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1.
The present research work was aimed to formulate clotrimazole encapsulated Cavamax W7 composite ethosomes by injection method
for improved delivery across epidermis. 32 factorial design was used to design nine formulations (F1-F9) and compared with ethosomal formulations (F10-F12). F9 with
vesicle size of 202.8 ± 4.8 nm, highest zeta potential (−83.6 ± 0.96 mV) and %EE of 98.42 ± 0.15 was selected as optimized
composite ethosome and F12 as reference ethosomal formulation. As revealed by transmission electron microscopy F9 vesicles
were more condensed, uniformly spherical in shape than F12 vesicles. Vesicular stability studies indicated F9 to be more stable
as compared to F12. Both F9 and F12 were incorporated in carbopol 934 gel base to get G1–G8 gel formulations and evaluated
for in vitro skin permeability. Cavamax W7 composite ethosomal optimized gel (G5) showed higher in vitro percent cumulative drug permeation (88.53 ± 2.10%) in 8 h and steady state flux (J
ss) of 3.39 ± 1.45 μg/cm2/min against the J
ss of 1.57 ± 0.23 μg/cm2/min for ethosomal gel (G1) and 1.13 ± 0.06 μg/cm2/min for marketed formulation. The J
ss flux of G5 was independent of amount of drug applied/unit area of skin. In vivo confocal laser scanning microscopic study of G5 depicted uniform and deeper penetration of rhodamine B (marker) in epidermis
from Cavamax W7 composite ethosomal gel in comparison to G1. Finally, G5 demonstrated better (p < 0.05) antifungal activity against Candida albicans and Aspergillus niger than G1 thus, signifying that Cavamax W7 composite ethosomes present a superior stable and efficacious vesicular system than
ethosomal formulation for topical delivery of clotrimazole. 相似文献
2.
Meloxicam gel was designed based on the matching of the solubility parameter (δ) of the drug with that of the polymer and subsequently with skin for improved dermal delivery of meloxicam. The δ of meloxicam (11.48 (cal/cm3)0.5) determined by solubility measurement was matched statistically to the solubility parameter of monomers, n-vinyl-2-pyrrolidone, polyvinyl alcohol (PVA), hydroxyl ethyl methacrylate, ethylene glycol methacrylate (EGMA) determined
by intrinsic viscosity measurement. Consequently gels were formulated by polymerization in selected solvent blend of water/ethyl
acetate (20:80) in which the drug showed maximum solubility. Thus, F1–F16 formulations designed were evaluated for physicochemical
properties, textural analysis, and in vitro drug release. On the basis of optimum characteristics, F2 (PVA, δ = 16.96 (cal/cm3)0.5) and F8 (EGMA, δ = 18.35 (cal/cm3)0.5) formulated by suspension polymerization were selected and subjected to skin irritation and topical anti-inflammatory studies.
The formulation F8 demonstrated significant (p < 0.05) of anti-inflammatory activity in comparison to marketed piroxicam gel and was free from irritation. 相似文献
3.
Vishal Gupta Manoj Kumar Puja Kumari C. R. K. Reddy Bhavanath Jha 《Journal of applied phycology》2011,23(2):209-218
This study reports on the optimization of protoplast yield from two important tropical agarophytes Gracilaria dura and Gracilaria verrucosa using different cell-wall-degrading enzymes obtained from commercial sources. The conditions for achieving the highest protoplast
yield was investigated by optimizing key parameters such as enzyme combinations and their concentrations, duration of enzyme
treatment, enzyme pH, mannitol concentration, and temperature. The significance of each key parameter was also further validated
using the statistical central composite design. The enzyme composition with 4% cellulase Onozuka R-10, 2% macerozyme R-10,
0.5% pectolyase, and 100 U agarase, 0.4 M mannitol in seawater (30‰) adjusted to pH 7.5 produced the highest protoplast yields
of 3.7 ± 0.7 × 106 cells g−1 fresh wt for G. dura and 1.2 ± 0.78 × 106 cells g−1 fresh wt for G. verrucosa when incubated at 25°C for 4–6 h duration. The young growing tips maximally released the protoplasts having a size of 7–15 μm
in G. dura and 15–25 μm in G. verrucosa, mostly from epidermal and upper cortical regions. A few large-size protoplasts of 25–35 μm, presumably from cortical region,
were also observed in G. verrucosa. 相似文献
4.
