Analysis of the Anaerobic Microbial Community Capable of Degrading p-Toluene Sulfonate

Three strains of Clostridium sp., 14 (VKM B-2201), 42 (VKM B-2202), and 21 (VKM B-2279), two methanogens, Methanobacterium formicicum MH (VKM B-2198) and Methanosarcina mazei MM (VKM B-2199), and one sulfate-reducing bacterium, Desulfovibrio sp. SR1 (VKM B-2200), were isolated in pure cultures from an anaerobic microbial community capable of degrading p-toluene sulfonate. Strain 14 was able to degrade p-toluene sulfonate in the presence of yeast extract and bactotryptone and, like strain 42, to utilize p-toluene sulfonate as the sole sulfur source with the production of toluene. p-Toluene sulfonate stimulated the growth of Ms. mazei MM on acetate. The sulfate-reducing strain Desulfovibrio sp. SR1 utilized p-toluene sulfonate as an electron acceptor. The putative scheme of p-toluene sulfonate degradation by the anaerobic microbial community is discussed.     

Methanogenic sarcina from an anaerobic microbial community degrading p-toluene sulfonate

The methanogenic strain MM isolated from an anaerobic microbial community degrading p-toluene sulfonate showed optimal values of temperature and pH for growth equal to 37 degrees C and 6.3-6.9, respectively. The doubling times of the isolate grown on methanol, acetate, and methylamines under the optimal conditions were 8.8, 19.1, and 10.3-28.1 h, respectively. The growth of strain MM was observed only when the cultivation medium contained casamino acids or p-toluene sulfonate. The G + C content of the DNA of the isolate was 40.3 mol%. This, together with DNA-DNA hybridization data, allowed the new isolate to be identified as a strain of the species Methanosarcina mazei. The new isolate differed from the known representatives of this species in that it was resistant to alkylbenzene sulfonates and able to demethylate p-toluene sulfonate when grown on acetate.     

Thermus kawarayensis sp. nov., a new member of the genus Thermus, isolated from Japanese hot springs

A long-rod-shaped thermophilic microorganism, strain KW11, was isolated from a hot springs located in the Kawarayu, Gunma, Japan. Cloning and preliminary sequence analysis of 16S rDNA showed that this isolate belongs to the genus Thermus. The cells were 10–20 m long, about 0.8 m in diameter, and produced no pigment in contrast with most of the Thermus species previously reported. KW11 was an aerobic heterotroph and grew at temperatures ranging from 40–73°C, with optimal growth occurring at 68°C. The pH range for growth was from 5.8–8.9, with optimal growth around pH 7. KW11 was sensitive to ampicillin, penicillin G, kanamycin, and streptomycin. The G+C content of DNA was 69 mol%. The main fatty acids were 16:0 (52.9%), iso-15:0 (22.1%), and iso-17:0 (15.6%). The 16S rDNA sequence of KW11 showed 96.0, 95.8, and 95.4% similarity with the sequences of T. aquaticus, T. igniterrae, and T. thermophilus, respectively, and less than 95% with other Thermus species. The physiological differences and phylogenetic evidence indicated that strain KW11 represents T. kawarayensis, a novel species of the genus Thermus. The type strain is isolate KW11^T (JCM12314, DSM16200).     

