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Our understanding of the diversity of life on our planet and the possibility of finding or sustaining life elsewhere in the universe plays a central role in supporting human space settling and exploration. Astrobiology and its outcomes require a multidisciplinary and comprehensive approach, in which the microbial, geological, chemical, astronomical, and physical domains of research are interlinked. An example of the applications of astrobiology and space microbiology is the use of extremophiles for in-situ resource utilization through biomining and bioleaching. To better understand the multidisciplinary research landscape in this area, we have quantitatively reviewed the global scientific literature on astrobiology with a focus on biomining and bioleaching through bibliometric network analysis, investigating patterns and trends in its development over time. The network analysis of the keywords co-occurrence highlights different connecting and overlapping clusters, illustrating the multidisciplinary character of astrobiology. Temporal analyses show a recent focus on topics related to microbiology and geomicrobiology, emphasizing the role that these fields will play in future astrobiology research. In conclusion, astrobiology, biomining, and bioleaching research are timely responding to the identification of these techniques as tools for biotechnological applications, expected to play a crucial role in long-term human space exploration.

THE ''LIfe in Space'' project was funded in the wake of the Italian Space Agency's proposal for the development of a network of institutions and laboratories conceived to implement Italian participation in space astrobiology experiments. Of primary concern for this project is the study of the origin of life in the Universe, a focus that will promote investigation into prebiotic chemistry in various possible scenarios, whether in polar or nonpolar solvents (e.g., Titan's environment). Such results will link with study of the effects of simulated space conditions on possible chemical bio- signatures. The limits of life as we know it will be investigated in ground-based experiments with microorganisms that have already demonstrated their resistance to extreme environments on Earth and to real or simulated space conditions. The potential survival of microorganisms will also be examined with up-to-date molecular methods. The ability of some microorganisms to produce atmospheric and surface biosignatures when exposed to simulated conditions will be tested and compared with the possible existence of bio- signatures on potentially habitable exoplanets. Furthermore, the search for potentially habitable exoplanets, with space- based observational methods, will be optimized by way of dedicated climate models with the capacity to predict the detectability of atmospheric biosignatures for a broad range of planetary conditions. The project embraces the four most important topics in astrobiological research, as listed below, along with relevant contributions from the participating Italian institutions. Origins and evolution of organic compounds of biological significance in space (comets, asteroids, rocky planets, and moons); Prebiotic syntheses, origin of life, and early life; The limits of life and biological habitability: origin, evolution and adaptation of life in extreme environments on Earth and in space; Biomarkers for life detection in the Solar System and on exoplanets.

The ever growing concerns about the impact of first generation bioethanol on food chain and on biodiversity have shifted the focus of research to second generation (2G) bioethanol technologies. The 2G-bioethanol's production relies on biomass feedstock that could provide a more sustainable energy generation without compromising food security and environment. Indeed, this production process exploits non-food crops, food crops residues, wastes of wood-based or food-based industries such as wood chips, skins or pulps from fruit pressing, respectively. Nevertheless, the industrial process of 2G-bioethanol's production is still in its infancy, indeed the future and the sustainability of the 2G-bioethanol strongly depend upon the development of the current technology. In this paper particular attention will be paid to the role of thermophilic microorganisms and their enzymes to the biotechnology's development of the bioethanol's production process.

Food wastes display a great potential for waste-based biorefineries in the frame of a bio-economy system. The bio-economy is an innovative economy model based on the sustainable use of renewable resources in agriculture and industry, and that takes in account biodiversity and environmental protection. To this aim, some key factors are need: the development of new technologies and processes, the identification of renewable feedstock not in competition with other production chains, the creation of new markets and competitiveness, the pushing of policymakers and stakeholders to work more closely together. Tomato industry, that is one of the most important sector of the world food industry, can display an enormous potential since it produces huge amounts of wastes. Such residues negatively impact on the sustainability of food industry, since their disposal represents one main issue in terms of environmental and economic impact. Nevertheless, they represent a cheap and renewable biomass that, in the frame of the biorefinery model, could be exploited for the production of chemicals and energy thus contributing to the sustainability of this production chain. In this paper the potentiality of the tomato-wastes biorefinery was investigated with particular regard to the Italian scenario. Some main aspects were investigated including the possible re-use strategies and the available examples of tomato wastes conversion into marketable products. The analysis of the state of the art showed that tomato wastes recycling in Italy is till limited. Indeed, the scalability of such processes at an industrial scale still remains to be assessed in order to open the way to new markets based on the exploitation of tomato wastes.

