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1.
Suction volume and filtering efficiency of silver carp (Hypophthalmichthys molitrix Val.) and bighead carp (Aristichthys nobilis Rich.) 总被引:1,自引:0,他引:1
Shuanglin Dong Deshang Li Xuwen Bing Qingfeng Shi Fang Wang 《Journal of fish biology》1992,41(5):833-840
Experiments were conducted to measure the suction volume of silver carp and bighead carp of age 1 + with respiratory chamber, and to calculate the suction volume and the filtering efficiency with respect to changes in concentrations of food particles. Suction volume (B. ml/mouth) and filtering efficiency (E. %) were calculated using the following formula: C 1=C0(1-BE/v)n where C0 and C1 were the concentrations of specific food particles at the beginning and at the end of experiment, respectively, V was the volume (ml) of experimental water, and n was the total number of observation of suction made during the experimental period. The relationships between suction volume (ml/mouth) of age I+ silver carp (Bh) and bighead carp (Ba) and their standard lengths (L, cm) were: B h=0.561L-8.94, Ba= 0.627L-7.48 while those of the fingerlings were: B h= O.l70L-0.837, Ba= 0.157L-0.418. The suction volume of the fingerlings was mainly affected by fish size, the function of temperature between 15 and 25° C being negligible. However, temperature affected filtering rate (filtered volume per unit time) through its effect on filtering frequency. The filtering efficiency of the fishes for rotifers (Brachionus caliciflorus) was 100 per cent. The relationships between filtering efficiency and sizes of food particles smaller than or equal to that of a rotifer were: E h=25.1 ln e.s.d. -13.6, Ea=22.2 In e.s.d. -33.1 where Eh and Ea were filtering efficiency of silver carp and bighead carp, respectively, and e.s.d. was the equivalent spherical diameter (μm) of food particles. 相似文献
2.
Eng-Seng Chan Peh-Phong Lee Pogaku Ravindra Kamatan Krishnaiah Wan-Ping Voo 《Applied microbiology and biotechnology》2010,86(1):385-391
The aim of this work was to develop a standard quantitative method to measure the acid tolerance of probiotic cells when exposed
to a simulated gastric fluid. Three model strains of different cell concentrations were exposed to a standard simulated gastric
fluid of fixed volume. The fluid pH ranged from pH 1.5 to 2.5. In general, the death kinetics followed an exponential trend.
The overall death constant, k
d, for all strains was found to be in a power relationship with the pH value and the initial cell concentration, and it can
be expressed as
k\textd\text = k\textAII( \textp\textH - \text9.0N0 - 0.\text19 ) {k_{\text{d}}}{\text{ = }}{k_{\text{AII}}}\left( {{\text{p}}{{\text{H}}^{ - {\text{9}}.0}}{N_0}^{ - 0.{\text{19}}}} \right) 相似文献
3.
Effect of nitrogen stress and abscisic acid on nitrate absorption and transport in barley and tomato
F. Stuart Chapin III David T. Clarkson John R. Lenton Colin H. S. Walter 《Planta》1988,173(3):340-351
The potential of barley (Hordeum vulgare L.) and tomato (Lycopersicon esculentum Mill.) roots for net NO
3
-
absorption increased two-to five fold within 2 d of being deprived of NO
3
-
supply. Nitrogen-starved barley roots continued to maintain a high potential for NO
3
-
absorption, whereas NO
3
-
absorption by tomato roots declined below control levels after 10 d of N starvation. When placed in a 0.2 mM NO
3
-
solution, roots of both species transported more NO
3
-
and total solutes to the xylem after 2 d of N starvation than did N-sufficient controls. However, replenishment of root NO
3
-
stores took precedence over NO
3
-
transport to the xylem. Consequently, as N stress became more severe, transport of NO
3
-
and total solutes to the xylem declined, relative to controls. Nitrogen stress caused an increase in hydraulic conductance (L
p) and exudate volume (J
v) in barley but decrased these parameters in tomato. Nitrogen stress had no significant effect upon abscisic acid (ABA) levels in roots of barley or flacca (a low-ABA mutant) tomato, but prevented an agerelated decline in ABA in wild-type tomato roots. Applied ABA had the same effect upon barley and upon the wild type and flacca tomatoes: L
p and J
v were increased, but NO
3
-
absorption and NO
3
-
flux to the xylem were either unaffected or sometimes inhibited. We conclude that ABA is not directly involved in the normal changes in NO
3
-
absorption and transport that occur with N stress in barley and tomato, because (1) the root ABA level was either unaffected by N stress (barley and flacca tomato) or changed, after the greatest changes in NO
3
-
absorption and transport and L
p had been observed (wild-type tomato); (2) changes in NO
3
-
absorption/transport characteristics either did not respond to applied ABA, or, if they did, they changed in the direction opposite to that predicted from changes in root ABA with N stress; and (3) the flacca tomato (which produces very little ABA in response to N stress) responded to N stress with very similar changes in NO
3
-
transport to those observed in the wild type.Abbreviation and symbols ABA
abscisic acid
- Jv
exudate volume
- Lp
root hydraulic conductance 相似文献
4.
