Long-term monitoring of soil microbiological activities in two forest sites in South tyrol in the italian alps.

We monitored microbiological properties in two forest sites over a period of 17 years (1993-2010) within the International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). The two study sites were located in South Tyrol in the Italian Alps at altitudes of 1,737 m a.s.l. (subalpine site IT01) and 570 m a.s.l. (submontane site IT02). Soil samples were collected in the late spring and autumn of 1993, 2000, and 2010, and were characterized by measuring respiration, key enzyme activities involved in the C, N, P, and S cycles and litter degradation, and the abundance of viable bacterial and fungal populations. Over the study period, an increase in mean annual air temperatures at both sites (+0.6°C and +0.8°C at IT01 and IT02, respectively) was calculated from trendlines. Significantly lower mean annual air temperatures, higher temperature fluctuations, and higher annual precipitation rates were observed at site IT01 than at site IT02. Subalpine site IT01 was characterized by significantly lower microbial activity (respiration, enzymes) and abundance than those at submontane site IT02. The year of sampling had a significant effect on all the parameters investigated, except for nitrification. Fungal abundance decreased consistently over the study period, while no consistent trend was noted among the other parameters investigated. Season only affected a few of the measured microbiological parameters: respiration and bacterial numbers were significantly higher in the spring than in the autumn, while the opposite was noted for xylanase and phosphatase activities. Soil fungi contributed essentially to xylanase and protease activities, while soil bacteria were mainly involved in degradation processes that required the activity of sulfatase.

Isolation and characterization of bacteria from ancient siberian permafrost sediment.

In this study, we isolated and characterized bacterial strains from ancient (Neogene) permafrost sediment that was permanently frozen for 3.5 million years. The sampling site was located at Mammoth Mountain in the Aldan river valley in Central Yakutia in Eastern Siberia. Analysis of phospolipid fatty acids (PLFA) demonstrated the dominance of bacteria over fungi; the analysis of fatty acids specific for Gram-positive and Gram-negative bacteria revealed an approximately twofold higher amount of Gram-negative bacteria compared to Gram-positive bacteria. Direct microbial counts after natural permafrost enrichment showed the presence of (4.7 ± 1.5) × 108 cells g-1 sediment dry mass. Viable heterotrophic bacteria were found at 0 °C, 10 °C and 25 °C, but not at 37 °C. Spore-forming bacteria were not detected. Numbers of viable fungi were low and were only detected at 0 °C and 10 °C. Selected culturable bacterial isolates were identified as representatives of Arthrobacter phenanthrenivorans, Subtercola frigoramans and Glaciimonas immobilis. Representatives of each of these species were characterized with regard to their growth temperature range, their ability to grow on different media, to produce enzymes, to grow in the presence of NaCl, antibiotics, and heavy metals, and to degrade hydrocarbons. All strains could grow at -5 °C; the upper temperature limit for growth in liquid culture was 25 °C or 30 °C. Sensitivity to rich media, antibiotics, heavy metals, and salt increased when temperature decreased (20 °C > 10 °C > 1 °C). In spite of the ligninolytic activity of some strains, no biodegradation activity was detected.

Devosia psychrophila sp. nov. and Devosia glacialis sp. nov., from alpine glacier cryoconite, and an emended description of the genus Devosia.

Two psychrophilic strains, Cr7-05(T) and Cr4-44(T), isolated from alpine glacier cryoconite, were characterized by using a polyphasic approach. Both strains were psychrophilic, showing good growth over a temperature range of 1-20 °C. The chemotaxonomic characteristics of these isolates included the presence of C(18:1)ω7c and summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c) as the major cellular fatty acids, Q-10 as the predominant ubiquinone and diphosphatidylglycerol, phosphatidylglycerol and unknown glycolipids as major polar lipids. The DNA G+C contents of strains Cr7-05(T) and Cr4-44(T) were 61.4 and 63.6 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belong to the genus Devosia. The 16S rRNA gene sequence similarity between the two strains was 98.6%, but DNA-DNA hybridization indicated 54% relatedness. Strains Cr7-05(T) and Cr4-44(T) exhibited 16S rRNA gene sequence similarity of 94.7-97.2 and 94.9-96.9%, respectively, to the type strains of recognized Devosia species. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strains Cr7-05(T) and Cr4-44(T) represent two novel species within the genus Devosia, for which the names Devosia psychrophila sp. nov. (type strain Cr7-05(T) =DSM 22950(T) =CGMCC 1.10210(T) =CIP 110130(T)) and Devosia glacialis sp. nov. (type strain Cr4-44(T) =CGMCC 1.10691(T) =LMG 26051(T)) are proposed. An emended description of the genus Devosia is also provided.