Humic acids (HA) are considered a promising and inexpensive source for novel multifunctional materials for a huge range of applications. However, aggregation and degradation phenomena in aqueous environment prevent from their full exploitation. A valid strategy to address these issues relies on combining HA moieties at the molecular scale with an inorganic nanostructured component, leading to more stable hybrid nanomaterials with tunable functionalities. Indeed, chemical composition of HA can determine their interactions with the inorganic constituent in the hybrid nanoparticles and consequently affect their overall physico-chemical properties, including their stability and functional properties in aqueous environment. As a fundamental contribution to HA materials-based technology, this study aims at unveiling this aspect. To this purpose, SiO

The Antarctic region is usually considered a pristine area. Nevertheless, regional warming effects and increasing human activities, including the presence of several research stations, are inducing considerable environmental changes that may affect the ecosystem’s functions. Therefore, during the XXXIII Antarctic expedition, we carried out an investigation in Terra Nova bay (Ross Sea), close to the Antarctic Specially Protected Area (ASPA) n.161. In particular, we compared the effects of two different types of impacts on the meiobenthic assemblages: anthropogenic impact (AI), associated with the activity of Mario Zucchelli Research Station (MZS), and natural impact (NI) attributable to a large colony of Adélie penguins (Pygoscelis adeliae) in Adelie Cove. For each impacted site, a respective control site and two sampling depths (20 and 50 m) were selected. Several environmental variables (pH, dissolved oxygen, major and minor ions, heavy metals, organic load, and sediment grain size) were measured and analysed, to allow a comprehensive characterization of the sampling areas. According to the criteria defined by Unites States Environmental Protection Agency (US EPA 2009), heavy metal concentrations did not reveal critical conditions. However, both the MZS (AI20) and penguin colony (NI20) sites showed higher heavy metal concentrations, the former due to human activities related to the Italian research station, with the latter caused by the penguins excrements. Meiobenthic richness and abundance values suggested that the worst ecological condition was consistently related to the Adélie penguins colony. Furthermore, the higher contribution of r-strategists corroborates the hypothesis that the chronic impact of the penguin colonies may have stronger effects on the meiobenthos than the human activities at the MZS. Food is not limited in shallow Antarctic bottoms, and microscale differences in primary and secondary production processes can likely explain the greater spatial heterogeneity, highlighted both by the univariate and multivariate attributes of meiobenthic assemblage (i.e., richness, diversity, abundance, whole structure assemblage, and rare taxa) at the deeper stations. As reported in other geographical regions, the assemblage structure of rare meiobenthic taxa is confirmed to be more susceptible to environmental variations, rather than the whole assemblage structure.

Among matrix metalloproteinases (MMPs), MMP-9/2 are key enzymes involved in the proteolysis of extracellular matrices in the inflammatory process and in cancer. Since MMP-9/2 expression levels, activity, and secretion is up-regulated during inflammation in response to pro-inflammatory cytokines, such as interleukin-6 (IL-6), many efforts have been devoted to identifying factors that could inhibit the IL-6-induced MMP-9/2 expression. Up to now, several reports indicated that polyphenols from fruits and vegetables are among the major components of health promotion for their antioxidant properties and also for their anti-inflammatory and anti-cancer agents. Among plant derived polyphenols, lemon (Citrus limon) peel extract (LPE) shows anti-cancer properties in various cancer types. In our previous work, we demonstrated that LPE can reduce IL-6-induced migration/invasiveness and MMP-9/2 up-regulation in some gastric cancer cell lines. This study aims to exploit the anti-cancer properties of LPE using an in vitro system model of inflammation, consisting of IL-6-exposed human primary colon cancer cells. We first analyzed the effect of LPE on IL-6-induced cell migration and invasiveness by wound healing and Boyden chamber assay, respectively. The MMP-2 mRNA expression levels and gelatinolytic activity in the cell culture media were determined by q-PCR analysis and gelatin zymography, respectively, and finally, the effects of LPE on IL-6-induced JAK2/STAT3 signaling pathways have been investigated by Western blotting analysis. Our results show that LPE is able to inhibit the IL-6-dependent cell migration and invasiveness associated with the up-regulation of MMP-2 expression levels and that these effects are correlated to the STAT3 phosphorylation in human primary T88 and T93 colon cancer cells.

Humic acids (HA) exhibit fascinating multifunctional features, yet degradation phenomena as well as poor stability in aqueous environments strongly limit their use. Inorganic nanoparticles are emerging as a powerful interface for the development of robust HA bio-hybrid materials with enhanced chemical stability and tunable properties. Hybrid organic-inorganic SiO2/HA nanostructures were synthesized via an in-situ sol-gel route, exploiting both physical entrapment and chemical coupling. The latter was achieved through amide bond formation between carboxyl groups of HA and the amino group of 3-aminopropyltriethoxysilane (APTS), as confirmed by Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. Monodisperse hybrid nanoparticles about 90 nm in diameter were obtained in both cases, yet Electron Paramagnetic Resonance (EPR) spectroscopy highlighted the different supramolecular organization of HA. The altered HA conformation was reflected in different antioxidant properties of the conjugated nanoparticles that, however, resulted in being higher than for pure HA. Our findings proved the key role of both components in defining the morphology of the final system, as well as the efficacy of the ceramic component in templating the HA supramolecular organization and consequently tuning their functional features, thus defining a green strategy for bio-waste valorization.

