The recently described aerobic, extremely halophihc archaeobaetenum, Halnbacterlum lacusprofandt was subJected to hpld analysis so that comparisons could be made between erastmg lipid data and that of the new Isolate. This mvestlgaUon showed that the major respwatory hpoqumones present were MK-8 and MK-8(VIII-H2), a feature found m other members of the family Halobactenaceae. The polar hptds comprised the dtether dertvatwes of phosphatidyl glycerol, phosphaUdyl glycerophosphate, phosphattdyl glycerosulphate, a dlglycosyl d]ether and its sulphatcd dertvaUve The data presented shows that Halobactenum lacusprofundl ts related to Hb saecharovorum and Hb. sodomense, and is m agreement with phylogenetic data 2.1NTRODUC~ONThe taxonomy of the famdy Halobactenaceae has undergone extensive revision within the last decade [l] A contributing factor to tlus has been Cor,espondence to B J "Iindall, DSM-Deutsche Sammlung yon Mikroorgamsmen und Zellkulturen GmbH. Mascheroder Weg lb. I)-3300 Braunschwelg, F R O the thscovery of new isolates which do not conform to the older concepts of halobactenal dlver-sRy. and to the use of molecular biologmal approaches combined with conventional btochenucal and physiological studies. While the present generic diversity of the farmly Halobacter:aeceae Is supported to some degree by 16S rRNA data the major evidence for the current dtvlsions comes from a combination of nucletc acid hybridisatton and polar hpld analyses [2][3][4][5]. In fact, R has been possible to show that, by using polar hpid analysis alone, the fanuly Halobactertaceae may be divided mto 9 different groups, of which 6 eor'~spond to the currently recogmsed genera [1,2,4,6]. That the remaining three groups have not been allocated separate genene status appears to rest on cert~un taxononuc formalities. In view of the fact that it is possible to accurately and reliably assign a new isolate to one of the existing genera within the fan'aly Halobactenaceae the newly descnbed speoes Halobactertulm lacusprofuadt [7] was subjeered to polar hpid analysis to deterrmne m which of the polar lipid groups tt belongs. 16S rRNA analysis showed that tins species was related to Halobactertum saccharovorum and Halobacterium sodomense Consequently the hpid c.ompositmn of antheutlc type strains of the latter two species were cempared with the hpld composltmn of HalobacterJum lacusprofundt, m order to proxqde 0378-1097/89/$03 50

A new toluene-producing bacterium, strain TA 4T (T = type strain), was isolated from anoxic sediments of a freshwater lake. The individual cells of this organism were nonmotile, gram-negative rods that were 0.9 to 1.2 by 2.5 to 3.2 pm. The optimum temperature and pH for growth were 22°C and pH 7.2, respectively. The G+C content of the DNA was 49 mol%. Toluene was produced from phenylalanine, phenylpyruvate, phenyllactate, and phenylacetate, and phenol was produced from tyrosine. Both the presence of a carbon source and the presence of a toluene precursor were essential for initiation of toluene production. Bacterial growth occurred under oxic and anoxic conditions. Acetate, ethanol, and formate were the major fermentation products of the bacterium when it was grown on glucose. The major lipoquinones were ubiquinone 8 and menaquinone 8 under both oxic and anoxic growth conditions. On the basis of the results of a 16s ribosomal DNA sequence analysis, we concluded that this organism is a member of the y subclass of the Proteobacteria, and we suggest the name Tolumonas auensis for this species.Anoxic waters are inhabited by a wide variety of bacteria, including sulfate reducers and methanogens, which have been studied extensively (31). The products of the sulfate reducers and methanogens, sulfide and methane, can be detected easily in water. Methane is produced almost exclusively by methanogens, and a major part of the sulfide found in anoxic lake water is the result of reduction of sulfate ions by sulfate reducers. However, in the anoxic parts of many freshwater lakes other compounds also accumulate, and the presence of these compounds cannot be explained by the activity of sulfate reducers and methanogens. One such compound is the aromatic hydrocarbon toluene, which has recently been detected at high concentrations (>3 pg/liter) in anoxic hypolimnia of several small lakes (9). This compound accumulated during the course of the year in the hypolimnion of a eutrophic lake, and accumulation began as soon as stratification of the water occurred and anoxic conditions were established (1 1). The time course of toluene accumulation clearly points to microbial production of this compound, and this finding makes the rather popular use of toluene as a tracer of pollution questionable. The bacteria responsible for toluene production in lakes are not known yet. In a previous study, microbial production of toluene in artificial anoxic lake water inoculated with lake sediment was observed under laboratory conditions (lo), but it was not clear which organisms were responsible for this production. Inhibitor experiments performed with 2-bromoethanesulfonate and molybdate revealed that the sulfate reducers and methanogens are not involved in production of toluene (unpublished data). In this paper we describe the isolation of a toluene-producing microorganism from anoxic lake sediments; this organism represents a new species of a new genus belonging to the y subclass of the Proteobacteria. MATERIALS AND METHODSMedia and cultivation ...

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The anaerobic, thermophilic archaebacterium, Pyrobaculum islandicum (Geo 3) was examined for the presence of lipoquinones. Thin layer chromatographic, HPLC, UV, and mass spectroscopic analysis showed that a menaquinone was present. No evidence was found for substitution of the 2‐methyl‐3‐polyisoprenyl‐1,4‐naphthoquinone ring nucleus. However, the C3 isoprenoid chain consisted of six fully saturated units, and shows that the major menaquinone in this organism corresponds to 2‐methyl‐3‐VI,V,IV,III,II,I‐dodecahydrohexaprenyl‐1, 4‐naphthoquinone (MK‐6H12).

Vulcanithermus mediatlanticus gen. nov., sp. nov., a novel member of the family Thermaceae from a deep-sea hot vent A novel thermophilic, microaerophilic, facultatively chemolithoheterotrophic bacterium designated strain TR T was isolated from a sample of a deep-sea hydrothermal chimney collected at the Rainbow vent field on the Mid-Atlantic Ridge (36˚149N). Gram-negative, non-spore-forming, non-motile rods occurred singly or in pairs. The organism grew in the temperature range 37-80˚C with an optimum at 70˚C and at pH 5?5-8?4 with an optimum around 6?7. The NaCl range for growth was 10-50 g l "1 with an optimum of 30 g l "1 . Strain TR T grew chemoorganoheterotrophically with carbohydrates, proteinaceous substrates, organic acids and alcohols using oxygen or nitrate as electron acceptors. The isolate was able to grow at oxygen concentrations from 0?5 to 21 %. Oxygen concentrations that promoted fastest growth ranged from 4 to 8 % under agitation. The novel isolate was able to grow lithoheterotrophically with molecular hydrogen as the energy source. The G+C content of the genomic DNA was 68?4 mol%. Phylogenetic analysis of the 16S rDNA sequence placed strain TR T within the phylum Deinococcus-Thermus of the Bacteria. On the basis of phenotypic and phylogenetic data, it is proposed that this isolate should be described as a member of a novel species of a new genus as Vulcanithermus mediatlanticus gen. nov., sp. nov. The type strain is