Alterations in growth temperature range and fatty acid composition of Thermus as a result of plasmid elimination

Elimination of plasmids from Thermus flavus, T. thermophilus and three wild Thermus strains caused alterations in growth temperature range, pigmentation and membrane fatty acids without affecting viability. Following plasmid elimination all Thermus strains lost their ability to grow above 70°C. In addition, the minimum growth temperature was lowered by 5–10°C. Fatty acids were reduced by an average of approximately 35%. In addition, the contribution of iso- and anteisobranched fatty acids were altered in four of the five strains. The iso C_15:0/iso C_17:0 ratio approached 1.0 in all strains, whereas the anteiso C_15:0/anteiso C_17:0 was reduced to 0.2. The iso C_16:0/normal-C_16:0 ratio increased in all strains due to an increase in iso C_16:0 in four strains and a reduction in normal-C_16:0 relative to iso C_16:0 in one strain. However, it was evident that the plasmid-free strains were able to compensate for these alterations in membrane fluidity to a certain extent by reducing the average chain length of isobranched acids. Altered fatty acid metabolism at the level of precursors may have influenced membrane composition and consequently growth temperature range.     

Effect of Temperature on Fatty Acid Composition of a White Thermus Strain

A white Thermus sp. strain, NCIMB 11245, showed high levels of anteiso C_17:0, anteiso C_17:1, normal C_16:1, and iso C_16:0 with low levels of iso C_15:0 + iso C_17:0 in comparison to yellow-pigmented strains. The fatty acid composition may be associated with precursor metabolism or the absence of carotene pigmentation.     

Kytococcus aerolatus sp. nov., isolated from indoor air in a room colonized with moulds

A Gram-positive, coccoid bacterial isolate (02-St-019/1^T), forming beige pigmented colonies was obtained from an indoor air sample. Based on 16S rRNA gene sequence similarity studies it was determined that this isolate 02-St-019/1^T belonged to the genus Kytococcus, showing sequence similarties of 98.6% to Kytococcus schroeteri DSM 13884^T and 98.3% to Kytococcus sedentarius DSM 20547^T, respectively. The diagnostic diaminoacid of the peptidoglycan was lysine, cell wall sugars were ribose and xylose. The major menaquinones detected were MK-7 and MK-8. The polar lipid profile consisted of the major phospholipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine and phosphatidylinositol mannoside. Fatty acid patterns were composed of major amounts of the iso- and anteiso-branched fatty acids anteiso C_17:0, iso C_15:0 and iso C_17:0 and unsaturated fatty acids (C_17:1 ω8c, iso C_17:1 ω9c, and C_17:1 ω8c) with smaller amounts of the straight-chain fatty acids C_15:0, C_16:0 and C_17:0. The results of DNA–DNA hybridizations and physiological and biochemical tests clearly allowed a genotypic and phenotypic differentiation of strain 02-St-019/1^T from the two described Kytococcus species. On the basis of these results a novel species to be named Kytococcus aerolatus sp. nov., is proposed, with the type strain 02-St-019/1^T (=DSM 22179^T=CCM 7639^T).     

Identification and characterization of thermophilic bacteria isolated from hot springs in Turkey

The present study was conducted to identify and characterize the thermophilic bacteria isolated from various hot springs in Turkey by using phenotypic and genotypic methods including fatty acid methyl ester and rep-PCR profilings, and 16S rRNA sequencing. The data of fatty acid analysis showed the presence of 17 different fatty acids in 15 bacterial strains examined in this study. Six fatty acids, 15:0 iso, 15:0 anteiso, 16:0, 16:0 iso, 17:0 iso, and 17:0 anteiso, were present in all strains. The bacterial strains were classified into three phenotypic groups based on fatty acid profiles which were confirmed by genotypic methods such as 16S rRNA sequence analysis and rep-PCR genomic fingerprint profiles. After evaluating several primer sets targeting the repetitive DNA elements of REP, ERIC, BOX and (GTG)₅, the (GTG)₅ and BOXA1R primers were found to be the most reliable technique for identification and taxonomic characterization of thermophilic bacteria in the genera of Geobacillus, Anoxybacillus and Bacillus spp. Therefore, rep-PCR fingerprinting using the (GTG)₅ and BOXA1R primers can be considered as a promising genotypic tool for the identification and characterization of thermophilic bacteria from species to strain level.     