Sulfobacillus sibiricus sp. nov., a New Moderately Thermophilic Bacterium

In the course of pilot industrial testing of a biohydrometallurgical technology for processing gold-arsenic concentrate obtained from the Nezhdaninskoe ore deposit (East Siberia, Sakha (Yakutiya)), a new gram-positive rod-shaped spore-forming moderately thermophilic bacterium (designated as strain N1) oxidizing Fe²⁺, S⁰, and sulfide minerals in the presence of yeast extract (0.02%) was isolated from a dense pulp. Physiologically, strain N1 differs from previously described species of the genus Sulfobacillus in having a somewhat higher optimal growth temperature (55°C). Unlike the type strain of S. thermosulfidooxidans, strain N1 could grow on a medium with 1 mM thiosulfate or sodium tetrathionate as a source of energy only within several passages and failed to grow in the absence of an inorganic energy source on media with sucrose, fructose, glucose, reduced glutathione, alanine, cysteine, sorbitol, sodium acetate, or pyruvate. The G+C content of the DNA of strain N1 was 48.2 mol %. The strain showed 42% homology after DNA–DNA hybridization with the type strain of S. thermosulfidooxidans and 10% homology with the type strain of S. acidophilus. The isolate differed from previously studied strains of S. thermosulfidooxidans in the structure of its chromosomal DNA (determined by the method of pulsed-field gel electrophoresis), which remained stable as growth conditions were changed. According to the results of the 16S rRNA gene analysis, the new strain forms a single cluster with the bacteria of the species Sulfobacillus thermosulfidooxidans (sequence similarity of 97.9–98.6%). Based on these genetic and physiological features, strain N1 is described as a new species Sulfobacillus sibiricus sp. nov.     

Fermentation of methoxyacetate to glycolate and acetate by newly isolated strains of Acetobacterium sp.

Three strains of new mesophilic homoacetogenic bacteria were enriched and isolated from sewage sludge and from marine sediment samples with methoxyacetate as sole organic substrate in a carbonate-buffered medium under anoxic conditions. Two freshwater isolates were motile, Gram-positive, non-sporeforming rods. The marine strain was an immotile, Gram-positive rod with a slime capsula. All strains utilized only the methyl residue of methoxyacetate and released glycolic acid. They also fermented methyl groups of methoxylated aromatic compounds and of betaine to acetate with growth yields of 6–10 g dry matter per mol methyl group. H₂/CO₂, formate, methanol, hexamethylene tetramine, as well as fructose, numerous organic acids, glycerol, ethylene glycol, and glycol ethers were fermented to acetate as well. High activities of carbon monoxide dehydrogenase (0.4–2.2 U x mg protein^–1) were detected in all three isolates. The guanine-plus-cytosine-content of the DNA of the freshwater isolates was 42.7 and 44.4 mol %, with the marine isolate it was 47.7 mol %. The freshwater strains were assigned to the genus Acetobacterium as new strains of the species A. carbinolicum. One freshwater isolate, strain KoMac1, was deposited with the Deutsche Sammlung von Mikroorganismen GmbH, Braunschweig, under the number DSM 5193.     

Anoxybacillus kamchatkensis sp. nov., a novel thermophilic facultative aerobic bacterium with a broad pH optimum from the Geyser valley, Kamchatka

A facultative aerobic, moderately thermophilic, spore forming bacterium, strain JW/VK-KG4 was isolated from an enrichment culture obtained from the Geyser valley, a geothermally heated environment located in the Kamchatka peninsula (Far East region of Russia). The cells were rod shaped, motile, peritrichous flagellated stained Gram positive and had a Gram positive type cell wall. Aerobically, the strain utilized a range of carbohydrates including glucose, fructose, trehalose, proteinuous substrates, and pectin as well. Anaerobically, only carbohydrates are utilized. When growing on carbohydrates, the strain required yeast extract and vitamin B₁₂. Anaerobically, glucose was fermented to lactate as main product and acetate, formate, ethanol as minor products. Aerobically, even in well-aerated cultures (agitated at 500 rpm), glucose oxidation was incomplete and lactate and acetate were found in culture supernatants as by-products. Optimal growth of the isolate was observed at pH^{25 C} 6.8–8.5 and 60°C. The doubling times on glucose at optimal growth conditions were 34 min (aerobically) and 40 min (anaerobically). The G+C content was 42.3 mol% as determined by T_m assay. Sequence analysis of the 16S rRNA gene indicated an affiliation of strain JW/VK-KG4 with Anoxybacillus species. Based on its morphology, physiology, phylogenetic relationship and its low DNA-DNA homology with validly published species of Anoxybacillus, it is proposed that strain JW/VK-KG4 represents a new species in the genus Anoxybacillus as A. kamchatkensis sp. nov. The type strain for the novel species is JW/VK-KG4^T (=DSM 14988, =ATCC BAA-549). The GenBank accession number for the 16S rDNA sequence is AF510985.     

