共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Q. Hurtado A. T. Critchley A. Trespoey G. Bleicher-Lhonneur 《Journal of applied phycology》2008,20(5):551-555
Kappaphycus striatum var. sacol was grown in two separate studies: (1) at two stocking densities, and (2) at four different depths, each for three different
durations of culture (30, 45 and 60 days) in order to determine the growth rate of the seaweed and evaluate the carrageenan
content and its molecular weight. The results demonstrated that stocking density, duration of culture and depth significantly
(P < 0.01) affected the growth rate, carrageenan content and molecular weight of K. striatum var. sacol. Decreasing growth rate was observed at both stocking densities and at four depths as duration of culture increased. A lower
stocking density (500 g m−1line−1) showed a higher growth rate for the shortest durations, i.e. 30 days, as compared to those grown at a higher density. Likewise,
decreasing growth rate was observed as depth increased, except at 50 cm after 60 days of culture. A 45-day culture period
produced the highest molecular weight at both stocking densities (500 g m−1line−1 = 1,079.5 ± 31.8 kDa, 1,000 g m−1line−1 = 1,167 ± 270.6 kDa). ‘Sacol’ grown for 30 days at 50 cm (1,178 kDa) to 100 cm (1,200 kDa) depth showed the highest values
of molecular weight of carrageenan extracted. The results suggested that K. striatum var. sacol is best grown at a stocking density of 500 g m−1line−1, at a depth of 50–100 cm, and for a duration of 30 days in order to provide the highest growth rate, carrageenan content
and molecular weight. 相似文献
2.
Nelso P. Navarro Andrés Mansilla Estela M. Plastino 《Journal of applied phycology》2010,22(4):385-394
The effects of UVB radiation on the different developmental stages of the carrageenan-producing red alga Iridaea cordata were evaluated considering: (1) carpospore and discoid germling mortality; (2) growth rates and morphology of young tetrasporophytes;
and (3) growth rates and pigment content of field-collected plant fragments. Unialgal cultures were submitted to 0.17, 0.5,
or 0.83 W m−2 of UVB radiation for 3 h per day. The general culture conditions were as follows: 12 h light/12 h dark cycles; irradiance
of 55 μmol photon.per square meter per second; temperature of 9 ± 1°C; and seawater enriched with Provasoli solution. All UVB irradiation treatments
were harmful to carpospores (
0.17 \textW \textm - 2 = 40.9 ±6.9% 0.17\;{\text{W}}\,{{\text{m}}^{ - 2}} = 40.9 \pm 6.9\% ,
0.5 \textW \textm - 2 = 59.8 ±13.4% 0.5\;{\text{W}}\,{{\text{m}}^{ - 2}} = 59.8 \pm 13.4\% ,
0.83 \textW \textm - 2 = 49 ±17.4% 0.83\;{\text{W}}\,{{\text{m}}^{ - 2}} = 49 \pm 17.4\% mortality in 3 days). Even though the mortality of all discoid germlings exposed to UVB radiation was unchanged when compared
to the control, those germlings exposed to 0.5 and 0.83 W m−2 treatments became paler and had smaller diameters than those cultivated under control treatment. Decreases in growth rates
were observed in young tetrasporophytes, mainly in 0.5 and 0.83 W m−2 treatments. Similar effects were only observed in fragments of adult plants cultivated at 0.83 W m−2. Additionally, UVB radiation caused morphological changes in fragments of adult plants in the first week, while the young
individuals only displayed this pattern during the third week. The verified morphological alterations in I. cordata could be interpreted as a defense against UVB by reducing the area exposed to radiation. However, a high level of radiation
appears to produce irreparable damage, especially under long-term exposure. Our results suggest that the sensitivity to ultraviolet
radiation decreases with increased algal age and that the various developmental stages have different responses when exposed
to the same doses of UVB radiation. 相似文献
3.