Humic acids (HA) are considered a promising and inexpensive source for novel multifunctional materials for a huge range of applications. However, aggregation and degradation phenomena in aqueous environment prevent from their full exploitation. A valid strategy to address these issues relies on combining HA moieties at the molecular scale with an inorganic nanostructured component, leading to more stable hybrid nanomaterials with tunable functionalities. Indeed, chemical composition of HA can determine their interactions with the inorganic constituent in the hybrid nanoparticles and consequently affect their overall physico-chemical properties, including their stability and functional properties in aqueous environment. As a fundamental contribution to HA materials-based technology, this study aims at unveiling this aspect. To this purpose, SiO2 nanoparticles have been chosen as a model platform and three different HAs extracted from composted biomasses, manure (HA_Man), artichoke residues (HA_Art) and coffee grounds (HA_Cof), were employed to synthetize hybrid HA-SiO2 nanoparticles through in-situ sol-gel synthesis. Prepared samples were submitted to aging in water to assess their stability. Furthermore, antioxidant properties and physico-chemical properties of both as prepared and aged samples in aqueous environment were assessed through Scanning Electron Microscopy (SEM), N2 physisorption, Simultaneous Thermogravimetric (TGA) and Differential Scanning Calorimetric (DSC) Analysis, Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR) spectroscopies. The experimental results highlighted that hybrid HA-SiO2 nanostructures acted as dynamic systems which exhibit structural supramolecular reorganization during aging in aqueous environment with marked effects on physico-chemical and functional properties, including improved antioxidant activity. Obtained results enlighten a unique aspect of interactions between HA and inorganic nanoparticles that could be useful to predict their behavior in aqueous environment. Furthermore, the proposed approach traces a technological route for the exploitation of organic biowaste in the design of hybrid nanomaterials, providing a significant contribution to the development of waste to wealth strategies based on humic substances.

The EPS-producing Pseudoalteromonas sp. MER144 was selected among 606 isolates from Antarctic seawater due to its evident slimy appearance on agar plates. The production of EPSs was enhanced by a step-by-step approach varying the carbon source, substrate and NaCl concentrations, temperature, and pH. Optimal conditions for the EPS production resulted at temperature of 4 °C and pH 7, with addition of 2% sucrose (w/v) and 3% NaCl (w/v). EPSs produced under optimal conditions were chemically characterized, resulting in a moderate carbohydrate content (35%), uronic acids (14%), and proteins (12%). Monosaccharide composition was estimated to be Glu:Man:GluN:Ara:GluA:GalA:Gal (1:0.36:0.26:0.06:0.06:0.05:0.03), while the estimated molecular weight was about 250 kDa. The addition of sucrose in the culture medium, by stimulating the EPS production, allowed MER144 to tolerate higher concentrations of mercury and cadmium. This finding was probably dependent on the presence of uronic acids and sulfate groups, which can bind cations, in the extracted EPSs. Monitoring EPS production under optimal conditions at different concentrations of mercury and cadmium revealed that EPS amounts increased at increasing heavy metal concentrations, indicating an adaptation to the stress conditions tested.

Astrobiology studies the origin and evolution of life on Earth and in the universe. According to the panspermia theory, life on Earth could have emerged from bacterial species transported by meteorites, that were able to adapt and proliferate on our planet. Therefore, the study of extremophiles, i.e. bacterial species able to live in extreme terrestrial environments, can be relevant to Astrobiology studies. In this work we described the ability of the thermophilic species Geobacillus thermantarcticus to survive after exposition to simulated spatial conditions including temperature's variation, desiccation, X-rays and UVC irradiation. The response to the exposition to the space conditions was assessed at a molecular level by studying the changes in the morphology, the lipid and protein patterns, the nucleic acids. G. thermantarcticus survived to the exposition to all the stressing conditions examined, since it was able to restart cellular growth in comparable levels to control experiments carried out in the optimal growth conditions. Survival was elicited by changing proteins and lipids distribution, and by protecting the DNA's integrity.

In this study, we firstly reported the production and the structural characterization of a novel hetero-exopolysaccharide namely EPS-K2 from the extremely halophilc Halomonas smyrnensis K2. Results revealed that EPS-K2 was mainly composed of three monosaccharides including mannose (66.69%), glucose (19.54%) and galactose (13.77%). EPS-K2 showed high thermostability with a degradation temperature around 260 °C, which could make it a suitable candidate for application in thermal processes. Moreover, EPS-K2 showed attractive functional properties. In fact, it exhibited potent antioxidant activity in a dose-dependent manner as assessed in analyses of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, iron chelating and DNA protection ability. Furthermore, EPS-K2 showed strong adhesion inhibition activity against Enterococcus faecalis (75.52 ± 3.35%) and Escherichia coli (61.95 ± 2.48%) at 1 g/l concentration, as well as a high biofilm disruption activity especially against E. coli (70.73 ± 2.78%), at 2 g/l concentration. According to its biotechnological properties, EPS-K2 could be exploited as functional ingredient in food, biomedicine, and pharmaceutical industries.

Production of extracellular polysaccharides by halophilic Archaea and Bacteria has been widely reported and the members of the genus Halomonas have been identified as the most potential producers. In the present work, a novel exopolysaccharide (EPS-S6) produced by the extremely halotolerant newly isolated Halomonas elongata strain S6, was characterized. According to the HPAE-PAD results, EPS-S6 was mainly composed of glucosamine, mannose, rhamnose and glucose (1:0.9:0.7:0.3). EPS-S6 was highly negatively charged and its molecular weight was about 270 kDa. Studies on its functional properties showed that EPS-S6 had several potential features. It has noticeable antioxidant activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH•) inhibition and DNA protection, good ability to inhibit and to disrupt pathogenic biofilms, excellent flocculation of kaolin suspension and interesting emulsifying properties at acidic, neutral and basic pH. Therefore, EPS-S6 could have potential biotechnological concern in several fields such as in food, cosmetic and environmental industries.

