10-methyl Fatty Acids Research Articles

Comparative Fatty Acid Profiling of Klebsiella pneumoniae and Rhodococcus rhodochrous Isolated from Spoilt Paints by Gas Chromatography

The use of fatty acids to study the differences in un-related microbes is limited. This study analyzes the fatty acids produced by two unrelated microorganisms: Klebsiella pneumoniae (Gram-negative, aerobic, non-endospore forming, usually encapsulated rod-shaped bacteria of the family Enterobacteriaceae) and Rhodococcus rhodochrous (metabolically versatile, non-spore-forming, non-motile actinomycete) isolated from spoilt paints. Fatty acids produced by the organisms were analyzed using an efficient MIDI-Sherlock gas chromatography method . K. pneumoniae was characterized by a high content of straight chain, branched chain, hydroxyl and cyclo-fatty acids made up of C12: 0, C13:0, C14:0 iso, C14:0, C15:0 iso, C15:0 anteiso, C15:1 ω 8c, C15:0, C16:0 iso, C16:1w5c, C16:0, C15:03OH, C17:1 ω 8c, C17:0 cyclo, C17:0, C18:1 ω5c and C18:0. R. rhodochrous was dominated by straight chain, monounsaturated and 10-methyl fatty acids. The inability to synthesize branched, cyclo- and hydroxyl- fatty acids, was observed in R. rhodochrous which composed mainly of C14: 0, C15: 1 ω 5c, C15:0, C16:1 ω 9c, C16:0, C17:1 ω 8c, C17:0, C17:0 10-methyl, C18: 1 ω 9c, C18.0, 10 methyl-C18:0 TBSA, C20:1 ω 9c, and C20:0. Descriptive statistics reveal a mean of 2.53, 15.10 and 15.15 for retention time (RT), equivalent chain length (ECL) and Peak name, respectively. Possible implications of the variations in fatty acid distribution may include differences in their abilities to produce various secondary metabolites and potentials to degrade a variety of xenobiotics.
 Keywords: Fatty acids, paints, Rhodococcus rhodochrous, Klebsiella pneumoniae

Preen oil chemical composition in herring gull Larus argentatus, common gull Larus canus and black-headed gull Chroicocephalus ridibundus confirms their status as two separate genera

Fatty acid and alcohol components of preen oil were determined in three gull species that belong to two systematic genera: herring gull Larus argentatus, common gull Larus canus and black-headed gull Chroicocephalus ridibundus. All gulls were captured in winter, in Gdańsk, Poland. All gulls produced monoesters composed of C7–C16 saturated fatty acids and C11–C20 saturated alcohols, with n-octanoic acid and n-hexadecanol as the major fatty acid and alcohol, respectively. Preen oils of black-headed gull had higher content of trimethyl fatty acids, 2,8-dimethylundecanoic acid, 2,6-dimethylundecanoic acid and 2,6-dimethylnonanoic acid, and lower content of 2-methyl fatty acids than oils of herring gull and common gull. Preen oils produced by black-headed gull also had lower content of 2-methyl alcohols. The relative contents of n-octanoic acid and n-hexadecanol did not differ among species. The differences among species are probably not a result of different diet, as all gulls fed mainly on household refuse. Hence, preen oil analysis confirmed the taxonomic relations among these gull species, that recently were placed into two different genera.

Nocardioides mesophilus sp. nov., isolated from soil

A short coccoid- to rod-shaped, motile, mesophilic actinobacterium, strain MSL-22(T), was isolated from soil on Bigeum Island, Korea. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MSL-22(T) formed an evolutionary lineage within the radiation of the genus Nocardioides. In particular, it formed a monophyletic lineage with Nocardioides jensenii KCTC 9134(T) with which it shared the highest sequence similarity of about 97.3%. However, DNA-DNA relatedness demonstrated that strain MSL-22(T) was distinct from its closest phylogenetic neighbours. The cell-wall peptidoglycan of strain MSL-22(T) contained LL-diaminopimelic acid. The predominant menaquinone was MK-8(H₄). Strain MSL-22(T) had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids, with iso-C₁₆:₀ as the major fatty acid. The DNA G+C content of the strain was 68.7 mol%. On the basis of phenotypic and phylogenetic evidence, the strain is separate from previously described members of the genus Nocardioides and represents a novel species in this genus, for which the name Nocardioides mesophilus sp. nov. is proposed. The type strain is MSL-22(T) (=DSM 19432(T)=KCTC 19310(T)).