Xuefei Lv Jing Shao Qunfang Zhou Maoyong Song Guibin Jiang 《Environmental Biology of Fishes》2009,85(1):23-29
To improve the use of the Chinese loach, Misgurnus anguillicaudatus, as a sentinel species for environmental investigations, normal ranges of plasma vitellogenin (Vtg) was studied. Male and
female loaches were collected every 2 months from November 2004 to September 2005, and a specific and sensitive competitive
enzyme-linked immunosorbent assay (ELISA) was used to determine plasma Vtg levels. Our data indicated that the average maximum
Vtg level of female loaches (757 ± 356 μg mL−1) appeared in March, approximately 1 month before spawning. Female plasma Vtg significantly correlated with gonadosomatic
index (GSI) which indicated that female plasma Vtg can be used as an indicator of the reproductive stages of the ovary. Low
detectable plasma Vtg levels was detected in a number of male loaches, and the highest average plasma Vtg concentration attained
to the level of μg mL−1; after exposure to estrogenic compounds by waterborne, injection or oral food, Vtg can be induced in male fish, so the presence
of Vtg in male loaches might be attributed to the ingestion of estrogenic substances in food, the contamination of estrogenic
compounds from the living environment, or the estrogen used by the local fish breeders to accelerate the rate of growth during
artificial culture. The results indicate that Vtg levels in male and female Chinese loaches will be very helpful in field
studies which use Chinese loach as a sentinel species. 相似文献
4.
The wolf spider Pardosa cribata Simon is the most abundant ground-dwelling spider inhabiting citrus orchards in eastern Spain. However, little is known about
its activity-density and its predatory role in the citrus agrosystem. Here we report on the activity-density of P. cribata monitored by pitfall traps, and on its capacity to prey on two citrus pests that appear both in the citrus canopy and the
ground cover, Ceratitis capitata (Wiedemman) and Myzus persicae (Sulzer), respectively. Pardosa cribata was present in citrus orchards throughout the year, with a peak in spring and a higher peak in summer. Pardosa cribata preyed on adults and third-instar larvae but not on pupae of C. capitata. A type II functional response was obtained for teneral-like adults, with an estimated attack rate (a′) of 0.771 ± 0.213 days−1 and a handling time (T
h) of 0.051 ± 0.013 days. Pardosa cribata also preyed efficiently on M. persicae, giving a type II functional response with an estimated attack rate and handling time of 2.833 ± 0.578 days−1 and 0.031 ± 0.001 days, respectively. The data reported here indicate that this wolf spider could play an important role
in regulating both these pests, and therefore might contribute to developing conservation biological control strategies for
citrus pests.
Handling Editor: Arne Jenssen. 相似文献
5.
The influence of predator exposure on the survival of hatchery red drum, Sciaenops ocellatus was investigated under laboratory conditions. Several prey-capture (attack distance, mean attack velocity, capture time,
and gape cycle duration) and anti-predator (reaction distance, response distance, mean velocity, and maximum velocity) performance
variables were quantified using high-speed video for juvenile red drum (25–30 mm standard length, L
S
) reared with and without predators (pinfish, Lagodon rhomboides). Univariate contrasts of prey-capture events demonstrated that attack distance (mean ± s.e.) was significantly greater in
red drum reared with (1.20 ± 0.16 mm) versus without (0.65 ± 0.09 mm) pinfish predators. During anti-predator events, red
drum reared with predators had approximately 300% greater reaction distance and 20%–30% greater response distance, mean velocity
and maximum velocity versus fish reared without predators; however, these differences were not statistically significant.
Following video assessments, a series of mortality experiments were conducted using free-ranging pinfish predators. Mortality
rates (Z) ranged from 0.047 to 0.060 (Z/hr/predator) and did not differ significantly among treatments. 相似文献
6.
Adewale Adewuyi Rotimi A Oderinde B. V. S. K. Rao R. B. N. Prasad B. Anjaneyulu 《Bioenergy Research》2012,5(3):713-718
Self-sufficiency in energy requirement is critical to the success of any developing economy. Apart from the search for alternatives, there is a need to achieve energy independence, directing much focus on biofuels. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics. Oil was extracted from the seeds of Blighia unijugata and Luffa cylindrica, subjected to chemical characterization and biodiesel production. The oil yield from the seed of B. unijugata was 50.82 ± 1.20% while that of L. cylindrica was 39.10 ± 0.20%. The biodiesel produced had ester content above 98%. The flash point of the biodiesel from B. unijugata and L. cylindrica was above 120°C while the phosphorus content was also below 1 ppm in both cases. The oxidative stability of B. unijugata was 44.30 ± 0.30 h, while that of L. cylindrica was lower than this value due to its high unsaturation. The copper strip corrosion value of the biodiesel was also found to be 1A. This study showed that the high free fatty acid content of B. unijugata and L. cylindrica seed oil can be reduced in a one-step pretreatment of esterification reaction using H2SO4 as catalyst thus reducing the problem of soap formation encountered when using oil with high free fatty acid for the production of biodiesel. 相似文献
7.
