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1.
1. Respiratory electron transport system (ETS) activity and oxygen consumption were measured at 10 °C for the hypogean amphipods Niphargus stygius (from two epikarst locations) and N. krameri (from a sinking river in a cave) and the epigean amphipod Gammarus fossarum (inhabiting a spring and a river). 2. ETS activity and oxygen consumption were compared between caves and the two surface locations, and between hypogean and epigean amphipods. ETS activities were found not to differ between animals from different locations, or between epigean and hypogean amphipods. As expected, the oxygen consumption of N. krameri and N. stygius was lower than that of G. fossarum. 3. The high ratio between ETS activity and oxygen consumption (ETS/R ratio) showed that N. krameri and N. stygius possess high metabolic potential that can be exploited for energy recovery and rapid restoration of body reserves immediately following the appearance of favourable conditions (food and/or oxygen). In contrast, G. fossarum exhibited a low ETS/R ratio, indicating exploitation of a great proportion of the metabolic potential for standard metabolism. 4. Feeding in N. stygius increased oxygen consumption but not ETS activity, and thus fed N. stygius had a much lower ETS/R ratio than starved ones. 5. A relatively high metabolic potential (i.e. high ETS/R ratio) may be an adaptation to hypogean life in amphipods, in that it improves survival under poor food and/or oxygen conditions. 相似文献
2.
The effects of light on the metabolic rates of the hypogean amphipod Niphargus stygius and the epigean amphipod Gammarus fossarum were compared by measuring oxygen consumption and respiratory electron transport system (ETS) activity. They were exposed to light intensities of 720 and 4700?lx at 10°C. Oxygen consumption increased significantly in N. stygius exposed to both low and high intensities of light, but no significant increase was observed in G. fossarum at either intensity. The increase of oxygen consumption in N. stygius was significantly greater at the higher light intensity. This indicates a stress response in which exploitation of half the metabolic potential for energy production in N. stygius during exposure to high light intensity constitutes an adverse effect on its metabolism, since this species usually uses less than 25% of its total metabolic potential for standard metabolic demands. 相似文献
3.
Decomposition of air-dried live Typha angustifolia (L) stems and leaves and Phragmites australis (Cav. Trin ex Steud.) leaves and culms were studied in a shallow freshwater lake (Lake Fehér, Fertő-Hanság National Park,
Hungary) using the litter bag technique. Samples were analyzed for dry mass, fiber (cellulose, hemicelluloses, lignin) and
nutrient (C, N, P, S) contents, litter-associated fungal biomass (ergosterol concentration), potential microbial respiration
(electron transport activity: ETS) and cellulolytic bacteria. In terms of mesh size, there were no significant differences
in the examined parameters of P. australis leaves and culms and T. angustifolia stems with leaves. P. australis leaves had the highest rate of decomposition and P. australis culms the lowest. Hemicellulose degraded more rapidly than the other fibers, while the lignin had the slowest rate of decomposition.
The ETS activity of the examined plant litter types increased from day 91st to 237th while decomposition processes were most active, ergosterol contents were high, and there were few cellulolytic bacteria.
The counts of cellulolytic bacteria fluctuated during the decomposition period, they were high at the beginning then they
decreased. In each case bacteria were found to be the first colonizers of plant detritus, and were followed by fungal growth. 相似文献
4.
5.
Walid Nosir Jim McDonald Steve Woodward 《Journal of industrial microbiology & biotechnology》2011,38(1):21-27
Fusaric acid (FA) (5-n-butylpuridine 2-carboxyl acid), a highly toxic secondary metabolite produced by Fusarium oxysporum strains, plays a significant role in disease development. The abilities of three F. oxysporum f. sp. gladioli (Massey) Snyder and Hansen isolates (G010; 649-91; and 160-57) to produce FA in infected Gladiolus corm tissues was evaluated in vitro in relation to the presence of two biological control agents, Trichoderma harzianum T22, and Aneurinobacillus migulanus. Pathogenicity tests were used to differentiate between the abilities of the F. oxysporum strains to secrete FA. FA was identified using LC/MS and quantified using HPLC. Isolate G010 was significantly more virulent
(P < 0.01) on Gladiolus grandiflorus corms; it secretes 1.8 μM FA/g fresh weight corm into inoculated Gladiolus. Moreover, G010 was the only isolate that produced FA among the three examined isolates. There was a correlation between
the corm lesion area and the FA secretion ability of F. oxysporum f. sp. gladioli (P < 0.001; r
2 = 0.96). No FA was detected in PDA cultures of F.oxysporum f. sp. gladioli isolates. The presence of T. harzianum T22 appeared to prevent FA secretion into the corms. In the presence of A. migulanus, however, the amount of FA secreted into the corm tissues increased. These results support the use of T. harzianum as an effective biological control agent against F. oxysporum f. sp. gladioli. 相似文献
6.
