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1.
To screen stimulators from Chinese medicinal insects for mycelial growth and polysaccharides production of Ganoderma lucidum, G. lucidum was inoculated into the media with and without supplementation of medicinal insect extracts. The ethyl acetate extract of
Eupolyphaga sinensis at 55 mg l−1 lead to significant increase in both biomass and intracellular polysaccharides (IPS) concentration from 8.53 ± 0.41 to 14.16 ± 0.43
and 1.28 ± 0.09 to 2.13 ± 0.11 g l−1, respectively. In addition, the ethyl acetate extract of Catharsius molossus at 55 mg l−1 significantly enhanced extracellular polysaccharides (EPS) production; the EPS yield increased from 350.9 ± 14.1 to 475.1 ± 15.3 mg
l−1. There were no new components in the two types of polysaccharides obtained by the addition of the insect extracts. 相似文献
2.
We studied the response of Brachionus patulus to different concentrations of the heavy metal Pb in the presence and absence of sediments. We conducted acute (LC50) and chronic (life table demography and population growth) toxicity tests using sediment levels of 0, 30 and 280 mg l−1 (=0, 17 and 170 NTU) and Pb at 0, 0.06 and 0.6 mg l−1. Experiments were conducted at 20 ± 1°C on a horizontal shaker and algal food (Chlorella vulgaris) was added at a density of 1.0 × 106 cells ml−1. The median lethal concentration (LC50 ± 95% Confidence intervals) of PbCl2 for B. patulus was 6.15 ± 1.08 mg l−1. Age-specific survivorship and fecundity curves showed increase in turbidity level resulted in decreased survival and offspring
production of the rotifers. Increase in Pb concentration too had a negative effect on the survival and reproductive output
of B. patulus. Statistically, average lifespan, life expectancy at birth, gross and net reproductive rates and the rate of population increase
were all significantly influenced by the concentration of Pb, turbidity level as well as the interaction of Pb concentration × turbidity
level. Rotifers exposed to 170 NTU did not grow regardless of the heavy metal concentration in the medium. Similarly, B. patulus exposed to 0.6 mg l−1 Pb did not survive beyond 10 days regardless of the turbidity level in the medium. The rate of population increase of B. patulus derived from the growth experiments was negative in all treatments containing Pb as low as 0.06 mg l−1 or turbidity level as low as 17 NTU. In treatments containing Pb or sediments, there existed no relation between the egg
ratio and the population density.
Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont and R. Rico-Martínez
Advances in Rotifer Research 相似文献
3.
Meiru Li Hongqing Li Huawu Jiang Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2008,93(3):249-255
Broussonetia papyrifera is well-known for its bark fibers, which are used for making paper, cloth, rope etc. This is the first report of a successful
genetic transformation protocol for B. papyrifera using Agrobacterium tumefaciens. Callus was initiated at a frequency of about 100% for both leaf and petiole explants. Shoots formed on these calli with
a success rate of almost 100%, with 14.08 and 8.36 shoots regenerating from leave-derived and petiole-derived callus, respectively.
For genetic transformation, leaf explants of B. papyrifera were incubated with A. tumefaciens strain LBA4404 harboring the binary vector pCAMBIA 1301 which contains the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene (gus-int) as a reporter gene. Following co-cultivation, leaf explants were cultured on Murashige and Skoog (Physiol Plant 15:473,
1962) (MS) medium supplemented with 1.5 mg l−1 benzyladenine (BA) and 0.05 mg l−1 indole-3-butyric acid (IBA) (CI medium) containing 5 mg l−1 hygromycin and 500 mg l−1 cefotaxime, in the dark. Hygromycin-resistant calli were induced from leaf explants 3 weeks thereafter. Regenerating shoots
were obtained after transfer of the calli onto MS medium supplemented with 1.5 mg l−1 BA, 0.05 mg l−1 IBA, and 0.5 mg l−1 gibberellic acid (GA3) (SI medium), 5 mg l−1 hygromycin and 250 mg l−1 cefotaxime under fluorescent light. Finally, shoots were rooted on half strength MS medium (1/2 MS) supplemented with 10 mg l−1 hygromycin. Transgene incorporation and expression was confirmed by PCR, Southern hybridisation and histochemical GUS assay.
Using this protocol, transgenic B. papyrifera plants containing desirable new genes can be obtained in approximately 3 months with a transformation frequency as high as
44%. 相似文献
4.
