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1.
We investigated the microdistribution of xylans in different cell types of Arabidopsis stem using immunolocalization methods with LM10 and LM11 antibodies. Xylan labeling in xylary fibers (fibers) was initially detected at the cell corner of the S(1) layer and increased gradually during fiber maturation, showing correlation between xylan labeling and general secondary cell wall formation processes in fibers. Metaxylem vessels (vessels) showed earlier development of secondary cell walls than fibers, but revealed almost identical labeling patterns to fibers during maturation. No difference in labeling patterns and intensity was detected in the cell wall of fibers, vessels and protoxylem vessels (proto-vessels) between LM10 and LM11, indicating that vascular bundle cells may be chemically composed of a highly homogeneous xylan type. Interestingly, interfascicular fibers (If-fibers) showed different labeling patterns between the two antibodies and also between different developmental stages. LM10 showed no labeling in primary cell walls and intercellular layers of If-fibers at the S(1) formation stage, but some labeling was detected in middle lamella cell corner regions at the S(2) formation stage. In contrast, LM11 revealed uniform labeling across the If-fiber cell wall during all developmental stages. These results suggest that If-fibers have different xylan deposition processes and patterns from vascular bundle cells. The presence of xylan was also confirmed in parenchyma cells following pectinase treatment. Together our results indicate that there are temporal and spatial differences in xylan labeling between cell types in Arabidopsis stem. Differences in xylan labeling between Arabidopsis stem and poplar are also discussed. 相似文献
2.
Two cellulolytic clostridia, one thermophilic and the other mesophilic, were isolated and characterized. Cells of the thermophile are gram-negative rods that are motile with lophotrichous flagella and spherical terminal endospores which swell the cells. The optimum growth temperature is 55 to 60 degrees C, with a range of 40 to 65 degrees C. The deoxyribonucleic acid composition is 35 mol% G + C. The name Clostridium cellulosi sp. nov. is proposed. The type strain is AS 1.1777. Cells of the mesophile are gram negative and motile with peritrichous flagella and terminal oval or spherical spores which swell the cells. The deoxyribonucleic acid composition is 34 mol% G + C. The name Clostridium cellulofermentans sp. nov. is proposed. The type strain is AS 1.1775. Both C. cellulosi AS 1.1777 and C. cellulofermentans AS 1.1775 are deposited in the China Committee for Culture Collection of Microorganisms, Institute of Microbiology, Academia Sinica, Beijing, People's Republic of China. 相似文献
3.
Biohydrogenation of linoleic acid by Clostridium sporogenes, Clostridium bifermentans, Clostridium sordellii and Bacteroides sp. 总被引:1,自引:0,他引:1
A. Verhulst G. Semjen U. Meerts G. Janssen G. Parmentier S. Asselberghs H. Van Hespen H. Eyssen 《FEMS microbiology letters》1985,31(4):255-259
Abstract Several strains of Clostridium bifermentans, Clostridium sporogenes and Clostridium sordellit and one strain of Bacteroides sp. hydrogenate linoleic acid into transvaccenic acid in vitro following the same pathway. Linoleic acid (18:2; 9- cis , 12- cis ) was first isomerised into 9- cis , 11- trans -octadecadienoic acid, after which the 9- cis double bond was reduced. These species also hydrogenated linoleic acid into an octadecenoic acid in vivo when mono-associated with gnotobiotic rats. Several other species of Clostridium and Bacteroides did not hydrogenate linoleic acid. 相似文献
4.
Steer T Collins MD Gibson GR Hippe H Lawson PA 《Systematic and applied microbiology》2001,24(3):353-357
A strictly anoxic, Gram-positive, sporeforming, rod-shaped bacterium was isolated from a chemostat inoculated with human faeces. The bacterium used carbohydrate as fermentable substrates, producing acetate, ethanol, carbon dioxide and hydrogen as the major products of glucose metabolism, and possessed a G + C content of 50.7 to 50.9 mol%. Comparative 16S rRNA gene sequencing showed that the unidentified bacterium represents a previously unrecognised sub-line within the Clostridium coccoides rRNA group of organisms. The nearest relatives of the unknown bacterium corresponded to Clostridium algidixylanolyticum, C. aerotolerans, C. celerecrescens, C. indolis, C. sphenoides, C. methoxybenzovorans and C. xylanolyticum but 16S rRNA sequence divergence values of >4% demonstrated that it represents a novel species. Based on the presented findings a new species, Clostridium hathewayi, is described. The type strain of Clostridium hathewayi is DSM = 13479T (= CCUG 43506 T). 相似文献
5.