Tatjana Simčič Franja Pajk Anton Brancelj 《Marine and Freshwater Behaviour and Physiology》2013,45(2):149-156
Electron transport system (ETS) activity and oxygen consumption (i.e. respiration, R) were measured in two amphibious isopods, epigean Ligia italica and hypogean Titanethes albus. The measurements were made in air and in water to estimate the exploitation of metabolic potential for actual metabolism in the two media. Oxygen consumption was measured in animals in air before their transfer to water, in water and again after their transfer back to air. Both species showed greater oxygen consumption during submergence in water than in air. Although epigean L. italica had higher oxygen consumption and ETS activity than hypogean T. albus, both species exhibited high and variable ETS/R ratios. A high and variable ETS/R ratio is one of the characteristics of amphibious isopods that enables them to cope with specific environmental conditions in their habitats. 相似文献
7.
M. V. Titova E. A. Berkovich O. V. Reshetnyak I. E. Kulichenko A. V. Oreshnikov A. M. Nosov 《Applied Biochemistry and Microbiology》2011,47(1):87-92
Peculiarities of respiration of cells cultures producing biologically active compounds (isoprenoids and alkaloids) were investigated
in order to optimize productivity of culture growth and biosynthesis. It had been revealed that studied cells cultures of
Dioscorea deltoidea Wall (producer of furistanol glycosides), Stephania glabra (Roxb.) Miers (producer of stepharin alkaloid) and Polyscias filicifolia Bailey (complex of biologically active agents) differ both in joint respiration activity and in ratio between cytochrome
and cyanide-resistant respiration, while changes of rate of total oxygen consumption and activity of alternative oxidase during
growth were found to be individual for every investigated culture. Maximum rate of oxygen consumption for cells of D. deltoidea and S. glabra was marked in the period preceding active synthesis of secondary metabolites (lag phase for D. deltoidea and exponential phase for S. glabra). The revealed trends can be used for further monitoring and regulation of growth and biosynthesis of secondary metabolites
in producing cell cultures during deep cultivation. 相似文献
8.
Fecundity and feeding of two introduced sibling biological control species, Galerucella calmariensis and G. pusilla (Coleoptera: Chrysomelidae) on purple loosestrife, Lythrum salicaria L. (Lythraceae) were compared at constant temperatures of 12.5, 15, 20, 25, and 27.5 °C. Larval feeding was also carried
out at 30 °C, but at this temperature, larvae developed only to the L2 stage and none pupated. Thus, data for this temperature
were not used in the analysis. There were significant species × temperature interactions in fecundity. Of the two species,
Galerucella pusilla laid more eggs. Although egg production of both species was lowest at 12.5 °C and increased to 20 °C, at higher temperatures,
the two species reacted differently. From 25 to 27.5 °C, egg production decreased for G. pusilla, but G. calmariensis fecundity peaked at 27.5 °C. Significant temperature × species × life-stage interactions were also observed in feeding.
For each species, the amount of feeding varied with temperature and stage of development. Galerucella pusilla adults consumed more foliage at 15, 20, and 27.5 °C. However, at 12.5 °C G. calmariensis adults fed more than G. pusilla. G. pusilla larvae consumed an average of 25% less foliage than G. calmariensis. The lower larval consumption of G. pusilla suggests that when food is limited, G. pusilla larvae may have a higher survival rate because of its ability to complete larval development with less food and produce more
progeny due to its greater fecundity. When food is not limited neither species would have a competitive advantage and both
species could coexist temporally and spatially. However, since G. calmariensis larvae consumed more leaf material, the larval stage of this species would have a greater impact on purple loosestrife than
G. pusilla. 相似文献
9.