Isolation and characterization of a new spore-forming sulfate-reducing bacterium growing by complete oxidation of catechol

A new mesophilic sulfate-reducing bacterium, strain Groll, was isolated from a benzoate enrichment culture inoculated with black mud from a freshwater ditch. The isolate was a spore-forming, rod-shaped, motile, gram-positive bacterium. This isolate was able of complete oxidation of several aromatic compounds including phenol, catechol, benzoate, p-and m-cresol, benzyl alcohol and vanillate. With hydrogen and carbon dioxide, formate or O-methylated aromatic compounds, autotrophic growth during sulfate reduction or homoacetogenesis was demonstrated. Lactate was not used as a substrate. SO _inf4 ^sup2- , SO _inf3 ^sup2- , and S₂O _inf3 ^sup2- were utilized as electron acceptors. Although strain Groll originated from a freshwater habitat, salt concentrations of up to 30 g·l^-1 were tolerated. The optimum temperature for growth was 35–37°C. The G+C content of DNA was 42.1 mol%. This isolate is described as a new species of the genus Desulfotomaculum.     

Isolation and characterization of a thermophilic acetotrophic strain of Methanothrix

An enrichment culture which converted acetate to methane at 60°C was obtained from a thermophilic anaerobic bioreactor. The predominant morphotype in the enrichment was a sheathed gas-vacuolated rod with marked resemblence to the mesophile Methanothrix soehngenii. This organism was isolated using vancomycin treatments and serial dilutions and was named Methanothrix sp. strain CALS-1. Strain CALS-1 grew as filaments typically 2–5 cells long, and cultures showed opalescent turbidity rather than macroscopic clumps. The cells were enclosed in a striated subunit-type sheath and there were distinct cross-walls between the cells, similar to M. soehngenii. The gas vesicles in cells were typically 70 nm in diameter and up to 0.5 m long, and were collapsed by pressures over 3 atm (ca. 300 kPa). Stationary-phase cells tended to have a higher vesicle content than did growing cells, and occasionally bands of cells were seen floating at the top of the liquid in stationary-phase cultures. Acetate was the only substrate of those tested which was used for methanogenesis by strain CALS-1, and acetate was decarboxylated by the aceticlastic reaction. The optimum temperature for growth of strain CALS-1 was near 60°C (doubling time=24–26 h), with no growth occurring at 70°C and 37°C. The optimum pH value for growth was near 6.5 in bicarbonate/CO₂ buffered medium and no growth occurred at pH 5.5 or pH 8.4. No growth was obtained below pH 7 when the medium was buffered with 20 mM phosphate. Strain CALS-1 grew in a chemically defined medium and required biotin. Sulfide concentrations over 1 mM were inhibitory to the culture, and growth was more rapid with 1 mM 2-mercaptoethane sulfonate (coenzyme M) or 1 mM titanium citrate as an accessory reductant than with 1 mM cysteine. It is likely that strain CALS-1 represents a new species in the genus Methanothrix.     

Two new species of anaerobic oxalate-fermenting bacteria,Oxalobacter vibrioformis sp. nov. and Clostridium oxalicum sp. nov., from sediment samples

Two types of new anaerobic bacteria were isolated from anoxic freshwater sediments. They grew in mineral medium with oxalate as sole energy source and with acetate as main carbon source. Oxalate as well as oxamate (after deamination) were decarboxylated to formate with growth yields of 1.2–1.4 g dry cell matter per mol oxalate degraded. No other organic or inorganic substrates were used, and no electron acceptors were reduced. Strain WoOx3 was a Gramnegative, non-sporeforming, motile vibrioid rod with a guanine-plus-cytosine content of the DNA of 51.6 mol%. It resembled the previously described genus Oxalobacter, and is described as a new species, O. vibrioformis. Strain AltOx1 was a Gram-positive, spore-forming, motile rod with a DNA base ratio of 36.3 mol% guanine-plus-cytosine. This isolate is described as a new species of the genus Clostridium, C. oxalicum.     

