Genomic Analysis Provides New Insights Into Biotechnological and Industrial Potential of Parageobacillus thermantarcticus M1

Parageobacillus thermantarcticus strain M1 is a Gram-positive, motile, facultative anaerobic, spore forming, and thermophilic bacterium, isolated from geothermal soil of the crater of Mount Melbourne (74°22′ S, 164°40′ E) during the Italian Antarctic Expedition occurred in Austral summer 1986–1987. Strain M1 demonstrated great biotechnological and industrial potential owing to its ability to produce exopolysaccharides (EPSs), ethanol and thermostable extracellular enzymes, such as an xylanase and a β-xylosidase, and intracellular ones, such as xylose/glucose isomerase and protease. Furthermore, recent studies revealed its high potential in green chemistry due to its use in residual biomass transformation/valorization and as an appropriate model for microbial astrobiology studies. In the present study, using a systems-based approach, genomic analysis of P. thermantarcticus M1 was carried out to enlighten its functional characteristics. The elucidation of whole-genome organization of this thermophilic cell factory increased our understanding of biological mechanisms and pathways, by providing valuable information on the essential genes related to the biosynthesis of nucleotide sugar precursors, monosaccharide unit assembly, as well as the production of EPSs and ethanol. In addition, gene prediction and genome annotation studies identified genes encoding xylanolytic enzymes that are required for the conversion of lignocellulosic materials to high-value added molecules. Our findings pointed out the significant potential of strain M1 in various biotechnological and industrial applications considering its capacity to produce EPSs, ethanol and thermostable enzymes via the utilization of lignocellulosic waste materials.

Isolation and Characterization of Strain Exiguobacterium sp. KRL4, a Producer of Bioactive Secondary Metabolites from a Tibetan Glacier

Extremophilic microorganisms represent a unique source of novel natural products. Among them, cold adapted bacteria and particularly alpine microorganisms are still underexplored. Here, we describe the isolation and characterization of a novel Gram-positive, aerobic rod-shaped alpine bacterium (KRL4), isolated from sediments from the Karuola glacier in Tibet, China. Complete phenotypic analysis was performed revealing the great adaptability of the strain to a wide range of temperatures (5-40 °C), pHs (5.5-8.5), and salinities (0-15% w/v NaCl). Genome sequencing identified KRL4 as a member of the placeholder genus Exiguobacterium_A and annotation revealed that only half of the protein-encoding genes (1522 of 3079) could be assigned a putative function. An analysis of the secondary metabolite clusters revealed the presence of two uncharacterized phytoene synthase containing pathways and a novel siderophore pathway. Biological assays confirmed that the strain produces molecules with antioxidant and siderophore activities. Furthermore, intracellular extracts showed nematocidal activity towards C. elegans, suggesting that strain KRL4 is a source of anthelmintic compounds.

Determination of flavor-potentiating compounds in different Italian tomato varieties

Umami taste, known as appetizing sensation, is mainly imparted by monosodium glutamate (MSG, the first identified umami factor) in synergistic combination with some 5' ribonucleotides such as inosine 5'-monophosphate, IMP, guanosine 5'-monophosphate, GMP, and adenosine 5'-monophoshate, AMP. The level of free glutamic acid in tomatoes is higher than in other vegetables or fruits and increases with ripening and industrial processing. In addition, due to the presence of bioactive metabolites, tomatoes and tomato-based products are among the most consumed healthy food items. The levels of the major umami compounds of tomato, that is, glutamate and 5'-ribonucleotides (GMP and AMP) were assessed in different parts (skin, outer flesh, and inner pulp) of known tomato varieties from southern Italy: San Marzano Originale, San Marzano 245, Black Tomato, Corbarino Corbara, Corbarino Nocera, and Superpomodoro (tomato hybrid). Such varieties were also investigated for their antioxidant properties through DMPD, DPPH, and ABTS assays, with San Marzano Originale showing the highest antioxidant power both in lipophilic and methanolic fractions. The concentration of umami compounds in tomato differs with the part of the fruit analyzed and is greatly dependent on the variety, being Corbarino Nocera the cultivar richest in glutamate and Superpomodoro in ribonucleotides. As for nutritional aspect, results confirm the great nutraceutical feature of San Marzano tomato, the most known variety used in industrial processes. PRACTICAL APPLICATIONS: This study was planned to develop a method to quantify the major umami compounds that strongly influence the organoleptic properties of many different tomato varieties. It is known that the sensory quality of fruits and vegetables is an important factor in consumer's choice. The analytical methods described here enabled the evaluation of the glutamate and 5'-ribonucleotides contents in six selected varieties of tomato from Campania region, and can be easily used to determine the sensory profile of commercial varieties, for example, those perceived as not very tasteful by consumers.