Nocardioides dilutes sp. nov. Isolated from Soil in Bigeum Island, Korea

A short coccoid-rod-shaped, nonmotile actinobacteria strain MSL-11T was isolated from soil in Bigeum Island, Korea. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain MSL-11T forms an evolutionary lineage within the radiation of the genus Nocardioides. The cell wall peptidoglycan of strain MSL-11T contained LL-diaminopimelic acid, indicating wall chemotype I. The predominant menaquinone was MK-8(H4). Strain MSL-11T had a cellular fatty acid profile containing straight-chain, branched, unsaturated, and 10-methyl fatty acids, with iso-C16:0 as a major fatty acid component detected. The DNA G + C content of the strain was 71.8 mol%. Comparative 16S rRNA gene sequencing revealed that the strains constituted a distinct subclade within the genus Nocardioides, displaying a 16S rRNA gene sequence similarity of about 95.68% with Nocardioides jensenii DSM 20641T. On the basis of both phenotypic and phylogenetic evidence, the strain is separated from previously described Nocardioides species and should be assigned to represent a novel species of the genus Nocardioides, for which the name Nocardioides dilutes sp. nov. is proposed. The type strain is strain MSL-11T (= KCTC 19288T = DSM 19318T).

Differences of heterotrophic 13CO2 assimilation by Pseudomonas knackmussii strain B13 and Rhodococcus opacus 1CP and potential impact on biomarker stable isotope probing

Motivated by the finding that Pseudomonas knackmussii B13 but not Rhodococcus opacus 1CP grows in the absence of externally provided CO(2), we investigated the assimilation of (13)CO(2) into active cells cultivated with non-labelled glucose as sole energy substrate. (13)C found in the bulk biomass indicated a substantial but different CO(2) assimilation by Pseudomonas and Rhodococcus, respectively (3500 per thousand and 2600 per thousand). Cellular fatty acids were labelled from -15 per thousand to 470 per thousand and amino acids from 500 per thousand to 24,000 per thousand demonstrating clear differences between various compound classes. 'You are what you eat plus 1 per thousand' is therefore only valid for the average bulk C without specific isotope signature deviation of the external CO(2) or carbonates. Odd-numbered and 10-methyl fatty acids, which are much more abundant in Rhodococcus or other Gram-positive bacteria, were up to fivefold higher enriched in (13)C relative to the Pseudomonas fatty acids. A high-level growth-phase-independent, labelling of the oxaloacetate-derived amino acids indicated heterotrophic CO(2) fixation by anaplerotic reactions known to replenish the tricarboxylic acid cycle. Although both strains assimilate CO(2) via similar general pathways, Rhodococcus depends to a much higher extent on carboxylations reactions with external CO(2) owing to the formation of odd-numbered fatty acids. As a general consequence, heterotrophic fixation of CO(2) should be taken into account in investigations of degradation experiments using isotope tracer compounds.

Nocardioides hwasunensis sp. nov.

Two novel actinomycete strains, designated HFW-18 and HFW-21(T), were isolated from a water sample around Hwasun Beach on the coast of Jeju Island, Republic of Korea. The cells of the organisms were aerobic, Gram-positive, non-motile rods. The temperature and initial pH ranges for growth were 4-37 degrees C and pH 5.1-9.1, respectively. They had LL-diaminopimelic acid in their cell-wall peptidoglycan, MK-8(H(4)) as the major menaquinone and DNA G+C contents of 71.1-72.2 mol%. The cellular fatty acids consisted of straight-chain saturated, branched, monounsaturated and 10-methyl fatty acids, with a major component of iso-C(16:0). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unknown phospholipid. The isolates were identical in terms of their 16S rRNA gene sequences and BOX-PCR DNA fingerprints. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolates occupied distinct positions within the radiation of the genus Nocardioides. According to 16S rRNA gene sequence similarity, the closest relatives were Nocardioides ganghwensis JC2055(T) (97.4%), Nocardioides oleivorans DSM 16090(T) (97.3%) and Nocardioides furvisabuli SBS-26(T) (97.0%). Levels of 16S rRNA gene sequence similarity between the isolates and other members of the genus Nocardioides were in the range 91.8-95.3%. On the basis of the phenotypic and molecular genetic data presented here, the isolates represent members of a novel species of the genus Nocardioides. The name Nocardioides hwasunensis sp. nov. is proposed, and the type strain is HFW-21(T) (=KCTC 19197(T)=DSM 18584(T)).