Mario C. N. Saparrat Geraldine E. Fermoselle Sebastián A. Stenglein Mónica B. Aulicino Pedro A. Balatti 《Mycopathologia》2009,168(1):41-47
Pseudocercospora griseola is the causal agent of angular leaf spot of common bean (ALS). It has undergone parallel coevolution with its host and two
major groups have been defined, “Andean” (P. griseola f. griseola) and “Mesoamerican” (P. griseola f. mesoamericana). The aim of this study was to analyze the nature and the level of the dark pigment synthesized by the representatives of
each group. After 21 days of incubation on potato dextrose agar medium, P. griseola f. griseola isolate S3b developed colonies with diameters of 17.5 ± 1.3 mm and concentric rings of pigmentation. Isolate T4 of P. griseola f. mesoamericana presented smaller colonies (9.9 ± 0.3 mm) with a uniform dark-gray color. Both isolates, S3b and T4, produced the same pigment,
a 1,8-dihydroxynaphthalene-melanin, although different in quantity and structural features as suggested by the IR spectrum.
The P. griseola f. griseola isolate S3b had a higher growth rate and melanin content as well as smaller sensitivity to melanin synthesis inhibitors compared
to the isolate T4 of P. griseola f. mesoamericana. These results suggest a possible link between melanin and growth in P. griseola. 相似文献
8.
Selection on traits conferring reduced predation may be opposed by selection on other traits associated with reproduction.
Here, we examined the hypothesis that traits associated with reproduction in Gammarus pulex are driven by predation. We studied G. pulex originating from ponds with two different kinds of predator regimes: (1) ponds with fish—often large, non-gap-limited predators
and (2) ponds without fish where invertebrates are the dominant predators—often small, gap-limited predators with a much more
restricted prey size range. We examined the body size of males and females in G. pulex amplexus pairs originating from fish and fishless ponds. We also examined, in the laboratory, their mating success, the number
of offspring per female and offspring mortality under different rearing conditions, with or without fish cue. Mating success,
defined as the percentage of amplexus pairs that produced live offspring, was higher for G. pulex from fishless ponds independent of rearing condition. Individuals from fish ponds were larger and they produced a higher
number of offspring which tended to be related to female body size. Offspring mortality was higher in populations from fish
ponds compared to populations from fishless ponds. Despite the higher offspring mortality, females from fish ponds had a higher
number of offspring alive after 13 weeks, which is the approximate time it takes for G. pulex to reach maturity. Our data imply that no trade-off between reducing body size to reduce mortality caused by fish and maximising
reproductive success exist in G. pulex from fish ponds. The strategy with many offspring may be the correct strategy in fishponds where predation pressure generally
is higher than in fishless ponds. 相似文献
9.
Anber Hassanein Latifa Hamama Karine Loridon Noëlle Dorion 《Plant cell reports》2009,28(10):1521-1530
Direct genetic transformation of mesophyll protoplasts was studied in Pelargonium × hortorum. Calcein and green-fluorescent protein (GFP) gene were used to set up the process. Electroporation (three electric pulses
from a 33-μF capacitor in a 250-V cm−1 electric field) was more efficient than PEG 6000 for membrane permeation, protoplast survival and cell division. Transient
expression of GFP was detected in 33–36% of electroporated protoplasts after 2 days and further in colonies. A protoplast
suspension conductivity of >1,500 μS cm−1 allowed high colony formation and plant regeneration. Stable transformation was obtained using the plasmid FAJ3000 containing
uidA and nptII genes. When selection (50 mg l−1 kanamycin) was achieved 6 weeks after electroporation, regenerated shoots were able to grow and root on 100 mg l−1 kanamycin. The maximum transformation efficiency was 4.5%, based on the number of colonies producing kanamycin-resistant
rooted plants or 0.7% based on the number of cultured protoplasts. Polymerase chain reaction (PCR) analysis on in vitro micropropagated
plants showed that 18 clones out of 20 contained the nptII gene, while the uidA gene was absent. These results were confirmed after PCR analyses of five glasshouse-acclimatized clones. 相似文献
10.