The biokinetics of glucose metabolism were evaluated in Aeromonas hydrophila during growth in an anaerobic biosystem. After approx 34 h growth, A. hydrophila metabolized 5,000 mg glucose l−1 into the end-products ethanol, acetate, succinate and formate. The maximum growth rate, μ
m, half saturation coefficients, K
s, microbial yield coefficient, Y, cell mass decay rate coefficient, k
d, and substrate inhibition coefficient, K
si were 0.25 ± 0.03 h−1, 118 ± 31 mg glucose l−1, 0.12 μg DNA mg glucose−1, 0.01 h−1, and 3,108 ± 1,152 mg glucose l−1, respectively. These data were used to predict the performance of a continuous growth system with an influent glucose concentration
of 5,000 mg l−1. Results of the analysis suggest that A. hydrophila will metabolize glucose at greater than 95% efficiency when hydraulic retention times (HRTs) exceed 7 h, whereas the culture
is at risk of washing out at an HRT of 6.7 h. 相似文献
5.
Wen Liu Xuesen Chen Guanjun Liu Qing Liang Tianming He Jianrong Feng 《Plant Cell, Tissue and Organ Culture》2007,88(3):289-299
Embryo rescue technique was used successfully to produce interspecific hybrids by crossing peach (P. persica) as a female parent with apricot (P. armeniaca) and plum (P. salicica). In those crosses that had ‘Yuhualu’ or ‘Zhonghuashoutao’ as female parents, hybrid embryos aborted from the 7th or 8th
week after pollination mainly due to post-pollination incompatibility. An embryo rescue protocol was established to rescue
such embryos and recover hybrid plants. Modified half-strength MS medium containing 4 mg l−1 6-BA and 0.5 mg l−1 IBA produced up to 90% germination in the embryos. Modified MS medium with 1.0 mg l−1 6-BA and 1.0 mg l−1 IBA gave the highest bud induction and multiplication whereas modified MS medium containing 0.5 mg l−1 IAA and 0.2 mg l−1 NAA gave the best rooting percentage. All the hybrids obtained using this embryo rescue technique were verified using simple
sequence repeat (SSR) markers. A series of pollen treatments were carried out to partially overcome pre-pollination incompatibility,
and it was found accidentally that pollen treatment with electrostatic field not only improved pollen germination but also
increased the multiplication coefficient of embryo-induced shoots. 相似文献
6.
T. Zhang 《In vitro cellular & developmental biology. Plant》2007,43(2):91-94
This study investigated the factors affecting in vitro flowering of Perilla frutescens. The shoots regenerated from cotyledonary and hypocotyl explants cultured on Murashige and Skoog (MS) medium supplemented
with benzyladenine (BA) and indole-3-acetic acid, each at 0.5 mg l−1, were excised and transferred to MS medium containing 30 g l−1 of sucrose, 8.25 g l−1 of ammonium nitrate, and 1.0 mg l−1 of BA. After 40 d of culture, 86.2% of shoots flowered and most of which self-fertilized in vitro and produced mature fruits with viable seeds. These seeds were germinated and plants were grown to maturity and flowered
in soil under greenhouse conditions. The in vitro flowering system reported in this study may facilitate rapid breeding of P. frutescens and offers a model system for studying the physiological mechanism of flowering. 相似文献
7.
Meiru Li Hongqing Li Huawu Jiang Xiaoping Pan Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2008,92(2):173-181
Jatropha curcas contains high amounts of oil in its seed and has been considered for bio-diesel production. A transformation procedure for
J. curcas has been established for the first time via
Agrobacterium tumefaciens infection of cotyledon disc explants. The results indicated that the efficiency of transformation using the strain LBA4404
and phosphinothricin for selection was an improvement over that with the strain EHA105 and hygromycin. About 55% of the cotyledon
explants produced phosphinothricin-resistant calluses on Murashige and Skoog (MS) medium supplemented with 1.5 mg l−1 benzyladenine (BA), 0.05 mg l−1 3–indolebutyric acid (IBA), 1 mg l−1 phosphinothricin and 500 mg l−1 cefotaxime after 4 weeks. Shoots were regenerated following transfer of the resistant calli to shoot induction medium containing
1.5 mg l−1 BA, 0.05 mg l−1 IBA, 0.5 mg l−1 gibberellic acid (GA3), 1 mg l−1 phosphinothricin and 250 mg l−1 cefotaxime, and about 33% of the resistant calli differentiated into shoots. Finally, the resistant shoots were rooted on
1/2 MS media supplemented with 0.3 mg l−1 IBA at a rate of 78%. The transgenic nature of the transformants was demonstrated by the detection of β-glucuronidase activity
in the primary transformants and by PCR and Southern hybridization analysis. 13% of the total inoculated explants produced
transgenic plants after approximately 4 months. The procedure described will be useful for both, the introduction of desired
genes into J. curcas and the molecular analysis of gene function. 相似文献
8.