Prokaryotic Diversity of the Composting Thermophilic Phase: The Case of Ground Coffee Compost

Waste biomass coming from a local coffee company, which supplied burnt ground coffee after an incorrect roasting process, was employed as a starting material in the composting plant of the Experimental Station of the University of Naples Federico II at Castel Volturno (CE). The direct molecular characterization of compost using ¹³C-NMR spectra, which was acquired through cross-polarization magic-angle spinning, showed a hydrophobicity index of 2.7% and an alkyl/hydroxyalkyl index of 0.7%. Compost samples that were collected during the early "active thermophilic phase" (when the composting temperature was 63 °C) were analyzed for the prokaryotic community composition and activities. Two complementary approaches, i.e., genomic and predictive metabolic analysis of the 16S rRNA V3-V4 amplicon and culture-dependent analysis, were combined to identify the main microbial factors that characterized the composting process. The whole microbial community was dominated by Firmicutes. The predictive analysis of the metabolic functionality of the community highlighted the potential degradation of peptidoglycan and the ability of metal chelation, with both functions being extremely useful for the revitalization and fertilization of agricultural soils. Finally, three biotechnologically relevant Firmicutes members, i.e., Geobacillus thermodenitrificans subsp. calidus, Aeribacillus pallidus, and Ureibacillus terrenus (strains CAF1, CAF2, and CAF5, respectively) were isolated from the "active thermophilic phase" of the coffee composting. All strains were thermophiles growing at the optimal temperature of 60 °C. Our findings contribute to the current knowledge on thermophilic composting microbiology and valorize burnt ground coffee as waste material with biotechnological potentialities.

Hetero-exopolysaccharide from the extremely halophilic Halomonas smyrnensis K2: production, characterization and functional properties in vitro

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.

Novel Psychrophiles and Exopolymers from Permafrost Thaw Lake Sediments

Thermokarst lakes are one of the most abundant types of microbial ecosystems in the circumpolar North. These shallow basins are formed by the thawing and collapse of ice-rich permafrost, with subsequent filling by snow and ice melt. Until now, permafrost thaw lakes have received little attention for isolation of microorganisms by culture-based analysis. The discovery of novel psychrophiles and their biomolecules makes these extreme environments suitable sources for the isolation of new strains, including for potential biotechnological applications. In this study, samples of bottom sediments were collected from three permafrost thaw lakes in subarctic Québec, Canada. Their diverse microbial communities were characterized by 16S rRNA gene amplicon analysis, and subsamples were cultured for the isolation of bacterial strains. Phenotypic and genetic characterization of the isolates revealed affinities to the genera Pseudomonas, Paenibacillus, Acinetobacter,Staphylococcus and Sphingomonas. The isolates were then evaluated for their production of extracellular enzymes and exopolymers. Enzymes of potential biotechnological interest included α and β-glucosidase, α and β-maltosidase, β-xylosidase and cellobiohydrolase. One isolate, Pseudomonas extremaustralis strain 2ASCA, also showed the capability to produce, in the loosely bound cell fraction, a levan-type polysaccharide with a yield of 613 mg/L of culture, suggesting its suitability as a candidate for eco-sustainable alternatives to commercial polymers.

