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Laboratory experiments have confirmed that the radiolytic decay rate of astrochemical ice analogues is dependent upon the solid phase of the target ice, with some crystalline molecular ices being more radio-resistant than their amorphous counterparts. The degree of radio-resistance exhibited by crystalline ice phases is dependent upon the nature, strength, and extent of the intermolecular interactions that characterise their solid structure. For example, it has been shown that crystalline CH3OH decays at a significantly slower rate when irradiated by 2 keV electrons at 20 K than does the amorphous phase due to the stabilising effect imparted by the presence of an extensive array of strong hydrogen bonds. These results have important consequences for the astrochemistry of interstellar ices and outer Solar System bodies, as they imply that the chemical products arising from the irradiation of amorphous ices (which may include prebiotic molecules relevant to biology) should be more abundant than those arising from similar irradiations of crystalline phases. In this present study, we have extended our work on this subject by performing comparative energetic electron irradiations of the amorphous and crystalline phases of the sulphur-bearing molecules H2S and SO2 at 20 K. We have found evidence for phase-dependent chemistry in both these species, with the radiation-induced exponential decay of amorphous H2S being more rapid than that of the crystalline phase, similar to the effect that has been previously observed for CH3OH. For SO2, two fluence regimes are apparent: a low-fluence regime in which the crystalline ice exhibits a rapid exponential decay while the amorphous ice possibly resists decay, and a high-fluence regime in which both phases undergo slow exponential-like decays. We have discussed our results in the contexts of interstellar and Solar System ice astrochemistry and the formation of sulphur allotropes and residues in these settings.

We present a dedicated experimental study of microscopic mechanisms controlling radiolysis and sputtering of astrophysical ices upon bombardment by cosmic-ray ions. Such ions are slowed down owing to inelastic collisions with bound electrons, resulting in ionization and excitation of ice molecules. In experiments on CO ice irradiation, we show that the relative contribution of these two mechanisms of energy loss to molecule destruction and sputtering can be probed by selecting ion energies near the peak of the electronic stopping power. We have observed a significant asymmetry, in both the destruction cross section and the sputtering yield, for pairs of ion energies corresponding to the same values of the stopping power on either side of the peak. This implies that the stopping power does not solely control these processes, as usually assumed in the literature. Our results suggest that electronic excitations represent a significantly more efficient channel for radiolysis and, likely, for sputtering of CO ice. We also show that the charge state of incident ions and the rate for CO ^+ production in the ice have a negligible effect on these processes.

Here we present the first Vacuum UltraViolet (VUV) photoabsorption spectra of ice analogues of Pluto and Charon ice mixtures. For Pluto the ice analogue is an icy mixture containing nitrogen (N 2 ), carbon monoxide (CO), methane (CH 4 ) and water (H 2 O) prepared with a 100:1:1:3 ratio, respectively. Photoabsorption of icy mixtures with and without H 2 O were recorded and no significant changes in the spectra due to presence of H 2 O were observed. For Charon a VUV photoabsorption spectra of an ice analogue containing ammonia (NH 3 ) and H 2 O prepared with a 1:1 ratio was recorded, a spectrum of ammonium hydroxide (NH 4 OH) was also recorded. These spectra may help to interpret the P-Alice data from New Horizons., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A novel Gram-stain-positive, aerobic, endospore-forming, non-motile, rod-shaped bacterium (strain JC229T) was isolated from a water sample collected from waterlogged alkaline soil. Strain JC229T was oxidase- and catalase-positive. Based on 16S rRNA gene sequence analysis, strain JC229T was identified as belonging to the genus Alteribacillus of the phylum Firmicutes and was found to be most closely related to Alteribacillus bidgolensis P4BT (97.9 % similarity), Bacillus iranensis X5BT (97.2 %) and Alteribacillus persepolensis HS136T (96.6 %), and more distantly related to other members of the genus Bacillus (<95.2 %). Strain JC229T was further identified to be distinctly related to the type strains of A. bidgolensis and B. iranensis (<26 % based on DNA-DNA hybridization and ΔTm of >5 °C). Strain JC229T grew optimally at pH 8 (range 5-11), at 35-40 °C (range 20-50 °C) and at a salinity of 3-5 % (range 0.5-24 %). The DNA G+C content was 40.2 mol%. Major cellular fatty acids of strain JC229T were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant quinone system was menaquinone 7. Polar lipids of strain JC229T included diphosphatidylglycerol, phosphatidylglycerol and two unidentified lipids. On the basis of morphological, physiological, genetic, phylogenetic and chemotaxonomic analyses, strain JC229T should be assigned to a novel species of the genus Alteribacillus, for which the name Alteribacillus alkaliphilus sp. nov. is proposed. The type strain is JC229T (=LMG 28999T=KCTC 33726T). It is also suggested to transfer B. iranensis to the genus Alteribacillus as Alteribacillus iranensis comb. nov.

