Parageobacillus thermantarcticus, an Antarctic Cell Factory: From Crop Residue Valorization by Green Chemistry to Astrobiology Studies

Knowledge of Antarctic habitat biodiversity, both marine and terrestrial, has increased considerably in recent years, causing considerable development in the studies of life science related to Antarctica. In the Austral summer 1986–1987, a new thermophilic bacterium, Parageobacillus thermantarcticus strain M1 was isolated from geothermal soil of the crater of Mount Melbourne (74°22′ S, 164°40′ E) during the Italian Antarctic Expedition. In addition to the biotechnological potential due to the production of exopolysaccharides and thermostable enzymes, successful studies have demonstrated its use in the green chemistry for the transformation and valorization of residual biomass and its employment as a suitable microbial model for astrobiology studies. The recent acquisition of its genome sequence opens up new opportunities for the use of this versatile bacterium in still unexplored biotechnology sectors

Chemistry of tropical eucheumatoids: Potential for food and feed applications

The use of seaweeds as additives in animal nutrition may be a valid option to traditional feed as they represent a rich source of minerals, carbohydrates and antioxidants. The aim of this study was to analyze the chemical composition and in vitro antioxidant capacity of two tropical eucheumatoids, Kappaphycus alvarezii and Kappaphycus striatus, in Malaysian wild offshore waters. The chemical analysis was performed via inductively coupled plasma–optical emission spectroscopy for evaluating the concentration of toxic (Cd, Pb, Hg, As) and essential elements (Mn, Fe, Cu, Ni, Zn, Se); NMR spectroscopy was used for carrageenans investigation. Furthermore, the soluble and fat-soluble antioxidant capacities were determined by FRAP, DPPH and ABTS assays. The chemical analysis revealed a higher content of trace elements in K. alvarezii as compared to K. striatus, and both exhibited a high mineral content. No significant differences in metal concentrations were found between the two species. Both samples showed a mixture of prevailing κ-and t-carrageenans. Finally, the levels of soluble and fat-soluble antioxidants in K. alvarezii were significantly higher than in K. striatus. Our findings suggest that K. alvarezii could be used as a potential feed additive because of its favorable chemical and nutritional features

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

Comparative fatty acid profiling of edible fishes in Kuala Terengganu, Malaysia.

The aim of this study was to compare the relative nutritional benefit of edible Malaysian fishes from the coast of Terengganu in Malaysia, as well as to perform a taxonomical characterization and metal assessment. Discrimination between species was carried out by a morphological and molecular approach, by evaluating the total concentrations of metals by ICP-MS analyses and the fatty acids (FA) composition using the GC–MS approach on the fish fillet tissues. The taxonomical studies detected fishes of 11 families and 13 species. The heavy metal assessment showed that all detected elements did not exceed the regulatory limit stated by Malaysian Food Regulations. The proportion of saturated fatty acids (SFA) ranged from 33 to 58.34%, followed by the polyunsaturated fatty acids (PUFA) values from 24 to 51.8%, and the lowest proportion was of monounsaturated fatty acids (MUFA), ranging from 12.7 to 35.9%. The ω-3/ω-6 PUFA and PUFA/SFA ratios were determined in the range 1.1 to 7.4 and 0.35 to 1.6, respectively. The C20:5 ω-3 and C22:6 ω-3 acids were detected at levels comparable to those found in the corresponding species from similar tropical marine ecosystems. The high FA values can be useful biochemical tools for comparing the relative nutritional benefits of these biodiverse and non-toxic edible Malaysian fishe

Fatty Acids in Waste Tissues: The Nutraceutical Value of Gonads and Livers from the Moroccan Hypophthalmichthys molitrix and Cyprinus carpio Fishes