Acinetobacter mesopotamicus sp. nov., Petroleum-degrading Bacterium, Isolated from Petroleum-Contaminated Soil in Diyarbakir, in the Southeast of Turkey

A new petroleum-degrading bacterium, designated strain GC2^T, was isolated from Bozkuş 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% of n-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-α- phosphatidic acid, dipalmitoyl (AP); predominant respiratory ubiquinone was Q-8 and C16:0, C18:1ω9c and C16:1 were the major cellular fatty acids. The 16S rRNA sequence analysis revealed that the strain GC2^T was a member of genus Acinetobacter and was most closely related to Acinetobacter lwoffii DSM 2403 ^T (99.79%), Acinetobacter pseudolwoffii ANC 5318 ^T (98.83%) and Acinetobacter harbinensis HITLi 7 ^T (98.14%). The rpoB and gyrB gene sequence analysis confirmed that the strain GC2^T was a member of genus Acinetobacter and that the closest relative was Acinetobacter lwoffii DSM 2403 ^T (99.08% and 100% similarity, respectively). DNA-DNA hybridization values between GC2^T and its closest relatives ranged from 65.6% (with A. lwoffii) to 5.1% (with A. 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 genus Acinetobacter, for which the name Acinetobacter mesopotamicus sp. 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.

Extracellular polymeric substances with metal adsorption capacity produced by Pseudoalteromonas sp. MER144 from Antarctic seawater

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.

Vibrio coralliirubri sp. nov., a new species isolated from mucus of red coral (Corallium rubrum) collected at Procida island, Italy

Strain Corallo1^T was isolated from mucus of red coral (Corallium rubrum) at Punta Pizzaco (Procida island, Naples, Italy). It was characterised as a Gram-stain negative, motile, rod-shaped bacterium. Strain Corallo1^T was found to show positive responses for cytochrome-c oxidase, catalase, reduction of nitrate and nitrite, β-galactosidase activity and hydrolysis of starch, xylan, peptone, Tween 40, Tween 80 and casein. Strain Corallo1^T was found to be mesophilic, neutrophilic to alkalophilic and slightly halophilic. According to analysis of the almost-complete 16S rRNA gene, strain Corallo1^T is closely related to Vibrio celticus (100% sequence similarity), Vibrio gigantis (100%), Vibrio crassostreae (99.7%), Vibrio artabrorum (99.7%) and Vibrio pomeroyi (99.6%). MLSA of five housekeeping genes (atpA, pyrH, recA, rpoA and rpoD) was performed to refine the phylogenetic relationships of strain Corallo1^T. A draft genome sequence of strain Corallo1^T was obtained. The DNA G+C content of this strain was determined to be 44.5 mol %. The major cellular fatty acids of strain Corallo1^T are C_16:1, n-C_16:0 and C_18:1, and the major isoprenoid ubiquinone is Q8. ANI indexes, in silico estimations of DDH values and wet lab DDH values demonstrated that strain Corallo1^T represents an independent genomospecies. Based on a polyphasic taxonomic characterisation, strain Corallo1^T is concluded to represent a novel species of the genus Vibrio, for which the name Vibrio coralliirubri sp. nov. is proposed. The type strain is Corallo1^T (= DSM 27495^T = CIP 110630^T).

Antioxidant activity and bioactive compound contents before and after in vitro digestion of new tomato hybrids

BACKGROUND

The antioxidant properties and bioactive compound contents of fresh new tomato hybrids before and after in vitro digestion were investigated. To this aim, the antioxidant activities of lipophilic, hydrophilic and polyphenolic extracts of tomato hybrids were determined by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), DMPD (N,N-dimethyl-p-phenylenediamine dihydrochloride) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methods respectively, while the bioactive compound contents were estimated via Folin-Ciocalteu (polyphenols), pH differential (anthocyanins) and high-performance liquid chromatography (lycopene and β-carotene) methods.

RESULTS

After the digestion process, a marked loss (ranging from 37 to 77%) of antioxidant capacity linked to the hydrophilic fraction was observed. In contrast, the lipophilic and methanolic fractions showed an increase in antioxidant activity (ranging from 9 to 40%) after gastric digestion, and a rapid decrease was observed after total digestion. Moreover, the presence of anthocyanins and carotenoids after simulated digestion was a notable result.