A new petroleum-degrading bacterium, designated strain GC2(T), was isolated from Bozkus 1 petroleum station in Diyarbakir, located in the southeast of Turkey. Cells were Gram-negative staining, aerobic, coccoid-rods, non-motile, non-spore-forming. The bacterium was found to degrade 100% ofn-alkanes ranging from C11 to C34 presented in the 1% crude oil after incubation of 7 days. The membrane phospholipids were 1,2 diacylglycero-3-phosphorylethanolamine (PEA), phosphatidylglycerol (PG), dipalmitoyl-sn-glycerol 1- phosphocholine (PC1), 1,2 dipalmitoyl-sn-glycero-3-phosphocholine monohydrate (PC3), cardiolipin also called diphosphatidylglycerol (CL) and l-alpha- phosphatidic acid, dipalmitoyl (AP); predominant respiratory ubiquinone was Q-8 and C16:0, C18:1 omega 9c and C16:1 were the major cellular fatty acids. The 16S rRNA sequence analysis revealed that the strain GC2(T)was a member of genusAcinetobacterand was most closely related toAcinetobacter lwoffiiDSM 2403( T)(99.79%),Acinetobacter pseudolwoffiiANC 5318( T)(98.83%) andAcinetobacter harbinensisHITLi 7( T)(98.14%). TherpoBandgyrBgene sequence analysis confirmed that the strain GC2(T)was a member of genusAcinetobacterand that the closest relative wasAcinetobacter lwoffiiDSM 2403( T)(99.08% and 100% similarity, respectively). DNA-DNA hybridization values between GC2(T)and its closest relatives ranged from 65.6% (withA. lwoffii) to 5.1% (withA. venetianus). The whole genome sequence of strain GC2(T)was obtained. The DNA G + C content of this strain was determined to be 42.9 mol %. ANI indexes, in silico estimations of DDH values and wet lab DDH values demonstrated that strain GC2(T)represents an independent genomospecies. On the basis of phenotypic characteristics, chemotaxonomic, phylogenetic data and DNA-DNA hybridization and whole genome analysis, we propose to assign strain GC2(T)as a new species of the genusAcinetobacter, for which the nameAcinetobacter mesopotamicussp. nov. is proposed. The type strain of this species is GC2(T)(DSM 26953 T = JCM 31073 T). The whole genome of strain GC2(T)has been deposited at DDBJ/ENA/GenBank under the accession JAALFF010000000.

In this study, we firstly reported the production and the structural characterization of a novel hetero-exopolysaccharide namely EPS-K2 from the extremely halophilc Halomonas smyrnensis K2. Results revealed that EPS-K2 was mainly composed of three monosaccharides including mannose (66.69%), glucose (19.54%) and galactose (13.77%). EPS-K2 showed high thermostability with a degradation temperature around 260 °C, which could make it a suitable candidate for application in thermal processes. Moreover, EPS-K2 showed attractive functional properties. In fact, it exhibited potent antioxidant activity in a dose-dependent manner as assessed in analyses of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, iron chelating and DNA protection ability. Furthermore, EPS-K2 showed strong adhesion inhibition activity against Enterococcus faecalis (75.52 ± 3.35%) and Escherichia coli (61.95 ± 2.48%) at 1 g/l concentration, as well as a high biofilm disruption activity especially against E. coli (70.73 ± 2.78%), at 2 g/l concentration. According to its biotechnological properties, EPS-K2 could be exploited as functional ingredient in food, biomedicine, and pharmaceutical industries.

In this paper, lemon and fennel wastes were recovered and used as secondary-raw polysaccharide sources. These polysaccharides were exploited as natural plasticizers of sodium alginate (A) based films, in order to improve sodium alginate performances, limited by its fragility, extending its potential application in a cost effective and eco-friendly way. Different green processes, such as maceration (MAC), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), were carried out for obtaining high yield of lemon and fennel polysaccharides (LP and FP). Actually, HPAE-PAD and TLC analyses evidenced the presence of xyslose, galactose, glucose and rhamnose monomers and galacturonic acid, typical of polysaccharides like pectin and xyloglucan chains. These findings were confirmed by NMR and FTIR spectroscopic analyses. Moreovers, gel filtration chromatography assessed the high molecular weight of recovered polysaccharides, particularly of FP waste fraction. The extracted polysaccharides were used as eco-friendly and cost-effective plasticizers of sodium alginate films (AFP and ALP). DSC analysis evidenced a significant decreasing of glass transition temperature of the polymer, tensile tests showed an enlightened rising of elongation at break and TGA analysis showed a faster degradation kinetics of AFP and ALP films, as expected in a plasticized system.