Nocardioides alpinus sp. nov., a psychrophilic actinomycete isolated from alpine glacier cryoconite.

A gram-positive, non-motile, rod-shaped, psychrophilic actinomycete, designated strain Cr7-14(T), was isolated from alpine glacier cryoconite. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cr7-14(T) was related to members of the genus Nocardioides and shared highest 16S rRNA gene sequence similarities with the type strains of Nocardioides furvisabuli (98.6 %), Nocardioides ganghwensis (98.2 %), Nocardioides oleivorans (98.1 %) and Nocardioides exalbidus (97.6 %). The predominant cellular fatty acids of strain Cr7-14(T) were C(17 : 1)ω8c (39.5 %) and iso-C(16 : 0) (32.4 %). The major menaquinone was MK-8(H(4)). The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The predominant cell-wall sugars were galactose and rhamnose. The polar lipid pattern contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, four unknown glycolipids and two unknown polar lipids. The genomic DNA G+C content was 71.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, a novel species, Nocardioides alpinus sp. nov., is proposed, with Cr7-14(T) ( = DSM 23325(T) = LMG 26053(T) = CGMCC 1.10697(T)) as the type strain.

Arthrobacter cryoconiti sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.

A Gram-stain-positive, aerobic, non-motile, psychrophilic bacterium, designated strain Cr6-08(T), was isolated from alpine glacier cryoconite. Growth of strain Cr6-08(T) occurred at 1-25 °C. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain Cr6-08(T) is most closely related to members of the genus Arthrobacter. Strain Cr6-08(T) possessed chemotaxonomic properties consistent with those of the genus Arthrobacter, such as peptidoglycan type A3α (l-Lys-L-Ala(4)), MK-9(H(2)) as major menaquinone and anteiso- and iso-branched compounds (anteiso-C(15 : 0) and iso-C(15 : 0)) as major cellular fatty acids. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown glycolipid and three unknown polar lipids. The genomic DNA G+C content of strain Cr6-08(T) was 57.3 mol%. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain Cr6-08(T) is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter cryoconiti sp. nov. is proposed. The type strain is Cr6-08(T) ( = DSM 23324(T)  = LMG 26052(T)  = CGMCC 1.10698(T)).

Candidimonas bauzanensis sp. nov., isolated from soil, and emended description of the genus Candidimonas Vaz-Moreira et al. 2011.

A Gram-negative, facultatively anaerobic, psychrophilic, motile rod, designated BZ59(T), was isolated from hydrocarbon-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ59(T) belonged to the genus Candidimonas and had highest 16S rRNA gene sequence similarity with Candidimonas nitroreducens SC-089(T) (97.7 %) and Candidimonas humi SC-092(T) (97.6 %). The ubiquinone was Q-8 and the major fatty acids were C(16 : 0), C(17 : 0) cyclo and summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH). The polar lipid profile contained the major compounds phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamine and diphosphatidylglycerol. The major polyamines were putrescine and spermidine; a minor amount of 2-hydroxyputrescine was present. The DNA G+C content of strain BZ59(T) was 61.6 mol%. Combined data from phenotypic, phylogenetic and DNA-DNA relatedness studies demonstrated that strain BZ59(T) represents a novel species of the genus Candidimonas, for which the name Candidimonas bauzanensis sp. nov. is proposed. The type strain is BZ59(T) (= DSM 22805(T) = LMG 26046(T) = CGMCC 1.10190(T)). The description of the genus Candidimonas is emended.

Cultured bacterial diversity and human impact on alpine glacier cryoconite.