The molecular structures of water-soluble and -insoluble hemicelluloses of bamboo leaf, and of a hemicellulosic xylan from the former, have been examined. It is concluded that all the materials have the same structural features on their main xylan chain, namely, the side-chains or residues (a) l-arabinofuranose, (b) O-galactopyranosyl-(1→5)-l-arabinofuranose, (c) O-galactopyranosyl-(1→4)-O-d-xylopyranosyl-(1→2)-l-arabinofuranose, (d) O-d-xylopyranosyl-(1→2)-O-l-arabinofuranosyl-(1→2)-l-arabinofuranose, (e) O-(d-glucopyranosyluronic acid)-(1→4)-O-d-xylopyranosyl-(1→4)-galactopyranose, and (f) d-glucopyranuronic acid and its 4-methyl ether. Feature (d) is proposed for the first time, but it may have been present in xylans studied by others. The main xylose chain in the soluble, insoluble, and xylan materials have, respectively, 1 in every 2.8, 4.0, and 7.6 xylan residues substituted by side residues or chains (a)–(e). It is concluded that the polysaccharide product recovered after methylation of the three hemicellulosic materials does not fully represent the quantitative composition of the materials subjected to methylation, although structural features (a), (d), and (e) are not much altered. When the soluble material was treated with dilute acid under mild conditions, most of (a) was removed, while (d) and other substituents, including those with l-arabinofuranose residues, were not removed to the same extent. 相似文献
6.
Phosphorus (P) recovery from liquid swine manure is an attractive technology when on-farm application of liquid swine manure is not an option. We developed a technology that enables separation of this P, but its high moisture content makes transportation difficult. In this work, we investigated dewatering procedures to concentrate the P product. Sludge rich in calcium phosphate (> 20% P2O5) was obtained using a field prototype, and it was further dewatered using a combination of polymer treatment and filter bags. Anionic polyacrylamide polymer treatment (> or = 20 mg/L) was effective to flocculate the P-rich sludge, which enhanced filtration and dewatering. Without polymer, filtration was incomplete due to clogging of filters. Non-woven polypropylene and monofilament filter bag fabrics with mesh size < or = 200 microm retained > 99% of suspended solids and total P. Solids content dramatically increased from about 1.5% to > 90%. These dewatered solids can be transported more economically off the farm for use as a valuable fertilizer material. 相似文献
7.
Summary A rapid method was developed for plasmid DNA screening from micro volume cultures of Clostridium acetobutylicum. It involves protoplastization by lysozyme, nuclease inhibition by incorporating EDTA or DEP, followed by lysis with high concentration of SDS. The whole lysate is applied directly to electrophoretic analysis. 相似文献
8.
In a previous study, a marine isolate Clostridium sp. EDB2 degraded 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) under anaerobic conditions (Bhushan B, Halasz A, Thiboutot S, Ampleman G, Hawari J (2004c) Chemotaxis-mediated biodegradation of cyclic nitramine explosives RDX, HMX, and CL-20 by Clostridium sp. EDB2. Biochem Biophys Res Commun 316:816–821); however, the enzyme responsible for CL-20 degradation was not known. In the present study, we isolated and purified an enzyme, from strain EDB2, responsible for CL-20 degradation. The enzyme was membrane-associated and NADH-dependent and had a molecular weight of 56 kDa (with SDS-PAGE). N-terminal amino acid sequence of enzyme revealed that it belonged to dehydrogenase class of enzymes. The purified enzyme degraded CL-20 at a rate of 18.5 nmol/h mg protein under anaerobic conditions. Carbon and nitrogen mass balance of the products were 100 and 64%, respectively. In LC–MS–MS studies, we detected three different initial metabolites from CL-20, i.e., mono-nitroso derivative, denitrohydrogenated product, and double-denitrated isomers with molecular weight of 422, 393, and 346 Da, corresponding to presumed empirical formulas of C6H6N12O11, C6H7N11O10, and C6H6N10O8, respectively. Identity of all the three metabolites were confirmed by using ring-labeled [15N]CL-20 and the nitro-group-labeled [15NO2]CL-20. Taken together, the above data suggested that the enzyme degraded CL-20 via three different routes: Route A, via two single electron transfers necessary to release two nitro-groups from CL-20 to produce two double-denitrated isomers; Route B, via a hydride transfer necessary to produce a denitrohydrogenated product; and Route C, via transfer of two redox equivalents to CL-20 necessary to produce a mono-nitroso derivative of CL-20. This is the first biochemical study which showed that CL-20 degradation can be initiated via more than one pathway. 相似文献
9.
