Jeotgalicoccus coquinae sp. nov. and Jeotgalicoccus aerolatus sp. nov., isolated from poultry houses.

Two Gram-stain-positive, non-motile, non-spore-forming cocci (strains MK-7(T) and MPA-33(T)) were isolated from poultry houses. Strain MK-7(T) was isolated on marine broth agar from coquina, a food supplement for female ducks used in a duck-fattening farm. Strain MPA-33(T) was isolated from the air of a turkey house on TSA after filter sampling. On the basis of 16S rRNA gene sequence similarity studies, both strains were shown to belong to the genus Jeotgalicoccus; MK-7(T) was most closely related to Jeotgalicoccus psychrophilus YKJ-115(T) (99.3 % similarity) and MPA-33(T) was most closely related to Jeotgalicoccus halotolerans YKJ-101(T) (98.8 %). The quinone system of MK-7(T) was composed of equal amounts of menaquinones MK-7 and MK-6 and that of MPA-33(T) contained 76 % MK-7 and 24 % MK-6. The polar lipid profile of strain MK-7(T) consisted of the major compounds diphosphatidylglycerol and phosphatidylglycerol and six unidentified lipids present in minor to moderate amounts. In strain MPA-33(T), diphosphatidylglycerol was the single predominant lipid, whereas phosphatidylglycerol was detected in moderate amounts. In addition, one unidentified phospholipid and four unidentified lipids were detected. Fatty acid profiles with iso-15 : 0 and anteiso-15 : 0 as major fatty acids supported the affiliation of the strains to the genus Jeotgalicoccus. The results of physiological and biochemical tests as well as DNA-DNA hybridizations allowed clear phenotypic differentiation of strains MK-7(T) and MPA-33(T) from the most closely related species. Strains MK-7(T) and MPA-33(T) therefore represent novel species, for which the names Jeotgalicoccus coquinae sp. nov. (type strain MK-7(T) =DSM 22419(T) =CCM 7682(T) =CCUG 57956(T)) and Jeotgalicoccus aerolatus sp. nov. (type strain MPA-33(T) =DSM 22420(T) =CCM 7679(T) =CCUG 57953(T)) are proposed.

Leucobacter aerolatus sp. nov., from the air of a duck barn.

A Gram-positive, non-spore-forming actinobacterium (Sj 10(T)) was isolated on tryptone soy agar from the air of a duck barn after filter sampling. Based on 16S rRNA gene sequence similarity studies, strain Sj 10(T) was shown to belong to the genus Leucobacter and was closely related to Leucobacter chromiireducens subsp. chromiireducens L-1(T) (97.8 %), Leucobacter tardus DSM 19811(T) (97.3 %) and Leucobacter luti RF6(T) (97.3 %). The peptidoglycan of strain Sj 10(T) contained 2,4-diaminobutyric acid in combination with a lower amount of lysine as diagnostic diamino acids. In addition, threonine, glycine, alanine and glutamic acid were found. Menaquinone MK-11 was the major respiratory quinone; MK-12 and MK-10 were detected in minor amounts. The polar lipid pattern consisted of phosphatidylglycerol, diphosphatidylglycerol and one unknown component each of a phospholipid, glycolipid and aminoglycolipid. Strain Sj 10(T) contained the major fatty acids anteiso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0), like other members of the genus Leucobacter. Results of DNA-DNA hybridization, physiological and biochemical tests enabled strain Sj 10(T) to be differentiated genotypically and phenotypically from the most closely related Leucobacter species. Strain Sj 10(T) represents a novel species of the genus Leucobacter, for which the name Leucobacter aerolatus sp. nov. is proposed, with Sj 10(T) (=DSM 22806(T) =CCM 7705(T)) as the type strain.

Dietzia aerolata sp. nov., isolated from the air of a duck barn, and emended description of the genus Dietzia Rainey et al. 1995.

A Gram-stain-positive, coccoid, non-endospore-forming actinobacterium (Sj14a(T)) was isolated from the air of a duck barn on tryptone soy agar after filter sampling. On the basis of 16S rRNA gene sequence similarity studies, strain Sj14a(T) was shown to belong to the genus Dietzia and was most closely related to Dietzia schimae (98.7 %), Dietzia cercidiphylli (98.4 %) and Dietzia maris (98.6 %). The major menaquinone was MK-8 (H(2)). The polar lipid profile included the major components diphosphatidylglycerol, phosphatidylglycerol, an unknown polar lipid and two unknown glycolipids. Phosphatidylinositol and two phosphatidylinositol mannosides, as well as several other unknown lipids, were also detected. The polyamine pattern contained the major compounds spermine and spermidine. The fatty acid profile, containing C(16 : 0), C(17 : 0), C(18 : 1)omega9c and 10-methyl C(18 : 0) as major fatty acids, supported the affiliation of strain Sj14a(T) to the genus Dietzia. The results of physiological and biochemical tests and DNA-DNA hybridizations allowed a clear phenotypic differentiation of strain Sj14a(T) from the most closely related species of the genus Dietzia. Strain Sj14a(T) represents a novel species, for which the name Dietzia aerolata sp. nov. is proposed, with the type strain Sj14a(T) (=DSM 45334(T) =CCM 7659(T)).