A Gram-stain-positive, non-endospore-forming, haloalkaliphilic actinobacterium, strain CK5T, was isolated from a soil sample, collected at Cape King (Antarctica), and its taxonomic position was investigated by using a polyphasic approach. Cells were cocci with orange pigmentation, non-motile and grew optimally at 25 °C and pH 9.0–9.5 in the presence of 2 % (w/v) NaCl. Cellular membrane contained MK-7 (72 %) and MK-8 (28 %), and anteiso-C15 : 0 (64.8 %), iso-C16 : 0 (13.3 %), n-C17 : 0 (9.9 %), n-C16 : 0 (4.0 %), n-C14 : 0 (3.7 %) as major cellular fatty acids. The DNA G+C content was 64.8 mol%. Strain CK5T, based on the 16S rRNA gene sequence similarity, was most closely related to Nesterenkonia jeotgali JG-241T (99.5 %), Nesterenkonia sandarakina YIM 70009T (99.4 %), Nesterenkonia lutea YIM 70081T (99.4 %), Nesterenkonia halotolerans YIM 70084T (99.3 %), Nesterenkonia xinjiangensis YIM 70097T (97.2 %), Nesterenkonia flava CAAS 251T (97.1 %) and Nesterekonia aethiopica CCUG 48939T (97.1 %). Strain CK5T revealed 31 % DNA–DNA relatedness with respect to N. sandarakina DSM 15664T, 29 % with respect to N. jeotgali DSM 19081T, 10 % with respect to N. lutea DSM 15666T and 1 % with respect to N. halotolerans, DSM 15474T, N. xinjiangensis DSM 15475T, N. aethiopica DSM 17733T and N. flava DSM 19422T. On the basis of 16S rRNA gene sequences, DNA–DNA hybridization and chemotaxonomic characteristics, strain CK5T represents a novel species of the genus Nesterenkonia, for which the name Nesterenkonia aurantiaca sp. nov. is proposed. The type strain is CK5T ( = DSM 27373T = JCM 19723T).

Bioinspired melanin based hybrid materials hold huge promise for developing multifunctional systems for a considerable set of applications. Yet, control of melanogenic pathway is a big challenge to allow rational design of nanostructured systems with tuned structures and improved properties. This study proves the ability of titanium ions interactions with melanin precursors in directing melanogenic pathway. To this purpose complementary spectroscopic evidences were collected to reveal that in the presence of a TiO2-sol, amino-acid complex of Ti(IV) ions and DOPA actually inhibits its cyclization, during oxidative process, thus leading to DOPA-based polyphenols, stable even in oxidative environment, rather than eumelanin. This hugely impacts on the biological properties of the final hybrid systems which, discloses relevant and durable antioxidant behavior but poor antimicrobial activity differently from DHICA-based hybrid nanostructures. Overall this study, discloses the high potential of ceramic templated approach in combination with the selection of melanin precursor in achieving a fine tuning of physico-chemical as well as bioactivity of melanin-TiO2 nanostructures, opening new scenarios towards the design of cutting-edge biomaterials with tailored biological properties.

Saline and hypersaline environments such as natural saline seas, lakes, coastal lagoons, marine salterns, deserts, saline soils, etc. are considered extreme habitats for microbial life. They harbor halophiles as well as halotolerant microorganisms growing in the absence of salt and in the same time tolerant to relatively high salt concentrations. Halophilic microorganisms suggest many advantages for biotechnological exploration like relatively short time course of fermentations, lack of pathogenicity and the production of stable biomolecules, such as exopolysaccharides (EPS), under the extreme conditions of the most industrial processes. The aim of this chapter is to present a summary of the status of the research about the structures and the biosynthesis of exopolysaccharides by halophilic microorganisms, including medium-released and biofilm embedded polysaccharides. Moreover, relationships between the structure and the function of the exopolysaccharides and their possible biotechnological and industrial applications, are discussed.

The thermal ecosystems, including geothermal springs, are proving to be source of thermophiles able to produce extracellular polysaccharides (EPSs). Among the sixteen thermophilic bacilli isolated from sediment sampled from Arzakan geothermal spring, Armenia, two best EPSs producer strains were identified based on 16S rRNA gene sequence analysis and phenotypic characteristics, and designated as Geobacillus thermodenitrificans ArzA-6 and Geobacillus toebii ArzA-8 strains. EPSs production was investigated under different time, temperature and culture media’s composition. The highest specific EPSs production yield (0.27 g g−1 dry cells and 0.22 g g−1 dry cells for strains G. thermodenitrificans ArzA-6 and G. toebii ArzA-8, respectively) was observed after 24 h when fructose was used as sole carbon source at 65 °C and pH 7.0. Purified EPSs displayed a high molecular mass: 5 × 105 Da for G. thermodenitrificans ArzA-6 and 6 × 105 Da for G. toebii ArzA-8. Chemical composition and structure of the biopolymers, determined by GC–MS, HPAE-PAD and NMR, showed that both the two EPSs are heteropolymers composed by mannose as major monomer unit. Optical rotation values [α] D 25 °C of the two EPSs (2 mg ml−1 H2O) were − 142,135 and − 128,645 for G. thermodenitrificans ArzA-6 and G. toebii ArzA-8, respectively.