To develop an integrated process of CO2-fixation and H2 photoproduction by marine green microalga Platymonas subcordiformis, the impact of algal cells grown in CO2-supplemented air bubble column bioreactor was investigated on H2 photoproduction regulated by carbonylcyanide m-chlorophenylhrazone. Highest cell growth (3.85 × 106 cells ml−1), starch content (0.25 ± 0.08 mg per 106 cells) and hydrogen production (50 ± 3 ml l−1) were achieved at 3% CO2-supplemented culture, which are respectively 1.4, 2.1, 1.5-fold of the air-supplemented culture. Improved H2 production correlated well with the increase in starch accumulation. In this process, the algal cells have been recycled
for stable H2 production of 40–50 ml l−1 over five cycles. 相似文献
9.
10.
Two oligosaccharides, a heptasaccharide (HS) and an octasaccharide (OS), isolated from Paris polyphylla var. yunnanensis, stimulated the growth and saponin accumulation of Panax ginseng hairy roots at 5–30 mg l−1. HS and OS at 30 mg l−1, fed separately to hairy root cultures at 10 days post-inoculation, increased the root biomass dry weight by more than 70%
to ∼20 g l−1 from 13 g l−1 and the total saponin content of roots by more than 1-fold to ∼3.5% from 1.6% (w/w). The results suggest that the two oligosaccharides
may have plant growth-regulatory activity in plant tissue cultures. 相似文献
11.
Abdolmohammad Abedian Kennari Nasrollah Ahmadifard Maryam Fallahi Kapourchali Jafar Seyfabadi 《Biologia》2008,63(3):407-411
The rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly
in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed
on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size. 相似文献
12.
Summary Plantlets of Capsicum annuum L. ev. Sweet Banana regenerated via somatic embryogenesis from immature zygotic embryos were capable of producing flower,
fruit, and seed when cultured in small tissue culture containers. In vitro floral buds were first formed on plantlets that grew on plantlet development medium [agar-gelled Murashige and Skoog (MS)
basal medium containing 1 mgl−1 (5.3 μM) α-naphthaleneacetic acid (NAA)] in a growth room at 22°C and continuous illumination. However, floral buds rarely developed
further into mature flowers. This problem was overcome using the vented autoclavable plant tissue culture containers. In vitro fruit formation and ripening was observed when liquid half-strength MS basal medium supplemented with 5 μg ml−1 silver thiosulfate, 1 mg l−1 (5.3 μM) NAA, and 3% sucrose was added to the surface of the plantlet development medium. Hand-pollination improved fruit set. Further
research in needed to determine why the pepper seeds formed in vitro failed to germinate. 相似文献
13.
14.
M. Helanto K. Kiviharju T. Granström M. Leisola A. Nyyssölä 《Applied microbiology and biotechnology》2009,83(1):77-83
l-Ribose is a rare and expensive sugar that can be used as a precursor for the production of l-nucleoside analogues, which are used as antiviral drugs. In this work, we describe a novel way of producing l-ribose from the readily available raw material l-arabinose. This was achieved by introducing l-ribose isomerase activity into l-ribulokinase-deficient Escherichia coli UP1110 and Lactobacillus plantarum BPT197 strains. The process for l-ribose production by resting cells was investigated. The initial l-ribose production rates at 39°C and pH 8 were 0.46 ± 0.01 g g−1 h−1 (1.84 ± 0.03 g l−1 h−1) and 0.27 ± 0.01 g g−1 h−1 (1.91 ± 0.1 g l−1 h−1) for E. coli and for L. plantarum, respectively. Conversions were around 20% at their highest in the experiments. Also partially purified protein precipitates
having both l-arabinose isomerase and l-ribose isomerase activity were successfully used for converting l-arabinose to l-ribose. 相似文献
15.
The fadBA operon in the fatty acid β-oxidation pathway of P. putida KCTC1639 was blocked to induce a metabolic flux of the intermediates to the biosynthesis of medium chain-length PHA (mcl-PHA).
Succinate at 150 mg l−1 stimulated cell growth and also the biosynthesis of medium chain-length-polyhydroxyalkanoate. pH-stat fed-batch cultivation
of the fadA knockout mutant P. putida KCTC1639 was carried out for 60 h, in which mcl-PHA reached 8 g l−1 with a cell dry weight of 10.3 g l−1. 相似文献
16.
A high-frequency and simple procedure for Agrobacterium tumefaciens-mediated genetic transformation of the medicinal plant Salvia miltiorrhiza was developed. Leaf discs were pre-cultured on MS medium supplemented with 6.6 μmol l−1 BAP and 0.5 μmol l−1 NAA for one day, then co-cultured with A. tumefaciens strain EHA105 harboring the plasmid pCAMBIA 2301 for three days on the same medium. Regenerated buds were obtained on selection
medium (co-culture medium supplemented with 60 mg l−1 kanamycin and 200 mg l−1 cefotaxime) after two cycles’ culture of 10 days each and then transferred to fresh MS medium with 60 mg l−1 kanamycin for rooting. Fifteen days later, the rooted plantlets were obtained and then successfully transplanted to soil.