Comparison of anion-exchange and ion-modified reversed-phase liquid chromatography for the determination of S-sulfocysteine

A dual Hg–Au amalgam electrode is used to detect S-sulfocysteine (SSC) in this study. There exist two main components in the acetonitrile (ACN) rat brain extracts, namely, Cl⁻ and GSSG (oxidized glutathione), that are active in our detection system (GSH is not extracted in ACN). Two strong anion-exchange columns from different companies were used to separate the samples under different conditions, but SSC and Cl⁻ were not separated at the optimum detection pH of 5.2. The signal from Cl⁻ was greatly decreased by lowering the potential at the downstream electrode, though it cannot be completely eliminated. While a silver cartridge removed Cl⁻ from micromoles to several millimoles without any negative effect on the SSC signal in aqueous standards, a large negative peak which interferes with SSC detection was unfortunately introduced when a silver cartridge was applied to brain tissue samples. However, SSC and Cl⁻ in the samples are successfully separated by ion-modified reversed-phase LC in acetate buffer at the optimum detection pH (5.2). The separation conditions are 20 mM acetic acid, 2% methanol, 0.5 mM cetyltrimethylammonium p-toluene sulfonate (CTMA) (pH 5.2). Most importantly, the sensitivity of SSC under the optimum separation conditions is not sacrificed. The detection limit is 8 nM (20 μl injected).     

Isolation and characterization of a thermophilic sulfate-reducing bacterium Desulfotomaculum thermoacetoxidans sp. nov.

An obligately anaerobic thermophilic sporeforming sulfate-reducing bacterium, named strain CAMZ, was isolated from a benzoate enrichment from a 58°C thermophilic anaerobic bioreactor. The cells of strain CAMZ were 0.7 m by 2–5 m rods with pointed ends, forming single cells or pairs. Spores were central, spherical, and caused swelling of the cells. The Gram stain was negative. Electron donors used included lactate, pyruvate, acetate and other short chain fatty acids, short chain alcohols, alanine, and H₂/CO₂. Lactate and pyruvate were oxidized completely to CO₂ with sulfate as electron acceptor. Sulfate was required for growth on H₂/CO₂, and both acetate and sulfide were produced from H₂/CO₂-sulfate. Sulfate, thiosulfate, or elemental sulfur served as electron acceptors with lactate as the donor while sulfite, nitrate, nitrite, betaine, or a hydrogenotrophic methanogen did not. The optimum temperature for growth of strain CAMZ was 55–60°C and the optimum pH value was 6.5. The specific activities of carbon monoxide dehydrogenase of cells of strain CAMZ grown on lactate, H₂/CO₂, or acetate with sulfate were 7.2, 18.1, and 30.8 mol methyl viologen reduced min^–1 [mg protein]^–1, respectively, indicating the presence of the CO/Acetyl-CoA pathway in this organism. The mol%-G+C of strain CAMZ's DNA was 49.7. The new species name Desulfotomaculum thermoacetoxidans is proposed for strain CAMZ.     

Acetonema longum gen.nov.sp.nov., an H2/CO2 acetogenic bacterium from the termite,Pterotermes occidentis

A previously undescribed, H₂-oxidizing CO₂-reducing acetogenic bacterium was isolated from gut contents of the wood-feeding termite, Pterotermes occidentis. Cells of representative strain APO-1 were strictly anaerobic, Gram-negative, endospore-forming motile rods which measured 0.30–0.40×6–60 m. Cells were catalase positive, oxidase negative, and had 51.5 mol percent G+C in their DNA. Optimum conditions for growth on H₂+CO₂ were at 30–33°C and pH (initial) 7.8, and under these conditions cells formed acetate according to the equation: 4 H₂+2 CO₂CH₃COOH+2 H₂O. Other energy sources supporting good growth of strain APO-1 included glucose, ribose, and various organic acids. Acetate and butyrate were major fermentation products from most organic compounds tested, however propionate, succinate, and 1,2-propanediol were also formed from some substrates. Based on comparative analysis of 16S rRNA nucleotide sequences, strain APO-1 was related to, but distinct from, members of the genus Sporomusa. Moreover, physiological and morphological differences between strain APO-1 and the six known species of Sporomusa were significant. Consequently, it is proposed herewith that a new genus, Acetonema, be established with strain APO-1 as the type strain of the new species, Acetonema longum. A. longum may contribute to the nutrition of P. occidentis by forming acetate, propionate and butyrate, compounds which are important carbon and energy sources for termites.     