[Purpose]: Processing and selection of fruits and vegetables generate high amounts of wastes that represent an economical and environmental issue for the agroindustry sector. Nevertheless, according to so called “biorefinery” approach, this waste biomass can be exploited for the recovery of value added molecules. In this paper the residues of industrial processing of fennels, carrots, lemons and tomatoes were used as sources of polyphenols., [Methods]:In order to optimize the recovery of polyphenols, different extraction techniques (maceration, ultrasound and microwave assisted extraction) were used in combination with different extraction media (water, ethanol, methanol and their mixtures). The polyphenols’ fractions were tested for their chemical and biological properties., [Results]: All the obtained phenol fractions showed high antioxidant power and scavenging ability towards stable radical species and hydrogen peroxide. Moreover, the isolated polyphenol mixtures (containing remarkable compounds like quercetin, kaempferol, naringin, hesperetin) also displayed potential activities as anti-cancer, anti-microbial and acetylcholinesterase inhibiting agents., [Conclusions]: Overall the obtained results showed that the residual matter produced by the industrial processing of fruits and vegetables contain high amounts of polyphenols. These polyphenolic fractions still retain their biological and antioxidant properties and therefore could be further exploited for other industrial applications., This work was partially supported by the project PON03PE_00107 BioPoliS (Development of green technologies for production of BIOchemicals and their use in preparation and industrial application of POLImeric materials from agricultural biomasses cultivated in a sustainable way in Campania region) funded by MIUR (Italian Ministry of University and Research). The authors wish also to thank the Spanish Ministry of Economy and Competitiveness for financial support (AGL2012-30803).

Four sponge-associated Antarctic bacteria (i.e., Winogradskyella sp. strains CAL384 and CAL396, Colwellia sp. strain GW185, and Shewanella sp. strain CAL606) were selected for the highly mucous appearance of their colonies on agar plates. The production of extracellular polymeric substances (EPSs) was enhanced by a step-by-step approach, varying the carbon source, substrate and NaCl concentrations, temperature, and pH. The EPSs produced under optimal conditions were chemically characterized, resulting in a moderate carbohydrate content (range, 15 to 28%) and the presence of proteins (range, 3 to 24%) and uronic acids (range, 3.2 to 11.9%). Chemical hydrolysis of the carbohydrate portion revealed galactose, glucose, galactosamine, and mannose as the principal constituents. The potential biotechnological applications of the EPSs were also investigated. The high protein content in the EPSs from Winogradskyella sp. CAL384 was probably responsible for the excellent emulsifying activity toward tested hydrocarbons, with a stable emulsification index (E 24 ) higher than those recorded for synthetic surfactants. All the EPSs tested in this work improved the freeze-thaw survival ratio of the isolates, suggesting that they may be exploited as cryoprotection agents. The addition of a sugar in the culture medium, by stimulating EPS production, also allowed isolates to grow in the presence of higher concentrations of mercury and cadmium. This finding was probably dependent on the presence of uronic acids and sulfate groups, which can act as ligands for cations, in the extracted EPSs. IMPORTANCE To date, biological matrices have never been employed for the investigation of EPS production by Antarctic psychrotolerant marine bacteria. The biotechnological potential of extracellular polymeric substances produced by Antarctic bacteria is very broad and comprises many advantages, due to their biodegradability, high selectivity, and specific action compared to synthetic molecules. Here, several interesting EPS properties have been highlighted, such as emulsifying activity, cryoprotection, biofilm formation, and heavy metal chelation, suggesting their potential applications in cosmetic, environmental, and food biotechnological fields as valid alternatives to the commercial polymers currently used.

Halophilic microorganisms are producers of a lot of new compounds whose properties suggest promising perspectives for their biotechnological exploration. Moderate halophilic bacterium Chromohalobacter canadensis 28 was isolated from Pomorie salterns as an extracellular polymer substance (EP) producer. The best carbon source for extracellular polymer production was found to be lactose, a sugar received as a by-product from the dairy industry. After optimization of the culture medium and physicochemical conditions for cultivation, polymer biosynthesis increased more than 2-fold. The highest level of extracellular polymer synthesis by C. canadensis 28 was observed in an unusually high NaCl concentration (15% w/v). Chemical analysis of the purified polymer revealed the presence of an exopolysaccharide (EPS) fraction (14.3% w/w) and protein fraction (72% w/w). HPLC analysis of the protein fraction showed the main presence of polyglutamic acid (PGA) (75.7% w/w). EPS fraction analysis revealed the following sugar composition (% w/w): glucosamine 36.7, glucose 32.3, rhamnose 25.4, xylose 1.7, and not identified sugar 3.9. The hydrogel formed by PGA and EPS fractions showed high swelling behavior, very good emulsifying and stabilizing properties, and good foaming ability. This is the first report for halophilic bacterium able to synthesize a polymer containing PGA fraction. The synthesized biopolymer shows an extremely high hydrophilicity, due to the simultaneous presence of PGA and EPS. The analysis of its functional properties and the presence of glucosamine in the highest proportion in EPS fraction clearly determine the potential of EP synthesized by C. canadensis 28 for application in the cosmetics industry.

Extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions as high temperatures, salt presence, low pH values, or high radiation levels. Among the adaptive strategies, exopolysaccharide (EPS) biosynthesis is one of the most common protective mechanisms. Although the EPS production is a process that requires a significant carbon investment for microorganisms, the benefits are significantly higher than costs considering the cell survival in their presence. These biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications in food, pharmaceutical, and other industrial fields. The increasing demand of natural polymers for industrial applications has led to a vibrant interest in the EPS production by microorganisms. There has been a substantial attractiveness in the isolation and identification of new microbial polysaccharides that might have innovative uses as emulsifiers, stabilizers, and gelling or texture-enhancing agents. Recent research on polysaccharide produced by extremophiles, isolated from Arctic and Antarctic regions, hypersaline environments, deep-sea hydrothermal vents, and volcanic areas, will be reported including chemical structures, fermentation technology, biotechnological and biomedical applications.

Extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions as high temperatures, salt presence, low pH values, or high radiation levels. Among the adaptive strategies, exopolysaccharide (EPS) biosynthesis is one of the most common protective mechanisms. Although the EPS production is a process that requires a significant carbon investment for microorganisms, the benefits are significantly higher than costs considering the cell survival in their presence. These biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications in food, pharmaceutical, and other industrial fields. The increasing demand of natural polymers for industrial applications has led to a vibrant interest in the EPS production by microorganisms. There has been a substantial attractiveness in the isolation and identification of new microbial polysaccharides that might have innovative uses as emulsifiers, stabilizers, and gelling or texture-enhancing agents. Recent research on polysaccharide produced extremophiles, isolated from hypersaline environments, deep-sea hydrothermal vents, and volcanic and hydrothermal areas, will be reported including chemical structures, fermentation technology, biotechnological and biomedical applications.

The bacterial species belonging to the group of Extremophiles, i.e. those microorganisms that are able to resist extreme environmental conditions, are an interesting biological model for Astrobiology. The relevance of assessing the resistance of bacterial species in spatial conditions has recently been highlighted also by the "AstRoMap European Astrobiology Roadmap" [1]. Indeed, according to the AstRoMap one main research issue in Astrobiology is represented by "life and habitability" i.e. the search for conditions limiting or sustaining life in the universe beyond the Earth. In this frame, the laboratory simulation of spatial conditions is one main approach to the identification of those microbial species that could potentially adapt to live in space on other planets. Here we present the results of our studies concerning the resistance of cells and spores of the thermophilic species Parageobacillus thermantarcticus in laboratory conditions simulating some space parameters. P. thermantarcticus was subjected to several stressors mimicking the space environment including: desiccation [2,3], UV radiations [2,3], X-rays [2,3] and gamma-rays [4]. Some preliminary results of the analysis, at a molecular level, of cells' response to stressing conditions are also reported[2,3,4]. References 1.Horneck et al. (2016) Astrobiology, 16: 201-43. 2.Mastascusa et al.(2014) O.L.E.B., 44: 231-7. 3.Di Donato et al. (2018) O.L.E.B., 48(1): 141-58. 4.Romano et al. (2018) Extremophiles, 10.1007/s00792-018-1049-0

This chapter will discuss some remarkable examples of extremophilic bacteria, isolated from different ecosystems, which produce exopolysaccharides (EPSs). The chapter will also cover the properties of EPSs produced by extremophiles and their possible commercial applications ranging from pharmaceutical to food processing, detoxification and bioremediation. This chapter will also cover the techniques that are used to purify, analyse and structurally characterise the bacterial EPSs; the state of the art in the field of bacterial EPSs research, with mention to the main examples of well-studied and commercially exploited EPSs; an overview of the main EPSs’ producing extremophiles that have been isolated from both aquatic and terrestrial environments; the description of the main biosynthetic routes leading to the EPSs production in archaeal and bacterial extremophiles, with reference to the enzymes involved and to the genetic manipulations for biosynthesis’s tailoring; the analysis of the most interesting biological properties of extremophiles’ EPSs (that can act as anti-inflammatory, immunomodulating and antiviral agents) and of their biotechnological applications in drug delivery systems; and the compendium of the most used techniques to perform the purification, the analysis of chemical composition, the identification of glycoside linkage position and substitution pattern, the determination of the molecular-weight distribution and the structural analysis of EPSs.

Extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions as high temperatures, salt presence, low pH values, or high radiation levels. Among the adaptive strategies, exopolysaccharide (EPS) biosynthesis is one of the most common protective mechanisms. Although the EPS production is a process that requires a significant carbon investment for microorganisms, the benefits are significantly higher than costs considering the cell survival in their presence. These biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications in food, pharmaceutical, and other industrial fields. The increasing demand of natural polymers for industrial applications has led to a vibrant interest in the EPS production by microorganisms. There has been a substantial attractiveness in the isolation and identification of new microbial polysaccharides that might have innovative uses as emulsifiers, stabilizers, and gelling or texture-enhancing agents. Recent research on polysaccharide produced extremophiles, isolated from hypersaline environments, deep-sea hydrothermal vents, and volcanic and hydrothermal areas, will be reported including chemical structures, fermentation technology, biotechnological and biomedical applications.