Growth response of barley and tomato to nitrogen stress and its control by abscisic acid,water relations and photosynthesis 总被引:14,自引:0,他引:14
Barley (Hordeum vulgare L.) and tomato Lycopersicon esculentum Mill.) were grown hydroponically and examined 2, 5, and 10 d after being deprived of nitrogen (N) supply. Leaf elongation rate declined in both species in response to N stress before there was any reduction in rate of dryweight accumulation. Changes in water transport to the shoot could not explain reduced leaf elongation in tomato because leaf water content and water potential were unaffected by N stress at the time leaf elongation began to decline. Tomato maintained its shoot water status in N-stressed plants, despite reduced water absorption per gram root, because the decline in root hydraulic conductance with N stress was matched by a decline in stomatal conductance. In barley the decline in leaf elongation coincided with a small (8%) decline in water content per unit area of young leaves; this decline occurred because root hydraulic conductance was reduced more strongly by N stress than was stomatal conductance. Nitrogen stress caused a rapid decline in tissue NO
3
-
pools and in NO
3
-
flux to the xylem, particularly in tomato which had smaller tissue NO
3
-
reserves. Even in barley, tissue NO
3
-
reserves were too small and were mobilized too slowly (60% in 2 d) to support maximal growth for more than a few hours. Organic N mobilized from old leaves provided an additional N source to support continued growth of N-stressed plants. Abscisic acid (ABA) levels increased in leaves of both species within 2 d in response to N stress. Addition of ABA to roots caused an increase in volume of xylem exudate but had no effect upon NO
3
-
flux to the xylem. After leaf-elongation rate had been reduced by N stress, photosynthesis declined in both barley and tomato. This decline was associated with increased leaf ABA content, reduced stomatal conductance and a decrease in organic N content. We suggest that N stress reduces growth by several mechanisms operating on different time scales: (1) increased leaf ABA content causing reduced cell-wall extensibility and leaf elongation and (2) a more gradual decline in photosynthesis caused by ABA-induced stomatal closure and by a decrease in leaf organic N.Abbreviation and symbols ABA
abscisic acid
- ci
leaf internal CO2 concentration
- Lp
root hydraulic conductance 相似文献
5.
Abstract— A 20–30 per cent stimulation of ATPase activity by added NaHCO3 was found in homogenates of a variety of mammalian tissues. The subcellular distribution of this (HCO3-)—stimulated activity was examined in detail using rat cerebral cortex. The stimulation was specific for the HCO3- ion and was predominantly localized in the mitochondrial subcellular fraction, in which a 2-fold stimulation by HCO3- was found. The effect of inhibitors supported the identification as the mitochondrial ATPase. Both sodium azide and thiocyanate were inhibitory. The effects of varying the Mg2+ concentration, HCO3- concentration, and pH were also studied. In the presence of HCO3- the Km for ATP was reduced approximately 3-fold. There was no effect of HCO3- on the ma + K) ATPase or Mg2+ ATPase from the microsomal fraction of rat cerebral cortex. Our findings have been discussed in relation to previous work on HCO3- stimulation of ATPae activity in subcellular fractions from other tissues, as well as its possible relevance to the known effects of HCO3- and carbonic anhydrase on active ion transport. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1403-1405
Gibberellin A1 (GA1), which was identified as the major GA from the GA-producing fungus Phaeosphaeria sp. L487, was accumulated in the culture with a maltose-yeast extract medium, its amount in the culture filtrate being about 50 mg per liter after a 3-week culture. The new fungal biosynthetic pathway to GA1 from GA9 via GA4 was elucidated by feeding experiments with synthetic [17-2H2]GA9 and [17-2H2]GA4. 相似文献
7.