Nocardioides exalbidus sp. nov., a novel actinomycete isolated from lichen in Izu-Oshima Island, Japan

A short coccoid- or rod-shaped, non-motile actinomycete strain RC825T was isolated from lichen in Izu-Oshima Island, Japan. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain RC825T forms an evolutionary lineage within the radiation of the genus Nocardioides. In particular, it forms a coherent cluster with Nocardioides oleivorans and Nocardioides ganghwensis with high sequence similarity of 98 and 97.5%, respectively. However, DNA–DNA hybridization experiment demonstrated that strain RC825T is distinct from its closest phylogenetic neighbors, N. oleivorans and N. ganghwensis, with 44 and 39% relatedness, respectively. The cell-wall peptidoglycan of strain RC825T contained LL-diaminopimelic acid, indicating wall chemotype I. The predominant menaquinone was MK-8(H4). Strain RC825T had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids, and the major fatty acid was iso-C16:0. The DNA G+C content of the strain was 74 mol%. On the basis of both phenotypic and phylogenetic evidence, the strain is separated from previously described Nocardioides species, and should be assigned to represent a novel species of the genus Nocardioides, for which the name Nocardioides exalbidus sp. nov. is proposed. The type strain is strain RC825T (=IAM 15416T=CCTCC AA206016T).

Reclassification of Arthrobacter duodecadis Lochhead 1958 as Tetrasphaera duodecadis comb. nov. and emended description of the genus Tetrasphaera

Phylogenetic analysis based on 16S rRNA gene sequences and chemotaxonomic features of Arthrobacter duodecadis Lochhead 1958 indicated that the bacterium belonged within the genus Tetrasphaera. A. duodecadis IAM 14868(T) could be distinguished from other species by the presence of 3-hydroxy meso-diaminopimelic acid in the peptidoglycan and a series of 10-methyl fatty acids. In addition, DNA-DNA relatedness studies indicated that the strain belonged to a genomic species that could be readily distinguished from its nearest neighbours, the type strains of Tetrasphaera elongata, Tetrasphaera japonica and Tetrasphaera australiensis. These features support our proposal to reclassify A. duodecadis in the genus Tetrasphaera, as Tetrasphaera duodecadis comb. nov. The type strain is IAM 14868(T) (=NBRC 12959(T) = ATCC 13347(T) = NCIMB 9222(T)). An emended description of the genus Tetrasphaera is given.

Evolutionary Variation in Feather Waxes of Passerine Birds

Abstract Feather waxes are ubiquitous in passerine birds, but their composition, phylogenetic distribution, and function are poorly characterized. We used gas chromatography–mass spectrometry to survey the diversity of saturated fatty acids in feather waxes of 91 taxa representing most major passerine groups, and used an independent phylogenetic hypothesis to explore evolutionary variation in the expression of those compounds. Saturated fatty acids are highly stable, and we obtained congruent results in comparisons of extracts from fresh material and from museum skins as much as a century old. All taxa expressed unbranched fatty acids, but in a broad range of proportions relative to their total saturated fatty-acid profile. The expression of three other classes of fatty acids was more variable, although each showed a high degree of conservation at the phylogenetic level corresponding approximately to avian families. The 2-methyl fatty acids were expressed in a number of families, often in high proportions, but were absent or low in all fringillid taxa surveyed except the Dickcissel (Spiza americana). The 3-methyl fatty acids were common only in fringillids and allies and in one genus of turdids (Zoothera). The 4-methyl compounds were comparatively rare and were abundant only in the Paridae, Polioptilinae, and Troglodytidae. Feather-wax composition is unlikely to be highly informative for reconstructing phylogenetic relationships, but study of secretion diversity in a comparative phylogenetic context holds promise for characterizing the functions of those compounds.

Sterically Hindered Triacylglycerol Analogues as Potent Inhibitors of Human Digestive Lipases

A novel class of inhibitors of human digestive lipases have been developed. Various sterically hindered triacylglycerols based on 2-methyl- and 2-butylglycerol, and/or 2-methyl fatty acids were synthesized. The triacylglycerol analogues were tested for their ability to form stable monomolecular films at the air/water interface by recording their surface-pressure/molecular-area compression isotherms. The inhibition of human pancreatic and gastric lipases by the sterically hindered triacylglycerol analogues was studied by using the monolayer technique with mixed films of 1,2-dicaprin, which contained variable proportions of each inhibitor. Triolein analogues that contain a butyl group at the 2-position of the glycerol backbone or methyl groups both at the 2-position of glycerol, and the alpha-position of each oleic acid residue were potent inhibitors; this caused a 50% decrease in HPL activity at 0.003 molar fraction.