The transgenic nature of the regenerated plants was confirmed by PCR, Southern hybridization analysis and GUS histochemical
assay. Averagely, 1.1 independent verified transgenics per explant plated were obtained through this protocol. Adopting this
procedure, positive transformed plants could be obtained within 2–3 months from mature seeds germination to transplant to
soil, and more than 1,000 transgenic plants with several engineered constructs encoding different genes of interest were produced
in our lab in the past two years. 相似文献
17.
More than 80% of diphenyl phthalate (DPP) at 100 mg l−1 was degraded by Sphingomonas chungbukensis KCTC 2955 in a mineral salts medium at pH 7.0 and 30°C within 48 h. The maximum specific degradation rate was 5 mg DPP l−1 h−1. It was rapidly converted to monophenyl phthalate and phthalic acid which were further degraded. 相似文献
18.
Mounir R Durieux A Bodo E Allard C Simon JP Achbani EH El-Jaafari S Douira A Jijakli MH 《Biotechnology letters》2007,29(4):553-559
Aureobasidium pullulans (de Bary) Arnaud (Ach 1-1) was grown in a glucose fed-batch fermentor to 106 g dry wt l−1 in 48 h. The cells were dried in a fluidized bed dryer with a final viability of 62%. After 7 months at 4°C, the viability
was 28% of the initial value (= 2.3 × 1010 c.f.u. g−1 dry matter). A protection level of 89% was achieved with the biomass preparation at 1 × 108 c.f.u. ml−1 after 28 and 7 days for apples stored respectively at 5 and 25°C against Penicillium expansum. Our process is suitable to produce large quantities of the strain Ach 1-1 as biological control agent for apple preservation. 相似文献
19.
Single-culture aerobic granules with <Emphasis Type="Italic">Acinetobacter calcoaceticus</Emphasis> 总被引:1,自引:0,他引:1
Aerobic granules are cultivated by a single bacterial strain, Acinetobacter calcoaceticus, in a sequencing batch reactor (SBR). This strain presents as a good phenol reducer and an efficient auto coagulator in the
presence of phenol, mediated by heat-sensitive adhesins proteins. Stable 2.3-mm granules were formed in the SBR following
a 7-week cultivation. These granules exhibit excellent settling attributes and degrade phenol efficiently at concentrations
of 250–2,000 mg l−1. The corresponding phenol degradation rate reached 993.6 mg phenol g−1 volatile suspended solids (VSS) day−1 at 250 mg l−1 phenol and 519.3 mg phenol g−1 VSS day−1 at 2,000 mg l−1 phenol concentration. Meanwhile, free A. calcoaceticus cells were fully inhibited at phenol >1,500 mg l−1. Denaturing gradient gel electrophoresis fingerprint profile demonstrated no genetic modification in the strain during aerobic
granulation. The present single-strain granules showed long-term structural stability and performed high phenol degrading
capacity and high phenol tolerance. The confocal laser scanning microscopic test revealed that live A. calcoaceticus cells principally distributed at 200–250 μm beneath the outer surface, with an extracellular polymeric substance layer covering
them to defend phenol toxicity. Autoaggregation assay tests demonstrated the possibly significant role of secreted proteins
on the formation of single-culture A. calcoaceticus granules. 相似文献
20.
The toxicity of three common antibiotics (streptomycin sulfate, tetracycline hydrochloride, and tylosin tartrate) to the freshwater
rotifer Brachionus calyciflorus and brackish-water rotifer B. plicatilis was investigated using full-lifespan exposure durations. Effects of each antibiotic on lifespan, lifetime reproduction, and
Malthusian parameter were assessed at seven nominal concentrations (ranging from 5.6 mg l−1 to 2,000 mg l−1) and a negative control. Lowest Observed Effect Concentrations (LOECs) were determined for reproduction and lifespan, while
1%, 10%, 25%, and 50% Inhibitory Concentrations (IC1, IC10, IC25, IC50) and 95% confidence intervals were estimated for all three endpoints. LOECs ranged from 5.6 mg l−1 to 90 mg l−1, with all LOECs less than 90 mg l−1 occurring in B. calyciflorus. The lowest IC1 concentrations were 3.91 mg l−1 for the effect of tetracycline on lifetime reproduction in B. calyciflorus and 4.06 mg l−1 for the effect of tylosin on lifetime reproduction in B. plicatilis. Overall, lifetime reproduction was the most sensitive endpoint and the Malthusian parameter was the least sensitive. IC1 values for lifetime reproduction were roughly one to two orders of magnitude lower than the corresponding IC50 values.
Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont and R. Rico-Martínez
Advances in Rotifer Research 相似文献