Volkan Cevik Carol D. Ryder Alexandra Popovich Kenneth Manning Graham J. King Graham B. Seymour 《Tree Genetics & Genomes》2010,6(2):271-279
The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes are involved in regulating fruit development and dehiscence in Arabidopsis. We tested the hypothesis that this class of genes are also involved in regulating the development of fleshy fruits, by exploring
genetic and phenotypic variation within the apple (Malus domestica) gene pool. We isolated and characterised the genomic sequences of two candidate orthologous FUL-like genes, MdMADS2.1 and MdMADS2.2. These were mapped using the reference population ‘Prima x Fiesta’ to loci on Malus linkage groups LG14 and LG06, respectively. An additional MADS-box gene, MdMADS14, shares high amino acid identity with the Arabidopsis SHATTERPROOF1/2 genes and was mapped to Malus linkage group LG09. Association analysis between quantitative fruit flesh firmness estimates of ‘Prima x Fiesta’ progeny
and the MdMADS2.1, MdMADS2.2 and MdMADS14 loci was carried out using a mixed model analysis of variance. This revealed a significant association (P < 0.01) between MdMADS2.1 and fruit flesh firmness. Further evidence for the association between MdMADS2.1 and fruit flesh firmness was obtained using a case–control population-based genetic association approach. For this, a polymorphic
repeat, (AT)n, in the 3′ UTR of MdMADS2.1 was used as a locus-specific marker to screen 168 apple accessions for which historical assessments of fruit texture attributes
were available. This analysis revealed a significant association between the MdMADS2.1 and fruit flesh firmness at both allelic (χ
2 = 34, df = 9, P < 0.001) and genotypic (χ
2 = 57, df = 32, P < 0.01) levels. 相似文献
11.
Antifreeze proteins depress the non-equilibrium freezing point of aqueous solutions, but only have a small effect on the equilibrium
melting point. This difference between the freezing and melting points has been termed thermal hysteresis activity (THA).
THA identifies the presence and relative activity of antifreeze proteins. Two antifreeze protein cDNAs, dafp-1 and dafp-4, encoding two self-enhancing (have a synergistic effect on THA) antifreeze proteins (DAFPs) from the beetle Dendroides canadensis, were introduced into the genome of Arabidopsis thaliana via Agrobacterium-mediated floral dip transformation. Southern blot analysis indicated multiple insertions of transgenes. Both DAFP-1 and/or
DAFP-4 were expressed in transgenic A. thaliana as shown by RT-PCR and Western blot. Apoplastic fluid from T
3 DAFP-1 + DAFP-4-producing transgenic A. thaliana exhibited THA in the range of 1.2–1.35°C (using the capillary method to determine THA), demonstrating the presence of functioning
antifreeze proteins (with signal peptides for extracellular secretion). The freezing temperature of DAFP-1 + DAFP-4-producing
transgenic A. thaliana was lowered by approximately 2–3°C compared with the wild type. 相似文献
12.
To investigate the nutritional value of the diatom Cyclotella cryptica as an alternative feed for aquaculture, its heterotrophic growth characteristics were studied. First, the proximate biochemical
composition and fatty acid profiles were studied under a controlled heterotrophic growth condition. The approximate total
ash, carbohydrate, lipid, and protein content were 245 mg g−1 (dry weight), 360 mg g−1, 165 mg g−1 and 260 mg g−1, respectively. Polyunsaturated fatty acids accounted for 24.5, 31.3, 45.1 and 17.3% of the total lipids in the phospholipid,
sterol, free fatty acid and triglyceride classes. Secondly, the effect of aeration and agitation rates on the specific growth
rate of C. cryptica under heterotrophic conditions was studied. The maximum specific growth rate was not significantly affected (P > 0.05) by the rate of agitation within the range of 100 to 160 rpm, but it was significantly affected (P > 0.05) by the rate of aeration. Optimal growth occurred when the aeration rate was within the range of 0.44 to 1.07 v/v/min. Viability measurements throughout the growth period showed that the C. cryptica cells remained viable in spite of the varied cultivation conditions. Hydrodynamic forces are an important parameter within
biological systems, and optimisation is crucial for the successful scale-up of microalgal cultivation systems. Whilst the
investigation was preliminary in nature, the information gained in this study will be useful for the continual development
of an alternative and cost-effective feed for bivalve spat rations. 相似文献
13.
Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation
outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings
and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining
large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence
rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage
group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in
QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation.
Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits
because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative
to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large
homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene
action more broadly in hybrids between these species for some traits. 相似文献
14.