Nocardioides aquiterrae sp. nov., isolated from groundwater in Korea.

A bacterial strain, GW-9T, which was isolated from groundwater in Korea, was subjected to a polyphasic taxonomic study using phenotypic characterization and phylogenetic and genetic methods. Phylogenetic analysis based on 16S rDNA sequences showed that strain GW-9T forms an evolutionary lineage within the radiation enclosing Nocardioides species and, in particular, a coherent cluster with Nocardioides pyridinolyticus. The cell-wall peptidoglycan type of strain GW-9T was based on LL-diaminopimelic acid as the diamino acid, indicating wall chemotype I. The predominant menaquinone was MK-8(H4). Strain GW-9T had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids. The major fatty acid was iso-C(16:0). The DNA G+C content of strain GW-9T was 73 mol%. The 16S rDNA of strain GW-9T was 99.2% similar to that of the type strain of Nocardioides pyridinolyticus and 94.9-96.0% similar to sequences of the type strains of other Nocardioides species. Differences in phenotypic characteristics and genetic distinctiveness indicate that strain GW-9T is separate from previously described Nocardioides species. Therefore, on the basis of the data presented, a novel species of the genus Nocardioides, Nocardioides aquiterrae sp. nov., is proposed. The type strain is strain GW-9T (=KCCM 41647T=JCM 11813T).

EVOLUTIONARY VARIATION IN FEATHER WAXES OF PASSERINE BIRDS

Abstract Feather waxes are ubiquitous in passerine birds, but their composition, phylogenetic distribution, and function are poorly characterized. We used gas chromatography–mass spectrometry to survey the diversity of saturated fatty acids in feather waxes of 91 taxa representing most major passerine groups, and used an independent phylogenetic hypothesis to explore evolutionary variation in the expression of those compounds. Saturated fatty acids are highly stable, and we obtained congruent results in comparisons of extracts from fresh material and from museum skins as much as a century old. All taxa expressed unbranched fatty acids, but in a broad range of proportions relative to their total saturated fatty-acid profile. The expression of three other classes of fatty acids was more variable, although each showed a high degree of conservation at the phylogenetic level corresponding approximately to avian families. The 2-methyl fatty acids were expressed in a number of families, often in high proportions...

Enhanced desulfurization in a transposon-mutant strain of Rhodococcus erythropolis.

The dsz desulfurization gene cluster from Rhodococcus erythropolis strain KA2-5-1 was transferred into R. erythropolis strain MC1109, unable to desulfurize light gas oil (LGO), using a transposon-transposase complex. As a result, two recombinant strains, named MC0203 and MC0122, were isolated. Resting cells of strain MC0203 decreased the sulfur concentration of LGO from 120 mg l(-1) to 70 mg l(-1) in 2 h. The LGO-desulfurization activity of strain MC0203 was about twice that of strain MC0122 and KA2-5-1. The 10-methyl fatty acids of strain MC0203 were about 28%-41% that of strain MC1109. It is likely that strain MC0203 had a mutation involving alkylenation or methylation of delta9-unsaturated fatty acids caused by the transposon inserted in the chromosome, which increased the fluidity of cell membranes and enhanced the desulfurization activity.

Janibacter terrae sp. nov., a bacterium isolated from soil around a wastewater treatment plant.

A bacterial strain, CS12T, which was isolated from soil around a wastewater treatment plant, was subjected to a polyphasic taxonomic study using phenotypic characterizations and genetic methods. The cell wall of strain CS12T contains meso-diaminopimelic acid as the diamino acid but no arabinose and galactose. The predominant menaquinone is MK-8(H4). Mycolic acids are absent. Strain CS12T has a cellular fatty acid profile containing saturated, unsaturated, branched and 10-methyl fatty acids. The major fatty acids are iso-C16:0, C18:1 omega9c and anteiso-C17:0, The G+C content is 69 mol%. A phylogenetic tree based on 16S rDNA sequences showed that strain CS12T forms an evolutionary lineage within the radiation enclosing the members of the family Intrasporangiaceae and, in particular, a coherent cluster with Janibacter limosus DSM 11140T. The level of 16S rDNA similarity between strain CS12T and J. limosus DSM 11140T is 98.7%. The phenotypic characteristics and DNA-DNA relatedness data indicate that strain CS12T should be distinguished from J. limosus DSM 11140T. Therefore, on the basis of the data presented, a new species of the genus Janibacter, Janibacter terrae, is proposed. The type strain of the new species is strain CS12T (= KCCM 80001T = JCM 10705T).

