Superoxide dismutase in anaerobes: survey.

Superoxide dismutase (SOD) was present in 23 of 28 strains of the genus Bacteroides tested. Several clostridia, anaerobic cocci, and anaerobic, grampositive, nonsporing rods contained measureable SOD, but the frequency of SOD occurrence was much lower than in the bacteroides. These data indicate that there is a large variation in SOD levels between genera and among species within a genus of anaerobic bacteria. There was also no correlation between source of isolate, SOD levels, and presumed pathogenicity of the isolate.     

Differential divergences of obligately insect-pathogenic Entomophthora species from fly and aphid hosts

Cecal microbiota of chicken was screened for bacteria involved in the biotransformation of isoflavones. A new facultative anaerobic bacterium, capable of deglycosylation of the isoflavone genistin, was isolated and identified as a Lactobacillus delbrueckii -like strain. The isolate MF-07 was Gram-positive, facultatively anaerobic, catalase negative, non-spore-forming, nonmotile and a straight rod. The polyphasic taxonomic data, along with 16S rRNA gene sequence comparison, demonstrated that the isolate MF-07 was most closely related to L. delbrueckii group of the Lactobacillus genus. Considerable amounts of genistein were accumulated with genistin as a substrate within the first 12 h of fermentation. Formononetin and daidzein were not metabolized. The influence of several carbon sources on the growth of the isolate MF-07 and biotransformation of genistin was also investigated. This is the first study in which an anaerobic Lactobacillus bacterium from the chicken intestinal tract that metabolizes genistin to produce its bioactive metabolite was identified and characterized.     

Catalase and superoxide dismutase in the cells of strictly anaerobic microorganisms

Strictly anaerobic microorganisms relating to various physiological groups were screened for catalase and superoxide dismutase (SOD) activity. All of the investigated anaerobes possessed the SOD activity, necessary for protection against toxic products of oxygen reduction. High specific activities of SOD were found in Acetobacterium woodii and Acetobacterium wieringae. Most of the investigated clostridia and acetogens were catalase-negative. A significant activity of catalase was found in Thermohydrogenium kirishiense, in representatives of the genus Desulfotomaculum, and in several methanogens. Methanobrevibacter arboriphilus had an exceptionally high catalase activity after growth in medium supplemented with hemin. Hemin also produced a strong positive effect on the catalase activity in many other anaerobic microorganisms. In methanogens, the activities of the enzymes of antioxidant defense varied in wide ranges depending on the stage of growth and the energy source.     

Ectothiorhodospira marismortui sp. nov., an obligately anaerobic,moderately halophilic purple sulfur bacterium from a hypersaline sulfur spring on the shore of the Dead Sea

A novel type of purple sulfur bacterium was isolated from a hypersaline sulfur spring on the shore of the Dead Sea. The cells of the isolate are irregularly rod-shaped or curved, and motile by means of a tuft of polar flagella. The photosynthetic system, containing bacteriochlorophyll a and carotenoids of the spirilloxanthin series, is located on stacks of lamellar membranes in the cell cytoplasm. The organism can grow either photoautotrophically with sulfide as electron donor, which is oxidized via extracellular sulfur to sulfate, or photoheterotrophically, using acetate, succinate, fumarate, malate or pyruvate as carbon sources. The bacterium is obligately anaerobic, and requires a source of reduced sulfur for growth. The isolate is moderately halophilic, and grows optimally at NaCl concentrations between 3 and 8%, temperatures between 30 and 45°C, and neutral pH. 16S ribosomal RNA oligonucleotide cataloging suggests a close relationship to purple sulfur bacteria of the genus Ectothiorhodospira. As the isolate differs greatly from the described members of the genus Ectothiorhodospira, we describe the isolate as a new species, and propose the name Ectothiorhodospira marismortui sp. nov.     