We observed a group of capped langurs for 12 mo in the Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. We recorded the
time of feeding on different food plant species, food categories, and the feeding heights of monkeys in trees. Capped langurs
spent 68% of their feeding time on leaves, 16% on flowers, and 16% on fruits. Feeding on leaves was consistently high (p < 0.01) during the year, with the highest feeding in May (85%) and the lowest in January (47%). The seasonal difference in
feeding on leaves is significant (p < 0.05): it was higher in summer and during monsoon. The feeding time on flowers was maximal (35%) in March and that on fruits
and seeds was minimal (38%) in January. Langurs ate 52 plant species throughout the year. The largest number of plants (6)
were species of Moraceae, and langurs spent more feeding time (20%) on them alone. The number of plants eaten per month varied
significantly (p < 0.05). Langurs ate Gmelina arborea, Albizzia lucida, Ficus glomereta, and Makania micrantha throughout the year. They spent 44% of their feeding time in terminal canopies and their average feeding height was 30–35 m.
This is the first study to examine the feeding ecology of capped langurs and provides baseline data for the species. 相似文献
15.
Mamdouh M. Nemat Alla Abdel-Hamid A. Khedr Mamdouh M. Serag Amina Z. Abu-Alnaga Reham M. Nada 《Acta Physiologiae Plantarum》2011,33(2):547-557
Forty-day-old seedlings of Atriplex
halimus were treated either with NaCl (50, 300 and 550 mM) for the subsequent 30 days or with 15% PEG for the subsequent 10 days.
As much as 50 mM of NaCl significantly increased shoot fresh and dry weight and height; nevertheless, 300 or 550 mM NaCl seemed
to have no effect. On the other hand, these growth parameters were not affected by drought after 3 or 6 days, but were reduced
after 10 days. The gas exchange parameters (photosynthetic rate, stomatal conductance and transpiration rate) were increased
by 50 mM NaCl, but decreased by 300 and 550 mM. These parameters were decreased in response to drought only after 10 days
of withholding water. In contrast to Na+, K+ was significantly decreased by NaCl but not by drought. The time course effect revealed that phosphoenol pyruvate carboxylase
(PEPC) protein was doubled in response to NaCl after 1 and 5 h and continued thereafter, higher than control, while drought
had no significant effect. Rubisco seemed unchanged by NaCl or drought. It could be concluded that the decrease in fresh weight
might be attributed to the decrease in water content. Moreover, the decrease in photosynthesis could result from a decrease
in stomatal conductance, a protective mechanism against water loss to improve water use efficiency. These findings indicate
that Atriplex
halimus tolerates NaCl and drought through decreasing growth, reducing gas exchange parameters to improve water use efficiency, uptake
Na+ and saving, if any, the photosynthetic enzyme particularly PEPC. 相似文献
16.
Despite species in the Rubus fruticosus complex (wild blackberry) being among the most invasive plants globally in regions with large annual fluctuations in water
availability, little is known about their water relations. We compared water relations of a prominent member of the complex,
R. armeniacus (Himalayan blackberry), with species native to the Pacific Northwest of North America (PNW), R. spectabilis (salmonberry) and R. parviflorus (thimbleberry). In eight stands of each species located near Portland, Oregon, USA, we measured mid-day hydraulic resistance
(R
plant), and daily time series of stomatal conductance (g
s), leaf water potential (Ψlf), and environmental conditions at four time periods spanning the 2007 growing season. Although all species maintained Ψlf above −0.5 MPa in spring, R. armeniacus maintained less negative Ψlf (≥−1.0 MPa) than the natives in summer, a factor attributable to advantages in both its root and shoot systems. R
plant of R. armeniacus was ≤0.1 MPa mmol−1 m2 s for the duration of the study, and approximately 25–50% of R
plant for the native species in summer. R. armeniacus had higher g
s compared to the native species throughout the spring and summer, with approximately twice their rates in summer. Our R
plant and g
s results show that R. armeniacus has access to more water during PNW summers than congeneric natives, allowing it to maintain high water-use, and potentially
helping it achieve higher growth and reproductive rates. Water relations may therefore be a critical component of the competitive
and invasive success of R. armeniacus and other R. fruticosus species worldwide. 相似文献
17.