Sporomusa termitida sp. nov., an H2/CO2-utilizing acetogen isolated from termites

H₂-oxidizing CO₂-reducing acetogenic bacteria were isolated from gut contents of Nasutitermes nigriceps termites. Isolates were strictly anaerobic, Gram negative, endospore-forming, straight to slightly curved rods (0.5–0.8×2–8 m) that were motile by means of lateral flagella. Cells were oxidase negative, but catalase positive and possessed a b-type cytochrome(s) associated with the cell membrane. Cells grew anaerobically with H₂+CO₂ as energy source and catalyzed a total synthesis of acetate from this gas mixture. H₂ uptake by a representative isolate (strain JSN-2) displayed a K _m=6 M and V _max=380 nmol x min^-1 x mg protein^-1. Other substrates used as energy sources for growth and acetogenesis included CO, methanol, betaine, trimethoxybenzoate, and various other organic acids. Succinate was also fermented, but propionate was formed from this substrate instead of acetate. Of a variety of sugars and sugar alcohols tested, only mannitol supported growth. Cells grew optimally at 30° C and pH 7.2 and required yeast extract or a source of amino acids (e.g. Casamino acids) for good growth. During initial enrichment and isolation, cells appeared sensitive to various reducing agents commonly employed in media for anaerobes. The DNA base composition of strain JSN-2 was 48.6 mol% G+C. On the bases of cell morphology, substrate utilization spectrum, and DNA base composition, strain JSN-2 is here-with proposed as the type strain of the new species Sporomusa termitida.Journal article no. 12513 from the Michigan Agricultural Experiment Station     

Anaerobic,alkaliphilic, saccharolytic bacterium <Emphasis Type="Italic">Alkalibacter saccharofermentans</Emphasis> gen. nov., sp. nov. from a soda lake in the Transbaikal region of Russia

Three strains of new obligately anaerobic alkaliphilic bacteria have been isolated as a saccharolytic component from the cellulolytic community of alkaline Lake Nizhnee Beloe (Transbaikal region, Russia), a lake with low salt concentration. DNA analysis of these strains showed an interspecies level of DNA similarity of 96–100%. Strain Z-79820 was selected for further investigations. Cells were Gram-positive, asporogenous, nonmotile short rods with pointed ends. The strain was a true alkaliphile: growth occurred from pH 7.2 to 10.2 with the optimum at pH 9.0. Strain Z-79820 was halotolerant and could grow in medium with up to 10% (w/v) NaCl, with the optimum between 0 and 4% NaCl. The new isolate obligately depended on Na⁺ ions in the form of carbonates or chlorides. Total Na⁺ content needed for optimal growth was 0.46 M Na⁺, with a wide range from 0.023–0.9 M Na⁺ at which growth also occurred. The isolate was a mesophile and grew at temperatures from 6 to 50°C (slow growth at 6 and 15°C) with an optimum at 35°C. The organotrophic organism fermented ribose, xylose, glucose, mannose, fructose, sucrose, mannitol, and peptone. The products of glucose fermentation were acetate, ethanol, formate, H₂, and CO₂. Yeast extract was required for some anabolic needs. The DNA G+C content of the type strain Z-79820 was 42.1 mol%. The new bacterium fell into the 16S rRNA gene cluster XV of the Gram-positive bacteria with low G+C content, where it formed an individual branch. Based on its growth characteristics and genotype traits, we propose the new genus and species named Alkalibacter saccharofermentans with the type strain Z-79820 (=DSM14828), Uniqem-218 (Institute Microbiology, RAS; ).     

