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1.
Two heterotrophic, thermophilic, sulfur-reducing archaea were isolated from the Guaymas Basin hydrothermal vent. The fermentation of proteinaceous and carbohydrate substrates was examined at 85°C for each isolate in the presence and absence of elemental sulfur and in coculture with a thermophilic methanogen. The heterotrophic isolates differed with respect to their requirement for sulfur. Both heterotrophic isolates exhibited a mixed organic acid fermentation from proteinaceous substrates; however, acetate was the sole organic acid produced from carbohydrate fermentation. In coculture fermentations with a thermophilic methanogen, the heterotrophic isolates exhibited enhanced growth and fermentation. Interspecies hydrogen transfer and elemental sulfur-reduction may be important microbial processes in deep-sea hydrothermal vent community metabolism. 相似文献
2.
Mechthild Pohlschroeder Susan B. Leschine Ercole Canale-Parola 《Archives of microbiology》1994,161(1):17-24
Two strains of obligately anaerobic, thermophilic spirochetes were isolated from cyanobacterial mat samples collected at freshwater hot springs in Oregon and Utah, USA. The isolates grew optimally between 48° and 52°C, and did not grow at 25° or 60°C. Both strains fermented various pentoses, hexoses, and disaccharides. Amino acids or cellulose did not serve as fermentable substrates for growth. H2, CO2, acetate, and lactate were end products of d-glucose fermentation. On the basis of physiological characteristics, guanine + cytosine content of DNA, and comparisons of 16S ribosomal RNA sequences, it was concluded that the two isolates were representatives of a novel species of Spirochaeta for which the name Spirochaeta caldaria is proposed. One of the two strains was grown in coculture with a thermophilic cellulolytic bacterium (Clostridium thermocellum) in a medium containing cellulose as the only fermentable substrate. In the coculture cellulose was broken down at a faster rate than in the clostridial monoculture. The results are consistent with the suggestion that interactions between cellulolytic bacteria and non-cellulolytic spirochetes enhance cellulose breakdown in natural environments in which cellulose-containing plant material is biodegraded. 相似文献
3.
S. S. Socransky S. C. Holt E. R. Leadbetter A. C. R. Tanner E. Savitt B. F. Hammond 《Archives of microbiology》1979,122(1):29-33
Sixty-eight strains of capnophilic fusiform Gram-negative rods from the human oral cavity were subjected to extensive physiologic characterization, tested for susceptibility to various antibiotics, and the mol-percent guanine plus cytosine of each isolate determined. The characteristics of the isolates were compared with 10 fresh and 2 stock isolates of Fusobacterium nucleatum. The isolates clearly differed from the Fusobacterium species on the basis of molpercent guanine plus cytosine, end products, growth in a capnophilic environment and fermentation of carbohydrates.All of the gliding isolates required CO2 and formed acetate and succinate, but not H2S, indole or acetylmethylcarbinol. All fermented glucose, sucrose, maltose and mannose. The organisms may be differentiated on the basis of fermentation of additional carbohydrates, hydrolysis of polymers and reduction of nitrate. Three species are proposed: Capnocytophaga ochracea, Capnocytophaga sputigena and Capnocytophaga gingivalis. Ten isolates did not fit into the proposed species. 相似文献
4.
Bacterial sulfur reduction in hot vents 总被引:1,自引:0,他引:1
E.A. Bonch-Osmolovskaya 《FEMS microbiology reviews》1994,15(1):65-77
Abstract: Elemental sulfur can be reduced through different microbial processes, including catabolically significant sulfur respiration and reduction of sulfur in the course of fermentation. Both of these processes are found in thermophilic microorganisms inhabiting continental and submarine hot vents, where elemental sulfur is one of the most common sulfur species. Among extreme thermophiles, respresented mainly by Archaea, sulfur-respiring bacteria include hydrogen-utilizing lithoautotrophs and heterotrophs, oxidizing complex organic substrates. Some marine heterotrophic sulfur-reducing Archaea were found to ferment peptides and polysaccharides, using elemental sulfur as an electron sink and thus avoiding the formation of molecular hydrogen which is highly inhibiting. Moderately thermophilic communities contain eubacterial sulfur reducers capable of lithotrophic and heterotrophic growth. Total mineralization of organic matter is carried out by a complex microbial system consisting of fermentative heterotrophs, which use elemental sulfur as an electron sink, and sulfur-respiring bacteria of the genus Desulfurella , which oxidize other fermentation products, yielding only COf2 and Hf2 S. The most remarkable thermophilic microbial community is the thermophilic cyanobacterial mat found in the Uzon caldera, Kamchatka, which contains elemental sulfur among the layers. Organic matter produced by the thermophilic Oscillatoria is completely and rapidly mineralized by means of sulfur reduction. 相似文献
5.
