A few studies have analyzedthe MW distribution and chemical characteristics of the polysaccharidic matrix innatural and induced biocrusts, and most of them have been carried out on sandysoils. However, the characteristics of the cyanobacterial polysaccharidic matrix maygreatly depend on soil type. The objective of this study was to examine the EPSsynthesis of two common arid soil cyanobacterial species, Phormidium ambiguum (nonN-fixing) and Scytonema javanicum (N-fixing) in both liquid culture and a solidsubstrate, and to analyze the MW distribution and monosaccharidic composition of thepolysaccharidic matrix developed in different soil types after inoculation with the twocyanobacterial species. We found that P. ambiguum showed a faster growth and a higherEPS synthesis in liquid culture, whereas S. javanicum showed a higher growthand led to a higher EPS content in the soil. EPS characterization in the inducedbiocrusts revealed important differences between species and soil types. S. javanicumled to a higher synthesis of more soluble and less condensed EPS (loosely-boundEPS), which were mainly composed of low MW weight (<50 kDa). P. ambiguumpromoted a higher amount of more condensed EPS (tightly-bound EPS), mainlycomposed of high MW molecules (1100-2000 kDa), which likely contributed to soilparticle consolidation and explain the higher surface resistance found in the soilsinoculated with this cyanobacterium. Inoculated soils showed a complex composition,with a high number of monosaccharides (from 11 to 12). Glucose was the mostabundant monosaccharide in all soil types, representing up to 90% of EPS in thesandy soil. In more complex soils (having higher EPS, organic carbon and nitrogencontents), galactose, mannose and xylose were also relatively abundant. On the whole,cyanobacterial species and soil type influenced the macromolecular distribution and chemicalcomposition of the biocrust polysaccharidic matrix, which is expected to have animportant role in biocrust succession and evolution of soil properties in dryland soils. [ABSTRACT FROM AUTHOR]

The main crude polysaccharides (CPS), extracted from two widely cultivated pomegranate varieties, Laffan and Wonderful, were studied and characterized. We obtained the highest CPS extraction yield (approximatively 10% w/w on dried matter) by 1 h of decoction (ratio 1/40 w/v). The predominant polymers (75–80%) of the CPS samples showed a hydrodynamic volume close to 2000 kDa by size exclusion chromatography and the exocarp and mesocarp profiles were very similar. The proton spectra ( 1 H NMR), according to sugar composition and gelling ability, confirmed the main polysaccharide fractions were pectin with different acylation and methylation degree. The CPS from Laffan and Wonderful mesocarp showed prebiotic properties in vitro with Lactobacillus and Bifidobacterium strains. The composition of the decoction (12% ellagitannins and 10% of CPS) obtained by a green extraction process of pomegranate by-products, makes it a suitable component of functional food formulations. [ABSTRACT FROM AUTHOR]

• Three polysaccharide fractions were obtained from 2 pomegranate variety by decoction. • DLS allowed discriminating polysaccharides with similar hydrodynamic volumes. • Pectic fractions had diverse acylation and methylation degree after 1H NMR analysis. • Uronic acids analysis confirmed the presence of pectic polysaccharides in peel. • Methylation analysis evidenced diverse polysaccharide structures in diverse varieties. Polysaccharides from pomegranate peel (Wonderful and Purple Queen® varieties) were extracted by hot water and fractionated using ethanol. Three fractions (F1-F2-F3) were obtained for each sample. Polysaccharides' yield was higher for Purple Queen®: 13% dw. Polysaccharides of the three fractions were characterized by size exclusion chromatography (SEC), dynamic light scattering (DLS), 1H NMR, methylation, and acylation degree. Differently from SEC , DLS highlighted some differences between the polysaccharides's molecular sizes of the fractions. The highest methylation and acylation degree was observed for F3 of Purple Queen®: 74.0% and 18.6%, respectively. The percentage of galacturonic acid confirmed the presence of pectin in almost all the fractions recognized as homogalacturonan. Arabinan and arabinogalactan were also found in all the collected F3 samples, although in different proportions. The stepwise fractionation process followed by a multi-methodological analytical investigation was helpful to improve the knowledge of the pectic polysaccharides of pomegranate. [ABSTRACT FROM AUTHOR]