Enterotoxin-like protein was extracted from spores of three enterotoxin-positive and three enterotoxin-negative strains of Clostridium perfringens type A by urea/mercaptoethanol, alkaline mercaptoethanol and alkaline dithiothreitol. Disc immunoelectrophoresis demonstrated that three distinct enterotoxin-like proteins could be extracted. In 7% acrylamide gels, type I, type II, and type III enterotoxinlike proteins had relative mobilities of 0.52, 0.63, and 0.73 respectively. In contrast to disc immunoelectrophoresis, immunoelectrophoresis in agar gel demonstrated identical electrophoretic properties for the various entertoxin-like proteins. Immunoelectrofocusing experiments gave isoelectric points of 4.43, 4.43, 4.36, and 4.52 for purified entertoxin and type I, type II, and type III enterotoxin-like proteins respectively. Ferguson plots (i.e., log relative mobility versus acrylamide concentration) yielded nonparallel lines which intersected at a nonsieving concentration of acrylamide indicating that the various species of enterotoxin-like protein differed in size. Estimation of the molecular weight of purified enterotoxin and the three species of enterotoxin-like protein was done by comparing the slopes obtained in Ferguson plots with those obtained using proteins of a known molecular weight. Molecular weights of 38000, 36500, 23000, and 15400 were obtained for purified enterotoxin, type I, type II, and type III enterotoxin-like protein respectively. Collectively, the evidence indicates that fractionation of the different species of enterotoxin-like protein was due primarily to differences in their size, and that different forms of enterotoxin-like protein can be extracted from spores of different strains of C. perfringens type A. 相似文献
10.
Summary A Clostridium sp., isolated from flooded soil amended with lindane (γ-BHC), decomposed methoxychlor, γ-BHC and heptachlor in that order
under anaerobic condition. During the bacterial degradation of ring-labelled C14-γ-BHC, there was a net loss of radioactivity from the reaction mixture. Release of C14O2 during the degradation of C14-γ-BHC was negligible. Methane was not detected as an end product of γ-BHC breakdown. re]19720406 相似文献
11.
Cultures of Clostridium KDHS2 reduced 15NO3- to 15NH4+ with a concurrent increase in molar growth yield of 15.7% compared with fermentatively grown bacteria. The bacteria exhibited a Ks (NO3-) of 0.5 mM and reduced NO3- maximally at a rate of 0.1 mumol h(-1) mg dry wt)-1. A partially purified nitrate reductase was obtained which had a Km (NO3-) of 0.15 mM. The reduction of 13NO3- to 13NH4+ by resting bacteria was not inhibited by NH4+, glutamate, glutamine, methionine sulphoximine or azaserine. Glutamine synthetase affected neither the synthesis nor the activity of the NO3(-)-reducing enzymes. The results are consistent with the hypothesis that NO3- reduction to NH4+ in this Clostridium sp. is dissimilative. SO32-, but not SO42-, inhibited the reaction, apparently at the level of NO2- reduction. 相似文献
12.
Song Y Liu C Molitoris DR Tomzynski TJ Lawson PA Collins MD Finegold SM 《Systematic and applied microbiology》2003,26(1):84-89
Seven obligately anaerobic, gram-positive, rod-shaped, spore-forming organisms isolated from human sources were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing showed that the strains were genetically highly related to each other (displaying >99% sequence similarity) and represent a previously unknown sub-line within the Clostridium coccoides rRNA group of organisms. Strains of the unidentified bacterium used carbohydrate as fermentable substrates, producing acetic acid and lactic acid as the major products of glucose metabolism. The closest described species to the novel bacterium corresponded to Clostridium clostridioforme, although a 16S rRNA sequence divergence of 3% demonstrated they represent different species. Genomic DNA-DNA pairing studies confirmed the separateness of the unknown species and Clostridium clostridioforme. Based on phenotypic and phylogenetic evidence, it is therefore proposed that the unknown bacterium, be classified as Clostridium bolteae sp. nov. The type strain of Clostridium bolteae is WAL 16351T (= ATCC(T) = BAA-613T, CCUG(T) = 46953T). 相似文献
13.