Role of fatty acids in cold adaptation of Antarctic psychrophilic Flavobacterium spp.

Cold-loving microorganisms developed numerous adaptation mechanisms allowing them to survive in extremely cold habitats, such as adaptation of the cell membrane. The focus of this study was on the membrane fatty acids of Antarctic Flavobacterium spp., and their adaptation response to cold-stress. Fatty acids and cold-response of Antarctic flavobacteria was also compared to mesophilic and thermophilic members of the genus Flavobacterium. The results showed that the psychrophiles produced more types of major fatty acids than meso- and thermophilic members of this genus, namely C_15:1 iso G, C_15:0 iso, C_15:0 anteiso, C_15:1 ω6c, C_15:0 iso 3OH, C_17:1 ω6c, C_16:0 iso 3OH and C_17:0 iso 3OH, summed features 3 (C_16:1 ω7cand/or C_16:1 ω6c) and 9 (C_16:0 10-methyl and/or C_17:1 iso ω9c). It was shown that the cell membrane of psychrophiles was composed mainly of branched and unsaturated fatty acids. The results also implied that Antarctic flavobacteria mainly used two mechanisms of membrane fluidity alteration in their cold-adaptive response. The first mechanism was based on unsaturation of fatty acids, and the second mechanism on de novo synthesis of branched fatty acids. The alteration of the cell membrane was shown to be similar for all thermotypes of members of the genus Flavobacterium.     

Exogenous Isoleucine and Fatty Acid Shortening Ensure the High Content of Anteiso-C15:0 Fatty Acid Required for Low-Temperature Growth of Listeria monocytogenes

Previous studies have demonstrated that the branched-chain fatty acid anteiso-C_15:0 plays a critical role in the growth of Listeria monocytogenes at low temperatures by ensuring sufficient membrane fluidity. Studies utilizing a chemically defined minimal medium revealed that the anteiso fatty acid precursor isoleucine largely determined the fatty acid profile and fatty acid response of the organism to lowered growth temperature. When isoleucine was sufficient, the fatty acid profile was very uniform, with anteiso fatty acids comprising up to 95% of total fatty acid, and the major fatty acid adjustment to low temperature was fatty acid chain shortening, which resulted in an increase of anteiso-C_15:0 solely at the expense of anteiso-C_17:0. When isoleucine was not supplied, the fatty acid profile became more complex and was readily modified by leucine, which resulted in a significant increase of corresponding iso fatty acids and an inability to grow at 10°C. Under this condition, the increase of anteiso-C_15:0 at low temperature resulted from the combined effect of increasing the anteiso:iso ratio and chain shortening. A branched-chain α-keto acid dehydrogenase-defective strain largely lost the ability to increase the anteiso:iso ratio. Cerulenin, an inhibitor of β-ketoacyl-acyl carrier protein synthase (FabF), induced a similar fatty acid chain shortening as low temperature did. We propose that the anteiso precursor preferences of enzymes in the branched-chain fatty acid biosynthesis pathway ensure a high production of anteiso fatty acids, and cold-regulated chain shortening results in a further increase of anteiso-C_15:0 at the expense of anteiso-C_17:0.     