Xue-Qin Xie Jie Wang Bao-Fu Huang Sheng-Hua Ying Ming-Guang Feng 《Applied microbiology and biotechnology》2010,86(5):1543-1553
A superoxide dismutase (SOD) was characterized from Beauveria bassiana, a fungal entomopathogen widely applied to insect control. This 209-aa enzyme (BbSod2) showed no more than 71% sequence identity
to other fungal Mn-SODs, sharing all conserved residues with the Mn-SOD family and lacking a mitochondrial signal. The SOD
activity of purified BbSod2 was significantly elevated by Mn2+, suppressed by Cu2+ and Zn2+ but inhibited by Fe3+. Overexpressing the enzyme in a BbSod2-absent B. bassiana strain enhanced its SOD activity (107.2 ± 6.1 U mg−1 protein) by 4–10-fold in different transformants analyzed. The best BbSod2-transformed strain with the SOD activity of 1,157.9 ± 74.7 U mg−1 was 93% and 61% more tolerant to superoxide-generating menadione in both colony growth (EC50 = 2.41 ± 0.03 versus 1.25 ± 0.01 mM) and conidial germination (EC50 = 0.89 ± 0.06 versus 0.55 ± 0.07 mM), and 23% more tolerant to UV-B irradiation (LD50 = 0.49 ± 0.02 versus 0.39 ± 0.01 J cm−2). Its virulence to Spodoptera litura larvae was enhanced by 26% [LT50 = 4.5 (4.2–4.8) versus 5.7 (5.2–6.4) days]. Our study highlights for the first time that the Mn2+-cofactored, cytosolic BbSod2 contributes significantly to the virulence and stress tolerance of B. bassiana and reveals possible means to improving field persistence and efficacy of a fungal formulation by manipulating the antioxidant
enzymes of a candidate strain. 相似文献
5.
Detpon Preechagoon Viroj Sumyai Suvatna Chulavatnatol Poj Kulvanich Thanee Tessiri Khanittha Tontisirin Thaned Pongjanyakul Verawan Uchaipichat Sirikul Aumpon Chaiyasit Wongvipaporn 《AAPS PharmSciTech》2010,11(3):1449-1455
The objectives of this study were to develop morphine sulfate sustained-release tablet formulations and to evaluate the bioequivalence
compared with a commercial brand. The physicochemical properties of the formulated and commercial tablets were determined
and compared. The bioequivalence investigation was carried out in 15 healthy male volunteers who received a single dose in
a randomized two-way crossover design. After dosing, serial blood samples were collected for a period of 24 h. Morphine concentration
was assayed by high-performance liquid chromatography with electrochemical detector. The log-transformed C
max and AUCs were statistically compared by analysis of variance, and the 90% confidence intervals (CIs) of the ratio of the log-transformed
C
max and AUCs between the most promising developed formulation and the commercial product were determined. It was found that the dissolution
rate profile of a developed formulation was similar to the commercial brand. Their similarity and difference factors were
well within limits. In the bioequivalence study, the AUClast and AUCinf between the test and the reference products were not statistically different (p = 0.227 and p = 0.468, respectively), with the 90% CIs of 83.4–102.6% and 87.7–139.4%, respectively. However, the C
max of the two formulations was significantly different (p = 0.019). The 90% CI of the developed formulation was 72.0–93.0% compared to the commercial product. In vitro dissolution of locally prepared morphine sulfate sustained-release tablets was comparable to commercial brand. However, the
results justified the conclusion of lack of bioequivalence of the developed product to the commercial one. 相似文献
6.