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.7% similarity) and Clostridium ramosum (96.6%). In contrast to these species, the isolate was devoid of alpha-galactosidase and -glucosidase and did not grow on maltose, melibiose, raffinose, rhamnose and trehalose. The hypothesis that strain SDG-Mt85-3Db represents a new bacterial species of the Clostridium cluster XVIII was confirmed by DNA-DNA hybridisation experiments. The G+C content of DNA of strain SDG-Mt85-3Db (30.7+/-0.8 mol%) was comparable with that of Clostridium butyricum, the type species of the genus Clostridium. The name Clostridium saccharogumia is proposed for strain SDG-Mt85-3Db (=DSM 17460T=CCUG 51486T). The second isolate, strain ED-Mt61/PYG-s6, was a mesophilic strictly anaerobic Gram-positive regular rod. Based on 16S rRNA gene sequence analysis, its nearest relatives were Clostridium amygdalinum (93.3%), Clostridium saccharolyticum (93.1%) and Ruminococcus productus (93.0%). The isolate differed from these species in its ability to dehydrogenate enterodiol. It also possessed alpha-arabinosidase and -galactosidase and had a higher G+C content of DNA (48.0 mol%). According to these findings, it is proposed to create a novel genus, Lactonifactor, and a novel species, Lactonifactor longoviformis, to accommodate strain ED-Mt61/PYG-s6. The type strain is DSM 17459T (=CCUG 51487T).     

Catalase and Superoxide Dismutase in the Cells of Strictly Anaerobic Microorganisms

Strictly anaerobic microorganisms relating to various physiological groups were screened for catalase and superoxide dismutase (SOD) activity. All of the investigated anaerobes possessed SOD activity, necessary for protection against toxic products of oxygen reduction. High specific activities of SOD were found in Acetobacterium woodii and Acetobacterium wieringae. Most of the investigated clostridia and acetogens were catalase-negative. A significant activity of catalase was found in Thermohydrogenium kirishiense, in representatives of the genus Desulfotomaculum, and in several methanogens. Methanobrevibacter arboriphilus had an exceptionally high catalase activity after growth in medium supplemented with hemin. Hemin also produced a strong positive effect on the catalase activity in many other anaerobic microorganisms. In methanogens, the activities of the enzymes of antioxidant defense varied in wide ranges depending on the stage of growth and the energy source.     

Microbial diversity of the brine-seawater interface of the Kebrit Deep, Red Sea, studied via 16S rRNA gene sequences and cultivation methods.

The brine-seawater interface of the Kebrit Deep, northern Red Sea, was investigated for the presence of microorganisms using phylogenetic analysis combined with cultivation methods. Under strictly anaerobic culture conditions, novel halophiles were isolated. The new rod-shaped isolates belong to the halophilic genus Halanaerobium and are the first representatives of the genus obtained from deep-sea, anaerobic brine pools. Within the genus Halanaerobium, they represent new species which grow chemoorganotrophically at NaCl concentrations ranging from 5 to 34%. The cellular fatty acid compositions are consistent with those of other Halanaerobium representatives, showing unusually large amounts of Delta7 and Delta11 16:1 fatty acids. Phylogenetic analysis of the brine-seawater interface sample revealed the presence of various bacterial 16S rRNA gene sequences dominated by cultivated members of the bacterial domain, with the majority affiliated with the genus Halanaerobium. The new Halanaerobium 16S rRNA clone sequences showed the highest similarity (99.9%) to the sequence of isolate KT-8-13 from the Kebrit Deep brine. In this initial survey, our polyphasic approach demonstrates that novel halophiles thrive in the anaerobic, deep-sea brine pool of the Kebrit Deep, Red Sea. They may contribute significantly to the anaerobic degradation of organic matter enriched at the brine-seawater interface.     