CONCLUSION

The bioavailability of bioactive metabolites from nutraceutical food and their healthful properties in humans are strictly dependent on the digestion process. © 2017 Society of Chemical Industry.

Aeribacillus composti sp. nov., a thermophilic bacillus isolated from olive mill pomace compost

A Gram-stain-positive, aerobic, endospore-forming, thermophilic bacterium, strain N.8^T, was isolated from the curing step of an olive mill pomace compost sample, collected at the Composting Experimental Centre (CESCO, Salerno, Italy). Strain N.8^T, based on 16S rRNA gene sequence similarities, was most closely related to Aeribacillus pallidus strain H12^T (=DSM 3670^T) (99.8 % similarity value) with a 25 % DNA-DNA relatedness value. Cells were rod-shaped, non-motile and grew optimally at 60 °C and pH 9.0, forming cream colonies. Strain N.8 was able to grow on medium containing up to 9.0 % (w/v) NaCl with an optimum at 6.0 % (w/v) NaCl. The cellular membrane contained MK-7, and C16 : 0 (48.4 %), iso-C17 : 0 (19.4 %) and anteiso-C17 : 0 (14.6 %) were the major cellular fatty acids. The DNA G+C content was 40.5 mol%. Based on phenotypic characteristics, 16S rRNA gene sequences, DNA-DNA hybridization values and chemotaxonomic characteristics, strain N.8^T represents a novel species of the genus Aeribacillus, for which the name Aeribacillus composti sp. nov. is proposed. The type strain is N.8^T (=KCTC 33824^T=JCM 31580^T).

Survival and Adaptation of the Thermophilic Species Geobacillus thermantarcticus in Simulated Spatial Conditions

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.

Thermophilic Geobacillus galactosidasius sp. nov. loaded γ-Fe2O3 magnetic nanoparticle for the preconcentrations of Pb and Cd

Thermophilic bacteria, Geobacillus galactosidasius sp nov. was loaded on γ-Fe2O3 magnetic nanoparticle for the preconcentrations of Pb and Cd by solid phase extraction before ICP-OES. pH and flow rate of the solution, amounts of biosorbent and magnetic nanoparticle, volume of sample solution, effects of the possible interferic ions were investigated in details. Linear calibration curves were constructed in the concentration ranges of 1.0-60ngmL(-1) for Pb and Cd. The RSDs of the method were lower than 2.8% for Pb and 3.8% for Cd. Certified and standard reference samples of fortified water, wastewater, poplar leaves, and simulated fresh water were used to accurate the method. LOD values were found as 0.07 and 0.06ngmL(-1) respectively for Pb and Cd. The biosorption capacities were found as 34.3mgg(-1) for Pb and 37.1mgg(-1) for Cd. Pb and Cd concentrations in foods were determined. Surface microstructure was investigated by SEM-EDX.

Nesterenkonia aurantiaca sp. nov., an alkaliphilic actinobacterium isolated from Antarctica

A Gram-stain-positive, non-endospore-forming, haloalkaliphilic actinobacterium, strain CK5^T, 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-C_15 : 0 (64.8 %), iso-C_16 : 0 (13.3 %), n-C_17 : 0 (9.9 %), n-C_16 : 0 (4.0 %), n-C_14 : 0 (3.7 %) as major cellular fatty acids. The DNA G+C content was 64.8 mol%. Strain CK5^T, based on the 16S rRNA gene sequence similarity, was most closely related to Nesterenkonia jeotgali JG-241^T (99.5 %), Nesterenkonia sandarakina YIM 70009^T (99.4 %), Nesterenkonia lutea YIM 70081^T (99.4 %), Nesterenkonia halotolerans YIM 70084^T (99.3 %), Nesterenkonia xinjiangensis YIM 70097^T (97.2 %), Nesterenkonia flava CAAS 251^T (97.1 %) and Nesterekonia aethiopica CCUG 48939^T (97.1 %). Strain CK5^T revealed 31 % DNA-DNA relatedness with respect to N. sandarakina DSM 15664^T, 29 % with respect to N. jeotgali DSM 19081^T, 10 % with respect to N. lutea DSM 15666^T and 1 % with respect to N. halotolerans, DSM 15474^T, N. xinjiangensis DSM 15475^T, N. aethiopica DSM 17733^T and N. flava DSM 19422^T. On the basis of 16S rRNA gene sequences, DNA-DNA hybridization and chemotaxonomic characteristics, strain CK5^T represents a novel species of the genus Nesterenkonia, for which the name Nesterenkonia aurantiaca sp. nov. is proposed. The type strain is CK5^T ( = DSM 27373^T = JCM 19723^T).