Mustonen AM Saarela S Nieminen P 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2008,178(2):199-208
Arvicolinae voles are small herbivores relying on constant food availability with weak adaptations to tolerate prolonged food
deprivation. The present study performed a comparative analysis on the responses to 4–18 h of food deprivation in the common
vole (Microtus arvalis) and the tundra vole (Microtus oeconomus). Both species exhibited rapid decreases in the plasma and liver carbohydrate concentrations during phase I of fasting and
the decline in the liver glycogen level was more pronounced in the tundra vole. The plasma thyroxine concentrations of the
common vole decreased after 4 h. Lipid mobilization (phase II of fasting) was indicated by the increased plasma free fatty
acid levels after 8–18 (the common vole) or 4–18 h (the tundra vole) and by the elevated lipase activities. In the tundra
vole, the plasma ghrelin concentrations increased after 12 h possibly to stimulate appetite. Both species showed increased
liver lipid concentrations after 4 h and plasma aminotransferase and creatine kinase activities after 12–18 h of food deprivation
implying liver dysfunction and skeletal muscle damage. No signs of stimulated protein catabolism characteristic to phase III
of fasting were present during 18 h without food. 相似文献
10.
Genetic variability of Trichomycterus from the region of Torotoro (Bolivia, Upper Amazon), distributed in the same watershed where the habitat is structured by
waterfalls, canyons and a cave, was studied by allozyme (twelve putative loci) and RFLP-mtDNA (DLoop and cytochrome b) analyses. Alloenzymatic variation studied by Correspondence Analysis and Maximum Likelihood Analysis revealed a four-group
structure, which was largely congruent with the distribution of the 14 mtDNA haplotypes. Two of these four clusters (I and II) were differentiated by two diagnostic loci (IDH and G3PDH), two semi-diagnostic loci (PGM and 6PGDH) and consequently a
very high Fst value (estimator θ = 0.77). Therefore, clusters I and II are reproductively isolated. The distribution limit of these two (sibling) species does not correspond to those of the morphological
species of Trichomycterus identified in this region: the epigean T. cf. barbouri and the hypogean T. chaberti. However, hypogean fish exhibited two mtDNA haplotypes, a private one and another shared with the epigean Trichomycterus from upstream reaches. 相似文献
11.
Marja Keinänen Reijo Käkelä Tiina Ritvanen Timo Myllylä Jukka Pönni Pekka J. Vuorinen 《Helgoland Marine Research》2017,71(1):4
Sprat (Sprattus sprattus) and small herring (Clupea harengus) are the dominant prey fish of Atlantic salmon (Salmo salar) in the Baltic Sea. If the fatty acid (FA) proportions of sprat and herring differ, the dietary history of ascending salmon could be determined from their FA profiles. Therefore, we investigated the FA composition of several age groups of whole sprat and small herring, caught from the three main feeding areas of salmon in autumn and spring. Oleic acid (18:1n-9) was the most prevalent FA in sprat and characteristic of this species. In herring, palmitic acid (16:0) was the most common FA, but herring lipid was characterized by n-6 polyunsaturated FAs, and moreover, by palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7). Due to the higher lipid content of sprat, the concentrations of all other FAs, excluding these, were higher in sprat than in herring. The concentration of docosahexaenoic acid (DHA, 22:6n-3) increased with an increase in the lipid content and was consequently highest in the youngest specimens, being in young sprat almost double that of young herring, and 2.6 times higher in the sprat biomass than in that of herring. As a result of a decrease in the DHA concentration with age, the ratio thiamine/DHA increased with respect to age in both species, and was lower in sprat than in herring. It is concluded that an abundance of DHA in the diet of salmon most likely increases oxidative stress because of the susceptibility of DHA to peroxidation, and thus decreases thiamine resources of fasting, prespawning salmon. Because the FA composition of sprat and herring differs, and the relative abundancies of prey fish differ between the feeding areas of salmon, the feeding area of ascending salmon can most probably be derived by comparing their FA profiles. 相似文献
12.
Pia Untalan Olafson Kevin B. Temeyer John H. Pruett 《Experimental & applied acarology》2011,53(2):147-165
13.