A Gram-stain-negative, diesel-oil-degrading, rod-shaped bacterium (designated JC234T) was isolated from a water sample collected from diesel-oil-contaminated backwaters in Kerala, India. Strain JC234T was oxidase- and catalase-positive, and grew at 20-35 °C and at pH 7-9. Cells contained bacteriochlorophyll-a, hydroxydemethylspheroidene and three unidentified carotenoids. Growth occurred under aerobic, microaerobic and phototrophic anaerobic conditions. Strain JC234T could utilize diesel-oil as a sole source of carbon and energy. Based on the 16S rRNA gene sequence analysis, strain JC234T belonged to the genus Hoeflea within the family Phyllobacteriaceae, and was closely related to Hoeflea alexandrii AM1V30T (98.1% 16S rRNA gene sequence similarity), Hoeflea halophila JG120-1T (97.6%) and other members of the genus Hoeflea ( < 96.4 ). Strain JC234T showed 22 ± 2% and 28 ± 1.5 % DNA-DNA hybridization with Hoeflea alexandrii KCTC 22096T and Hoeflea halophila KCTC 23107T, respectively. The DNA G+C content of strain JC234T was 54.3 mol %. The major cellular fatty acids were C18 : 1ω7c/C18 : 1ω6c, C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and phosphatidylglycerol were the major polar lipids. Strain JC234T contained Q10 as the predominant ubiquinone. On the basis of morphological, physiological, genetic, phylogenetic and chemotaxonomical analyses, we conclude that strain JC234T represents a novel species of the genus Hoeflea, for which the name Hoefleaolei sp. nov. is proposed. The type strain is JC234T ( = KCTC 42071T = LMG 28200T). An emended description of the genus Hoeflea is also provided.

A Gram-stain-positive, solvent-tolerating, aerobic, rod-shaped bacterium that formed terminal endospores was isolated from the organic solvent acetophenone. The strain, designated JC23T, was oxidase- and catalase-positive. The strain grew in the presence of a wide range of organic solvents with partition coefficients (log p values) between 1 and 4, which are exceptionally toxic to micro-organisms. Based on 16S rRNA gene sequence analysis, strain JC23T was identified as belonging to the genus Lysinibacillus and was most closely related to Lysinibacillus manganicus Mn1-7T (98.5 % similarity), L. massiliensis 440831T (97.2 %) and L. chungkukjangi 2RL3-2T (96.8 %). DNA-DNA relatedness of strain JC23T with the type strains of the closest species was <39 %. Strain JC23T grew chemo-organoheterotrophically with optimal growth at pH 7 (range pH 6-9) and at 35 °C (range 25-40 °C). The DNA G+C content was 41 mol%. Major cellular fatty acids of strain JC23T were iso-C15 : 0, iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The cell-wall peptidoglycan type was determined to be A4α (l-Lys-d-Asp), which is in agreement with the cell-wall characteristics of the genus Lysinibacillus. The predominant quinone system was MK-7. Polar lipids of strain JC23T included diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, β-gentiobiosyldiacylglycerol, two unidentified phospholipids and two unidentified lipids. On the basis of our morphological, physiological, genetic, phylogenetic and chemotaxonomic analyses, we conclude that strain JC23T should be assigned to a novel species of the genus Lysinibacillus, for which the name Lysinibacillus acetophenoni sp. nov. is proposed. The type strain is strain JC23T ( = CCUG 57911T = KCTC 13605T = NBRC 105754T = DSM 23394T).