Sizova MV Izquierdo JA Panikov NS Lynd LR 《Applied and environmental microbiology》2011,77(7):2282-2291
Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to a Clostridium clariflavum strain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation. 相似文献
6.
Fermentation products and plant cell wall-degrading enzymes produced by monocentric and polycentric anaerobic ruminal fungi 总被引:1,自引:0,他引:1
Five anaerobic fungal isolates from the bovine rumen were grown on Coastal Bermuda grass (CBG) leaf blades and monitored over a 9-day period for substrate utilization, fermentation products, cellulase, and xylanase activities. Two of the fungal isolates showed monocentric growth patterns; one (isolate MC-1) had monoflagellated zoospores and morphologically resembled members of the genus Piromyces; the other (isolate MC-2) had multiflagellated zoospores and resembled members of the genus Neocallimastix. Three other isolates (PC-1, PC-2, and PC-3) exhibited polycentric growth and have not yet been described in the literature; these isolates were characterized by differences in morphology. All of the isolates degraded CBG to approximately the same extent (70% [dry weight]) in 9 days. Fermentation product accumulation was concurrent with substrate utilization. The major fermentation products for all isolates were formate, acetate, D-(-)-lactate, L-(+)-lactate, ethanol, carbon dioxide, and hydrogen. Succinate was produced by all cultures, with the exception of MC-1. Fermentation balances revealed different profiles for each isolate. As a group, monocentric isolates produced a greater ratio of oxidized to reduced products when grown on glucose or CBG than did the polycentric isolates, which produced a nearly equal ratio of these products. All isolates exhibited cellulolytic and xylanolytic activities, including endoglucanase, exoglucanase, beta-glucosidase, xylanase, and beta-xylosidase activities. Increasing enzyme activity correlated with the accumulation of fermentation products and substrate utilization. The optimum pH for the enzymatic activity of polycentric isolates was within a more narrow range (pH 6.4 to 7.0) than that of the monocentric isolates (pH 5.5 to 7.5). Activity toward cellulosic substrates was not detected until after the disappearance of reducing sugars. Xylanase activity was found to be five to seven times that of carboxymethyl cellulase activity for all cultures grown on CBG. 相似文献
7.
Abstract An anaerobic ethanologenic strain of extremely thermophilic bacteria isolated from a New Zealand hot spring resembled Thermoanaerobium brockii in morphology and cell-wall ultrastructure. However, antibodies produced against the New Zealand isolate did not crossreact with the type strain of T. brockii . The New Zealand isolate strain Tok6-B1 fermented a wider range of carbohydrate substrates, including pentoses, and was less inhibited by a hydrogen atmosphere. Ethanol and acetate were major end-products and lactate a minor product of glucose fermentation. Under a hydrogen atmosphere, these 3 end-products were formed in approximately equal amounts. 相似文献
8.