Microbacterium suwonense sp. nov., isolated from cow dung

An actinomycete strain, designated M1T8B9^T, was isolated from cow dung in Suwon, Republic of Korea. The isolate was a Gram-positive, nonmotile, and non-spore-forming bacterium. Phylogenetic evaluation based on 16S rRNA gene sequence similarity showed that this isolate belongs to the genus Microbacterium, with its closest neighbors being Microbacterium soli DCY17^T (98.2%) and Microbacterium esteraromaticum DSM 8609^T (98.0%). The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, and one unknown glycolipid. Strain M1T8B9^T contained the major fatty acids C_15:0 anteiso, C_16:0 iso, C _17:0 anteiso, and C_15:0 iso, and the cell-wall peptidoglycan was of type B2β. According to DNA-DNA hybridization studies, strain M1T8B9^T showed 42% and 26% relatedness with M. soli DCY17^T and M. esteraromaticum DSM 8609^T, respectively. On the basis of the data presented, strain M1T8B9^T is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium suwonense sp. nov. is proposed. The type strain is M1T8B9^T (=KACC 14058^T =NBRC 106310^T).     

Fatty acid analysis as a chemotaxonomic tool for taxonomic and epidemiological characterization of four fish pathogenic Tenacibaculum species

Aims: In this work, fatty acid content and profiles were analysed in order to differentiate the species Tenacibaculum maritimum, Tenacibaculum gallaicum, Tenacibaculum discolor and Tenacibaculum ovolyticum that are pathogenic for cultured marine fish and to assess the potential of fatty acid profiles as a tool for epizootiological typing. Methods and Results: The fatty acid methylesters (FAMEs) were extracted from cells grown on marine agar for 48 h at 25°C and were prepared and analysed according to the standard protocol of the MIDI/Hewlett Packard Microbial Identification System. The cellular fatty acid profiles of Tenacibaculum strains tested were characterized by the presence of large amounts of branched (36·1–40·2%) and hydroxylated (29·6–31·7%) fatty acids. The FAME products from the four species significantly (P < 0·05) differed in the content of iso‐C_15:03‐OH, iso‐C_16:03‐OH, iso‐C_15:1G, summed feature 3 (a component that contains C_16:1ω7c and/or iso‐C_15:0 2‐OH), iso‐C_16:0, C_17:1ω6c, C_15:03‐OH, iso‐C_17:03‐OH. Conclusions: Results of present study demonstrated the existence of differences in the fatty acids content between the T. maritimum isolates from different marine fish/geographical origin and between strains of T. maritimum, T. discolor, T. gallaicum and T. ovolyticum. Significance and Impact of the Study: Profiling of fatty acids may be a useful tool to distinguish T. maritimum from other Tenacibaculum species pathogenic for fish as well as for epizootiological differentiation of T. maritimum isolates.     

Description of <Emphasis Type="Italic">Hymenobacter daejeonensis</Emphasis> sp. nov., isolated from grass soil,based on multilocus sequence analysis of the 16S rRNA gene, <Emphasis Type="Italic">gyr</Emphasis>B and <Emphasis Type="Italic">tuf</Emphasis> genes

A polyphasic taxonomic study was carried out on strains PB105^T and PB108 isolated from a grass soil in Korea. The cells of the strains were Gram-stain negative, non-spore-forming, non-motile, and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of these strains with Bacteroidetes, which showed high pairwise sequence similarities with Hymenobacter algoricola VUG-A23a^T (99.2%), Hymenobacter fastidiosus VUG-A124a^T (97.4%), and Hymenobacter daecheongensis Dae14^T (96.9%). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Hymenobacter. The major fatty acids were identified as C_15:0 iso, C_15:0 anteiso, C_16:1 ω5c, C_15:0 iso 3-OH, C_17:0 iso 3-OH, summed feature 3 (C_16:1 ω6c and/or C_16:1 ω7c/t), and summed feature 4 (C_17:1 anteiso B and/or C_17:1 iso I). The major cellular polar lipids were identified as phosphatidylethanolamine, an unidentified aminolipid, and two unidentified lipids. The respiratory quinone was identified as MK-7 and the genomic DNA G+C content was determined to be 64.5 mol% for strain PB105^T and 64.1 mol% for strain PB108. DNA–DNA hybridization value of type strain PB105^T with H. algoricola VUG-A23a^T was 32.3% (reciprocal 39.2). Based on the combined genotypic and phenotypic data, we propose that strains PB105^T and PB108 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter daejeonensis sp. nov. is proposed. The type strain is PB105^T (=?KCTC 52579^T?=?JCM 31885^T).     