Two Gram-stain-positive, diesel oil-degrading, solvent-tolerant, aerobic, endospore-forming, rod-shaped bacteria were isolated from a contaminated laboratory plate. Based on 16S rRNA gene sequence analysis, strains JC228(T) and JC279 were identified as belonging to the genus Bacillus within the family Bacillaceae of the phylum Firmicutes and were found to be most closely related to Bacillus carboniphilus JCM 9731(T) (98.1% 16S rRNA gene sequence similarity) and shared <96.0% 16S rRNA gene sequence similarity with other members of the genus Bacillus . The DNA-DNA hybridization value between the two strains was 88±2%. Strain JC228(T) showed 23.4±1% reassociation (based on DNA-DNA hybridization) with B. carboniphilus LMG 18001(T). The DNA G+C content of strains JC228(T) and JC279 was 39 and 38.4 mol%, respectively. Both strains were positive for catalase and oxidase activities, and negative for hydrolysis of starch and Tween 80. Strains JC228(T) and JC279 grew chemoorganoheterotrophically with optimum growth at pH 7 (range pH 7-9.5) and 35 °C (range 25-40 °C). Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified phospholipid (PL2) were the major polar lipids. Major cellular fatty acids were iso-C(15 : 0), anteiso-C(15 : 0), iso-C(17 : 0) and C(16 : 0). Whole-cell hydrolysates contained l-alanine, d-alanine, d-glutamic acid and meso-diaminopimelic acid. Both strains utilized diesel oil as sole carbon and energy source. The results of physiological, biochemical, chemotaxonomic and molecular analyses allowed clear differentiation of strains JC228(T) and JC279 from their closest phylogenetic neighbours. Therefore strains JC228(T) and JC279 represent a novel species of the genus Bacillus , for which the name Bacillus oleivorans sp. nov. is proposed. The type strain is JC228(T) ( = LMG 28084(T) = CCTCC AB 2013353(T))., (© 2015 IUMS.)

Two bacterial strains (JC109(T) and JC261) were isolated from a sediment sample collected from a shrimp cultivation pond in Tamil Nadu (India). Cells were Gram-stain-negative, motile rods. Both strains were positive for catalase and oxidase, hydrolysed Tween 80, and grew chemo-organoheterotrophically with an optimal pH of 6 (range pH 4-9) and at 30 °C (range 25-40 °C). Based on 16S rRNA gene sequence analysis, strains JC109(T) and JC261 were identified as belonging to the genus Alcanivorax with Alcanivorax dieselolei B-5(T) (sequence similarity values of 99.3 and 99.7%, respectively) and Alcanivorax balearicus MACL04(T) (sequence similarity values of 98.8 and 99.2%, respectively) as their closest phylogenetic neighbours. The 16S rRNA gene sequence similarity between strains JC109(T) and JC261 was 99.6%. The level of DNA-DNA relatedness between the two strains was 88%. Strain JC109(T) showed 31 ± 1 and 26 ± 2% DNA-DNA relatedness with A. dieselolei DSM 16502(T) and A. balearicus DSM 23776(T), respectively. The DNA G+C content of strains JC109(T) and JC261 was 54.5 and 53.4 mol%, respectively. Polar lipids of strain JC109(T) included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phospholipids and two unidentified lipids. The major fatty acids were C10:0, C12:0, C16:0, C12:0 3-OH, C16:1ω7c, C18:1ω7c and C19:0 cyclo ω8c. Both strains could utilize diesel oil and a variety of xenobiotics as carbon and energy sources. The results of physiological, biochemical, chemotaxonomic and molecular analyses allowed the clear differentiation of strains JC109(T) and JC261 from all other members of the genus Alcanivorax. Strains JC109(T) and JC261 are thus considered to represent a novel species, for which the name Alcanivorax xenomutans sp. nov. is proposed. The type strain is JC109(T) ( = KCTC 23751(T) = NBRC 108843(T))., (IUMS.)