Seven obligately anaerobic, Gram-positive, rod-shaped, spore-forming organisms isolated from human faecal specimens were characterized using phenotypic and molecular taxonomic methods. Strains of the unidentified bacterium used carbohydrates as fermentable substrates, producing acetic acid, isovaleric acid and phenylacetic acid (PAA) as the major products of glucose metabolism, and possessed a G +C content of approximately 29.8 mol%. Comparative 16S rRNA gene sequencing showed that the 7 strains were genetically highly related to each other (displaying >99.5% sequence similarity) and represent a previously unknown sub-line within the Clostridium Cluster XI. The closest described species to the novel bacterium is Clostridium glycolicum, although a 16S rRNA sequence divergence of 4% demonstrates that they represent different species. Genomic DNA-DNA pairing studies confirmed the separateness of the unknown species and C. glycolicum (30.6% similarity between the proposed type strain of the novel species, WAL 16138, and C. glycolicum ATCC 14880(T)). Based on morphologic, phenotypic and phylogenetic evidence, it is therefore proposed that the unknown bacterium be classified as C. bartlettii sp. nov. The type strain of C. bartlettii is WAL 16138(T) (= ATCCBAA-827(T)=CCUG48940(T)). 相似文献
14.
A. Ueki T. Hirono E. Sato A. Mitani K. Ueki 《World journal of microbiology & biotechnology》1991,7(3):385-393
A newly isolated, anaerobic, mesophillic bacterium, Clostridium sp. strain YK-3, ferments pentoses, hexoses, oligosaccharides and polysaccharides, such as soluble starch and glycogen, to ethanol and acetate. The potential of this strain for ethanol and amylase production has been examined. Ethanol was the major product and acetate a minor one. The organism could grow with soluble starch in the presence of 40 g ethanol/l. Extracellular -amylase activity was detected when the strain was cultivated with soluble starch, glycogen or dextrin. The optimum pH of this amylase was 5.5 to 7.5 with an optimum temperature of 50°C.The authors are with the Laboratory of Applied Microbiology, Faculty of Agriculture, Yamagata University, Tsuruoka 997, Japan. 相似文献
15.
《Enzyme and microbial technology》2005,36(5-6):824-831
One anaerobic, proteolytic bacterium isolated from Schirmacher oasis, Antarctica was characterised taxonomically. Based on morphology, biochemical characteristics and 16S rRNA sequence the isolate was identified as Clostridium species with closest similarity with Clostridium subterminale. Isolate was psychrotrophic forming maximum cell mass between 5 and 10 °C and produced extracellular protease. Growth was observed in the pH range of 6.5–8.5 with optimum at pH 8. Protease was purified 12.7-fold with a total yield of 26.2%. Effect of temperature, pH and salt concentration on enzyme activity were studied. Protease was found to be a serine-type metaloenzyme, which is active in a broad range of pH. It was moderately thermolabile and resistant to SDS. Enzyme kinetics revealed a tendency to decrease Km with increase in temperature for casein substrate. 相似文献
16.
Production of hexanoic acid from d-galactitol by a newly isolated Clostridium sp. BS-1 总被引:1,自引:0,他引:1
Byoung Seung Jeon Byung-Chun Kim Youngsoon Um Byoung-In Sang 《Applied microbiology and biotechnology》2010,88(5):1161-1167
In a study screening anaerobic microbes utilizing d-galactitol as a fermentable carbon source, four bacterial strains were isolated from an enrichment culture producing H2, ethanol, butanol, acetic acid, butyric acid, and hexanoic acid. Among these isolates, strain BS-1 produced hexanoic acid
as a major metabolic product of anaerobic fermentation with d-galactitol. Strain BS-1 belonged to the genus Clostridium based on phylogenetic analysis using 16S rRNA gene sequences, and the most closely related strain was Clostridium sporosphaeroides DSM 1294T, with 94.4% 16S rRNA gene similarity. In batch cultures, Clostridium sp. BS-1 produced 550 ± 31 mL L−1 of H2, 0.36 ± 0.01 g L−1 of acetic acid, 0.44 ± 0.01 g L−1 of butyric acid, and 0.98 ± 0.03 g L−1 of hexanoic acid in a 4-day cultivation. The production of hexanoic acid increased to 1.22 and 1.73 g L−1 with the addition of 1.5 g L−1 of sodium acetate and 100 mM 2-(N-morpholino)ethanesulfonic acid (MES), respectively. Especially when 1.5 g L−1 of sodium acetate and 100 mM MES were added simultaneously, the production of hexanoic acid increased up to 2.99 g L−1. Without adding sodium acetate, 2.75 g L−1 of hexanoic acid production from d-galactitol was achieved using a coculture of Clostridium sp. BS-1 and one of the isolates, Clostridium sp. BS-7, in the presence of 100 mM MES. In addition, volatile fatty acid (VFA) production by Clostridium sp. BS-1 from d-galactitol and d-glucose was enhanced when a more reduced culture redox potential (CRP) was applied via addition of Na2S·9H2O. 相似文献
17.