Scott P. Burns Maria Gallo Barry L. Tillman 《In vitro cellular & developmental biology. Plant》2012,48(1):58-66
Agrobacterium-mediated transformation, employing direct shoot organogenesis, allows for mature transgenic plants to be obtained quickly
(3–4 mo). In this study, peanut (Arachis hypogaea L.) cultivars Florida-07, Georgia Green, Georgia Brown, New Mexico Valencia A, and VC-2 were selected to test their shoot
induction response for use in future transformation experiments. Two types of cotyledon explants were examined, those that
previously had an attached embryo axis upon cotyledon separation (explant A) and those that were embryo axis-free upon separation
(explant B). Explants were placed onto a shoot induction medium with N
6-benzyladenine concentrations ranging from 10–80 μM for Florida-07, Georgia Green, and VC-2; 10–20 μM for Georgia Brown; and
10–640 μM for New Mexico Valencia A. Following a 4-wk culture period, explants were visually rated based on a scale of 1–4,
where 1 indicated slight greening, but no growth, and 4 indicated greening, adventitious bud formation, as well as small leaf
expansion. A difference in shoot induction was observed for the cotyledon explants examined (P > t = <0.0001). Explant A had greater shoot induction with a visual rating of 1.8 ± 0.1; explant B had a rating of 1.6 ± 0.1
(P > t = <0.0001). Additionally, cultivars responded to the culture conditions differently (cultivar × N
6-benzyladenine interaction). Georgia Green on 10 μM N
6-benzyladenine produced the most shoot buds (24.6%) and the highest visual rating (2.1), followed by VC-2 on 10 μM N
6-benzyladenine (22.1%, 1.8), New Mexico Valencia A on 640 μM N
6-benzyladenine (21.4%, 1.8), Georgia Brown on 80 μM N
6-benzyladenine (9.0%, 1.7), and Florida-07 on 40 μM N
6-benzyladenine (7.1%, 1.8). Of the tested varieties, Georgia Green, New Mexico Valencia A, and VC-2 were best suited for future
transformation experiments based on their shoot bud production. 相似文献
7.
Abbas Ali Gheisari Abbas Sanei Abdolhossein Samie Mohamad Mehdi Gheisari Majid Toghyani 《Biological trace element research》2011,142(3):557-571
This experiment was conducted to evaluate the effect of zinc, manganese, and copper sources (inorganic vs. organic) in the
diet on laying performance and eggshell quality characteristics. One hundred and eighty Hy-Line W-36 layers at 38 weeks of
age were allocated to 36-layer cages of five hens each. Each six cages were randomly assigned to one of the six experimental
diets fed from 38 to 53 week of age. In three experimental treatments, the basal diet was supplemented with 65–75–7 or 65–75–7
or 40–40–7 mg/kg of Zn, Mn, and Cu, respectively, from their oxide or sulfate sources. Three other groups were fed diets supplemented
with 20–20–3.5 or 40–40–7.5 or 60–60–10.5 mg/kg of organic forms of Zn, Mn, and Cu, respectively. Dietary treatments significantly
did affect feed intake (P < 0.001), feed conversion ratio (P < 0.001) and percentage of broken eggs (P < 0.05). Substitution of Zn and Mn oxides (65 and 75 mg kg−1, respectively) with equal amounts of their sulfate forms significantly improved feed intake, feed conversion ratio, percentage
of broken eggs, and Haugh Unit (P < 0.05). In addition, laying hens maintained their performance when substitution of Zn and Mn oxides and Cu sulfate (65,
75, and 7 mg kg−1, respectively) reduced up to 20, 20, and 3.5 mg kg−1 by amino acid complexes of the microelements. The results showed that a corn–soybean diet supplemented with the organic forms
of Zn, Mn, and Cu at a dosage 50% to 75% lower than NRC recommendation is sufficient to maintain laying performance and can
improve eggshell and albumen qualities of the egg in laying hens. 相似文献
8.
This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids
(TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated.
All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation
of 9 and 30 Hz. The measurements were repeated within a run and within several days or months. The UV–Vis spectrophotometry
was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from
1 to 40 mg kg−1 for corn flours and from 9 to 40 mg kg−1 for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240 mg kg−1 TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3 mg kg−1, respectively. The computed repeatability (n = 3–12) and intermediate precision (n = 6–28) RSD values at 9 and 30 Hz are comparable: 0.1–17.1% and 5.3–14.7% for corn flours as compared with 1.4–9.1% and 4.2–23.0%
for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly
screen the flours for their nutritional potential based on the total carotenoid concentration. 相似文献
9.