David J. Richardson Glenn F. King David J. Kelly Alastair G. McEwan Stuart J. Ferguson J. Barry Jackson 《Archives of microbiology》1988,150(2):131-137
Phototrophic growth of Rhodobacter capsulatus (formerly Rhodopseudomonas capsulata) under anaerobic conditions with either butyrate or propionate as carbonsource was dependent on the presence of either CO2 or an auxiliary oxidant. NO
-
3
, N2O, trimethylamine-N-oxide (TMAO) or dimethylsulphoxide (DMSO) were effective provided the appropriate anaerobic respiratory pathway was present. NO
-
3
was reduced extensively to NO
-
3
, TMAO to trimethylamine and DMSO to dimethylsulphide under these conditions. Analysis of culture fluids by nuclear magnetic resonance showed that two moles of TMAO or DMSO were reduced per mole of butyrate utilized and one mole of either oxidant was reduced per mole of propionate consumed. The growth rate of Rb. capsulatus on succinate or malate as carbon source was enhanced by TMAO in cultures at low light intensity but not at high light intensities. A new function for anaerobic respiration during photosynthesis is proposed: it permits reducing equivalents from reduced substrates to pass to auxiliary oxidants present in the medium. The use of CO2 or auxiliary oxidants under phototrophic conditions may be influence by the availability of energy from light. It is suggested that the nuclear magnetic resonance methodology developed could have further applications in studies of bacterial physiology.Abbreviations DMS
dimethylsulphide
- DMSO
dimethylsulphoxide
- TMA
trimethylamine
- TMAO
trimethylamine-N-oxide
- NMR
nuclear magnetic resonance 相似文献
8.
An oxygen transfer model was established for Pichia pastoris growing on glycerol and methanol in a stirred tank bioreactor and expressing a recombinant human serum albumin (rHSA). This
was based on pseudo-steady state mass balance, where the volumetric O2 transfer coefficient, k
L
a, was estimated as a function of power input per unit volume and aeration rate. Under pseudo-steady state, the O2 transfer rate model matched the O2 uptake rate obtained from a previous macrokinetic model. This procedure was also applied to estimate biomass concentration
by using the on-line rolling identification approach. 相似文献
9.
Lawrence T. Novak 《Biotechnology and bioengineering》1979,21(8):1457-1468
The objective of this study was to determine the role of agitation conditions in the oxidation of nitrite ions by Nitrobacter. Batch reaction kinetic experiments were conducted in baffled stirred tanks. The range of agitation conditions studied was 6200 ? 95700 ergs/cm3 sec. This power input corresponds to 3.2 ? 45.6 hp/ 1000 gal, or a “hem Scale” of 3 ? 9. After a lag phase, the reaction kinetics were found to be zero order with respect to nitrite over a concentration range of 590 to 10 mg/liter nitrite nitrogen (NO2?-N). The zero-order rate constants were found to significantly decrease with increasing impeller power input per volume of liquid (P / V). 相似文献
10.
11.