Molecular analysis of intact preen waxes of Calidris canutus (Aves: Scolopacidae) by gas chromatography/mass spectrometry.

The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additional resolution to the analysis of wax esters. The C21-C32 wax esters are composed of complex mixtures of hundreds of individual isomers. The odd carbon-numbered wax esters are predominantly composed of even carbon-numbered n-alcohols (C14, C16, and C18) esterified predominantly with odd carbon-numbered 2-methyl fatty acids (C7, C9, C11, and C13), resulting in relatively simple distributions. The even carbon-numbered wax esters show a far more complex distribution due to a number of factors: (i) Their n-alcohol moieties are not dominated by even carbon-numbered n-alcohols esterified with odd carbon-numbered 2-methyl fatty acids, but odd and even carbon-numbered n-alcohols participate in approximately equal amounts; (ii) odd carbon-numbered methyl-branched alcohols participate abundantly in these wax ester clusters; and (iii) with increasing molecular weight, various isomers of the 2,6-, 2,8-, and 2,10-dimethyl branched fatty acids also participate in the even carbon-numbered wax esters. The data demonstrate that there is a clear biosynthetic control on the wax ester composition although the reasons for the complex chemistry of the waxes are not yet understood.

Dust-borne bacteria in animal sheds, schools and children's day care centres.

A total of 316 bacterial strains, including psychrophiles, mesophiles and thermophiles, were isolated and identified from indoor dusts in schools, children's day care centres and animal sheds. Several species which had not previously been reported from indoor environments were found: Sphingomonas, Brevibacterium, Nocardiopsis, Deinococcus and Rhodococcus/Gordona. A new psychrophilic actinomycete genus was also found in animal sheds, representing a new undescribed peptidoglycan type and an unusual whole-cell fatty acid composition. The indoor dusts of animal sheds contained mainly the Gram-negative genera Pseudomonas, Pantoea, Flavobacterium and Xanthomonas early in the indoor feeding season, but changed to a composition dominated by Bacillus, Micrococcus and mesophilic and thermophilic actinomycetes towards the end of the season. The dust contained, and air-borne bacterial flora in schools and day care centres were dominated by, Gram-positive bacilli and actinomycetes, notably Bacillus cereus, Brevibacillus brevis, B. licheniformis, B. subtilis and species of Arthrobacter, Corynebacterium, Rhodococcus/Gordona, Nocardiopsis sp., Deinococcus, Staphylococcus and Micrococcus. Indoor air and dust contained Klebsiella oxytoca, Acinetobacter calcoaceticus, Ac. lwoffi, Bacillus cereus and Nocardiopsis dassonvillei with the status of hazard group II. Indoor dusts of animal sheds contained eight different 3-hydroxy fatty acids, the 2-hydroxy fatty acid 14:0 and two 10-methyl fatty acids, whereas in dusts from schools and day care centres, these were below the detection level (< 3.5 ng mg-1). The 3-and 2-hydroxy fatty acids could be assigned to one or more of the dust-contained cultivable strains, but 10-methyl C16:0 was not present in any of the strains isolated. The dusts from schools and children's day care centres contained 0.2-0.3 ng of endotoxin mg-1 and 0.5-1.4 ng of beta-D-glucan mg-1, whereas the dusts from animal sheds contained more 0.3-41 ng mg-1 and 8-35 ng mg-1, respectively.