Thiofractor thiocaminus gen. nov., sp. nov., a novel hydrogen-oxidizing, sulfur-reducing epsilonproteobacterium isolated from a deep-sea hydrothermal vent chimney in the Nikko Seamount field of the northern Mariana Arc

A novel chemolithoautotrophic hydrogen-oxidizing and sulfur-reducing bacterium, strain 496Chim(T), was isolated from a deep-sea hydrothermal vent chimney collected from the hydrothermal field at the summit of Nikko Seamount field, in the Mariana Arc. Cells were rods or curved rods, motile by means of a single polar flagellum. Growth was observed between 15 and 45?°C (optimum 37?°C; doubling time, 2.1?h) and between pH 5.3 and 8.0 (optimum pH 6.0). The isolate was a strictly anaerobic, obligate chemolithoautotroph capable of growth using molecular hydrogen as the sole energy source, carbon dioxide as the sole carbon source, ammonium or nitrate as the sole nitrogen source, and elemental sulfur as the electron acceptor. The G+C content of genomic DNA was 35?mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolate belonged to the class Epsilonproteobacteria, but the isolate was distantly related to the previously described Epsilonproteobacteria species potentially at the genus level (<90?%). On the basis of its physiological and molecular characteristics, strain 496Chim(T) (=DSM 22050(Τ)?=?JCM 15747(Τ)?=?NBRC 105224(Τ)) represents the sole species of a new genus, Thiofractor, for which the name Thiofractor thiocaminus is proposed.     

Isolation of Thermoanaerobacter keratinophilus sp. nov., a novel thermophilic, anaerobic bacterium with keratinolytic activity

Several thermophilic anaerobic bacteria with keratinolytic activity growing at temperatures between 50 degrees C and 90 degrees C were isolated from samples collected on the island of S?o Miguel in the Azores (Portugal). On the basis of morphological, physiological, and 16S rDNA studies, the isolate 2KXI was identified as a new species of the genus Thermoanaerobacter, designated Thermoanaerobacter keratinophilus. This strain, which grows optimally at 70 degrees C, pH 7.0, and 0.5% NaCl, is the first member of the genus Thermoanaerobacter that has been described for its ability to degrade native keratin. Around 70% of native wool was solubilized after 10 days of incubation under anaerobic conditions. The strain was shown to possess intracellular and extracellular proteases optimally active at 60 degrees C, pH 7.0, and 85 degrees C, pH 8.0, respectively. Keratin hydrolysis was demonstrated in vitro using a sodium dodecyl sulfate gel containing feather meal. The extracellular protease responsible for breaking down keratin fibers was purified to homogeneity in only one step by applying hydroxyapatite column chromatography. The enzyme belongs to the serine-type proteases and has a molecular mass of 135 kDa.     

Isolation and characterization of xanthan-degrading Enterobacter sp. nov. LB37 for reducing the viscosity of xanthan in petroleum industry

A Gram-negative, straight rod and facultative anaerobic bacterium was isolated from soil sample. It exhibits the phenotypic characteristics consistent with its classification in the genus Enterobacter. The isolate ferment glucose to acid and gas. Arginine dihydrolase, ornithin decarboxylase and gelatinase but not deoxyribonuclease was produced by this isolate. There was no hydrogen sulfide production. On the basis of the phenotypic data, together with phylogenetic analysis based on 16S rDNA gene sequences, this strain should represent a novel species of the genus Enterobacter and was designated as LB37. The strain LB37 could degrade xanthan molecules resulting in the rapid decrease of the viscosity of xanthan solution used in oil drilling process. Endoxanthanase activity was also detected in the culture supernatant. To our knowledge, it is the first report on the microbes being involved in the xanthan degradation for oil industry. The isolate LB37 would be useful for potential application in enhanced oil recovery and oil drilling field.     

Isolation and characterization of Pediococcus halophilus from salted anchovies (Engraulis anchoita)

The presence of bacteria in salted anchovies during and at the end of the curing process was investigated. Attempts to isolate bacteria under aerobic or anaerobic conditions led to the isolation of only bacteria of the genus Pediococcus which were identified as Pediococcus halophilus. The isolates correspond to a rather heterogeneous group in which some of the members differ in some biochemical tests from the types described in the literature.     