The symbiotic dinoflagellate microalgae of corals (Symbiodinium spp.) contain high concentrations of dimethylsulfoniopropionate (DMSP), a multifunctional metabolite commonly found in many
species of marine algae and dinoflagellates. A photoprotective antioxidant function for DMSP and its breakdown products has
often been inferred in algae, but its role(s) in the coral–algal symbiosis remains elusive. To examine potential correlations
between environmental and physiological parameters and DMSP, total DMSP (DMSPt, from the host coral and zooxanthellae), particulate DMSP (DMSPp, from the zooxanthellae only), coral surface area, and total protein, as well as zooxanthellae density, chlorophyll concentration,
cell volume and genotype (i.e., clade) were measured in five coral species from the Diploria-Montastraea-Porites species complex in Bermuda along a depth gradient of 4, 12, 18, and 24 m. DMSPt concentrations were consistently greater than DMSPp concentrations in all species suggesting the possible translocation of DMSP from symbiont to host. D. labyrinthiformis was notably different from the other corals examined, showing DMSPp and DMSPt increases (per coral surface area or tissue biomass) with increasing water depth. However, overall, there were no consistent
depth-related patterns in DMSPp and DMSPt concentrations. Further research, investigating dimethylsulfide (DMS), dimethylsulfoxide, and acrylate levels and DMSP-lyase
activity in correlation with other biomarker endpoints that have been shown to be depth (i.e., temperature and light) responsive
are needed to substantiate the significance of these findings. 相似文献
12.
Initial steps in the degradation of benzene sulfonic acid, 4-toluene sulfonic acids,and orthanilic acid in Alcaligenes sp. strain O-1 总被引:2,自引:0,他引:2
Thomas Thurnheer Daniel Zürrer Otmar Höglinger Thomas Leisinger Alasdair M. Cook 《Biodegradation》1990,1(1):55-64
Alcaligenes sp. strain O-1 grew with benzene sulfonate (BS) as sole carbon source for growth with either NH4
+ or NH4
+ plus orthanilate (2-aminobenzene sulfonate, OS) as the source(s) of nitrogen. The intracellular desulfonative enzyme did not degrade 3- or 4-aminobenzene sulfonates in the medium, although the enzyme in cell extracts degraded these compounds. We deduce the presence of a selective permeability barrier to sulfonates and conclude that the first step in sulfonate metabolism is transport into the cell. Cell-free desulfonation of BS in standard reaction mixtures required 2 mol of O2 per mol. One mol of O2 was required for a catechol 2,3-dioxygenase. When meta ring cleavage was inhibited with 3-chlorocatechol in desalted extracts, about 1 mol each of O2 and of NAD(P)H per mol of BS were required for the reaction, and SO3
2- and catechol were recovered in high yield. Catechol was shown to be formed by dioxygenation in an experiment involving 18O2. 4-Toluene sulfonate was subject to NAD(P)H-dependent dioxygenation to yield SO3
2- and 4-methylcatechol, which was subject to meta cleavage. OS also required 2 mol of O2 per mol and NAD(P)H for degradation, and SO3
2- and NH4
+ were recovered quantitatively. Inhibition of ring cleavage with 3-chrorocatechol reduced the oxygen requirement to 1 mol per mol of OS SO3
2- (1 mol) and an unidentified organic intermediate, but no NH4
+, were observed. 相似文献
13.
High-calcifying cells of Emiliania huxleyi were grown on a synthetic seawater medium and the effect of nitrate (NO- 3) concentration on growth, calcite accumulation, calcification rate and DIC (dissolved inorganic carbon) utilisation determined. The stoichiometry between NO- 3 utilisation and calcite production was 1:6·5 (mol/mol). Calcification and growth were tightly coupled: calcite production ceased when cultures entered the stationary phase due to NO- 3 depletion, but by adding a pulse of NO- 3 growth and calcification were restored. The initial C/N ratio in the medium was important in relation to calcification rate. At 20 µM NO- 3 the total DIC (2 mM) was rapidly depleted, the calcification rate subsequently declining, whereas at 5 and 10 µM NO- 3 rates of calcification were constant at 20 g carbon cell-1 × 1014·h-1 throughout culture growth, excess DIC being present relative to the available NO- 3. Calcite production per unit NO- 3 was similar for isolates of E. huxleyi from neritic, oligotrophic and nitrate-rich waters. In laboratory cultures, where the photon flux density is optimised for growth, the initial NO- 3 concentration is a reliable indicator of final calcite yield. 相似文献
14.