Hymenobacter swuensis sp. nov., a Gamma-Radiation-Resistant Bacteria Isolated from Mountain Soil

Gram stain-negative and non-motile bacteria, designated as DY53^T and DY43, were isolated from mountain soil in South Korea prior exposure with 5 kGy gamma radiation. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strains belonged to the family Cytophagaceae in the class Cytophagia. 16S rRNA gene sequence similarity of strains DY53^T and DY43 was 100 %. The highest degrees of sequence similarities of strains DY53^T and DY43 were found with Hymenobacter perfusus A1-12^T (98.8 %), Hymenobacter rigui WPCB131^T (98.5 %), H. yonginensis HMD1010^T (97.9 %), H. xinjiangensis X2-1g^T (96.6 %), and H. gelipurpurascens Txg1^T (96.5 %). The DNA G+C content of the novel strains DY53^T and DY43 were 59.5 mol%. Chemotaxonomic data revealed that strains possessed major fatty acids such as C_15:0 iso, C_15:0 anteiso, C_16:1 ω5c, summed feature 3 (16:1 ω7c/ω6c), summed feature 4 (17:1 anteiso B/iso I) and C_17:0 iso, and major polar lipid was phosphatidylethanolamine. The novel strains showed resistance to gamma radiation, with a D10 value (i.e., the dose required to reduce the bacterial population by tenfold) in excess of 5 kGy. Based on these data, strains DY53^T and DY43 should be classified as representing a novel species, for which the name Hymenobacter swuensis sp. nov. is proposed, with the type strain DY53^T (=KCTC 32018^T = JCM 18582^T) and DY43 (=KCTC 32010).     

Exogenous isoleucine and fatty acid shortening ensure the high content of anteiso-C15:0 fatty acid required for low-temperature growth of Listeria monocytogenes

Previous studies have demonstrated that the branched-chain fatty acid anteiso-C15:0 plays a critical role in the growth of Listeria monocytogenes at low temperatures by ensuring sufficient membrane fluidity. Studies utilizing a chemically defined minimal medium revealed that the anteiso fatty acid precursor isoleucine largely determined the fatty acid profile and fatty acid response of the organism to lowered growth temperature. When isoleucine was sufficient, the fatty acid profile was very uniform, with anteiso fatty acids comprising up to 95% of total fatty acid, and the major fatty acid adjustment to low temperature was fatty acid chain shortening, which resulted in an increase of anteiso-C15:0 solely at the expense of anteiso-C17:0. When isoleucine was not supplied, the fatty acid profile became more complex and was readily modified by leucine, which resulted in a significant increase of corresponding iso fatty acids and an inability to grow at 10 degrees C. Under this condition, the increase of anteiso-C15:0 at low temperature resulted from the combined effect of increasing the anteiso:iso ratio and chain shortening. A branched-chain alpha-keto acid dehydrogenase-defective strain largely lost the ability to increase the anteiso:iso ratio. Cerulenin, an inhibitor of beta-ketoacyl-acyl carrier protein synthase (FabF), induced a similar fatty acid chain shortening as low temperature did. We propose that the anteiso precursor preferences of enzymes in the branched-chain fatty acid biosynthesis pathway ensure a high production of anteiso fatty acids, and cold-regulated chain shortening results in a further increase of anteiso-C15:0 at the expense of anteiso-C17:0.     