Isolation and characterization of Pediococcus halophilus from salted anchovies (Engraulis anchoita).

The presence of bacteria in salted anchovies during and at the end of the curing process was investigated. Attempts to isolate bacteria under aerobic or anaerobic conditions led to the isolation of only bacteria of the genus Pediococcus which were identified as Pediococcus halophilus. The isolates correspond to a rather heterogeneous group in which some of the members differ in some biochemical tests from the types described in the literature.     

Description of a Novel Symbiotic Bacterium from the Brittle Star, Amphipholis squamata

A gram-negative, marine, facultatively anaerobic bacterial isolate designated strain AS-1 was isolated from the subcuticular space of the brittle star, Amphipholis squamata. Its sensitivity to O/129 and novobiocin, overall morphology, and biochemical characteristics and the moles percent guanine-plus-cytosine composition of its DNA (42.9 to 44.4) suggest that this isolate should be placed in the genus Vibrio. Strain AS-1 was not isolated from ambient seawater and is distinct from described Vibrio species. This symbiotic bacterium may assist its host as one of several mechanisms of nutrient acquisition during the brooding of developing embryos.     

Isolation of hexavalent chromium-reducing Cr-tolerant facultative anaerobes from tannery effluent

Several facultative anaerobes tolerant to high levels of chromate (>400 mg/ml) were isolated from tannery effluents. These isolates displayed varying degrees of Cr(VI) reduction under aerobic and anaerobic conditions at room temperature (24+/-2 degrees C). Interestingly, eight isolates were efficient in reducing 70% Cr(VI) anaerobically. This includes 5 isolates of genus Aerococcus, two isolates of Micrococcus and single isolate of genus Aeromonas. These isolates were subjected to further characterization for possible use in Cr(VI) detoxification of industrial wastes. This is the first report of Aerococcus sp. capable of Cr(VI) reduction >70% anaerobically. These bacteria were further checked for tolerance to a variety of other heavy metals. Our study indicates the possible use of these bacteria in environmental clean up.     

Genome sequence of Peptoniphilus rhinitidis 1-13T, an anaerobic coccus strain isolated from clinical specimens

A new Peptoniphilus species has been isolated from samples from a patient who was scheduled for endoscopic sinus surgery for chronic rhinosinusitis. The isolate, Peptoniphilus rhinitidis 1-13(T) (KCTC 5985(T)), can use peptone as a sole carbon source and produce butyrate as a metabolic end product. This is the first report of the draft genome sequence of a novel species in the genus Peptoniphilus within the group of Gram-positive anaerobic cocci.     

Paraliobacillus ryukyuensis gen. nov., sp. nov., a new Gram-positive,slightly halophilic,extremely halotolerant,facultative anaerobe isolated from a decomposing marine alga

A slightly halophilic, extremely halotolerant, alkaliphilic, and facultatively anaerobic rod bacterium was isolated from a decomposing marine alga collected in Okinawa, Japan. The isolate, designated O15-7(T), was Gram-positive, endospore-forming, catalase-positive, menaquinone-7-possessing bacterium that is motile by peritrichous flagella. The isolate was an inhabitant of marine environments; the optimum NaCl concentration for growth was 0.75-3.0% (w/v) with a range of 0-22.0%, and the optimum pH was 7.0-8.5 with a range of 5.5-9.5. Catalase was produced in aerobic cultivation but not in anaerobic cultivation. Carbohydrate, sugar alcohol or a related carbon compound was required for growth. In aerobic cultivation, the isolate produced pyruvate, acetate and CO(2) from glucose, and in anaerobic cultivation, it produced lactate, formate, acetate and ethanol with a molar ratio of approximately 2 : 1 : 1 for the last three products. No gas was produced anaerobically. Lactate yield per consumed glucose was markedly affected by the pH of the fermentation medium: 51% at pH 6.5 and 8% at pH 9.0. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Phylogenetically, the isolate occupied an independent lineage within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1 with the highest 16S rRNA gene sequence similarity of 95.2% to the genus Gracilibacillus. For this isolate, Paraliobacillus ryukyuensis gen. nov., sp. nov. was proposed. The type strain, O15-7(T) (G+C535.6 mol%), has been deposited in the DSMZ, IAM, NBRC, and NRIC (DSM 15140(T)=IAM 15001(T)=NBRC 10001(T)=NRIC 0520(T)).     