Oxygen consumption and the composition of skeletal muscle tissue after training and inactivation in the European woodmouse (Apodemus sylvaticus) 总被引:1,自引:0,他引:1
H. Hoppeler S. L. Lindstedt E. Uhlmann A. Niesel L. M. Cruz-Orive E. R. Weibel 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1984,155(1):51-61
Summary In European woodmice the amount and intensity of daily activity was compared to oxygen uptake and to the potential for oxidative metabolism of heart and skeletal muscle. One group of animals was inactivated by exposition to light during night time; another group of animals was trained by enforced running on a treadmill. The oxidative potential of the muscle tissue was assessed by morphometry of capillaries and mitochondria. A novel sampling technique was used which allowed us to obtain morphological data related to single muscles, to muscle groups, and finally to whole body muscle mass.Reducing the spontaneous activity by ten fold had no effect on oxygen uptake nor on capillaries or mitochondria in locomotory muscles. Mitochondrial volume was reduced, however, in heart and diaphragm. Enforced running increased the weight specific maximal oxygen uptake significantly. It also increased the mitochondrial volume in heart and diaphragm as well as in M. tibialis anterior. Capillary densities were neither affected by training nor by inactivation. A significant correlation was found between the capillary density and the volume density of mitochondria in all muscles analysed morphometrically. For the whole skeletal muscle mass of a European woodmouse the inner mitochondrial membranes were estimated to cover 30 m2. The oxygen consumption per unit time and per unit volume of muscle mitochondrion was found to be identical in all groups of animals (4.9 ml O2 min–1 cm–3).Symbols
S
v
(im,m) surface area of inner mitochondrial membranes per unit mitochondrial volume
-
V
v
(mt, f) volume density of mitochondria (mitochondrial volume per fiber volume)
-
V (mt)
total mitochondrial volume
-
V (f)
muscle volume
-
N
A (c, f)
capillary density
- (f)
mean fiber cross-sectional area 相似文献
15.
J. G. Shirani Ranasinghe Ming-Cheh Liu Yoichi Sakakibara Yumiko Takeshita Nobuhiro Fukuda Tetsuo Nasu Masahito Suiko 《Journal of Molecular Catalysis .B, Enzymatic》2001,12(1-6)
In our previous studies, we have demonstrated the stereoselective and manganese-dependent sulfation of tyrosine and Dopa isomers by human monoamine (M)-form phenol sulfotransferase (PST). In the present study, we investigated the occurrence of these phenomena in vivo using Sprague–Dawley rats as an experimental model. Three groups of six male rats were orally introduced with 1 ml of, respectively, 3 mM, 10 mM and 30 mM MnCl2 with a constant level of 0.2 mM
-m-tyrosine per day for 7 days. Their urine was collected and analyzed for the presence of sulfated
-m-tyrosine (
-m-TyrS) by ion-pair HPLC using a C18 reversed-phase column. The level of urinary
-m-TyrS, which was detected in the urine of the MnCl2-treated rats but not control rats, appeared to increase proportionally to the amount of MnCl2 administered. Chiral HPLC was employed to differentiate the
-form and
-form m-TyrS present in the urine sample of MnCl2-treated rats. Both
-m-TyrS and
-m-TyrS were detected, with the
-form being present at significantly higher level than the
-form. 相似文献
16.
Pattern and extent to which the main shoot of rice (Oryza sativa L.) cv. Pusa 33 assimilates NO3- when grown under lowland conditions was determined in a field study. The in vivo NR (nitrate reductase) activity is low as compared to the value in other cereals grown under aerobic soil conditions. The leaf blades had higher NR activity (g fr. wt.)-1 than the sheaths and stem. Calculation of total NO3- (mol) reduced in the main shoot, obtained by integrating the in vivo NR assay values per plant part and per day over the duration for which the various plant parts on the main shoot remained metabolically active, showed that out of the total reduced N at harvest, 16.6% was assimilated via the enzyme nitrate reductase. In the leaf sheaths and stem the NO3- was reduced to slightly over 50% of the total NO3- that was reduced in the main shoot. The rest of the amount was reduced in the leaf blades. 相似文献
17.
METABOLISM OF HEXOSES IN RAT CEREBRAL CORTEX SLICES 总被引:3,自引:0,他引:3
Abstract—
18.
