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1.
An immobilization matrix, Drizit, was examined for use in the bioremediation of oil in asaltwater system. The support was examined by scanning electron microscopy, cell-loadingcapacity, absorption of Ekofisk crude oil, the effect on cell recoverability of dryingDrizit-immobilized cells at room temperature, 55°C or freeze drying and storage for up to 3months, and the capability of immobilized Pseudomonas fluorescens to enhance biodegradation ofpetrol (Slovene diesel) in a saltwater system. Results showed that Drizit is an ideal immobilizationsubstratum for use in bioremediation, and the substratum was found to have a good cell-loadingcapacity (3·75 mg protein g−1 substratum) and a high absorbency of oil(7·49 g Ekofisk g−1 substratum). After drying the immobilized cells at roomtemperature, 55°C or freeze drying and subsequent storage, cells were not recoverable after 2weeks, 1 week or 2 months, respectively, and a significant decrease was seen in the number ofcells recovered after drying and 1 week's storage in all cases. Enhanced biodegradation of C13–C18 pristane and phytane, in petrol (Slovene diesel) occurred with theimmobilization of Ps. fluorescens to Drizit. An average degradation of 73·8%occurred in the immobilized system in comparison with the free system which resulted in anaverage degradation of 39·8%. When the two systems were supplemented with nitrates andphosphates, degradation in the free supplemented system increased to an average of 72·4%.However, no significant difference in biodegradation was found between the immobilized systemand the immobilized system supplemented with nitrates and phosphates which achieved anaverage degradation of 74.15%.  相似文献   

2.
Coalified residues of the xylem and peripheral structure tissues (stereomc) from perminei alized (CaCO3) Lower Devonian Psilophyton dawsomi have been analysed by Hash pyrolysis-gas chromatography-mass spectrometry. Both yielded C1-C3 alkylphenols, C1-C3 alkylbenzenes, C1-C3 alkylnaphthalenes, although with varying relative abundances. The stereomc also generated a scries of n -alk-1-cries and H-alkanes (C3C24, maximum at C10) which is believed to be derived from the cuticle. The sources of the aromatic compounds are discussed, and while it is concluded that those in the xylem are derived from lignin, the macromolecule having been degraded by diagencsis and thermal maturation, the molecular sources of those from the stereomc may also include a wide range of substances including simple phenolic acids, flavonoids and non-lignin polyphenolics. Possible functions for the stereome are discussed.  相似文献   

3.
Abstract Two constitutive acetoacetyl-CoA (AcAc-CoA) reductases were purified from Alcaligenes eutrophus . Incorporation of [1-14C]-acetyl-CoA into poly-3-hydroxybutyrate (PHB) by systems reconstituted from purified preparations of either 3-ketothiolase, AcAc-CoA reductase and PHB synthase, occurred only when NADPH-AcAc-CoA reductase was present. The NADH reductase was active with all of the d (−)- and l (+)-3-hydroxyacyl-CoA substrates tested (C4-C10), whereas the NADPH reductase was only active with d (−)-3-hydroxyacyl-CoAs (C4-C6). The products of AcAc-CoA reduction by the NADH- and NADPH-linked enzymes were l (+)-3-hydroxybutyryl-CoA and d (−)-3-hydroxybutyryl-CoA, respectively. The NADH-linked enzyme had an M r of 150,000 (containing identical M r 30,000 sub-units) and the NADPH-linked enzyme appeared to be a tetramer ( M r 84,000) with identical sub-units ( M r 23,000). K mapp values of 22 μM and 5 μM for AcAc-CoA and 13 μM (NADH) and 19 μM (NADPH) for the coenzymes were determined for the NADH- and NADPH-linked enzymes, respectively.  相似文献   

4.
Four ecotypes of Phragmites australis from different habitats in northwest China were examined to compare their photosynthetic characteristics. In a swamp ecotype, the Δ 13C value of leaf materials was −34.0‰, and bundle sheath cells contained a small amount of organelles and round-shaped chloroplasts, as being similar to typical C3 plants. In a dune ecotype, the Δ 13C value was −20.9‰ and bundle sheath cells contained oval-shaped chloroplasts with poorly-developed grana. In light and heavy salt meadow ecotypes, Δ 13C values were −30.6‰ and −35.6‰, respectively. The shape of bundle sheath chloroplasts in the light salt meadow ecotype was intermediate between those of the swamp and dune ecotypes. Abundance of bundle sheath organelles in the heavy salt meadow ecotype was intermediate. The swamp ecotype had photosynthetic enzyme activities typical of C3 type plants, whereas the dune ecotype had an increased activity of phosphoenolpyruvate carboxylase (PEPC), a key C4 enzyme, and a decreased ribulose 1,5-bisphosphate carboxylase (Rubisco) activity. The light salt meadow and heavy salt meadow ecotypes had substantial activities of PEPC, which indicates potential for C4 photosynthesis. These data suggest that this species evolved the C3-like ecotype in swamp environments and the C4-like C3-C4 intermediate in dune desert environments, and C3-like C3-C4 intermediates in salt environments.  相似文献   