In the present study attempt was made for preparation of isotretinoin-hydroxypropyl β cyclodextrin (HP-β-CD) inclusion complex
and encapsulate this complex in elastic liposomes to study the effect of dual carrier approach on skin targeting of isotretinoin.
The isotretinoin HP-β-CD complex was prepared by freeze-drying method and characterized by IR spectroscopy. The drug and drug-CD
complex loaded elastic liposomal formulation were prepared and characterized in vitro, ex-vivo and in vivo for shape, size, entrapment efficiency, no. of vesicles per cubic mm, in vitro skin permeation and deposition study, photodegradation and skin toxicity assay. The transdermal flux for different vesicular
formulations was observed between 10.5 ± 0.5 to 13.9 ± 1.6 μg/cm2/h. This is about 15-21 folds higher than that obtained from drug solution (0.7 ± 0.1 μg/cm2/h) and 4-5 folds higher than obtained with drug-CD complex solution (2.7 ± 0.1 μg/cm2/h). The amount of drug deposit was found to increase significantly (p < 0.05) by cyclodextrin complexation (30.1 ± 0.1 μg). The encapsulation of this complex in elastic liposomal formulation
further increases its skin deposition (262.2 ± 21 μg). The results of skin irritation study using Draize test also showed
the significant reduction in skin irritation potential of isotretinoin elastic liposomal formulation in comparison to free
drug. The results of the present study demonstrated that isotretinoin elastic liposomal formulation possesses great potential
for skin targeting, prolonging drug release, reduction of photodegradation, reducing skin irritation and improving topical
delivery of isotretinoin. 相似文献
10.
Wan L Zhu S Li Y Liu S Yang H Li S Li Y Cheng J Lu X 《Applied microbiology and biotechnology》2011,91(3):543-551
Blocking the CD28/B7 costimulatory pathway is a promising strategy in the treatment of graft rejection, graft-versus-host
disease and autoimmune diseases. LEA29Y, a high-affinity variant of cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4Ig),
is a more potent inhibitor of the interaction between CD28 and B7 than is CTLA4Ig. In a previous study, LEA29Y was produced
in a mammalian cell system, which is time-consuming and expensive. To obtain LEA29Y more efficiently and cost effectively,
we attempted to produce LEA29Y using a Pichia pastoris expression system. The gene encoding LEA29Y, with an additional 6-His tag at the N-terminus, was cloned into the yeast vector
pPIC9K and expressed in the P. pastoris strain GS115. Under the optimized induction conditions for protein expression (inoculum density, OD600 = 80; methanol concentration added daily, 1.0–3.0%; induction time point, 72–96 h; culture medium pH = 6.0), the yield of
purified LEA29Y was approximately 30 mg l−1 by one-step Ni-agarose affinity chromatography. PNGase F treatment showed the purified LEA29Y to be post-translational modified
by N-linked glycosylation. In biological function assays, LEA29Y expressed in P. pastoris demonstrated specific binding to B7-1/B7-2-positive Raji cells and also suppressed lymphocyte proliferation in a dose-dependent
manner. These results suggest that LEA29Y produced in P. pastoris is biologically active and will be useful for experimental therapy on immunotherapy for transplant rejection and autoimmune
diseases. 相似文献
11.
Mountain-grown ginseng (Panax ginseng C. A. Meyer; Sansam in Korean) is believed to possess more potent biological activity than red ginseng. This study examined
the endothelium-dependent vasorelaxant effects and possible mechanisms of crude ginsenosides from adventitious roots of Korean
mountain-grown ginseng (GS-ARMG) and red ginseng (GS-RG) in isolated rat aorta pre-contracted with norepinephrine. GS-ARMG
(0.03–3.0 mg/mL) produced transient acute relaxation in a concentration-dependent manner, with a maximum relaxation (mean ± SEM)
of 90 ± 9% and a median effective concentration (EC50) of 0.09 ± 0.07 mg/mL. GS-ARMG displayed about 25-fold more potent activity than GS-RG (maximum relaxation 50 ± 4%, EC50 2.34 ± 1.30 mg/mL). Relaxations induced by both GS-ARMG (1.0 mg/mL) and GS-RG (1.0 mg/mL) were nearly abolished by endothelial
ablation or pre-treatment with N
G
-nitro-l-arginine, a nitric oxide synthase inhibitor, or by methylene blue, a soluble guanylate cyclase inhibitor. These inhibitory
effects, however, revealed different sensitivity of GS-ARMG and GS-RG; the maximum relaxations attained were 30–38% and 13–17%
that of untreated preparations, respectively, but indomethacin and cyclooxygenase inhibitors did not affect the response.