The anthropogenic effect on the microbial communities in alpine glacier cryoconites was investigated by cultivation and physiological characterization of bacteria from six cryoconite samples taken at sites with different amounts of human impact. Two hundred and forty seven bacterial isolates were included in Actinobacteria (9%, particularly Arthrobacter), Bacteroidetes (14%, particularly Olleya), Firmicutes (0.8%), Alphaproteobacteria (2%), Betaproteobacteria (16%, particularly Janthinobacterium), and Gammaproteobacteria (59%, particularly Pseudomonas). Among them, isolates of Arthrobacter were detected only in samples from sites with no human impact, while isolates affiliated with Enterobacteriaceae were detected only in samples from sites with strong human impact. Bacterial isolates included in Actinobacteria and Bacteroidetes were frequently isolated from pristine sites and showed low maximum growth temperature and enzyme secretion. Bacterial isolates included in Gammaproteobacteria were more frequently isolated from sites with stronger human impact and showed high maximum growth temperature and enzyme secretion. Ecotypic differences were not evident among isolates of Janthinobacterium lividum, Pseudomonas fluorescens, and Pseudomonas veronii, which were frequently isolated from sites with different degrees of anthropogenic effect.

Tistrella bauzanensis sp. nov., isolated from soil.

A Gram-reaction-negative, strictly aerobic, motile, rod-shaped bacterium, designated strain BZ78(T), was isolated from soil from an industrial site. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ78(T) belonged to the family Rhodospirillaceae and formed a coherent cluster with the type strain of Tistrella mobilis (98.3 % pairwise similarity). The predominant cellular fatty acids of strain BZ78(T) were C18:1ω7c (58.3 %), C19:0ω8c cyclo (11.5 %), C18:1 2-OH (10.9 %) and C14:0 3-OH (6.4 %). The predominant ubiquinone was Q-10. The genomic DNA G+C content of strain BZ78(T) was 65.8 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain BZ78(T) is considered to represent a novel species of the genus Tistrella, for which the name Tistrella bauzanensis sp. nov. is proposed. The type strain is BZ78(T) ( = DSM 22817(T)  = CGMCC 1.10188(T)  = LMG 26047(T)).

Glaciimonas immobilis gen. nov., sp. nov., a member of the family Oxalobacteraceae isolated from alpine glacier cryoconite.

Strains Cr9-30(T) and Cr9-12 were isolated from alpine glacier cryoconite. Both strains were Gram-negative-staining, non-motile, rod-shaped and psychrophilic, showing good growth over the temperature range 1-20 °C. Phylogenetic analysis of 16S rRNA gene sequences revealed that the two strains formed a distinct branch within the family Oxalobacteraceae and were most closely related to members of the genus Collimonas. The 16S rRNA gene sequence similarity between strains Cr9-30(T) and Cr9-12 was 99.0 %. The two strains showed highest 16S rRNA gene sequence pairwise similarity with Collimonas pratensis LMG 23965(T) (96.6 and 96.1 % for strains Cr9-30(T) and Cr9-12, respectively), Collimonas arenae LMG 23964(T) (96.5 and 96.3 %, respectively) and Collimonas fungivorans LMG 21973(T) (96.4 and 96.2 %, respectively). The predominant cellular fatty acids were summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH), C16:0 and C18:1ω7c. The DNA G+C content of strain Cr9-30(T) was 51.0 mol%. On the basis of phenotypic characteristics and phylogenetic analysis, strains Cr9-30(T) and Cr9-12 represent a novel species in a new genus of the family Oxalobacteraceae, for which the name Glaciimonas immobilis gen. nov., sp. nov. is proposed. The type strain of Glaciimonas immobilis is Cr9-30(T) ( = DSM 23240(T) = LMG 25547(T)).

Sphingomonas glacialis sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.

A non-motile, rod-shaped, yellow bacterium, designated C16y(T), was isolated from alpine glacier cryoconite. Cells behaved Gram-positively, were aerobic and psychrophilic (good growth at 1-25 °C). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain C16y(T) was related to the genus Sphingomonas and had highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082(T) (97.6  %) and Sphingomonas echinoides DSM 1805(T) (97.2  %). DNA-DNA hybridization demonstrated that strain C16y(T) could not be considered as a member of either Sphingomonas oligophenolica or Sphingomonas echinoides. Strain C16y(T) contained Q-10 as the predominant ubiquinone and C18:1 and C16:0 were the dominant fatty acids. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, five unidentified glycolipids, two unidentified aminophospholipids and two unidentified lipids. The major polyamines were the triamines sym-homospermidine and spermidine. The G+C content was 67.9 mol%. Combined data from phenotypic, phylogenetic and DNA-DNA relatedness studies demonstrated that strain C16y(T) is a representative of a novel species of the genus Sphingomonas, for which we propose the name Sphingomonas glacialis sp. nov. The type strain is C16y(T) (=DSM 22294(T) =CGMCC 1.8957(T) =CIP 110131(T) [corrected]).