Role of Bacterial Exopolysaccharides as Agents in Counteracting Immune Disorders Induced by Herpes Virus

Extreme marine environments, such as the submarine shallow vents of the Eolian Islands (Italy), offer an almost unexplored source of microorganisms producing unexploited and promising biomolecules for pharmaceutical applications. Thermophilic and thermotolerant bacilli isolated from Eolian vents are able to produce exopolysaccharides (EPSs) with antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2). HSV-2 is responsible for the most common and continuously increasing viral infections in humans. Due to the appearance of resistance to the available treatments, new biomolecules exhibiting different mechanisms of action could provide novel agents for treating viral infections. The EPSs hinder the HSV-2 replication in human peripheral blood mononuclear cells (PBMC) but not in WISH (Wistar Institute Susan Hayflic) cells line, indicating that cell-mediated immunity was involved in the antiviral activity. High levels of Th1-type cytokines were detected in PBMC treated with all EPSs, while Th2-type cytokines were not induced. These EPSs are water soluble exopolymers able to stimulate the immune response and thus contribute to the antiviral immune defense, acting as immunomodulators. As stimulants of Th1 cell-mediated immunity, they could lead to the development of novel drugs as alternative in the treatment of herpes virus infections, as well as in immunocompromised host.

Evaluation of heavy metals, cytotoxicity, and antioxidant activity of tomatoes grown in toxic muddy soils

This research studies tomatoes grown in polluted soils to ascertain their phytochemical and nutritive features. Pulp and seeds from tomatoes grown in muddy soils were analyzed for their antioxidant power and their toxicity because of the possibility that heavy metals were present in the soils. An antioxidant assay on methanol extracts was made by using DDPH, while an ABTS [2,2'-Azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid)] assay was used to evaluate the antioxidant activity of lipophilic fractions. Results of the antioxidant assay showed that the tomatoes maintained a high level of antioxidant activity especially in the lipophilic fractions which contain the most representative compounds. Cytotoxic activity was performed on HeLa, PDAC, and A375 cell lines by [3-(4,5-dimethylthiazol-2-yl)-2,5-phenyl-2H-tetrazolium bromide] (MTT) assay. Results showed that neither the seeds, nor the pulp, of the extracts was cytotoxic. The presence of heavy metals was evaluated by using spectroscopy of atomic absorption with a graphite oven. Test results show the absence of heavy metals and these results have an interesting scientific role because they provide useful information for promoting food safety.

Extremophiles survival to simulated space conditions: an astrobiology model study

In this work we investigated the ability of four extremophilic bacteria from Archaea and Bacteria domains to resist to space environment by exposing them to extreme conditions of temperature, UV radiation, desiccation coupled to low pressure generated in a Mars’ conditions simulator. All the investigated extremophilic strains (namely Sulfolobus solfataricus, Haloterrigena hispanica, Thermotoga neapolitana and Geobacillus thermantarcticus) showed a good resistance to the simulation of the temperature variation in the space; on the other hand irradiation with UV at 254 nm affected only slightly the growth of H. hispanica, G. thermantarcticus and S. solfataricus; finally exposition to Mars simulated condition showed that H. hispanica and G. thermantarcticus were resistant to desiccation and low pressure.