None of the receptor antagonists, atropine, diphenhydramine, [D-Pro2, D-Trp7, 9]-substance P, or propranolol, caused any significant inhibition to GS-ARMG-induced relaxation; however, atropine or propranolol
caused a 10% reduction in the relaxation, suggesting possible involvement of a muscarinic receptor or a β-adrenoceptor in
the GS-ARMG-induced relaxation. These results demonstrate that GS-ARMG produces endothelium-dependent relaxation of isolated
rat aorta similar to that of GS-RG; increased nitric oxide production and increased vascular levels of cGMP in endothelial
cells could contribute to the relaxation. However, GS-ARMG has more potent activity than GS-RG to relax isolated rat aorta
though an active substance(s), which might be higher in mountain-grown ginseng due to the growing conditions on mountains
or the processing during manufacture of GS-ARMG. These factors may contribute to understanding the biological beneficial effects
of mountain-grown ginseng. 相似文献
12.
Vicentini FT Casagrande R Verri WA Georgetti SR Bentley MV Fonseca MJ 《AAPS PharmSciTech》2008,9(2):591-596
The purpose of this study was to develop a lyotropic liquid crystalline formulation using the emulsifier vitamin E TPGS and
evaluate its behavior after incorporation of a flavonoid, quercetin. The physical (macro and microscopic), chemical (determination
of quercetin content by the HPLC method) and functional (determination of quercetin antioxidant activity by DPPH• assay) stability of the lamellar liquid crystalline formulation containing flavonoid was evaluated when stored at 4 ± 2 °C;
30 ± 2 °C/70 ± 5% RH (relative humidity) and 40 ± 2 °C/70 ± 5% RH during 12 months. The lamellar liquid crystalline structure
of the formulation was maintained during the experiment, however chemical and functional stability results showed a great
influence of the storage period in all conditions tested. A significant decrease in quercetin content (approximately 40%)
was detected during the first month of storage and a similar significant loss in antioxidant activity was detected after 6 months.
The remaining flavonoid content was unchanged during the final 6 months of the experimental period. The results suggest possible
interactions between quercetin and the liquid crystalline formulation, which could inhibit or reduce the quercetin activity
incorporated in the system. In conclusion, the present study demonstrated that incorporation of quercetin (1%) did not affect
the liquid crystalline structure composed of vitamin E TPGS/IPM/PG–H2O (1:1) at 63.75/21.25/15 (w/w/w). Nevertheless, of the total quercetin incorporated in the system only 60% was free to act as an antioxidant. 相似文献
13.
Zinc has been reported to enhance the response to interferon (IFN) or PEG-IFN plus ribavirin therapy, improve liver function,
and ameliorate hematologic side effects in patients with chronic hepatitis C. However, the role of zinc supplementation during
IFN therapy in chronic hepatitis B infection (CHB) remains unclear. We therefore aimed to report the results of zinc and IFN-alpha-2a
therapy in children with CHB. Twenty-two naive, HBeAg-positive children (mean age 10.4 ± 4.4 years) received IFN-α2a (9 MU/m2 sc) for 6 months plus peroral zinc (7.5 mg/day for <10 years and 10 mg/day for >10 years) for 12 months. Serum zinc, alanine
aminotransferase (ALT), complete blood count, hepatitis B virus DNA (HBV DNA), and serological markers were measured. Histological
(HR) and sustained response (SR) were evaluated at 6 months after completion of therapy. Normalization of ALT, HBeAg seroconversion,
and HBV DNA < 10,000 copies/ml were considered as SR. HR was defined as decrease in Knodell histological activity index (HAI)
score by at least 2 points compared to baseline. End of therapy ALT level and log HBV DNA were significantly lower than pretherapy
levels (p = 0.001 and p = 0.001, respectively), while zinc level was not different. Portal inflammation score significantly decreased after therapy
(p = 0.043), however, total HAI and other HAI components were not different. SR and HR were 25% and 52.9%. In conclusion as
a first study investigating the effect of zinc and IFN combination therapy in children with CHB, SR and HR rates were not
better than previously reported monotherapy or combination therapies. 相似文献
14.