• Two polysaccharides fractions were collected after fruit decoction and centrifugation. • Hydrodynamic volumes of polysaccharides evaluated by DLS were from 237 nm to 425 nm. • Galacturonic acid ranged from 28.3% to 40.3% in PF1 and from 14.5% to 22.3% in PF2. • The highest methylation degree was for the PF1 fractions, from 56% to 83% • The highest acylation degree was from 47 to 68 % for the less soluble PF2 fractions. The study analysed polysaccharides and phenolic compounds in widely consumed but little studied date fruits varieties such as Sukkari, Ajwa, Segae, Barrny and Khalas harvested at Tamr stage. The total phenols were in similar amount in the five varieties and ranged from 20 to 50 mg/100 g DW. The decoction and successive centrifugation made it possible to collect two main polysaccharide fractions for all the selected fruits. For each variety the first fraction was more abundant, with a lower swelling capacity and a higher amount of galacturonic acid (28.3% to 40.1%). The second fraction was only soluble in alkaline solution, with an average galacturonic acid content of only 17%. The different structure of the two polysaccharide fractions was also confirmed by the composition in neutral sugars and the degrees of methylation and acetylation. The proposed extraction procedure could be applied for larger scale extraction of the date fruit polysaccharides. [ABSTRACT FROM AUTHOR]

The development of biological soil crusts (BSCs) is widely recognized as beneficial to soil fertility due to their contribution to the stabilization of soils and to the increase in their carbon and moisture content. An important role in these processes is played by the extracellular polysaccharidic (EPS) matrix embedding microbial cells and soil particles in BSCs. The present study was aimed at investigating the molecular and chemical features of the EPSs and the degradation processes of the polysaccharidic matrix (i.e. dehydrogenase and sucrase activities) in induced biological soil crusts (IBSCs) of different ages displayed within an investigation area in Hobq Desert (Dalatequi County, Inner Mongolia, China). Two operationally-defined EPS fractions, the colloidal (C-EPS) and the EDTA extractable (tightly bound, TB-EPS) fractions, were analyzed. In BSCs, C-EPSs are loosely bound to cells and sediments while TB-EPSs are tightly bound to the crustal biotic and abiotic constituents of the crusts. In this study, the C-EPS and TB-EPS fractions extracted from the IBSCs of different age (4-, 6- and 8-years old IBSCs) were found present in comparable amounts but showed marked differences in terms of their molecular size distribution and monosaccharidic composition. C-EPS showed to be mostly constituted by sugar fractions with molecular weight (MW) distributed in the range 2000-76 kDa and in the range 64-0.34 kDa. Conversely, the TB-EPSs showed to be prominently constituted by one fraction having a MW in the range 2000-76 kDa. While the chemical and macromolecular characteristics of TB-EPSs did not show significant changes with the age of the crusts, the older IBSCs showed a lower content of low MW C-EPSs, as well a higher number of different types of monosaccharides constituting the C-EPS. Moving from these results, it can be hypothesized that C-EPSs, which are dispersed in the soil and thus more accessible, have been rather easily degraded by the heterotrophic microorganisms dwelling in mature IBSCs and reduced to low MW carbohydrates that are easily metabolized by chemoheterotrophs. This hypothesis is supported by the higher activity observed in older IBSCs of the two enzymes associated with sugar degradation in the soil, dehydrogenases and sucrases, that is consistent with an increased release of low MW carbohydrates in the crusts. The results obtained suggest that the colloidal fraction of the EPSs, which is more dispersed in the soil, is more easily degradable by the microflora, while the EPS fraction tightly bound to the soil particles, which is characterized by a high MW, plays a key role in giving a structural stability to the crusts and in affecting the hydrological behavior of the soil covered by IBSCs. [ABSTRACT FROM AUTHOR]

Abstract: Seventeen purple non-sulfur bacterial strains, isolated from the trophic lake Averno, Naples, Italy, were phylogenetically classified and their H2-producing performances were tested utilizing various synthetic substrates and the fermentation broth derived from the spontaneous fermentation of vegetable residues. All the strains showed the capability to produce hydrogen on at least one of the four carbon substrates tested (malic, lactic, acetic and succinic acid). On lactate, Rhodopseudomonas palustris strain AV33 showed the best maximum production rate (50.7 ± 2.6 mL (H2) L−1 h−1), with a mean rate, calculated on the whole period of production, of 17.9 mL ± 0.7 (H2) L−1 h−1. In the presence of acetate, AV33 produced only few mL of H2, but intracellularly accumulated poly-β-hydroxybutyrate up to a concentration of 21.4 ± 3.4% (w/w) of cell dry weight. Rp. palustris AV33 also produced H2 on the fermentation broth supplemented with Fe, with a maximum production rate of 16.4 ± 2.3 mL (H2) L−1 h−1 and a conversion yield of 44.2%. [Copyright &y& Elsevier]