Degradative actions of microbial xylanolytic activities on hemicelluloses from rhizome of Arundo donax

Polysaccharidases from extremophiles are remarkable for specific action, resistance to different reaction conditions and other biotechnologically interesting features. In this article the action of crude extracts of thermophilic microorganisms (Thermotoga neapolitana, Geobacillus thermantarcticus and Thermoanaerobacterium thermostercoris) is studied using as substrate hemicellulose from one of the most interesting biomass crops, the giant reed (Arundo donax L.). This biomass can be cultivated without competition and a huge amount of rhizomes remains in the soil at the end of cropping cycle (10–15 years) representing a further source of useful molecules. Optimization of the procedure for preparation of the hemicellulose fraction from rhizomes of Arundo donax, is studied. Polysaccharidases from crude extracts of thermophilic microorganisms revealed to be suitable for total degradative action and/or production of small useful oligosaccharides from hemicelluloses from A. donax. Xylobiose and interesting tetra- and pentasaccharide are obtained by enzymatic action in different conditions. Convenient amount of raw material was processed per mg of crude enzymes. Raw hemicelluloses and pretreated material show antioxidant activity unlike isolated tetra- and pentasaccharide. The body of results suggest that rhizomes represent a useful raw material for the production of valuable industrial products, thus allowing to increase the economic efficiency of A. donax cultivation.

Antioxidant and cytotoxic activities investigation of tomato seed extracts

Biological activities of different varieties of tomato seed extracts were evaluated to verify the potential antioxidant and/or antiproliferative activity of the bioactive metabolites present in them. Findings demonstrated that among all the varieties investigated (San Marzano Rosso, San Marzano Giallo, Corbarino, Black Tomato and San Marzano/Black Tomato hybrid) San Marzano Rosso seed extract exhibited the highest free radical-scavenging activity with 68% of 2,2-Diphenyl-1-picrylhydrazyl radical inhibition, and the best cytotoxic activity evaluated by using the brine shrimp test (LD50: 23,198 ppm) and 3-(4,5-dimethylthiazol-2-yl)-2,5-phenyl-2H-tetrazolium bromide assay on A375 cell line (IC50: 137.7 μg/mL).

Bioactivity of tomato hybrid powder: antioxidant compounds and their biological activities

The antioxidant and cytotoxic activities and the polyphenolic and anthocyanin contents of tomato hybrid powders were studied. Tomato powders were obtained, starting from the fresh fruits that had undergone an industrial process of drying and pulverization at two different temperatures. Antioxidant activities were evaluated in different extracts by using spectrophotometric assays: 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid and N,N-dimethyl-p-phenylenediamine dihydrochloride cation radical inhibition for lipophilic and hydrophilic extracts, respectively, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay for polyphenolic extracts. Moreover, polyphenolic and anthocyanin contents were also carried out to detect the presence of these bioactive compounds. The effect of cytotoxic activity in vitro of tomato hybrid powder extracts on T47D (human breast carcinoma) cells was also evaluated. Results showed good antioxidant activities in lipophilic, polyphenolic, and hydrophilic extracts of samples that were obtained at a lower temperature. Extracts of the sample obtained at a higher temperature presented moderate antioxidant activity, lower than the extracts of other samples, which was probably due to the loss of labile antioxidant compounds during the industrial process. Very interesting was the presence of anthocyanins in both samples, even if in traces, and also a moderate cytotoxicity of a lipophilic extract on T47D cells. Therefore, tomato hybrid powders, on the basis of their multifunctional properties, could have a biotechnological application in agri-food or cosmetic industries as an additive for improving nutritional and/or bioactive qualities of commercial products used in daily nutrition and cosmetics.