Fishes are an important component of human nutrition, mainly acting as source of essential fatty acids in the prevention of cardiovascular disorders. The increase in their consumption has led to a growth of fishes waste; therefore, the disposal and recycling of waste has become a key issue to address, in accordance with circular economy principles. The Moroccan Hypophthalmichthys molitrix and Cyprinus carpio fishes, living in freshwater and marine environments, were collected at mature and immature stages. The fatty acid (FA) profiles of liver and ovary tissues were investigated by GC-MS and compared with edible fillet tissues. The gonadosomatic index, the hypocholesterolemic/hypercholesterolemic ratio, and the atherogenicity and thrombogenicity indexes were measured. Polyunsaturated fatty acids were found to be abundant in the mature ovary and fillet of both species, with a polyunsaturated fatty acids/saturated fatty acids ratio ranging from 0.40 to 1.06 and a monounsaturated fatty acids/polyunsaturated fatty acids ratio between 0.64 and 1.84. Saturated fatty acids were found to be highly abundant in the liver and gonads of both species (range 30-54%), as well as monounsaturated fatty acids (range 35-58%). The results suggested that the exploitation of fish wastes, such as the liver and ovary, may represent a sustainable strategy for the achievement of high value-added molecules with nutraceutical potential

Chemoenzymatic preparation of α-6-sulfoquinovosyl-1,2-O-diacylglycerols

Synthesis of a-6-sulfoquinovosyl-1,2-O-diacylglycerols is achieved by a versatile chemo-enzymatic stereoselective procedure that involves the use of a-D-glucosidase activity from the Mediterranean mollusc Aplysia fasciata. The synthetic procedure is designed to obtain a wide diversity of regio- and stereo-isomers of these compounds that have gained great interest as antineoplastic agents and potent inhibitors of DNA polymerases

Terpene biosynthesis in the nudibranch Doriopsilla areolata

Biogenesis of the enantiomeric sesquiterpenes 1 and 5 of the marine nudibranch Doriopsilla areolata was investigated by feeding of [1-13C]glucose, [1,2-13C2]glucose, and [1,2-13C2]acetate. Evidence is presented that supports de novo origin of both compounds via mevalonic acid

Enzymatic synthesis and 3-D structure of anti-proliferative acidic (MeGlcUA) xylotetrasaccharide

Anomerically free acidic xylo-oligosaccharides have shown interesting biological properties when tested against Gram-positive and Gram-negative aerobically grown bacteria, as well as against Helicobacter pylori, sarcoma-180 and other tumors. We report here a structure-activity relationship study on the role of 4-O-methyl glucuronic acid (MeGlcUA) in regulating aggregation of beta-polyxylosides of (9H-fluoren-9-yl)- methanol obtained via the action of Thermotoga neapolitana xylanase. Neutral compounds from mono- to penta-beta-1,4 xylosides were obtained from this biocatalyzed reaction. In addition. acidic components among products, carrying an alpha-1,2 4-O-methyl glucuronic acid (MeGlcUA) were also isolated. An anti-proliferative test of these compounds on human epithelial EFO 27 ovarian cancer cells indicated that the presence of MeGlcUA modulates their biological activity, while its absence induces molecular aggregation. The three-dimensional structure of the most active MeGlcUA beta-polyxyloside was investigated by resorting to NOESY experiments supported by dynamic force-field calculations with/without constraints. The 3D structure is characterized by all sugars possessing a (4)C(1) chair conformation. The MeGlcUA moiety, and the external and middle xyloses adopt a hairpin-shaped conformation, generating a non-planar arrangement of the molecule with the aromatic ring folding back toward the carbohydrate chain. Such a non-planar conformation may justify the lack of aggregation

Biogenesis of 3-alkylpyridine alkaloids in the marine mollusc Haminoea Orbignyana

Das gemeinsame Motiv der marinen Naturstoffklasse der Alkylpyridin-Alkaloide ist ein Stickstoffheterocyclus mit einem Alkylsubstituenten in 3-Stellung. Diese Zuschrift liefert die ersten experimentellen Hinweise zur Biosynthese dieser Verbindunge