Microbial EPSs are ubiquitous in the extreme environments where they are crucial for microbial survival. Most of the functions attributed to EPSs are related to a protective role, which are dependent on the ecological niches in which the producer microorganisms live. They could support the microbial communities to tolerate extremes of temperature, salt concentration and nutrient supply, building an interface between the bacterial cell and its surrounding environment. Several EPSs produced by microorganisms from extreme habitats show biotechnological promise. By examining their structure and chemical/physical characteristics, it is possible to gain insight into their commercial application; they are employed in several fields ranging from food-processing to pharmaceutical industries, through to the bioremediation ability of polluted areas. Considering that most of extreme ecosystems and, therefore, the respective microbial communities are still unexplored, it is reasonable to hypothesize that the isolation of new microorganisms, together with their biomolecules, in particular exopolysaccharides, will provide interesting perspectives for new industrial processes in several fields.

Extremophiles can be isolated from several extreme environments that resemble the environmental conditions in space and in other Solar System bodies, therefore they are considered as valuable biological models for Astrobiology studies. Indeed, thanks to their ability to survive to a variety of stressing conditions, these organisms could have been able to resist to the interstellar transport to Earth, as hypothesize by the panspermia theory of the origin of life on Earth. The relevance of extremophiles as biological models has recently been highlighted also by the "AstRoMap European Astrobiology Roadmap"1, that envisages the implementation of microbiological experiments in laboratory by simulating the extraterrestrial environments, in order to identify those microbial species that could potentially adapt to live in space on other planets. In this frame, we pointed out our attention on four extremophilic bacteria from the Archaea and Bacteria domains i.e. Sulfolobus solfataricus, Haloterrigena hispanica, Thermotoga neapolitana and Parageobacillus thermantarcticus2. All the selected bacteria were able to resist to several stressing conditions mimicking the space environment. In particular, P.thermantarcticus showed to be one of the most resistant species after exposition to a variety of conditions3 from the absence of water to the irradiation with ionising radiations (x-rays and ?-rays). In this report, our recent results regarding the adaptation and the molecular mechanisms involved in the resistance and inactivation of this species in space simulated conditions will be presented.

Among plant polyphenols, lemon peels extract (LPE) from the residues of the industrial processing of lemon (Citrus limon) shows anti-proliferative properties in cancer cells and anticholinesterase activity. In this study, we analyze the anti-cancer properties of LPE on migration and invasiveness in MKN-28 and AGS human gastric cancer cell lines either in the absence or presence of the pro-inflammatory cytokine IL-6. We find that the pretreatment with non-cytotoxic concentrations (0.5&ndash, 1 &mu, g/ml of gallic acid equivalent) of LPE inhibits interleukin-6 (IL-6)-induced cell migration and invasiveness in MKN-28 and AGS cells, as analyzed by wound and matrigel assays. Pretreatment with LPE is able to prevent either IL-6-induced matrix metalloproteinases (MMP)-9/2 activity, as assessed by gel zymography, or mRNA and protein MMP-9/2 expression, as evaluated by qPCR and Western blotting analysis, respectively. These LPE effects are associated with an IL-6-dependent STAT3 signaling pathway in MKN-28 and AGS cells. Furthermore, LPE shows acetylcholinesterase inhibitory activity when assayed by the Ellman method. In conclusion, our results demonstrate that LPE reduces the invasiveness of gastric MKN-28 and AGS cancer cells through the reduction of IL-6-induced MMP-9/2 up-regulation. Therefore, these data suggest that LPE exerts a protective role against the metastatic process in gastric cancer.

The ever growing concerns about the threats of first generation bioethanol on food supplies and biodiversity have shifted the focus of research to second generation biofuel technologies. The second generation bioethanol's technologies provide sustainable energy without compromising food security and environment since they exploit non-food crops or non-food parts of crops and wastes of wood-based or food-based industries such as wood chips, skins and pulp from fruit pressing. The key step of the bioethanol's production processes is represented by the hydrolysis of the biomass to C5 and C6 sugars: such process relies on the use of bacterial enzymes that are mainly derived from extremophilic microorganisms. These microorganisms can be found in extreme environments, generally characterized by atypical temperature, pH, pressure, salinity, toxicity and radiation levels. Their enzymes (also named extremozymes) possess unique properties of considerable biotechnological significance that make them very useful for the industrial transformation of biomass to ethanol. In this report a survey of extremophiles and related enzymes that have been used for the bioconversion of waste biomass (not in competition with food chain) to bioethanol, is given.

Herpes simplex virus type 1 (HSV-1) is responsible of common and widespread viral infections in humans through the world, and of rare, but extremely severe, clinical syndromes in the central nervous system. The emergence of resistant strains to drugs actually in use encourages the searching for novel antiviral compounds, including those of natural origin. In this study, the recently described poly-γ-glutamic acid (γ-PGA-APA), produced by the marine thermotolerant Bacillus horneckiae strain APA, and previously shown to possess biological and antiviral activity, was evaluated for its anti-HSV-1 and immunomodulatory properties. The biopolymer hindered the HSV-1 infection in the very early phase of virus replication. In addition, the γ-PGA-APA was shown to exert low cytotoxicity and noticeable immunomodulatory activities towards TNF-α and IL-1β gene expression. Moreover, the capacity to positively modulate the transcriptional activity of the cytokine genes was paired with increased level of activation of the transcription factor NF-kB by γ-PGA-APA. Overall, as non-cytotoxic biopolymer able to contribute in the antiviral defense against HSV-1, γ-PGA-APA could lead to the development of novel natural drugs for alternative therapies.