5.
Two types of Indian crude oil (Bombay High and Gujarat) were tested for their biodegradability by Acinetobacter calcoaceticus and Alcaligenes odorans. Acinetobacter calcoaceticus S30 and Alc. odorans P20 degraded Bombay High crude oil by 50% and 45%, while only 29% and 37% of Gujarat crude oil (heavy crude oil) was degraded by these isolates, respectively. Acinetobacter calcoaceticus and Alc. odorans in combination deraded 58% and 40% of Bombay High and Gujarat crude oils, respectively, which were significantly higher than that of by individual cultures. Acinetobacter calcoaceticus S30 degraded more of the alkanes fraction than the aromatics fraction of both crude oils. GC fingerprinting of alkane fraction showed major degradation of heptadecane (C17), octadecane (C18), nonadecane (C19), eicosane (C20), docosane (C22), tricosane (C23) and tetracosane (C24) of crude oil, while the Alc. odorans P20 degraded alkanes and aromatics equally. The asphaltenic component increased in both types of crude oil after biodegradation. The two strains grew very well on n -alkane up to C33 as well as on pristane (branched-chain alkane) but could not grow on cycloalkanes. Acinetobacter calcoaceticus S30 could not grow on pure polycyclic aromatic hydrocarbon (PAH) compounds except naphthalene but Alc. odorans P20 could grow on anthracene, phenanthrene, dibenzothiophene, fluorene, fluoranthene, pyrene and chrysene.  相似文献   

6.
Chemostat enrichment of sulphate-reducing bacteria from the large gut   总被引:1,自引:0,他引:1  
Electron donor-limited chemostat enrichments were used to isolate sulphate-reducing bacteria (SRB) from human faeces. When acetate, lactate, propionate, butyrate or amino acids were used as electron donors, SRB identical to those found using traditional isolational methods (agar shake dilution series) were obtained. However, chemostat enrichments facilitated the isolation of SRB able to metabolize mixtures of alcohols (C1-C5) and mixtures of fatty acids (C2-C6) which had not been detected by the direct isolation techniques.  相似文献   

7.
The diet of African hippopotamids can be documented through δ 13C analyses of enamel and other tissues. Analysis of a 10-million-year sequence of hippopotamids in and near the Lake Turkana Basin of northern Kenya shows that hippos have included a substantial fraction of C3 vegetation in their diets since the late Miocene when C4 vegetation first appears in hippo diet as a measurable fraction. The C4 component of vegetation becomes dominant (>50%) by Upper Burgi time ( c . 2 million years ago) but does not reach 100% for all individuals. It is therefore not unexpected that the δ 13C values of modern hippopotamids show a higher fraction of dietary C3 biomass than has been estimated from traditional observations. Analysis of δ 18O of hippos from different stratigraphic levels shows no systematic trend over time; the average value for fossil hippos over the last 10 million years is similar to that of modern hippos from the Omo River system.  相似文献   