Akira Yanai Teruhiko Beppu Kei Arima 《Bioscience, biotechnology, and biochemistry》2013,77(1):149-151
Lipogenesis in the fatty liver of rat, which was induced by feeding an amino acid unbalanced diet containing 8% casein supplemented with 0.3% dl-methionine, has been studied by measuring the incorporation of glycerol-1-14C, palmitate-1-14C, citrate-1,5-14C, pyruvate-1-14C and pyruvate-2-14C into various lipid fractions and 14CO2 during in vitro incubation of liver slices.The total radioactivity of liver lipid per 100 g of the body and the incorporation of each substrate into triglyceride in the lipid were significantly higher in the imbalance group than the control group. Conversion of each substrate to 14CO2 was not imparied in the imbalance group.It is evident from these results that the induction of this type of fatty liver is due mainly to the triglyceride synthesis by both the fatty acid synthesis and the transesterification of fatty acid.These results are considered to support the previous assumption in which acetate-1-14C was used as a precursor. 相似文献
19.
P. Haddadi B. Yazdi-samadi M. R. Naghavi A. Kalantari P. Maury A. Sarrafi 《Plant biotechnology reports》2011,5(2):135-146
The objective of the present research was to map QTLs associated with agronomic traits such as days from sowing to flowering,
plant height, yield and leaf-related traits in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus). Two field experiments were conducted with well-irrigated and partially irrigated conditions in randomized complete block
design with three replications. A map with 304 AFLP and 191 SSR markers with a mean density of 1 marker per 3.7 cM was used
to identify QTLs related to the studied traits. The difference among RILs was significant for all studied traits in both conditions.
Three to seven QTLs were found for each studied trait in both conditions. The percentage of phenotypic variance (R
2) explained by QTLs ranged from 4 to 49%. Three to six QTLs were found for each yield-related trait in both conditions. The
most important QTL for grain yield per plant on linkage group 13 (GYP-P-13-1) under partial-irrigated condition controls 49% of phenotypic variance (R
2). The most important QTL for 1,000-grain weight (TGW-P-11-1) was identified on linkage group 11. Favorable alleles for this QTL come from RHA266. The major QTL for days from sowing
to flowering (DSF-P-14-1) were observed on linkage group 14 and explained 38% of the phenotypic variance. The positive alleles for this QTL come from
RHA266. The major QTL for HD (HD-P-13-1) was also identified on linkage group 13 and explained 37% of the phenotypic variance. Both parents (PAC2 and RHA266) contributed
to QTLs controlling leaf-related traits in both conditions. Common QTL for leaf area at flowering (LAF-P-12-1, LAF-W-12-1) was detected in linkage group 12. The results emphasise the importance of the role of linkage groups 2, 10 and 13 for studied
traits. Genomic regions on the linkage groups 9 and 12 are specific for QTLs of leaf-related traits in sunflower. 相似文献
20.
Koshi Arai Tetsu Ando Sadahiro Tatsuki Kenji Usui Yoshiko Ohguchi Matsuo Kurihara 《Bioscience, biotechnology, and biochemistry》2013,77(12):3165-3168
Lipoxygenase-3, the major component of the enzyme in rice grain, was purified 2980-fold with a yield of 7% from embryos. The purified enzyme had a specific activity of 280 μmol O2 formed/min per mg protein. This enzyme was inactivated by SH compounds, such as cysteine and glutathione. The inactivation was prevented by the addition of catalase or replacement of the air by N2 gas. These two treatments were also effective for the stable storage of the purified enzyme. The molecular weights measured by sodium dodecyl sulfate gel and gradient gel electrophoresis were 93,000 and 89,000, respectively, indicating that the enzyme is a single polypeptide chain. The purified enzyme contained 0.73 Fe atom per molecule. The absorption spectrum suggested that the enzyme is a non-heme iron protein. Some similarities in amino-acid composition were observed between rice, soybean, and pea lipoxygenases. The purified enzyme specifically produced 9-d-hydroperoxy-10,12(E,Z)-octadecadienoic acid when linoleic acid was used as a substrate. 相似文献
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