The Lipid A from the haloalkaliphilic bacterium Salinivibrio sharmensis strain BAG(T)

Lipid A is a major constituent of the lipopolysaccharides (or endotoxins), which are complex amphiphilic macromolecules anchored in the outer membrane of Gram-negative bacteria. The glycolipid lipid A is known to possess the minimal chemical structure for LPSs endotoxic activity, able to cause septic shock. Lipid A isolated from extremophiles is interesting, since very few cases of pathogenic bacteria have been found among these microorganisms. In some cases their lipid A has shown to have an antagonist activity, i.e., it is able to interact with the immune system of the host without triggering a proinflammatory response by blocking binding of substances that could elicit such a response. However, the relationship between the structure and the activity of these molecules is far from being completely clear. A deeper knowledge of the lipid A chemical structure can help the understanding of these mechanisms. In this manuscript, we present our work on the complete structural characterization of the lipid A obtained from the lipopolysaccharides (LPS) of the haloalkaliphilic bacterium Salinivibrio sharmensis. Lipid A was obtained from the purified LPS by mild acid hydrolysis. The lipid A, which contains different number of fatty acids residues, and its partially deacylated derivatives were completely characterized by means of electrospray ionization Fourier transform ion cyclotron (ESI FT-ICR) mass spectrometry and chemical analysis.

Flocculating performances of exopolysaccharides produced by a halophilic bacterial strain cultivated on agro-industrial waste

This study reports the first systematic investigation of the flocculation dynamics of exopolysaccharides (EPSs) produced by a halophilic bacterial strain grown on pretreated molasses as fermentation substrate. The potential use of these EPSs as an easily biodegradable, natural alternative for synthetic polyelectrolytes which are widely used and contain toxic and carcinogenic monomers was investigated. Flocculating activities of the EPS samples in synthetic water, synthetic sea water and natural sea water media which were used as model raw waters were monitored via the Photometric Dispersion Analyser (PDA 2000) instrument and removals were determined by measuring residual turbidities. One of the six EPS specimens, which formed the largest flocs thus performed highest turbidity removal, exhibited flocculation performance and particle removal efficiency comparable with commercial cationic, nonionic and anionic synthetic polyelectrolytes.

Exopolysaccharides from extremophiles: from fundamentals to biotechnology

Exopolysaccharides (EPSs) make up a substantial component of the extracellular polymers surrounding most microbial cells in extreme environments like Antarctic ecosystems, saline lakes, geothermal springs or deep sea hydrothermal vents. The extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions, e.g. high temperatures, salt, low pH or temperature, high radiation. Among these adaptation strategies, EPS biosynthesis is one of the most common protective mechanisms. The unusual metabolic pathways revealed in some extremophiles raised interest in extremophilic microorganisms as potential producers of EPSs with novel and unusual characteristics and functional activities under extreme conditions. Even though the accumulated knowledge on the structural and theological properties of EPSs from extremophiles is still very limited, it reveals a variety in properties, which may not be found in more traditional polymers. Both extremophilic microorganisms and their EPSs suggest several biotechnological advantages, like short fermentation processes for thermophiles and easily formed and stable emulsions of EPSs from psychrophiles. Unlike mesophilic producers of EPSs, many of them being pathogenic, extremophilic microorganisms provide non-pathogenic products, appropriate for applications in the food, pharmaceutical and cosmetics industries as emulsifiers, stabilizers, gel agents, coagulants, thickeners and suspending agents. The commercial value of EPSs synthesized by microorganisms from extreme habitats has been established recently.

Chemical Composition of Two Exopolysaccharides from Bacillus thermoantarcticus

The thermophilic bacterium Bacillus thermoantarcticus produces two exocellular polysaccharides (EPS 1 and EPS 2), which can be obtained from the supernatant of liquid cultures by cold-ethanol precipitation, in yields as high as 400 mg liter(sup-1). The EPS fraction was produced with all substrates tested, although a higher yield was obtained with mannose as the carbon and energy source. The EPS content was proportional to the total biomass. On a weight basis, EPS 1 and EPS 2 represented about 27 and 71%, respectively, of the total carbohydrate fraction. EPS 1 is a sulfate heteropolysaccharide containing mannose and glucose in a relative molar proportion of 1.0 and 0.7, respectively. EPS 2 is a sulfate homopolysaccharide containing mannose as the major component. The absolute configurations of hexoses were shown to be d for both EPSs. Nuclear magnetic resonance spectra confirmed the presence of (alpha)-d-mannose and (beta)-d-glucose in EPS 1 and only (alpha)-d-mannose in EPS 2. In addition, (sup1)H nuclear magnetic resonance analysis and chemical analysis indicated the presence of pyruvic acid in EPS 2.