The impact of nutrition on spore yields for various fungal entomopathogens in liquid culture

Spore yields were measured for various fungal entomopathogens grown in six nutritionally different liquid media with low and high carbon concentrations (8 and 36 g l^–1, respectively) at carbon-to-nitrogen (C:N) ratios of 10:1, 30:1 and 50:1. Six fungi were tested: two Beauveria bassiana strains, three Paecilomyces fumosoroseus strains and one Metarhizium anisopliae strain. Spore yields were examined after 2, 4 or 7 days growth. In general, highest spore yields were obtained in media containing 36 g/l and a C:N ratio of 10:1. After 4 days growth, highest spore yields were measured in the three Paecilomyces isolates (6.9–9.7 × 10⁸ spores ml^–1). Spore production by the B. bassiana isolates was variable with one isolate producing high spore yields (12.2 × 10⁸ spores ml^–1) after 7 days growth. The M. anisopliae isolate produced low spore concentrations under all conditions tested. Using a commercial production protocol, a comparison of spore yields for the coffee berry borer P. fumosoroseus and a commercial B. bassiana isolate showed that highest spore concentrations (7.2 × 10⁸ spores ml^–1) were obtained with the P. fumosoroseus isolate 2-days post-inoculation. The ability of the P. fumosoroseus strain isolated from the coffee berry borer to rapidly produce high concentrations of spores prompted further testing to determine the desiccation tolerance of these spores. Desiccation studies showed that ca. 80% of the liquid culture produced P. fumosoroseus spores survived the air-drying process. The virulence of freshly produced, air-dried and freeze-dried coffee berry borer P. fumosoroseus blastospores preparations were tested against silverleaf whiteflies (Bemisia argentifolii). While all preparations infected and killed B. argentifolii, fresh and air-dried preparations were significantly more effective. These results suggest that screening potential fungal biopesticides for amenability to liquid culture spore production can aid in the identification of commercially viable isolates. In this study, P. fumosoroseus was shown to possess the production and stabilization attributes required for commercial development.     

Characterization of Desulfovibrio fructosovorans sp. nov.

Desulfovibrio strain JJ isolated from estuarine sediment differed from all other described Desulfovibrio species by the ability to degrade fructose. The oxidation was incomplete, leading to acetate production. Fructose, malate and fumarate were fermented mainly to succinate and acetate in the absence of an external electron acceptor. The pH and temperature optima for growth were 7.0 and 35° C respectively. Strain JJ was motile by means of a single polar flagellum. The DNA base composition was 64.13% G+C. Cytochrome c ₃ and desulfoviridin were present. These characteristics established the isolate as a new species of the genus Desulfovibrio, and the name Desulfovibrio fructosovorans is proposed.     

Fermentation of 2-methoxyethanol by Acetobacterium malicum sp. nov. and Pelobacter venetianus

Anaerobic bacteria degrading 2-methoxyethanol were enriched from freshwater sediments, and three strains were isolated in pure culture. Two of them were Grampositive non-spore-forming rods and grew strictly anaerobically by acetogenic fermentation. Optimal growth occurred at 30°C, initial pH 7.5–8.0. 2-Methoxyethanol and 2-ethoxyethanol were fermented to acetate and corresponding alcohols. Hydrogen plus carbon dioxide, formate, acetoin, l-malate, lactate, pyruvate, fructose, and methoxyl groups of 3,4,5-trimethoxybenzoate and 3,4,5-trimethoxycinnamate were fermented to acetate. 1,2-Propanediol was fermented to acetate, propionate, and propanol. Strain MuME1 was described as a new species, Actetobacterium malicum. It had a DNA base composition of 44.1 mol% guanine plus cytosine. The third strain, which was identified as Pelobacter venetianus, fermented 2-methoxyethanol to methanol, ethanol, and acetate.     