Hymenobacter psychrophilus sp. nov., a psychrophilic bacterium isolated from soil.

A non-motile, rod-shaped, red-pigmented bacterium, designated strain BZ33r(T), was isolated from soil of an industrial site. Cells stained Gram-negative and were aerobic and psychrophilic, showing good growth at 1-20 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ33r(T) was related to members of the genus Hymenobacter and had highest sequence similarity with Hymenobacter aerophilus DSM 13606(T) (97.5 %). The predominant cellular fatty acids were anteiso-C(15 : 0) (20.3 %), summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH; 20.2 %), iso-C(15 : 0) (20.0 %), summed feature 4 (iso-C(17 : 1) I and/or anteiso-C(17 : 1) B; 8.2 %) and C(16 : 1)ω5c (7.9 %). Strain BZ33r(T) had MK-7 as the major menaquinone. The polyamine pattern contained sym-homospermidine as the major compound with moderate amounts of spermidine. Phosphatidylethanolamine, three unknown aminophospholipids, two unknown aminolipids, two unknown glycolipids and five unknown polar lipids were present in the polar lipid profile. The G+C content of the DNA was 61.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain BZ33r(T) is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter psychrophilus sp. nov. is proposed. The type strain is BZ33r(T) ( = DSM 22290(T)  = CGMCC 1.8975(T)  = LMG 25548(T)).

Pseudomonas bauzanensis sp. nov., isolated from soil.

A Gram-negative, aerobic, motile rod, designated BZ93(T), was isolated from soil from an industrial site. The strain grew at 5-30 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ93(T) was related to members of the genus Pseudomonas and was related most closely to Pseudomonas xiamenensis C10-2(T) (97.8 % 16S rRNA gene sequence similarity) and Pseudomonas pertucinogena IFO 14163(T) (97.4 %). The predominant cellular fatty acids of strain BZ93(T) were C(18 : 1)ω7c (54.8 %), summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH; 10.3 %), C(16 : 0) (9.9 %) and C(17 : 0) cyclo (7.4 %). The major quinone was ubiquinone 9. The major phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown phospholipid. The genomic DNA G+C content was 61.8 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness, a novel species, Pseudomonas bauzanensis sp. nov., is proposed. The type strain is BZ93(T) ( = DSM 22558(T)  = CGMCC 1.9095(T) = LMG 26048(T)).

Arthrobacter alpinus sp. nov., a psychrophilic bacterium isolated from alpine soil.

An aerobic, Gram-reaction-positive, non-motile, psychrophilic bacterium, designated strain S6-3(T), was isolated from alpine soil. Cells exhibited a rod-coccus growth cycle and produced a yellow pigment. Growth occurred at 1-25 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S6-3(T) was related to members of the genus Arthrobacter, sharing highest sequence similarities with the type strains of Arthrobacter psychrolactophilus (97.9 %) and Arthrobacter stackebrandtii (97.6 %). Strain S6-3(T) had MK-9(H(2)) as the major menaquinone and anteiso-C(15 : 0) as the major fatty acid. The cell-wall peptidoglycan was of type A3alpha l-Lys-l-Thr-Ala(3). The predominant cell-wall sugars were galactose and rhamnose. The genomic DNA G+C content of strain S6-3(T) was 61.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain S6-3(T) is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter alpinus sp. nov. is proposed. The type strain is S6-3(T) (=DSM 22274(T) =CGMCC 1.8950(T)).

Agromyces bauzanensis sp. nov., isolated from soil.