T. Dennis Thomas 《In vitro cellular & developmental biology. Plant》2009,45(5):591-598
Protoplast culture and plant regeneration of an important medicinal plant Tylophora indica were achieved through callus regeneration. Protoplasts were isolated from leaf mesophyll cells and cultured at a density
of 5 × 105 protoplasts per gram fresh weight, which is required for the highest frequency of protoplast division (33.7%) and plating
efficiency (9.3%). The first division was observed 2 d after plating and the second division after 4 d. Culture medium consists
of Murashige and Skoog (MS) liquid medium with 4 μM 2,4-D, 0.4 M mannitol and 3% (w/v) sucrose with pH adjusted to 5.8. After 45 d of culture at 25°C in the dark, protoplasts formed colonies consisting of about
100 cells. The protoplast-derived microcalli were visible to the naked eye within 60 d of culture and reached a size of 0.2–0.4 mm
in diameter after 90 d. Calli of 0.2–0.4-mm size were transferred to MS medium supplemented with 2,4-D (4 μM), 3% (w/v) sucrose and 0.8% (w/v) agar, formed friable organogenic calli (7-8 mm size) after 8 wk under incubation in normal light period supplemented with
200 μmol m−2 S−1 of day light fluorescent illumination. The calli were transferred to MS medium supplemented with thidiazuron (TDZ) (1–7 μM)
and naphthalene acetic acid (NAA) (0.2–0.4 μM) for regeneration. The calli developed shoot buds after 3–4 wk, and the frequencies
of calli-forming shoots varied from 5% to 44%. Optimum shoot regeneration occurred on MS medium supplemented with 5 μM TDZ
and 0.4 μM NAA. On this medium, 44% cultures responded with an average number of 12 shoots per callus. Whole plants were recovered
following rooting of shoots in 1/2 MS medium supplemented with 3 μM indole 3-butyric acid. 相似文献
15.
Use of Acadian marine plant extract powder from Ascophyllum nodosum in tissue culture of Kappaphycus varieties 总被引:1,自引:0,他引:1
Anicia Q. Hurtado Dianne Aster Yunque Keneth Tibubos Alan T. Critchley 《Journal of applied phycology》2009,21(6):633-639
Three varieties of Kappaphycus alvarezii (Kapilaran, KAP), Tambalang purple (PUR), Adik-adik (AA), and one variety of Kappaphycus striatum var. sacol (green sacol (GS) were used to determine the efficiency of Acadian marine plant extract powder (AMPEP) as a culture medium
at different concentrations, for the regeneration of young plants of Kappaphycus varieties, using tissue culture techniques for the production of seed stock for nursery and outplanting purposes for the
commercial cultivation of carrageenophytes. A shorter duration for shoot formation was observed when the explant was treated
with AMPEP + Plant Growth Regulator (PGR = PAA + zeatin at 1 mg L−1) compared to AMPEP when used singly. However, four explants responded differently to the number of days required for shoot
formation. The KAP variety took 46 days to form shoots at 3–4 mg L−1 AMPEP + PGR; while PUR required 21 days at 3–5 mg L−1 AMPEP and 3–4 mg L−1 AMPEP + PGR. AA required 17 days at 3–5 mg L−1 AMPEP and AMPEP + PGR; and GS 25 days at 1 mg L−1 AMPEP + PGR. It was observed that among the four explants used, PUR and AA initiated shoot formation with the use of AMPEP
only at higher concentrations (3–5 mg L−1) after a shorter period. Only PUR responded positively to ESS/2 for shoot initiation. The use of AMPEP alone and/or in combination
with PGR as a culture medium in the propagation of microplantlets using tissue culture technique is highly encouraging. 相似文献
16.