Taxonomic studies on a psychrophilic Clostridium from vacuum-packed beef: Description of Clostridium estertheticum sp. nov. 总被引:2,自引:0,他引:2
M.D. Collins U.M. Rodrigues R.H. Dainty R.A. Edwards T.A. Roberts 《FEMS microbiology letters》1992,96(2-3):235-239
Abstract Taxonomic studies were performed on an anaerobic Gram-positive, spore-forming, psychrophilic bacterium originally isolated from spoiled vacuum-packed refrigerated beef. Based on the present finding it is proposed that this unknown psychrophilic bacterium be classified as a new species of the genus Clostridium , as Clostridium estertheticum sp. nov. The type strain is NCIMB 12511. 相似文献
18.
《Systematic and applied microbiology》2020,43(5):126104
Lignocellulose is considered a major source of renewable energy that serve as an alternative to the fossil fuels. Members of the genus Clostridium are some of the many microorganisms that have the ability to degrade lignocellulose efficiently to sugar, which can be further converted to biofuel. In this study, we isolated twelve Clostridium strains from hot spring samples of Yunnan and Tibet, of which isolates SYSU GA15002T and SYSU GA17076 showed low 16S rRNA gene sequence identity profiles to any of the validly named Clostridium strains (<94.0%). Studies using a polyphasic taxonomy approach concluded that the two isolates represent one novel species of the genus Clostridium, for which we propose the name Clostridium thermarum sp. nov., with SYSU GA15002T as the type strain of the species. Isolate SYSU GA15002T has an optimum growth temperature at 45 °C. Fermentation of the substrates cellobiose, cellulose, xylan and untreated straw powder by this strain results in the production of ethanol, along with acetate and formate. The complete pathways for the conversion of cellulose and xylan to ethanol is also predicted from the genome of isolate SYSU GA15002T, which revealed a single step conversion of lignocellulosic biomass through consolidated bioprocessing. This paper is a comprehensive study encompassing isolation, polyphasic taxonomy, lignocellulose biodegradation and the genomic information of Clostridium in Yunnan-Tibet hot springs. 相似文献
19.
《Journal of Fermentation Technology》1988,66(4):467-472
Three thermophilic Clostridium strains were isolated from soil as cellulose-fermenting bacteria wich produced ethanol, lactic acid, and acetic acid from cellulose at 60°C. To increase ethanol productivity, strains no. 187 was mutated with N-methyl-N′-nitro-N-nitrosguanidine. The resultant mutant, no 187-102-27, was superior to the original strain in ethanol production, and produced less lactic and acetic acid. The activities of some enzymes involved in the biosynthesis of the lactic and acetic acid of mutant no. 187-102-27 were lower than those of the original strain. These results are highly consistent with the acid production of the mutant strain being low. 相似文献
20.
The process of biodrying could be a good solution for municipal solid waste management, allowing the production of fuel with an interesting energy content. Previous work (Adani, F., Baido, D., Calcaterra, E., Genevini, P.L., 2002. The influence of biomass temperature on biostabilization-biodrying of municipal solid waste. Bioresource Technology 83 (3), 173-179) has indicated that appropriate management of the processing parameters (air-flow rate and biomass temperatures) could achieve biomass drying in very short times (8-9 days). However, the data of that work also evidenced that if the conditions do not consider pile turning, and the air-flow is always from one direction, temperature gradients arise within the biomass, resulting in a lack of homogeneity in the moisture and energy content of the final product. Therefore, a new laboratory study was conducted on municipal solid waste biodrying-biostabilization in an effort to obtain homogeneous final products. Our proposal to solve this lack of homogeneity is to periodically invert the air-flow direction. Thus, in line with a previous study, two trials, A and B, were carried out, dividing the biomass into three layers to study temperature and moisture gradients throughout the process, and a third trial (C) simulating air-flow inversion at regular intervals was introduced. The results suggest that the daily inversion of air-flow eliminates marked temperature differences and leads to a homogeneous final product. 相似文献