Virgibacillus natechei sp. nov., A Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in Southwest of Algeria

A novel, Gram-positive, moderately halophilic bacterium, oxidase- and catalase-positive designated FarD^T was isolated from sediments of a saline lake located in Taghit, 93 km from Bechar, southwest of Algeria. Cells were rod-shaped, endospore forming, and motile. Growth occurred at 15–40 °C (optimum, 35 °C), pH 6.0–12.0 (optimum, 7.0) and in the presence of 1–20 % NaCl (optimum, 10 %). Strain FarD^T used glucose, mannitol, melibiose, d-mannose, and 5 ketogluconate. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, and three phospholipids; MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C_15:0, anteiso C_17:0, C_20:0, and anteiso C_19:0. The DNA G+C content was 42.1 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA gene sequence indicated that strain FarD^T had as its closest relative Virgibacillus salinus (similarity of 96.3 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain FarD^T is proposed as a novel species of the genus Virgibacillus within the order Clostridiales, for which the name V. natechei is proposed. The type strain is FarD^T (=DSM 25609^T = CCUG 62224^T).     

Isolation and characterization of a protease-producing novel haloalkaliphilic bacterium <Emphasis Type="Italic">Halobiforma</Emphasis> sp. strain BNMIITR from Sambhar lake in Rajasthan,India

A novel haloalkaliphilic bacterium designated as strain BNMIITR was isolated from a soil sample collected from Sambhar lake, Rajasthan, in northern India. Colonies of the isolated strain were dark orange and comprised Gram-negative bacilli; there was a slight pleomorphism towards the stationary phase of growth. Experiments revealed that the isolate can grow in the range of 2–5 M NaCl, pH 6–11 and 18–55 °C, with optimum growth observed at 3 M NaCl, pH 8–8.5 and 45 °C. No growth was observed in culture medium without NaCl. The isolate showed no requirement for magnesium sulphate heptahydrate (MgSO₄ ^.7H₂O) for growth. Major cellular fatty acids were C _14:0, C _15:0 iso, C _15:0 anteiso, C _16:0, C _17:0 iso, C _17:0 anteiso and C _20:2 w6, 9c. The result of 16S rRNA gene sequence analysis showed 98 % sequence similarity with Halobiforma lacisalsi and Hbf. haloterrestris. Halobiforma sp. strain BNMIITR showed resistance towards several antibiotics and produced an extracellular alkaline protease. The crude enzyme was found to be active in broad range of alkaline pH and temperature (30–80 °C).     

Tepidanaerobacter acetatoxydans sp. nov., an anaerobic, syntrophic acetate-oxidizing bacterium isolated from two ammonium-enriched mesophilic methanogenic processes

Four anaerobic syntrophic acetate-oxidizing bacteria, the thermotolerant strains Re1^T, Re2, T1 and T2, were isolated from two different mesophilic methanogenic systems. The strains originate from sludge of a continuously stirred laboratory-scale reactor containing high levels of ammonium and from a high ammonium enrichment culture. Comparative 16S rRNA gene sequence analysis confirmed that the strains belong to the Firmicutes-Clostridia class. The most closely related species to strains Re1^T, Re2, T1 and T2 was Tepidanaerobacter syntrophicus, with a 16S rRNA gene sequence identity of 96%. The DNA-DNA relatedness of strains Re2, T1 and T2 to strain Re1^T was 92, 102, 81%, respectively. The gene encoding the acetogen key enzyme formyltetrahydrofolate synthetase (FTHFS) was detected and partly sequenced from the strains. In pure culture the bacteria used different organic compounds as carbon and energy source, such as organic acids, alcohols, sugars and amino acids. Furthermore, acetate-oxidizing ability was observed during co-cultivation with a hydrogen-consuming Methanoculleus sp. The bacteria were found to be spore-forming, rod-shaped and motile, and possessed Gram-positive cell walls. The four strains were thermotolerant and grew at temperatures between 25 and 55 °C. Strain Re1^T had a DNA G + C content of 38.4% and the major fatty acids were C_18:1 w7c, C_18:1 w9c, anteiso-C_17:0, C_16:1 w7c and C_18:0. The genetic and phenotypic properties of strains Re1^T, Re2, T1 and T2 suggest classification as representatives of a novel species of the genus Tepidanaerobacter; the name Tepidanaerobacter acetatoxydans sp. nov. is suggested. The type strain of T. acetatoxydans is Re1^T (=DSM 21804^T = JCM 16047^T).     