Solovchenko A Khozin-Goldberg I Recht L Boussiba S 《Marine biotechnology (New York, N.Y.)》2011,13(3):527-535
In order to develop a practical approach for fast and non-destructive assay of total fatty acid (TFA) and pigments in the
biomass of the marine microalga Nannochloropsis sp. changes in TFA, chlorophyll, and carotenoid contents were monitored in parallel with the cell suspension absorbance.
The experiments were conducted with the cultures grown under normal (complete nutrient f/2 medium at 75 μmol PAR photons/(m2 s)) or stressful (nitrogen-lacking media at 350 μmol PAR photons/(m2 s)) conditions. The reliable measurement of the cell suspension absorbance using a spectrophotometer without integrating
sphere was achieved by deposition of cells on glass–fiber filters in the chlorophyll content range of 3–13 mg/L. Under stressful
conditions, a 30–50% decline in biomass and chlorophyll, retention of carotenoids and a build-up of TFA (15–45 % of dry weight)
were recorded. Spectral regions sensitive to widely ranging changes in carotenoid-to-chlorophyll ratio and correlated changes
of TFA content were revealed. Employing the tight inter-correlation of stress-induced changes in lipid metabolism and rearrangement
of the pigment apparatus, the spectral indices were constructed for non-destructive assessment of carotenoid-to-chlorophyll
ratio (range 0.3–0.6; root mean square error (RMSE) = 0.03; r
2 = 0.93) as well as TFA content of Nannochloropsis sp. biomass (range 5.0–45%; RMSE = 3.23 %; r
2 = 0.89) in the broad band 400–550 nm normalized to that in chlorophyll absorption band (centered at 678 nm). The findings
are discussed in the context of real-time monitoring of the TFA accumulation by Nannochloropsis cultures under stressful conditions. 相似文献
17.
Nicola D’Amelio Luca Fontanive Fulvio Uggeri Furio Suggi-Liverani Luciano Navarini 《Food biophysics》2009,4(4):321-330
Caffeine complexation by chlorogenic acid (3-caffeoylquinic acid, CAS Number [327-97-9]) in aqueous solution as well as caffeine–chlorogenate
complex in freshly prepared coffee brews have been investigated by high-resolution 1H-NMR. Caffeine and chlorogenic acid self-associations have also been studied and self-association constants have been determined
resorting to both classical isodesmic model and a recently introduced method of data analysis able to provide also the critical
aggregation concentration (cac). Furthermore, caffeine–chlorogenate association constant was measured. For the caffeine, the
average value of the self-association constant determined by isodesmic model (K
i = 7.6 ± 0.5 M−1) is in good agreement with the average value (K
a = 10 ± 1.8 M−1) determined with the method which permits the determination of the cac (8.43 ± 0.05 mM). Chlorogenic acid shows a slight
decreased tendency to aggregation with a lower average value of association constants (K
i = 2.8 ± 0.6 M−1; K
a = 3.4 ± 0.6 M−1) and a critical concentration equal to 24 ± 1 mM. The value of the association constant of the caffeine–chlorogenate complex
(30 ± 4 M−1) is compatible with previous studies and within the typical range of reported association constants for other caffeine–polyphenol
complexes. Structural features of the complex have also been investigated, and the complex conformation has been rediscussed.
Caffeine chemical shifts comparison (monomeric, complexed, coffee brews) clearly indicates a significant amount of caffeine
is complexed in beverage real system, being chlorogenate ions the main complexing agents. 相似文献
18.