Fermentation products and plant cell wall-degrading enzymes produced by monocentric and polycentric anaerobic ruminal fungi. 总被引:10,自引:7,他引:3
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Five anaerobic fungal isolates from the bovine rumen were grown on Coastal Bermuda grass (CBG) leaf blades and monitored over a 9-day period for substrate utilization, fermentation products, cellulase, and xylanase activities. Two of the fungal isolates showed monocentric growth patterns; one (isolate MC-1) had monoflagellated zoospores and morphologically resembled members of the genus Piromyces; the other (isolate MC-2) had multiflagellated zoospores and resembled members of the genus Neocallimastix. Three other isolates (PC-1, PC-2, and PC-3) exhibited polycentric growth and have not yet been described in the literature; these isolates were characterized by differences in morphology. All of the isolates degraded CBG to approximately the same extent (70% [dry weight]) in 9 days. Fermentation product accumulation was concurrent with substrate utilization. The major fermentation products for all isolates were formate, acetate, D-(-)-lactate, L-(+)-lactate, ethanol, carbon dioxide, and hydrogen. Succinate was produced by all cultures, with the exception of MC-1. Fermentation balances revealed different profiles for each isolate. As a group, monocentric isolates produced a greater ratio of oxidized to reduced products when grown on glucose or CBG than did the polycentric isolates, which produced a nearly equal ratio of these products. All isolates exhibited cellulolytic and xylanolytic activities, including endoglucanase, exoglucanase, beta-glucosidase, xylanase, and beta-xylosidase activities. Increasing enzyme activity correlated with the accumulation of fermentation products and substrate utilization. The optimum pH for the enzymatic activity of polycentric isolates was within a more narrow range (pH 6.4 to 7.0) than that of the monocentric isolates (pH 5.5 to 7.5). Activity toward cellulosic substrates was not detected until after the disappearance of reducing sugars. Xylanase activity was found to be five to seven times that of carboxymethyl cellulase activity for all cultures grown on CBG. 相似文献
9.
E. A. Bonch-Osmolovskaya T. G. Sokolova N. A. Kostrikina G. A. Zavarzin 《Archives of microbiology》1990,153(2):151-155
A new type of thermophilic cyanobacterial mat, rich in elemental sulfur and containing large numbers of sulfur-reducing bacteria able to utilize different growth substrates at 55° C, was found in the Uzon caldere (Kamchatka). One of the largest groups among these organisms were acetate-oxidizing sulfur-reducing bacteria, numbering 106 cells · cm–3 of mat. The pure culture of a sulfur-reducing eubacterium growing on acetate was isolated. Cells of the new isolate are Gram-negative short rods, often in pairs, motile, with a single polar flagellum. The optimal temperature for growth is 52 to 57° C, with no growth observed at 42 or 73° C. The pH optimum is 6.8 to 7.0. The new isolate is demonstrated to be a true dissimilatory sulfur reducer: it is an obligate anaerobe, it is unable to ferment organic substrates and it can use no electron acceptors other than elemental sulfur. Acetate is the only energy and carbon source, and H2S and CO2 are growth products. No cytochromes were detected. The G+C content of DNA is rather low, only 31.4 mol%. Thus, morphological and physiological features of the new isolate are quite close to those of Desulfuromonas. But on the grounds of a significant difference in the G+C content of DNA, the absence of cytochromes and because of its thermophilic nature, a new genus Desulfurella is proposed with the type species Desulfurella acetivorans. 相似文献
10.
A thermophilic, strictly anaerobic eubacterium which utilized an unusually limited range of substrates was isolated from a sludge and pulp sample from a paperpulp cooling tank at a paper-board factory in Finland. The organism grew only with beech wood or oat spelt xylan; no growth occurred with soluble sugars, other polysaccharides, peptone, or yeast extract. The organism was rod-shaped, long (up to 20 m), thin (0.3 m), gramnegative, and in late-exponential and stationary phase cultures formed ball of yarn like structures; endospores were not observed and the organism was not motile. The organism grew fastest (=0.08 – 0.09 h-1) at 65 to 75°C and pH 6.5 to 8.4, with a maximum growth temperature between 75 and 80°C and an upper pH limit near 9. During growth on beech xylan the isolate produced only acetate, H2, and CO2 as fermentation products. The guanine + cytosine (G+C) content of the isolates cellular DNA was 34%. The unusual morphology of the isolate is characteristic of the genus Dictyoglomus, and the limited substrate range, higher G+C ratio, and different fermentation products indicated that the isolate was a new species in that genus. 相似文献
11.