A Gram-stain-positive, aerobic bacterium, designated strain BZ41(T), was isolated from hydrocarbon-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ41(T) was related to members of the genus Agromyces and showed highest similarity with the type strain of Agromyces ramosus (96.8 %). The morphological, biochemical and chemotaxonomic characteristics of the new isolate were consistent with the description of the genus Agromyces. The cell-wall peptidoglycan of strain BZ41(T) was of type B2γ and contained the amino acids 2,4-diaminobutyric acid, alanine, glycine and glutamic acid in an approximate molar ratio of 1.8 : 0.7 : 1.1 : 1.0. The predominant cell-wall sugars were galactose, glucose, mannose and rhamnose. Strain BZ41(T) had MK-12 and MK-11 as major menaquinones and contained anteiso-C15:0 and anteiso-C17:0 as major fatty acids. The genomic DNA G+C content of strain BZ41(T) was 69.7 mol%. On the basis of phenotypic characteristics and genotypic analysis, strain BZ41(T) is considered to represent a novel species of the genus Agromyces, for which the name Agromyces bauzanensis sp. nov. is proposed. The type strain is BZ41(T) (=DSM 22275(T) =CGMCC 1.8984(T)).

Dyadobacter psychrophilus sp. nov., a psychrophilic bacterium isolated from soil.

A Gram-negative, aerobic bacterium, designated strain BZ26(T), was isolated from hydrocarbon-contaminated soil. The strain was psychrophilic, showing good growth over a temperature range of 1-20 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ26(T) was related to members of the genus Dyadobacter and had highest 16S rRNA gene sequence similarity to Dyadobacter alkalitolerans 12116(T) (98.1 %), Dyadobacter koreensis KCTC 12537(T) (97.5 %) and Dyadobacter ginsengisoli Gsoil 043(T) (97.2 %). Strain BZ26(T) had MK-7 as the major menaquinone and summed feature 3 (C(16 : 1)omega7c/iso-C(15 : 0) 2-OH), C(16 : 1)omega5c and iso-C(15 : 0) as major fatty acids. The genomic DNA G+C content of strain BZ26(T) was 48.9 mol%. On the basis of phenotypic characteristics and genotypic analysis, strain BZ26(T) is considered to represent a novel species of the genus Dyadobacter, for which the name Dyadobacter psychrophilus sp. nov. is proposed. The type strain is BZ26(T) (=DSM 22270(T) =CGMCC 1.8951(T)).

Sphingopyxis bauzanensis sp. nov., a psychrophilic bacterium isolated from soil.

Strain BZ30(T) was isolated from hydrocarbon-contaminated soil. The Gram-negative, aerobic bacterium was psychrophilic and able to grow at temperatures ranging from 1 to 30 °C. The predominant cellular fatty acids of strain BZ30(T) were summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH) (37.4 %), C(18 : 1)ω7c (19.6 %), C(16 : 0) (8.2 %), C(14 : 0) 2-OH (8.0 %) and C(16 : 0) 2-OH (5.0 %). The predominant ubiquinone was Q-10. Major polar lipids were sphingoglycolipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. Spermidine was the major polyamine. The genomic DNA G+C content was 64.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain BZ30(T) belonged to the family Sphingomonadaceae of the α-4 group of the phylum Proteobacteria, and was related to the members of the genus Sphingopyxis, sharing the highest sequence similarities with the type strains of Sphingopyxis chilensis (98.3 %), S. witflariensis (98.2 %), S. taejonensis (97.4 %) and S. ginsengisoli (97.2 %). On the basis of the phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain BZ30(T) represents a novel species of the genus Sphingopyxis, for which the name Sphingopyxis bauzanensis is proposed. The type strain is BZ30(T) (=DSM 22271(T) =CGMCC 1.8959(T) =CIP 110136(T)).

Pedobacter bauzanensis sp. nov., isolated from soil.

A Gram-negative, aerobic, rod-shaped, non-motile bacterium, designated BZ42(T), was isolated from the soil of an industrial site. Strain BZ42(T) was able to grow at 5-25 °C. The major fatty acids were iso-C(15 : 0) (46.2 %), C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH (23.2 %) and iso-C(17 : 0) 3-OH (9.1 %). The predominant menaquinone was MK-7. The genomic DNA G+C content was 36.5 mol% (HPLC). 16S rRNA gene sequence phylogenetic analysis revealed that strain BZ42(T) was a member of the genus Pedobacter, family Sphingobacteriaceae, and 16S rRNA gene sequence similarities between strain BZ42(T) and the type strains of species of the genus Pedobacter with validly published names were 90.4-93.2 %. On the basis of phenotypic, chemotaxonomic and phylogenetic distinctiveness, strain BZ42(T) was considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter bauzanensis sp. nov. is proposed. The type strain is BZ42(T) (=DSM 22554(T) =CGMCC 1.10187(T) =CIP 110134(T)).