Gigi W. C. Ho Kenneth M. Y. Leung Dmitry L. Lajus Jasmine S. S. Ng Benny K. K. Chan 《Hydrobiologia》2009,621(1):21-32
The level of fluctuating asymmetry (FA), which is defined as random deviations from perfect bilateral symmetry in the morphological
traits of an organism, increases with increasing developmental instability, and it may be used as an indicator of environmental
and/or genetic stresses. This study attempted to relate FA levels in the opercular plates of the barnacle Amphibalanus (Balanus) amphitrite with shore height and body trace metal concentrations. Barnacles were collected from both low and mid shores at six coastal
locations with various degrees of marine pollution in Hong Kong. Four opercular traits, namely scutum length, tergum length,
scutum width, tergum width were measured in the specimen while concentrations of five common trace metals (Cd, Cu, Cr, Mn
and Zn) were determined in their body tissues using inductively coupled plasma-atomic emission spectrophotometry. Among the
four traits, only tergum length and scutum width fulfilled the assumption of FA while their measurement errors were low. Across
all sites, mid-shore A. amphitrite consistently exhibited a significantly higher FA level in scutum width than that in low-shore barnacles, but FA levels in
tergum length were similar between the two shore heights. These results suggested that FA was trait-dependent, and mid-shore
barnacles were possibly under high physical stress, such as desiccation and high temperature, leading to high developmental
instability. Although no positive association was observed between FA and metal contamination in low-shore A. amphitrite, FA level in tergum length significantly increased with decreasing body concentration of manganese (Mn) in these barnacles.
Such a negative relationship may be explained by the mechanism of bioaccumulation and physiological role of Mn in A. amphitrite with respect to the formation of barnacle shell plates.
Handling editor: T. P. Crowe 相似文献
14.
Several predatory mites have been found in association with the coconut mite, Aceria guerreronis Keifer, in northeast Brazil. However, the latter still causes damage to coconut in that region. The objectives of this work
were to compare the frequencies of occurrence of Neoseiulus (Phytoseiidae) and Proctolaelaps (Melicharidae) species on standing and aborted coconuts in coastal Pernambuco State, northeast Brazil and to analyze their
possible limitations as control agents of the coconut mite, based on evaluations of the restrictions they may have to access
the microhabitat inhabited by the pest and their functional and reproductive responses to increasing densities of the latter.
Neoseiulus baraki (Athias-Henriot) was found mostly on standing coconuts whereas Proctolaelaps bickleyi (Bram) was found mostly on aborted coconuts. Measurements of the entrance to the microhabitat occupied by the coconut mite,
between the bracts and the subjacent fruit surface, showed that this different pattern of predator prevalence could be related
to predator sizes, although other environmental factors could not be disregarded. Progressively higher predation rate of N. baraki was observed up to an experimental density that corresponded to 1,200 coconut mites per fruit, which is close to the average
number determined in northeast Brazil, reducing slightly afterwards. Predation rate of P. bickleyi reduced consistently but slightly with increasing prey densities, but in absolute values, rates were always much higher than
determined for N. baraki. The excessively high killing capacity of P. bickleyi, probably related to its high feeding requirement, may be detrimental in terms of stability. In fact, such high requirement
for food suggests that P. bickleyi might not have a strong relation with the coconut mite and that the latter may not be its main food source under natural
conditions. It is concluded that body sizes of both predators and the exceedingly high feeding requirement of P. bickleyi may limit their performance as control agents of the coconut mite. 相似文献
15.
Lima FL de Carvalho MA Apolônio AC Bemquerer MP Santoro MM Oliveira JS Alviano CS Farias Lde M 《Journal of industrial microbiology & biotechnology》2008,35(2):103-110
Aggregatibacter (Actinobacillus) actinomycetemcomitans P7–20 strain isolated from a periodontally diseased patient has produced a bacteriocin (named as actinomycetemcomitin) that is
active against Peptostreptococcus anaerobius ATCC 27337. Actinomycetemcomitin was produced during exponential and stationary growth phases, and its amount decreased until
it disappeared during the decline growth phase. It was purified by ammonium sulphate precipitation (30–60% saturation), and
further by FPLC (mono-Q ionic exchange and Phenyl Superose hydrophobic interaction) and HPLC (C-18 reversed-phase). This bacteriocin
loses its activity after incubation at a pH below 7.0 or above 8.0, following heating for 30 min at 45°C, and after treatment
with proteolytic enzymes such as trypsin, α-chymotrypsin, and papain. Actinomycetemcomitin has a molecular mass of 20.3 KDa
and it represents a new bacteriocin from A. actinomycetemcomitans. 相似文献
16.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
17.
The present study on efficacy of different Glomus species, an arbuscular mycorrhizal (AM) fungus (G. aggregatum, G. fasciculatum, G. mosseae, G. intraradices) on various growth parameters such as biomass, macro and micronutrients, chlorophyll, protein, cytokinin and alkaloid content
and phosphatase activity of pink flowered Catharanthus roseus plants showed that all Glomus species except G. intraradices enhanced the chlorophyll, protein, crude alkaloid, phosphorus, sulphur, manganese and copper contents of C. roseus plants along with phosphatase activity significantly over uninoculated plants. However only G. mosseae and G. fasciculatum exhibited superior symbiotic relationship with the plant. G. mosseae was found to be the best for increasing the crude alkaloid content (8.19%) in leaf and also in increasing the quantity of
important alkaloids vincristine and vinblastine. 相似文献
18.