8.
The aim of this study was to analyse individual polar lipid analogues, within each lipid family present, of fusobacteria using fast atom bombardment mass spectrometry (FAB-MS). Polar lipid extracts were prepared, washed and dried. Samples, dispersed in a matrix of m -nitrobenzyl alcohol, were analysed by negative ion FAB-MS using xenon as the reagent gas. Major anion peaks observed in the low mass region of mass/charge (m/z), 211, 221, 225, 227, 239, 241, 249, 251, 253, 255, 273, 277, 279, 281, 289 and 291, were consistent with the presence of C13:1, C14:3, C14:1, C14:0, C15:1, C15:0, C16:3, C16:2, C16:1, C16:0, unknown, C18:3, C18:2, C18:1, unknown and C19:3 carboxylate anions. In the high mass region, major anion peaks observed with m/z 644, 646, 648, 660, 662, 672, 673, 674, 686, 688, 689, 690, 698, 700, 701, 703, 714, 716, 717 and 719 were consistent with the presence of phosphatidylethanolamine (PE) (29:2), PE (29:1), PE (29:0), PE (30:1), PE (30:0), PE (31:2), first isotope of PE (31:2), PE (31:1), PE (32:2), PE (32:1), first isotope peak of PE (32:1), PE (30:0), PE (33:3), PE (33:2), phosphatidylglycerol (PG) (31:3), PG (31:2), PE (34:2), PE (34:1), PG (32:2) and PG (32:1). We conclude that FAB-MS can provide data on individual analogues of PE and PG from Fusobacterium spp. not readily obtained by other means. Furthermore, the phospholipid profile is diagnostic for the genus.  相似文献   

9.
The fatty acid composition of the total lipids from two Conidiobolus species was studied by gas—liquid chromatography. The major fatty acids of C. lamprauges were palmitic acid (C16:0), oleic acid (C18:1), linolenic acid (C18:3), and arachidonic acid (C20:4). For C. eurymitus , myristic acid (C14:0), C16:0, and linoleic acid (C18:2) were the most abundant acids. The fatty acid composition of C. eurymitus was quite different from that of the Conidiobolus species as mentioned in other reports. The lipid composition of the total lipids of C. lamprauges and C. eurymitus was also studied by thinchrography on quartz rods. Triglycerides and phospholipids were the major components in the two Conidiobolus species.  相似文献   

10.
Abstract— The fatty acid composition of cerebrosides, sulphatides and ceramides has been determined at 20 days postpartum in the brains of Quaking mutant mice and of littermate controls. There was a significant deficit in the proportion of long-chain fatty acids (C22-C24) affecting both normal and a-hydroxy fatty acids of the cerebrosides. The proportion of normal but not the a-hydroxy long-chain fatty acids of the sulphatides was also decreased. Striking and disproportionate deficits of the C24:1 and C24 h:1 fatty acids of cerebrosides, sulphatides and ceramides characterized the brain of the Quaking mutant, and an increased proportion of C23 h:O fatty acid was found in the cerebrosides and sulphatides of the brain of this mutant. We compared these data with findings on the Jimpy mutant which has been examined by the same techniques. The deficiency of long-chain fatty acids which was found in the cerebrosides and sulphatides of both mutants was less extensive but more selective in the Quaking mutant.  相似文献   

11.
At 14° C, standard metabolic rate (75·1 mg O2 h−1 kg−1), routine metabolic rate (108.8 mg O2 h−1 kg−1), active metabolic rate ( c . 380 mg O2 h−1 kg−1), critical swimming speed (Ucrit 1·7 BL s−1), heart rate 47 min−1), dorsal aortic pressure (3·2 kPa) and ventilation frequency (63 min−1) for triploid brown trout Salmo trutta were within the ranges reported for diploid brown trout and other salmonids at the same temperature. During prolonged swimming ( c . 80% U crit), cardiac output increased by 2·3-fold due to increases in heart rate (1·8-fold) and stroke volume (1·2-fold). At 18° C, although standard and routine metabolic rates, as well as resting heart rate and ventilation frequency increased significantly, active metabolic rate and certain cardiorespiratory variables during exercise did not differ from those values for fish acclimated to 14° C. As a result, factorial metabolic scope was reduced (2·93-fold at 18° C v . 5·13-fold at 14° C). Therefore, it is concluded that cardiorespiratory performance in triploid brown trout was not unusual at 18° C, but that reduced factorial metabolic scope may be a contributing factor to the mortality observed in triploid brown trout at temperatures near 18° C.  相似文献   

12.
Abstract: Over 60 Salsola species of Chenopodiaceae from South Africa were studied for their photosynthesis type, using δ13C analysis and light microscopy of leaf anatomy. These species cover about 70 % of the total list of Southern African Salsola species and grow naturally in South and Southwest African desert regions. All species are shrubby forms and belong to the single subsection Caroxylon. Only C4 photosynthesis was found in the Salsola species determined with 13C/12C carbon isotope discrimination values that ranged from - 11.04 to - 14.03 % (PDB), plus the presence of a Kranz type assimilation tissue anatomy. The apparent absence of C3 in Salsola in South and Southwest Africa and the known presence of C3 and C3 - C4 intermediate photosynthesis in Caroxylon, Salsola species in Asia strongly indicate that the genus Salsola originated in Asia and later migrated to South Africa.  相似文献   