Amphibacillus fermentum sp. nov. and Amphibacillus tropicussp. nov., New Alkaliphilic,Facultatively Anaerobic,Saccharolytic Bacilli from Lake Magadi

New alkaliphilic, saccharolytic, rod-shaped, gram-positive bacteria resistant to heating and drying and phylogenetically affiliated to the Bacilluslineage were isolated under strictly anaerobic conditions from sediments of the alkaline and highly mineralized Lake Magadi. Strain Z-7792 forms endospores; in strain Z-7984, endospore formation was not revealed. The strains are capable of both anaerobic growth (at the expense of fermentation of glucose and certain mono- and disaccharides with the formation of formate, ethanol, and acetate) and aerobic growth. Among polysaccharides, the strains hydrolyze starch, glycogen, and xylan. Yeast extract or methionine are required for growth. The strains are strict alkaliphiles exhibiting obligate requirement for Na⁺and carbonate ions, but not for Cl^–ions. Growth occurs at a total mineralization as high as 3.3–3.6 M Na⁺, with an optimum at 1–1.7 M Na⁺. Strain Z-7792 is an obligate alkaliphile with a pH growth range of 8.5–11.5 and an optimum of 9.5–9.7. Strain Z-7984 grows in a pH range of 7.0–10.5 with an optimum at 8.0–9.5. Both strains are mesophiles having a growth optimum at 37–38°C. The G+C contents of the DNA of strains Z-7792 and Z-7984 are 39.2 and 41.5 mol %, respectively. These isolates of facultatively anaerobic, strictly alkaliphilic, Na⁺-dependent bacilli can be considered representatives of the ecological group adapted to life at drying-up shoals of soda lakes. Because of their independence of NaCl and lack of obligate dependence on sodium carbonates, the isolates are to be assigned to athalassophilic organisms. According to their physiological and phylogenetic characteristics, they taxonomically belong to group 1 of the species of bacilli with a low G+C content and occupy a position intermediate between the genera Amphibacillusand Gracilibacillus.The isolates are described as new species of Amphibacillus: A. fermentum(type strain, Z-7984^T) and A. tropicus(type strain, Z-7792^T).     

Desulfacinum subterraneumsp. nov., a New Thermophilic Sulfate-Reducing Bacterium Isolated from a High-Temperature Oil Field

A new thermophilic sulfate-reducing bacterium isolated from the high-temperature White Tiger oil field (Vietnam) is described. Cells of the bacterium are oval (0.4–0.6 by 0.6–1.8 m), nonmotile, non-spore-forming, and gram-negative. Growth occurs at 45 to 65°C (with an optimum at 60°C) at NaCl concentrations of 0 to 50 g/l. In the course of sulfate reduction, the organism can utilize lactate, pyruvate, malate, fumarate, ethanol, salts of fatty acids (formate, acetate, propionate, butyrate, caproate, palmitate), yeast extract, alanine, serine, cysteine, and H₂+ CO₂(autotrophically). In addition to sulfate, the bacterium can use sulfite, thiosulfate, and elemental sulfur as electron acceptors. In the absence of electron acceptors, the bacterium can ferment pyruvate and yeast extract (a yet unrecognized capacity of sulfate reducers) with the formation of acetate and H₂. The G+C content of DNA is 60.8 mol %. The level of DNA–DNA hybridization of the isolate (strain 101^T) and Desulfacinum infernum(strain BG1^T) is as low as 34%. Analysis of the nucleotide sequence of 16S rDNA places strain 101^Tin the phylogenetic cluster of the Desulfacinumspecies within the sulfate reducer subdivision of the delta subclass of Proteobacteria. All these results allowed the bacterium studied to be described as a new species, Desulfacinum subterraneumsp. nov., with strain 101 as the type strain.     

Bacterial Metabolism of Arylsulfonates: 1. Benzene Sulfonate as Growth Substrate for Pseudomonas testosteroni H-81

Pseudomonas testosteroni H-8 utilizes as sole carbon source benzene sulfonate (BS), p-toluene sulfonate (pTS), and ethylbenzene sulfonate (EBS) but not higher homologs. Growth on BS was rapid (generation time, 3 hr) and efficient (Y = 57), and resulted in accumulation of sulfate. As the culture is acid-sensitive, the medium must be heavily buffered to permit extensive growth. The BS oxidase system is inducible. Cells grown on BS, but not glutamate, oxidized BS, pTS, or EBS without lag (QO₂ = 50 to 100). Oxygen uptake on BS is temperature-dependent and sensitive to cyanide. Complete oxidation of 1 μmole of BS consumed approximately 5.7 μmoles of oxygen.