Sradhanjali Singh Lala Behari Sukla Baroda Kanta Mishra 《Indian journal of microbiology》2011,51(4):477-481
Thermophilic bacteria are actively prevalent in hot water springs. Their potential to grow and sustain at higher temperatures
makes them exceptional compare to other microorganism. The present study was initiated to isolate, identify and determine
the feasibility of extraction of copper using thermophilic heterotrophic bacterial strain. Bacillus stearothermophilus is a thermophilic heterotrophic bacterium isolated from hot water spring, Atri, Orissa, India. This bacterium was adapted
to low-grade chalcopyrite ore and its efficiency to solubilize copper from Malanjkhand low-grade ore was determined. The low-grade
copper ore contains 0.27% Cu, in which the major copper-bearing mineral is chalcopyrite associated with other minerals present
as minor phase. Variation in parameters such as pulp-density and temperatures were studied. After 30 days of incubation, it
was found that Bacillus stearothermophilus solubilize copper up to 81.25% at pH 6.8 at 60°C. 相似文献
12.
Masaharu Tasaki Yoichi Kamagata Kazunori Nakamura Eiichi Mikami 《Archives of microbiology》1991,155(4):348-352
A new thermophilic sulfate-reducing bacterium, strain TSB, that was spore-forming, rod-shaped, slightly motile and gram-positive, was isolated from a butyrate-containing enrichment culture inoculated with sludge of a thermophilic methane fermentation reactor. This isolate could oxidize benzoate completely. Strain TSB also oxidized some fatty acids and alcohols. SO
inf4
sup2-
, SO
inf3
sup2-
, S2O
inf3
sup2-
and NO
inf3
sup-
were utilized as electron acceptors. With pyruvate or lactate the isolate grew without an external electron acceptor and produced acetate. The optimum temperature for growth was 62°C. The G+C content of DNA was 52.8 mol%. This isolate is described as a new species, Desulfotomaculum thermobenzoicum. 相似文献
13.
Twenty-five Campylobacter isolates were screened for production of antimicrobial substances using a deferred antagonism assay. Sixteen isolates showed
activity against either Staphylococcus aureus, Salmonella enterica serovar Enteritidis or Candida albicans. The inhibitory activity was sensitive to treatment with pronase E, trypsin and pepsin, suggesting that the antimicrobial
compound(s) are proteinaceous. Activity spectra of isolates included S. aureus, Micrococcus luteus, Streptococcus sp., Bacillus subtilis, a drug-resistant clinical isolate of S. aureus and one isolate of C. albicans. Producing isolates showed cross-immunity and inhibitory activity was only observed on solid media. The findings of this
study suggest that Campylobacter produces proteinaceous inhibitory substances. 相似文献
14.
Coprothermobacter platensis is an anaerobic, proteolytic, thermophilic bacterium, which is phylogenetically related to the genera Fervidobacterium and Thermotoga. The organism was found to reduce thiosulfate to sulfide during growth on carbohydrates and proteinaceous substrates. Growth on glucose was inhibited by hydrogen, but this inhibition was overcome by thiosulfate reduction, stirring, increasing the headspace volume and coculturing with a hydrogen-consuming methanogen. Alanine was detected during glucose fermentation, its formation was influenced by the hydrogen concentration in the gas phase suggesting an electron sink mechanism, as was previously reported for the phylogenetically related Thermotogales and the archaeal hyperthermophile Pyrococcus furiosus. 相似文献
15.
By enrichment with xylose, nine mesophilic strains of anaerobic bacteria were obtained from various sources. Two isolates appear to belong to the genus Eubacterium. Six other strains belong to the genus Clostridium. Three of the isolated strains utilized larch wood xylan. The percentage of utilization of xylose and xylan and the yield of fermentation end products — viz. acetic acid and butyric acid-are equivalent to that of Clostridium acetobutylicum (ATCC 824) and reported thermophilic strains. 相似文献
16.
H J Busscher M van der Kuijl-Booij HC van der Mei 《Journal of industrial microbiology & biotechnology》1996,16(1):15-21
Recent work on biosurfactant release by thermophilic dairy streptococci is reviewed. There is a suggestion thatStreptococcus thermophilus isolates may release biosurfactants that stimulate detachment of already-adhering cells and leave an anti-adhesive coating on a substratum. A previously published rapid screening method is described for the identification of biosurfactant-releasing microorganisms, and growth medium supplements to enhance biosurfactant release by thermophilic dairy streptococci are reported. New experimental work described includes the isolation and purification of biosurfactants from dairy isolates by thin layer chromatography. Many compounds isolated were extremely surface-active and reduced the water surface tension to values around 30 mJ m–2 at a concentration of 10 mg ml–1. Most importantly, the thin layer chromatograms of various isolates resembled each other, and an adsorbed purified compound from one isolate retarded the deposition to glass of another isolate by a factor of two. Provided our findings implicate that these biosurfactants could also be adsorbed to heat exchanger plates in pasteurizers and thereby retard colonization by thermophilic streptococci, these compounds may have major economic implications. Further work is required, however. 相似文献
17.