Two strains (JC83, JC84(T)) of obligately anaerobic, H2S-producing bacteria were isolated from estuarine sediment samples collected from Gangasagar, West Bengal, India. Cells were Gram-stain-negative, non-motile rods. Both strains were positive for oxidase, negative for catalase, hydrolysed casein, reduced nitrate and utilized citrate. Both strains grew chemoorganoheterotrophically with optimal pH of 7-8 (range 7-10) and at 30 °C (range 25-37 °C). C16 : 1ω7c, C18 : 1ω7c, C16 : 0 and C12 : 0 were the major fatty acids of both strains with minor amounts of C14 : 0, C12 : 0 3-OH and C18 : 0. Polar lipids of both strains included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, phosphatidylcholine, phosphatidylinositol, an unidentified aminolipid (AL2), an unidentified phospholipid (PL2) and an unidentified lipid (L3). MK-6 was the major respiratory quinone. The DNA G+C content of strains JC83 and JC84(T) was 25.0 and 24.6 mol%, respectively. The strains showed DNA reassociation >85 % (86.0±0.5 %) (based on DNA-DNA hybridization). Based on 16S rRNA gene sequence analysis, both strains were identified as belonging to the family Campylobacteraceae of the class Epsilonproteobacteria with Arcobacter marinus CL-S1(T) (95.4 % sequence similarity) as their closest phylogenetic neighbour. On the basis of morphological, physiological and chemotaxonomic characteristics as well as phylogenetic analysis, strains JC83 and JC84(T) are considered to represent a novel species, for which the name Arcobacter anaerophilus sp. nov. is proposed. The type strain is JC84(T) ( = KCTC 15071(T) = MTCC 10956(T) = DSM 24636(T)). An emended description of the genus Arcobacter is provided.

A Gram-stain-positive, oxidase-negative, starch-hydrolysing, actinobacterium (strain JC82(T)) was isolated from a soda lake in Lonar, India. Based on 16S rRNA gene sequence similarity studies, strain JC82(T) belonged to the genus Georgenia and was most closely related to Georgenia muralis 1A-C(T) (96.8 %) and other members of the genus Georgenia (<96.5 %). The DNA G+C content of strain JC82(T) was 73.4 mol%. The cell-wall amino acids were alanine, glutamic acid and lysine with peptidoglycan type A4α. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, an unidentified lipid (L1) and an unidentified glycolipid (GL3). The predominant isoprenoid quinone was menaquinone MK-8(H(4)). Anteiso-C(15 : 0) was the predominant fatty acid and significant proportions of iso-C(14 : 0), C(14 : 0), C(16 : 0), iso-C(15 : 0) and iso-C(16 : 0) were also detected. Strain JC82(T) produced thermostable alkaline amylase. The results of physiological and biochemical tests allowed a clear phenotypic differentiation of strain JC82(T) from all other members of the genus Georgenia. Based on these data, strain JC82(T) represents a novel species of the genus Georgenia, for which the name Georgenia satyanarayanai sp. nov. is proposed. The type strain is JC82(T) ( = KCTC 19802(T) = NBRC 107612(T)).

An oval to rod-shaped, Gram-stain-negative, phototrophic bacterium, strain JA738(T), was isolated from a sediment sample collected from a pink pond. Strain JA738(T) was non-motile and had vesicular-type intracellular photosynthetic membranes. Bacteriochlorophyll a and carotenoids of the spheroidene series were present as the major photosynthetic pigments. Strain JA738(T) required thiamine and pantothenate for growth. The major cellular fatty acids were C(18 : 1)ω7c, C(18 : 1)ω5c, C(18 : 0) and C(18 : 1)ω7c11-methyl; minor amounts of C(10 : 0) 3-OH and C(16 : 0) were also present. The major quinone was Q-10 and major polar lipids were phosphatidylglycerol, phosphatidylethanolamine and two unidentified sulfolipids (SL1-2). Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA738(T) clustered with species of the genus Rhodovulum in the class Alphaproteobacteria. Strain JA738(T) was most closely related to Rhodovulum adriaticum DSM 2781(T) (96.4 % 16S rRNA gene sequence similarity) and other members of the genus Rhodovulum (<96.1 %). On the basis of phenotypic and molecular genetic evidence, it is proposed that strain JA738(T) should be classified as a novel species of the genus Rhodovulum for which the name Rhodovulum bhavnagarense sp. nov. is proposed. The type strain is JA738(T) ( = DSM 24766(T) = KCTC 15110(T)).