Luteimonas terricola sp. nov., a psychrophilic bacterium isolated from soil.

Strain BZ92r(T) was isolated from hydrocarbon-contaminated soil. Cells were Gram-negative, aerobic, rod-shaped and cold-adapted (growth at 1-25 degrees C). The major fatty acids were iso-C(15 : 0) (25.6 %), iso-C(17 : 1)omega9c (24.9 %), iso-C(11 : 0) (18.4 %) and iso-C(11 : 0) 3-OH (16.2 %). The predominant ubiquinone was ubiquinone-8. The genomic DNA G+C content was 72.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BZ92r(T) was a member of the genus Luteimonas (94.5-95.2 % 16S rRNA gene sequence similarity). On the basis of phenotypic, chemotaxonomic and phylogenetic distinctiveness, strain BZ92r(T) was considered to represent a novel species of the genus Luteimonas. The name Luteimonas terricola sp. nov. is proposed, with BZ92r(T) (=DSM 22344(T) =CGMCC 1.8985(T)) as the type strain.

Microbial communities and activities in alpine and subalpine soils.

Soil samples were collected along two slopes (south and north) at subalpine (1500-1900 m, under closed vegetation, up to the forest line) and alpine altitudes (2300-2530, under scattered vegetation, above the forest line) in the Grossglockner mountain area (Austrian central Alps). Soils were analyzed for a number of properties, including physical and chemical soil properties, microbial activity and microbial communities that were investigated using culture-dependent (viable heterotrophic bacteria) and culture-independent methods (phospholipid fatty acid analysis, FISH). Alpine soils were characterized by significantly (P<0.01) colder climate conditions, i.e. lower mean annual air and soil temperatures, more frost and ice days and higher precipitation, compared with subalpine soils. Microbial activity (soil dehydrogenase activity) decreased with altitude; however, dehydrogenase activity was better adapted to cold in alpine soils compared with subalpine soils, as shown by the lower apparent optimum temperature for activity (30 vs. 37 degrees C) and the significantly (P<0.01-0.001) higher relative activity in the low-temperature range. With increasing altitude, i.e. in alpine soils, a significant (P<0.05-0.01) increase in the relative amount of culturable psychrophilic heterotrophic bacteria, in the relative amount of the fungal population and in the relative amount of Gram-negative bacteria was found, which indicates shifts in microbial community composition with altitude.

On-line monitoring of microbial volatile metabolites by proton transfer reaction-mass spectrometry.

A method for analysis of volatile organic compounds (VOCs) from microbial cultures was established using proton transfer reaction-mass spectrometry (PTR-MS). A newly developed sampling system was coupled to a PTR-MS instrument to allow on-line monitoring of VOCs in the dynamic headspaces of microbial cultures. The novel PTR-MS method was evaluated for four reference organisms: Escherichia coli, Shigella flexneri, Salmonella enterica, and Candida tropicalis. Headspace VOCs in sampling bottles containing actively growing cultures and uninoculated culture medium controls were sequentially analyzed by PTR-MS. Characteristic marker ions were found for certain microbial cultures: C. tropicalis could be identified by several unique markers compared with the other three organisms, and E. coli and S. enterica were distinguishable from each other and from S. flexneri by specific marker ions, demonstrating the potential of this method to differentiate between even closely related microorganisms. Although the temporal profiles of some VOCs were similar to the growth dynamics of the microbial cultures, most VOCs showed a different temporal profile, characterized by constant or decreasing VOC levels or by single or multiple peaks over 24 h of incubation. These findings strongly indicate that the temporal evolution of VOC emissions during growth must be considered if characterization or differentiation based on microbial VOC emissions is attempted. Our study may help to establish the analysis of VOCs by on-line PTR-MS as a routine method in microbiology and as a tool for monitoring environmental and biotechnological processes.