13.
SYNOPSIS. An age-autolyzed culture of Chroomonas salina , grown under cool-white light with glycerol, produced waxy lipid constituting about 44% of total matter harvested. This lipid was composed of 87% wax ester, 9% triglyceride, 3% polar lipid and 1% hydrocarbon. The major wax ester species were identified by total carbon number as C26(28%), C28(35%), C30(15%). The main fatty acid components of the wax esters were 12:0 (39%), 14:0 (30%), 16:0 (14%), while the main alcohols were 14:0 (53%) and 16:0 (40%). The hydrocarbon fraction showed saturated paraffins ranging from C17 to C33, with odd-numbered chain components predominating. No polyunsaturated components were detected in the wax ester or hydrocarbon fractions. This is the first record of wax ester production by a cryptomonad or a marine phytoplankter.  相似文献   

14.
The fatty acid compositions for 40 strains of moderately halophilic Gram-negative rods were determined by gas-liquid chromatography. The strains studied were included in the genera: Vibrio, Deleya, Alteromonas, Chromobacterium, Flavobac-terium and Pseudomonas. Although there were quantitative differences all strains showed more or less similar spectra of fatty acids ranging from C12 to C20 chain. The major fatty acid species were C16:0, C16:1 and C18:1. Most striking was the predominance of the C18:1 component, the major fatty acid in extracts of 29 of the 40 strains.  相似文献   

15.
Gibberellin biosynthesis pathways were investigated using isotopically-labelled C19- and C20-gibberellins and cell-free preparations from immature seed of Phaseous coccineus cv. Prizewinner. The initial steps in an early 13-hydroxylation pathway involved the conversion gibberellin A12-aldehyde (GA12-aldehyde) to GA12 which was 13-hydroxylated to yield GA53, Metabolism of GA53 yielded GA44. In contrast to other cell-free systems, GA44 was not further converted, either as a δ-lactone or an open-lactone structure, to the C-20 aldehyde GA19. GA19 was, however, metabolised to GA20, GA5 and GA1. GA20 represented a branch point in the pathway as it was converted both to GA1, which was an end product, and GA5 which was further converted to GA6. Like GA1, GA6 was also an end-product of the early 13-hydroxylation pathway.
A non-13-hydroxylation pathway involving GA4, GA15, GA24 GA37 and GA36 also originated from GA12. The terminal product of this pathway was the 3β-hydroxy C19-gibberellin, GA4.  相似文献   

16.
Over 1,000 m of Upper Ordovician to Lower Silurian mixed carbonate and clastic strata on Anticosti Island are nearly tectonically undisturbed, despite their proximity to the Northern Appalachians fronting Quebec's Gulf of St. Lawrence. Natural cliffs exposed along the coast and rivers in the eastern part of the island make a relatively conformable sequence belonging to the Ashgill and Llandovery Series. Fossil communities interpreted as depth-associated in life are especially repetitious in the Becscie, Gun River, Jupiter, and Chicotte Formations (Llandovery Series), and to a lesser degree in the Upper Vaureal and Ellis Bay Formations (Ashgill Series). Preliminary study of the pattern of changeovers in Eocoelia, Pentamerus and Stricklandia communities suggests that Anticosti seas deepened and shallowed three and a half times during the Early Silurian. High water peaks were reached during B1-B2, C1-C2 and C4-C5 times, with a final deepening trend beginning in late C5 time. Age determinations of these events are based on the occurrence of graptolites (with some new records from Anticosti) keyed to the standard graptolite zones, and species of the Eocoelia lineage are also useful for correlation. The profile of the Anticosti sea-level curve compares well with other curves reconstructed from the Lower Silurian of New York, Michigan, and Iowa. Widespread synchronism in sea-level changes on the North American platform is thus corroborated.  相似文献   