Physiology of Sporeforming Bacteria Associated with Insects II. Lipids of Vegetative Cells

Lipid composition was studied in two strains each of mid-log phase cells of Bacillus thuringiensis, B. larvae, B. popilliae, B. alvei, and B. lentimorbus. Total lipids varied from 2.5 to 3.5% of the cell dry weight of B. thuringiensis to 4.3 to 5.0% of B. popilliae. Phospholipids in the organisms examined ranged from 55 to 79% of total lipids; neutral lipids averaged from 13 to 45%. Common phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and lysophosphatidylethanolamine. 1,2-Diglycerides, methyl esters, free fatty acids, and hydrocarbons were found in all the organisms studied. Branched-chain fatty acids constituted more than 50% of the total fatty acids in B. thuringiensis, B. larvae, B. popilliae, and B. alvei, whereas, in B. lentimorbus, normal-chain acids constituted more than 50%. Anteiso-C₁₅ (12-methyltetradeconoate) was the most abundant acid (30 to 50%) in B. alvei, B. larvae, B. popilliae, and B. lentimorbus. In contrast, B. thuringiensis contained more iso-C₁₃ (7%), iso-C₁₅ (17%), normal-C₁₆ (24%), and iso-C₁₇ (18%) than anteiso-C₁₅ (6%). The distribution of individual fatty acids was similar in the phospholipids and neutral lipids of each organism. However, the total amount of iso, anteiso, and normal isomers differed.     

<Emphasis Type="Italic">Paenibacillus albilobatus</Emphasis> sp. nov., isolated from acidic soil on Jeju Island

A rod-shaped, white color colony with lobate architectures, strain h2^T was isolated from a moderately acidic soil on Jeju Island, Republic of Korea. Comparative analysis of the 16S rRNA gene sequence showed that the strain h2^T is closely related to Paenibacillus relictisesami DSM 25385^T (97.4%, 16S rRNA gene sequence similarity), Paenibacillus azoreducens KACC 11244^T (97.2%), and Paenibacillus cookii LMG 18419^T (97.0%). DNA-DNA hybridization indicated that the strain h2^T has relatively low levels of DNA-DNA relatedness with respect to P. relictisesami DSM 25385^T (10.2%) and P. azoreducens KACC 11244^T (13.7%). Additionally, the genomic DNA G + C content of h2^T is 51.5 mol%. The isolated strain grew at pH 4.0–9.0 (optimum, pH 6.0–7.0) and 0–5% (w/v) NaCl (optimum, 0%) and a temperature of 15–45°C (optimum 35°C). The quinones in the strain are MK-6 and MK-7, and the predominant fatty acid is C_15:0 anteiso (32.1%) followed by C_17:0 anteiso (26.5%), and C_16:0 iso (21.0%). Based on its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain h2^T is proposed as a novel species in the genus Paenibacillus, for which the name Paenibacillus albilobatus sp. nov. is proposed (= KCCM 43269^T = JCM 32395^T = LMG 30408^T). The type strain of Paenibacillus albilobatus is h2^T.     

Effects of Growth Pressure and Temperature on Fatty Acid Composition of a Barotolerant Deep-Sea Bacterium

The effects of pressure and temperature on the fatty acid composition in a barotolerant deep-sea bacterium that had branched-chain fatty acids were examined. The major fatty acids of the strain at atmospheric pressure were iso-C_15:0, C_16:1, iso-C_17:0, and iso-C_17:1. As the growth pressure increased, the proportion of unsaturated fatty acid increased because of an increase in the proportion of iso-C_17:1. On the other hand, as the growth temperature decreased, the proportion of unsaturated fatty acid increased because of the increase in the proportion of C_16:1 and C_18:1.     