Tarun Kumar Verinder Wahla Piyush Pandey R. C. Dubey D. K. Maheshwari 《World journal of microbiology & biotechnology》2009,25(2):277-285
Biological control of the cyst forming nematode Heterodera cajani was studied on sesame using plant growth promoting rhizobacteria (PGPR) Pseudomonas aeruginosa LPT3 and LPT5. Based on plant growth promoting attributes, two fluorescent pseudomonads, LPT3 and LPT5 were evaluated for
their efficacy against cyst forming nematode Heterodera cajani that parasitize Sesamum indicum. Pseudomonas aeruginosa LPT5 produced IAA, HCN, chitinase, glucanase and siderophore, and also solubilized inorganic phosphate in vitro. Moreover,
LPT5 resulted in mortality of second stage juveniles of H. cajani, which was 13% higher as compared to P. aeruginosa LPT3. Interestingly, when both strains were inoculated together for the management of H. cajani on Sesamum indicum the population of H. cajani was reduced significantly, in field trial. Approximately 60% reduction in cyst and juveniles population was recorded with
LPT5 coated seeds, while LPT3 resulted in 49% reduction in cyst and juvenile population as compared to control. Plants grown
with seeds bacterized with LPT5 and reduced doses of urea, diammonium phosphate (DAP), muriate of potash (K) and gypsum gave
maximum increase in yield, in comparison to that of plants raised under the influence of recommended or full doses of the
chemical fertilizers. Pseudomonas aeruginosa LPT5 also showed excellent root colonization. 相似文献
18.
In many species, males are shorter-lived than females, and, mostly anecdotally, shorter lifespan was also attributed to Daphnia males. This does not necessarily stay in accordance with the biological roles of the sexes in Daphnia. Daphnia females maximize their fitness by maximizing the number of produced offspring, which incurs costs associated with quick attainment
of large body size: metabolic costs of fast growth and increased risk of predation. In contrast, Daphnia males maximize fitness by maximizing the number of fertilized females, and seem to follow the strategy that enables them
to maximize the lifetime female encounter rate, which should increase with lengthening lifespan. As arguments exist both in
favour and against males living longer than females, we tested for differences in physiological lifespan of Daphnia magna males and females. Although maximum observed lifespan was always equal or longer in males than in females, no statistically
significant differences were found. The results indicate that Daphnia males should not be considered short-lived anymore. 相似文献
19.
The effect of feeding Lactobacillus fermentum I5007 on the immune system of weaned pigs with or without E. coli challenge was determined. Twenty-four weaned barrows (6.07 ± 0.63 kg BW) were randomly assigned to one of four treatments
(N = 6) in a factorial design experiment. The first two treatments consisted of healthy piglets with half of the pigs receiving
no treatment while the other half was orally administered with L. fermentum I5007 (108 CFU/ml) at a daily dose of 20 ml. Pigs in the second two treatments were challenged on the first day with 20 ml of E. coli K88ac (108 CFU/ml). Half of these pigs were not treated while the remaining pigs were treated with 20 ml of L. fermentum I5007 (108 CFU/ml). Peripheral blood lymphocytes subsets were determined using flow cytometry. The intestinal mucosal immunity of the
pigs was monitored by real time polymerase chain reaction. The cytokine content of the pig’s serum was also analyzed. Oral
administration of L. fermentum I5007 increased blood CD4+ lymphocyte subset percentage as well as tumor necrosis factor-α and interferon-γ expression in the ileum. Pigs challenged
with E. coli had elevated jejunal tumor necrosis factor-α while interferon-γ expression was increased throughout the small intestine.
There was no difference in the concentration of the cytokines interleukin-2, interleukin-6, tumor necrosis factor-α and interferon-γ
in the serum. CD8+ and CD4+/CD8+ in peripheral blood were not affected by treatment. In conclusion, L. fermentum I5007 can enhance T cell differentiation and induce ileum cytokine expression suggesting that this probiotic strain could
modulate immune function in piglets. 相似文献
20.
Choong-Jae Kim Yun-Ho Jung Chi-Yong Ahn Young-Ki Lee Hee-Mock Oh 《Journal of applied phycology》2010,22(2):181-186
The present study investigated the adsorption of turbid materials such as clays, by microalgae. Among six tested microalgae,
including Chlorophyceae and Cyanophyceae, a cyanobacterium, Phormidium parchydematicum strain KCTC 10851BP, and unicellular alga, Chlorella vulgaris strain UTEX 265, showed a higher turbidity-removal efficiency (TRE) of 99% and 93%, respectively, for clay-containing water
after 24 h, which was much higher than the 36% for the control. The TREs of all the treatments were >95% after 24 h, except
for the treatment with a lower algal density and optical density (OD) = 0.1. Phormidium parchydematicum demonstrated a slightly higher TRE than a polyaluminum chloride coagulant (Al13(OH)28Cl9SO4) for a turbid field water. Scanning electron microscope (SEM) observations revealed a dense adsorption of clay particles
to the surface of P. parchydematicum. Thus, it would appear that P. parchydematicum and C. vulgaris can be used for clay removal in turbid water by sedimentation through microalgae–clay flocculation. 相似文献