Selective enrichment and characterization of a phosphorus-removing bacterial consortium from activated sludge

Under alternating aerobic/anaerobic conditions and without additional carbon sources, a bacterial consortium consisting initially of 18 bacterial strains was obtained in a sequence batch reactor. The phosphorus removal capability could only be maintained using sterile filtrate of activated sludge as medium. The addition of calcium and magnesium salts, as well as vitamins and trace elements, to autoclaved sterile filtrate of activated sludge was not sufficient to achieve stable phosphorus removal. A further enrichment by subcultivation on solid, agar, freezing, and shortening of the aerobic and anaerobic phases led to a defined bacterial consortium consisting of four strains. On the basis of physiological and chemotaxonomic characterization, and partial 16S rRNA sequencing, one of the organisms was identified as Delftia acidovorans. A further isolate belonged to the Bacillus cereus group, and the third isolate was identified as Microbacterium sp.. The remaining strain seems to represent a new genus within the Flavobacteriaceae. Under continuous chemostat conditions, this consortium was able to remove up to 9.6 mg P/l phosphate in the aerobic phase and released up to 8.5 mg/l in the anaerobic phase. Up to 25 mg P-polyphosphate/g dry mass was stored under aerobic conditions.     

Microbial Diversity of the Brine-Seawater Interface of the Kebrit Deep, Red Sea, Studied via 16S rRNA Gene Sequences and Cultivation Methods

The brine-seawater interface of the Kebrit Deep, northern Red Sea, was investigated for the presence of microorganisms using phylogenetic analysis combined with cultivation methods. Under strictly anaerobic culture conditions, novel halophiles were isolated. The new rod-shaped isolates belong to the halophilic genus Halanaerobium and are the first representatives of the genus obtained from deep-sea, anaerobic brine pools. Within the genus Halanaerobium, they represent new species which grow chemoorganotrophically at NaCl concentrations ranging from 5 to 34%. The cellular fatty acid compositions are consistent with those of other Halanaerobium representatives, showing unusually large amounts of Δ7 and Δ11 16:1 fatty acids. Phylogenetic analysis of the brine-seawater interface sample revealed the presence of various bacterial 16S rRNA gene sequences dominated by cultivated members of the bacterial domain, with the majority affiliated with the genus Halanaerobium. The new Halanaerobium 16S rRNA clone sequences showed the highest similarity (99.9%) to the sequence of isolate KT-8-13 from the Kebrit Deep brine. In this initial survey, our polyphasic approach demonstrates that novel halophiles thrive in the anaerobic, deep-sea brine pool of the Kebrit Deep, Red Sea. They may contribute significantly to the anaerobic degradation of organic matter enriched at the brine-seawater interface.     

Isolation of facultatively aerobic actinomycetes from the gut, parent soil and mound materials of the termites Procubitermesaburiensis and Cubitermes severus

Abstract Isolates of the genus Streptomyces were readily obtained from the intestines of two African species of soil-feeding termites by an aerobic explant technique using starch casein medium, and from their parent soil and mound materials by dilution plating. Discriminant analysis of the isolates, based on 44 representative characters, showed that the population derived directly from the termites was significantly different from that of the feed soil or the mound. The termite gut was considered to be a good source of unusual actinomycetes, but strains isolated under aerobic conditions are likely to be allochthons selected by the intestinal environment, which is highly alkaline and anaerobic. An anaerobic, filamentous isolate was obtained which may be a component of the prokaryotic symbiont population mediating termite digestion.