Castellaniella gen. nov., to accommodate the phylogenetic lineage of Alcaligenes defragrans, and proposal of Castellaniella defragrans gen. nov., comb. nov. and Castellaniella denitrificans sp. nov.

Comparative 16S rRNA gene sequence analysis indicates that two distinct sublineages exist within the genus Alcaligenes: the Alcaligenes faecalis lineage, comprising Alcaligenes aquatilis and A. faecalis (with the three subspecies A. faecalis subsp. faecalis, A. faecalis subsp. parafaecalis and A. faecalis subsp. phenolicus), and the Alcaligenes defragrans lineage, comprising A. defragrans. This phylogenetic discrimination is supported by phenotypic and chemotaxonomic differences. It is proposed that the A. defragrans lineage constitutes a distinct genus, for which the name Castellaniella gen. nov. is proposed. The type strain for Castellaniella defragrans gen. nov., comb. nov. is 54PinT (=CCUG 39790T = CIP 105602T = DSM 12141T). Finally, on the basis of data from the literature and new DNA-DNA hybridization and phenotypic data, the novel species Castellaniella denitrificans sp. nov. (type strain NKNTAUT = DSM 11046T = CCUG 39541T) is proposed for two strains previously identified as strains of A. defragrans.

Vertical distribution of the methanotrophic community after drainage of rice field soil.

Anoxic soils, such as flooded rice fields, are major sources of the greenhouse gas CH(4) while oxic upland soils are major sinks of atmospheric CH(4). Nevertheless, CH(4) is also consumed in rice fields where up to 90% of the produced CH(4) is oxidized in a narrow oxic zone around the rice roots and in the soil surface layer before it escapes into the atmosphere. After 1 day drainage of rice field soil, CH(4) oxidation was detected in the top 2-mm soil layers, but after 8 days drainage the zone of CH(4) oxidation extended to 8 mm depth. Simultaneously, the potential for CH(4) production decreased, but some production was still detectable after 8 days drainage throughout the soil profile. The vertical distribution of the methanotrophic community was also monitored after 1 and 8 days drainage using denaturing gradient gel electrophoresis after PCR amplification with primer sets targeting two regions on the 16S rRNA gene that are relatively specific for methylotrophic alpha- and gamma-Proteobacteria, and targeting two functional genes encoding subunits of key enzymes in all methanotrophs, i.e. the genes for the particulate methane monooxygenase (pmoA) and the methanol dehydrogenase (mxaF). Drainage stimulated the methanotrophic community. Eight days after drainage, new methanotrophic populations appeared and a distinct methanotrophic community developed. The population structure of type I and II methanotrophs was differently affected by drainage. Type II methanotrophs (alpha-Proteobacteria) were present throughout the soil core directly after drainage (1 day), and the community composition remained largely unchanged with depth. Only two new type II populations appeared after 8 days of drainage. Drainage had a more pronounced impact on the type I methanotrophic community (gamma-Proteobacteria). Type I populations were not or only weakly detected 1 day after drainage. However, after 8 days of drainage, a large diversity of type I methanotrophs were detected, altough they were not evenly distributed throughout the soil core but dominated at different depths. A distinct type I community structure had developed within each soil section between 0 and 20 mm soil depth, indicating the widening of suitable habitats for methanotrophs in the rice field soil within 1 week of drainage.

Molecular analyses of novel methanotrophic communities in forest soil that oxidize atmospheric methane.

Forest and other upland soils are important sinks for atmospheric CH(4), consuming 20 to 60 Tg of CH(4) per year. Consumption of atmospheric CH(4) by soil is a microbiological process. However, little is known about the methanotrophic bacterial community in forest soils. We measured vertical profiles of atmospheric CH(4) oxidation rates in a German forest soil and characterized the methanotrophic populations by PCR and denaturing gradient gel electrophoresis (DGGE) with primer sets targeting the pmoA gene, coding for the alpha subunit of the particulate methane monooxygenase, and the small-subunit rRNA gene (SSU rDNA) of all life. The forest soil was a sink for atmospheric CH(4) in situ and in vitro at all times. In winter, atmospheric CH(4) was oxidized in a well-defined subsurface soil layer (6 to 14 cm deep), whereas in summer, the complete soil core was active (0 cm to 26 cm deep). The content of total extractable DNA was about 10-fold higher in summer than in winter. It decreased with soil depth (0 to 28 cm deep) from about 40 to 1 microg DNA per g (dry weight) of soil. The PCR product concentration of SSU rDNA of all life was constant both in winter and in summer. However, the PCR product concentration of pmoA changed with depth and season. pmoA was detected only in soil layers with active CH(4) oxidation, i.e., 6 to 16 cm deep in winter and throughout the soil core in summer. The same methanotrophic populations were present in winter and summer. Layers with high CH(4) consumption rates also exhibited more bands of pmoA in DGGE, indicating that high CH(4) oxidation activity was positively correlated with the number of methanotrophic populations present. The pmoA sequences derived from excised DGGE bands were only distantly related to those of known methanotrophs, indicating the existence of unknown methanotrophs involved in atmospheric CH(4) consumption.