17.
Free Fatty Acid Composition of Human and Rat Peripheral Nerve   总被引:7,自引:6,他引:1  
Abstract: The free fatty acid (FFA) composition of peripheral nerve resembles that of erythrocytes but the composition of both is different from that of brain and other tissues. Approximately 75% of FFAs of nerve and erythrocytes are saturated and <5% are polyunsaturated whereas in brain and other tissues, 30-45% of FFAs are saturated and 25-50% are polyunsaturated. Approximately 10-15% of the total FFA of nerve have very long chain lengths [C24, C26, C28, and C30]. The presence of these very long-chain FFAs in endoneurium cannot be accounted for by the retention of erythrocytes or by lipid degradation. During Wallerian degeneration a significant increase of 18:1, associated with a decrease of saturated FFAs, was found in rat sciatic endoneurium, but normal values were approached when fiber regeneration was well under way. The FFA composition with chain length ≥C26 were not, however, significantly altered with degeneration or repair of nerves. The metabolic significance of this striking difference between nerve and brain FFA composition is unknown but may reflect different functional properties.  相似文献   

18.
Plant cuticle is an extracellular lipid-based matrix of cutin and waxes, which covers aerial organs and protects them from many forms of environmental stress. We report here the characterization of CER8 / LACS1 , one of nine Arabidopsis long-chain acyl-CoA synthetases thought to activate acyl chains. Mutations in LACS1 reduced the amount of wax in all chemical classes on the stem and leaf, except in the very long-chain fatty acid (VLCFA) class wherein acids longer than 24 carbons (C24) were elevated more than 155%. The C16 cutin monomers on lacs1 were reduced by 37% and 22%, whereas the C18 monomers were increased by 28% and 20% on stem and leaf, respectively. Amounts of wax and cutin on a lacs1-1 lacs2-3 double mutant were much lower than on either parent, and lacs1-1 lacs2-3 had much higher cuticular permeability than either parent. These additive effects indicate that LACS1 and LACS2 have overlapping functions in both wax and cutin synthesis. We demonstrated that LACS1 has synthetase activity for VLCFAs C20–C30, with highest activity for C30 acids. LACS1 thus appears to function as a very long-chain acyl-CoA synthetase in wax metabolism. Since C16 but not C18 cutin monomers are reduced in lacs1 , and C16 acids are the next most preferred acid (behind C30) by LACS1 in our assays, LACS1 also appears to be important for the incorporation of C16 monomers into cutin polyester. As such, LACS1 defines a functionally novel acyl-CoA synthetase that preferentially modifies both VLCFAs for wax synthesis and long-chain (C16) fatty acids for cutin synthesis.  相似文献   

19.
The von Bertalanffy growth parameters for common wolf–fish Anarhichas lupus in the North Sea were: male: L ∞=111·2 cm, t 0=–0·43 and K =0·12; and female: L ∞=115·1 cm, t 0=–0·39 and K =0·11, making this the fastest growing stock reported. Resting metabolic rates (RMR±S.E.) and maximum metabolic rates (MMR±S.E.) for six adult common wolf–fish (mean weight, 1·39 kg) at 5° C were 12·18±1·6 mg O2 kg–1 h–1 and 70·65±7·63 mg O2 kg–1 h–1 respectively, and at 10° C were 25·43±1·31 mg O2 kg–1 h–1 and 113·84±16·26 mg O2 kg–1 h–1. Absolute metabolic scope was 53% greater at 10° C than at 5° C. The diet was dominated by Decapoda (39% overall by relative occurrence), Bivalvia (20%) and Gastropoda (12%). Sea urchins, typically of low energy value, occupied only 7% of the diet. The fast growth probably resulted from summer temperatures approximating to the optimum for food processing and growth, but may have been influenced by diet, and reduced competition following high fishing intensity.  相似文献   

20.
Arthrobacter nicotianae KCC B35 isolated from blue-green mats densely covering oil sediments along the Arabian Gulf coast grew well on C10 to C40 n -alkanes as sole sources of carbon and energy. Growth on C20 to C40 alkanes was even better than on C10 to C18 alkanes. Biomass samples incubated for 6 h with n -octacosane (C28) or n -nonacosane (C29) accumulated these compounds as the predominant constituent alkanes of the cell hydrocarbon fractions. The even chain hexadecane C16 and the odd chain pentadecane C15 were the second dominant constituent alkanes in C28 and C29 incubated cells, respectively. n -Hexadecane-incubated cells accumulated in their lipids higher proportions of C16-fatty acids than control cells not incubated with hydrocarbons. On the other hand, C28 and C29-incubated cells did not contain any fatty acids with the equivalent chain lengths, but the fatty acid patterns of the cell lipids suggest that there should have been mid-chain oxidation of these very long chain alkanes. This activity qualifies A. nicotianae KCC B35 to be used in cocktails for bioremediating environments polluted with heavy oil sediments.  相似文献   

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