Simultaneous nutrients and carbon removal during pretreated swine slurry degradation in a tubular biofilm photobioreactor 总被引:1,自引:0,他引:1
Ignacio de Godos Cristina González Eloy Becares Pedro A. García-Encina Raúl Muñoz 《Applied microbiology and biotechnology》2009,82(1):187-194
The biodegradation potential of an innovative enclosed tubular biofilm photobioreactor inoculated with a Chlorella sorokiniana strain and an acclimated activated sludge consortium was evaluated under continuous illumination and increasing pretreated
(centrifuged) swine slurry loading rates. This photobioreactor configuration provided simultaneous and efficient carbon, nitrogen,
and phosphorous treatment in a single-stage process at sustained nitrogen and phosphorous removals efficiencies ranging from
94% to 100% and 70–90%, respectively. Maximum total organic carbon (TOC), NH4
+, and PO4
3− removal rates of 80 ± 5 g C mr
−3 day−1, 89 ± 5 g N mr
−3 day−1, and 13 ± 3 g P mr
−3 day−1, respectively, were recorded at the highest swine slurry loadings (TOC of 1,247 ± 62 mg L−1, N–NH4
+ of 656 ± 37 mg L−1, P–PO4
3+ of 117 ± 19 mg L−1, and 7 days of hydraulic retention time). The unusual substrates diffusional pathways established within the phototrophic
biofilm (photosynthetic O2 and TOC/NH4
+ diffusing from opposite sides of the biofilm) allowed both the occurrence of a simultaneous denitrification/nitrification
process at the highest swine slurry loading rate and the protection of microalgae from any potential inhibitory effect mediated
by the combination of high pH and high NH3 concentrations. In addition, this biofilm-based photobioreactor supported efficient biomass retention (>92% of the biomass
generated during the pretreated swine slurry biodegradation). 相似文献
19.
Nitrifying granules cultivation in a sequencing batch reactor at a low organics-to-total nitrogen ratio in wastewater 总被引:4,自引:0,他引:4
It is possible to cultivate aerobic granular sludge at a low organic loading rate and organics-to-total nitrogen (COD/N) ratio
in wastewater in the reactor with typical geometry (height/diameter = 2.1, superficial air velocity = 6 mm/s). The noted nitrification
efficiency was very high (99%). At the highest applied ammonia load (0.3 ± 0.002 mg NH4+–N g total suspended solids (TSS)−1 day−1, COD/N = 1), the dominating oxidized form of nitrogen was nitrite. Despite a constant aeration in the reactor, denitrification
occurred in the structure of granules. Applied molecular techniques allowed the changes in the ammonia-oxidizing bacteria
(AOB) community in granular sludge to be tracked. The major factor influencing AOB number and species composition was ammonia
load. At the ammonia load of 0.3 ± 0.002 mg NH4+–N g TSS−1 day−1, a highly diverse AOB community covering bacteria belonging to both the Nitrosospira and Nitrosomonas genera accounted for ca. 40% of the total bacteria in the biomass. 相似文献
20.
We have previously estimated the productivity and photosynthetic efficiency of the microalga Chlorella sp. grown in an outdoor open thin-layer photobioreactor under climate conditions typical of the Middle European region, i.e.
with many days unsuitable for intensive growth of algae (cloudy and rainy days, low air temperature, low solar PAR input).To
estimate the real potential productivity of the bioreactor, we collected data on algae yields obtained during clear summer
day periods. Cultivation was performed in fed-batch cycles in a bioreactor with a 224 m2 culture area (length 28 m, slope 1.7%), and a 6–7 mm-thick layer of algal culture. The suspension volume in the bioreactor
was 2,000 L. The mean values found for Třeboň (49°N), Czech Republic, as an average of several sunny summer cultivation periods
in July, were: net areal productivity, P
net = 38.2 g dry weight (DW) m-2 day-1; net volumetric productivity, Pvol, = 4.3 g algal DW L-1 day-1, photosynthetic efficiency (based on PAR), ηnet = 7.05%. The peak values were: P
net about 50 g (DW) m-2 day-1, ηnet about 9%. Algal growth rate was practically linear up to high biomass densities (40–50 g DW L-1, corresponding to an areal density of 240–300 g DW m-2), at which point the culture was harvested. The concentration of dissolved oxygen increased from about 10 mg L-1 at the beginning to about 23 mg L-1 at the end of culture area at noon. Use of the above-described technology for economical production of bioethanol is proposed. 相似文献