Karl O. Stetter 《Origins of life and evolution of the biosphere》1984,14(1-4):809-815
Continental and submarine solfataric fields turned out to contain various extremely thermophilic anaerobic organisms which all belong to the archaebacteria. They are living autotrophically on sulphur, hydrogen and CO2 or by methanogenesis or heterotrophically on different organic substrates by sulphur respiration or, less frequently, by fermentation. The most extremely thermophilic isolates are growing between 80 and 110°C with an optimum around 105°C. 相似文献
18.
One-hundred and fifty different thermophilic bacteria isolated from a volcanic island were screened for detection of an alkane
hydroxylase gene using degenerated primers developed to amplify genes related to the Pseudomonas putida and Pseudomonas oleovorans alkane hydroxylases. Ten isolates carrying the alkJ gene were further characterized by 16s rDNA gene sequencing. Nine out of ten isolates were phylogenetically affiliated with
Geobacillus species and one isolate with Bacillus species. These isolates were able to grow in liquid cultures with crude oil as the sole carbon source and were found to degrade
long chain crude oil alkanes in a range between 46.64% and 87.68%. Results indicated that indigenous thermophilic hydrocarbon
degraders of Bacillus and Geobacillus species are of special significance as they could be efficiently used for bioremediation of oil-polluted soil and composting
processes. 相似文献
19.
From a methanogenic fixed-bed reactor fed with hydroquinone as sole energy and carbon source, a rodshaped bacterium was isolated in pure culture which could degrade hydroquinone and gentisate (2,5-dihydroxybenzoate). In syntrophic coculture with either Desulfovibrio vulgaris or Methanospirillum hungatei, also benzoate could be degraded. Other substrates such as sugars, fatty acids, alcohols, and cyclohexane derivatives were not degraded. Sulfate, sulfite, or nitrate were not used as external electron acceptor. The isolate was a Gram-negative, non-motile, nonsporeforming strict anaerobe; the guanine-plus-cytosine content of the DNA was 53.2±1.0 mol%. In pure culture, hydroquinone was degraded to acetate and benzoate, probably via an intermediate carboxylation. In syntrophic mixed cultures, all three substrates were converted completely to acetate. Phenol was never detected as a fermentation product. 相似文献
20.
Moderately thermophilic acidophilic bacteria were isolated from geothermal (30-83 degrees C) acidic (pH 2.7-3.7) sites in Yellowstone National Park. The temperature maxima and pH minima of the isolates ranged from 50 to 65 degrees C, and pH 1.0-1.9. Eight of the bacteria were able to catalyze the dissimilatory oxidation of ferrous iron, and eleven could reduce ferric iron to ferrous iron in anaerobic cultures. Several of the isolates could also oxidize tetrathionate. Six of the iron-oxidizing isolates, and one obligate heterotroph, were low G+C gram-positive bacteria ( Firmicutes). The former included three Sulfobacillus-like isolates (two closely related to a previously isolated Yellowstone strain, and the third to a mesophilic bacterium isolated from Montserrat), while the other three appeared to belong to a different genus. The other two iron-oxidizers were an Actinobacterium (related to Acidimicrobium ferrooxidans) and a Methylobacterium-like isolate (a genus within the alpha -Proteobacteria that has not previously been found to contain either iron-oxidizers or acidophiles). The other three (heterotrophic) isolates were also alpha-Proteobacteria and appeared be a novel thermophilic Acidisphaera sp. An ARDREA protocol was developed to discriminate between the iron-oxidizing isolates. Digestion of amplified rRNA genes with two restriction enzymes ( SnaBI and BsaAI) separated these bacteria into five distinct groups; this result was confirmed by analysis of sequenced rRNA genes. 相似文献