Bacterial exopolysaccharides from extreme marine habitats: production, characterization and biological activities

Many marine bacteria produce exopolysaccharides (EPS) as a strategy for growth, adhering to solid surfaces, and to survive adverse conditions. There is growing interest in isolating new EPS producing bacteria from marine environments, particularly from extreme marine environments such as deep-sea hydrothermal vents characterized by high pressure and temperature and heavy metal presence. Marine EPS-producing microorganisms have been also isolated from several extreme niches such as the cold marine environments typically of Arctic and Antarctic sea ice, characterized by low temperature and low nutrient concentration, and the hypersaline marine environment found in a wide variety of aquatic and terrestrial ecosystems such as salt lakes and salterns. Most of their EPSs are heteropolysaccharides containing three or four different monosaccharides arranged in groups of 10 or less to form the repeating units. These polymers are often linear with an average molecular weight ranging from 1 × 10⁵ to 3 × 10⁵ Da. Some EPS are neutral macromolecules, but the majority of them are polyanionic for the presence of uronic acids or ketal-linked pyruvate or inorganic residues such as phosphate or sulfate. EPSs, forming a layer surrounding the cell, provide an effective protection against high or low temperature and salinity, or against possible predators. By examining their structure and chemical-physical characteristics it is possible to gain insight into their commercial application, and they are employed in several industries. Indeed EPSs produced by microorganisms from extreme habitats show biotechnological promise ranging from pharmaceutical industries, for their immunomodulatory and antiviral effects, bone regeneration and cicatrizing capacity, to food-processing industries for their peculiar gelling and thickening properties. Moreover, some EPSs are employed as biosurfactants and in detoxification mechanisms of petrochemical oil-polluted areas. The aim of this paper is to give an overview of current knowledge on EPSs produced by marine bacteria including symbiotic marine EPS-producing bacteria isolated from some marine annelid worms that live in extreme niches.

Acetamide derivatives with antioxidant activity and potential anti-inflammatory activity

This study reports the synthesis and antioxidant activity of some new acetamide derivatives. The compounds' structures were elucidated by NMR analysis and their melting points were measured. The in vitro antioxidant activity of these compounds was tested by evaluating the amount of scavenged ABTS radical and estimating ROS and NO production in tBOH- or LPS-stimulated J774.A1 macrophages. All compounds were tested for their effect on cell viability by an MTT assay and by a Brine Shrimp Test.

Anoxybacillus thermarum sp. nov., a novel thermophilic bacterium isolated from thermal mud in Euganean hot springs, Abano Terme, Italy

A novel aerobe thermophilic endospore-forming bacterium designated strain AF/04(T) was isolated from thermal mud located in Euganean hot springs, Abano Terme, Padova, Italy. Strain AF/04(T) was Gram-positive, motile, rod-shaped, occurring in pairs, or filamentous. The isolate grew between 55 and 67 degrees C (optimum 65 degrees C) and at pH 6.0-7.5 (optimum pH 7.2). The strain was aerobic and grew on maltose, trehalose, and sodium acetate as sole carbon sources. The G + C content of DNA was 53.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AF/04(T) falls within the genus Anoxybacillus. Levels of 16S rRNA gene sequence similarity between strain AF/04(T) and the type strains of recognized Anoxybacillus species ranged from 95 to 99%. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid iso-C15:0 and anteiso-C17:0) supported the affiliation of strain AF/04(T) to the genus Anoxybacillus. Based on phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence analysis and DNA-DNA hybridization data, it was proposed that strain AF/04(T) (=DSM 17141(T) = ATCC BAA 1156(T)) should be placed in the genus Anoxybacillus as the type strain of a novel species, Anoxybacillus thermarum sp. nov.