Mitochondrial β-Oxidation of 2-Methyl Fatty Acids in Rat Liver

The mitochondrial β-oxidation of 2-methyl fatty acids was studied with coupled rat liver mitochondria and purified enzymes. Measurements of mitochondrial respiration supported by 2-methyl fatty acids, straight chain fatty acids, or their coenzyme A (CoA) thioesters revealed that free short-chain and medium-chain 2-methyl fatty acids are oxidized nearly or as efficiently as are their straight chain analogs. Long-chain 2-methyl hexadecanoyl-CoA is also oxidized, although more slowly than its unbranched counterpart. However, medium-chain 2-methyldecanoyl-CoA, in contrast to its unbranched analog, is not oxidized at all. Of all acyl-CoA dehydrogenases only long-chain acyl-CoA dehydrogenase acts on medium-chain and long-chain 2-methylacyl-CoA thioesters. The resultant 2-methyl-2-enoyl-CoA thioesters are substrates of the mitochondrial trifunctional β-oxidation complex which catalyzes the sequential hydration, dehydrogenation, and thiolytic cleavage of 2-methyl-substituted substrates to yield chain-shortened acyl-CoA thioesters and propionyl-CoA. The matrix enzymes L-3-hydroxyacyl-CoA dehydrogenase and 3-ketoacyl-CoA thiolase, in contrast to enoyl-CoA hydratase, are inactive with medium-chain and long-chain 2-methyl-substituted chain substrates. The specificity of the β-oxidation enzymes toward 2-methyl-branched substrates forms the basis for assays of long-chain acyl-CoA dehydrogenase and the trifunctional β-oxidation complex in the presence of their mitochondrial isozymes. It is concluded that rat liver mitochondria can oxidize 2-methyl fatty acids, but does so most effectively with medium-chain and short-chain ones that can enter mitochondria directly in a carnitine-independent manner.

Phospholipid Ester-linked Fatty Acid Biomarkers of Acetate-oxidizing Sulphate-reducers and Other Sulphide-forming Bacteria

Summary: The phospholipid ester-linked fatty acids were examined in four Desulfobacter strains (2ac9, AcBa, 3acl0 and 4acll), a Desulfobacter-like ‘fat vibrio’ (AcKo) and Desulfotomaculum acetoxidans (5575), which are all sulphate-reducing bacteria that oxidize acetate. A thermophilic sulphate reducer, Desulfovibrio thermophilus, and two sulphur-reducing bacteria, Desulfuromonas acetoxidans (11070) and a Campylobacter-like spirillum (5175), were also studied. The Desulfobacter spp. were characterized by significant quantities of 10-methylhexadecanoic acid. Other 10-methyl fatty acids were also detected in Desulfobacter spp. No 10-methyl fatty acids were detected in the other organisms examined, supporting the use of 10-methylhexadecanoic acid as a biomarker for Desulfobacter. High levels of cyclopropyl fatty acids, including two isomers of both methylenehexadecanoic (cyl7:0) and methyleneheptadecanoic (cyl8:0) acids, were also characteristic of Desulfobacter spp. The influence of the volatile fatty acids (VFA) propionate, isobutyrate, isovalerate and 2-methylbutyrate on the lipid fatty acid distribution was studied with two Desulfobacter strains (2ac9, AcBa) and Desulfotomaculum acetoxidans. Although these sulphate reducers cannot oxidize the VFA, their presence in the acetate growth medium caused a shift in the fatty acid distribution in favour of odd-numbered and branched chains by apparent direct incorporation into the fatty acids as chain initiators. The Desulfobacter strains were distinguished from other sulphide-forming bacteria by the percentage of unsaturated and the percentage of branched fatty acids.

Taxonomic Significance of Cellular Fatty Acid Composition in Some Coryneform Bacteria

A total of 76 strains of coryneform bacteria belonging to the genera Arthrobacter, Brevibacterium, Caseobacter, Cellulomonas, Corynebacterium, and Curtobacterium were divided into four groups on the basis of their cellular fatty acid compositions. Cells with saturated and monounsaturated straight-chain fatty acids were designated type I. Strains in this group had meso-diaminopimelic acid and arabinogalactan in their cell walls. In some strains, 10-methyl fatty acids were found. Type I was divided into six subtypes based on fatty acid composition. Type II cells contained iso-anteiso acids and were found in 43 strains of Arthrobacter, Brevibacterium, Cellulomonas, Curtobacterium, and coryneform bacteria with diaminobutyric acid-peptidoglycan. Small differences in fatty acid composition were found among the strains of this type, and the fatty acid compositions of type II strains varied remarkably depending on the media used. Type III strains were characterized by the presence of ω-cyclohexyl fatty acids. In two strains of Curtobacterium pusillum, approximately 60% of the cellular fatty acid was ω-cyclohexyl undecanoic acid. Type IV strains had highly complex patterns of iso, anteiso, normal, saturated, unsaturated, 10-methyl, and 2-hydroxy fatty acids. Five strains of Arthrobacter simplex, Arthrobacter tumescens, and “Brevibacterium lipolyticum” possessed this type of fatty acid composition.