Enrique Gino Medrano Jesus Esquivel Alois Bell Jeremy Greene Phillip Roberts Jack Bacheler James Marois David Wright Robert Nichols Juan Lopez 《Current microbiology》2009,59(4):405-412
Recently, we showed that the southern green stink bug (SGSB), Nezara viridula (L.), can transmit Pantoea agglomerans (Ewing and Fife), an opportunistic bacterium, into green cotton bolls resulting in plant disease. Here, we hypothesized that
our established model could be used to determine if the SGSB was a general, non-discriminate vector by using two other opportunistic
bacterial pathogens of bolls (Pantoea
ananatis [Serano] and Klebsiella
pneumoniae [Schroeter]) and the known fungal pathogen Nematospora coryli (Peglion). Variants of P. ananatis (strain Pa-1R) and K. pneumoniae (strain Kp 5-1R) selected for rifampicin (Rif) resistance were used as bacterial opportunists. N.
coryli was detected only from laboratory-reared SGSB directly exposed to the fungus. Both Pa-1R and Kp 5-1R were recovered from
SGSB previously provided a contaminated food source (2 days), sterile food (5 days), and then harvested after being caged
on bolls (2 days) at levels reaching 103 and 104 colony forming units (cfus) per insect, respectively. However, bolls caged with insects infected with Pa-1R or Kp 5-1R and
with evidence of feeding did not become diseased nor were either opportunists detected from boll tissues. Insects infected
with N. coryli transmitted the pathogen, which resulted in diseased bolls and fungi concentrations reached 106 cfus/g locule tissue at 2 weeks following the caging period. Notably, each of the three pathogens independently caused boll
disease when mechanically inoculated using a needle puncture. Generally, these results suggest that cotton pathogen acquisition
by the SGSB was not sufficient to determine whether the insects were disease vectors of the opportunists. 相似文献
19.
Purkan Ihsanawati Yana M. Syah Debbie S. Retnoningrum Achmad S. Noer Shigeru Shigeoka Dessy Natalia 《Biologia》2012,67(1):41-47
Most of isoniazid-resistant Mycobacterium tuberculosis evolved due to mutation in the katG gene encoding catalase-peroxidase. A set of new mutations, namely T1310C, G1388T, G1481A, T1553C, and A1660G, which correspond
to amino acid substitutions of L437P, R463L, G494D, I518T, and K554E, in the katG gene of the L10 clinical isolate M. tuberculosis was identified. The wild-type and mutant KatG proteins were expressed in Escherichia coli BL21(DE3) as a protein of 80 kDa based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. The mutant
KatG protein exhibited catalase and peroxidase activities of 4.6% and 24.8% toward its wild type, respectively, and retained
19.4% isoniazid oxidation activity. The structure modelling study revealed that these C-terminal mutations might have induced
formation of a new turn, perturbing the active site environment and also generated new intramolecular interactions, which
could be unfavourable for the enzyme activities. 相似文献
20.
Karin Nuernberg Jaroslav Slamecka Jozef Mojto Jozef Gasparik Gerd Nuernberg 《European Journal of Wildlife Research》2011,57(4):795-803
The aim of this investigation was to characterise the fatty acid composition within intramuscular fat (IMF) of two muscles
(breast and thigh) from 28 pheasants, ten wild ducks and 27 black coots from Slovakia. A high variability for all single fatty
acids (FA) and the total fat concentration in muscles of wild birds was identified. Black coots deposited the highest fat
in breast muscle whereas wild ducks and pheasants accumulated more lipids in thigh muscle. In general, the content of polyunsaturated
fatty acids (PUFA) of the IMF in wild bird muscles was high, and the saturated FA concentration was lower compared with muscles
of domestic farm animals. The ratio between PUFA and saturated fatty acids (PSQ) ranked between 0.6 and 1.2, and the ratio
of n-6/n-3 fatty acid was favourably low in black coot and wild pheasants (3.2 and 2.9, respectively). Farmed pheasants had increased
IMF and more saturated and n-6 fatty acids deposited in thigh muscle but not in breast muscle. 相似文献