Exiguobacterium himgiriensis sp. nov. a novel member of the genus Exiguobacterium, isolated from the Indian Himalayas

The taxonomic position of an orange coloured bacterium, strain K22–26^T isolated from a soil sample was studied using a polyphasic approach. The organism had phenotypic and chemotaxonomic properties consistent with its allocation into the genus Exiguobacterium. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain K22–26^T belongs to the genus Exiguobacterium and was related to Exiguobacterium aurantiacum DSM 6208^T (99.0 %) Exiguobacterium mexicanum DSM 16483^T (98.6 %), Exiguobacterium aquaticum (98.6 %), Exiguobacterium aestuarii DSM 16306^T (98.1 %), Exiguobacterium profundum DSM 17289^T (98.1 %) and Exiguobacterium marinum DSM 16483^T (97.9 %), whereas sequence similarity values with respect to other Exiguobacterium species with validly published names were between 92.5–94.0 %. The major polar lipids detected were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The major menaquinone was determined to be MK-7 (83 %) whereas MK-8 (11 %) and MK-6 (6 %) occur in smaller amounts. The peptidoglycan of the strain was found to contain l-lysine as the diagnostic diamino acid. The major fatty acids detected were iso C_13:0 (11.2 %), anteiso C_13:0 (15.4 %), iso C_15:0 (13.2 %) and iso C_17:0 (16.1 %). However, analysis of the DNA–DNA relatedness confirmed that strain K22–26^T belongs to a novel species. The G + C content of the strain K22–26^T was determined to be 50.1 mol %. The novel strain was distinguished from closely related type species of the genus Exiguobacterium using DNA–DNA relatedness and phenotypic data. Based on these differences, the strain K22–26^T should be classified as a novel species of the genus Exiguobacterium, for which the name Exiguobacterium himgiriensis sp. nov. strain K22–26^T (= MTCC 7628^T = JCM 14260^T) is proposed.     

Fatty acid composition ofAerobacter aerogenes

The fatty acid composition of the whole cell and cell wall ofAerobacter aerogenes was studied employing column and gas-chromatographic technique. The cell wall contained a greater percentage of total lipid, complex lipid, and free fatty acids compared to the whole cell. Palmitic acid and oleic acid were the most abundant fatty acids found in the free fatty acid and complex lipid fractions. A saturated C₁₇ fatty acid and small quantities of a branched C₁₆ and iso and anteiso C₁₂ fatty acids were detected. The glyceride fractions of the whole cell and cell wall contained very few fatty acids.     

<Emphasis Type="Italic">Hymenobacter jeollabukensis</Emphasis> sp. nov., isolated from soil

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterial strain, designated 1-3-3-8^T, was isolated from soil and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 1-3-3-8^T belongs to the family Cytophagaceae of phylum Bacteroidetes and is most closely related to Hymenobacter paludis KBP-30^T (96.8% similarity), Hymenobacter ocellatus Myx2105^T (96.8%), Hymenobacter coalescens WW84^T (95.6%), and Hymenobacter deserti ZLB-3^T (95.4%). The G + C content of the genomic DNA of strain 1-3-3-8^T was 63.6 mol%. The isolate contained C_15:0 iso (28.4%), summed feature 4 (C_17:1 anteiso B/C_17:1 iso I; 18.9%), and C_15:0 anteiso (17.6%) as major fatty acids, MK-7 as the predominant respiratory quinone, and sym-homospermidine as the predominant polyamine. The major polar lipids were phosphatidylethanolamine and an unidentified lipid. The phenotypic and chemotaxonomic data supported the affiliation of strain 1-3-3-8^T with the genus Hymenobacter. The DNA-DNA relatedness between strain 1-3-3-8^T and H. paludis KCTC 32237^T and H. ocellatus DSM 11117^T were 24.5 and 27.4% respectively, clearly showing that the isolate is not related to them at the species level. Overall, the novel strain could be differentiated from its phylogenetic neighbors on the basis of several phenotypic, genotypic, and chemotaxonomic features. Therefore, strain 1-3-3-8^T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter jeollabukensis sp. nov. has been proposed. The type strain is 1-3-3-8^T (= KCTC 52741^T = JCM 32192^T).