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1.
Mycobacteriocins produced by rapidly growing mycobacteria are Tween-hydrolyzing esterases. 总被引:3,自引:1,他引:2
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Smegmatocin, a protein produced by Mycobacterium smegmatis ATCC 14468, was found to have an esterase activity, hydrolyzing Tween 80, polyoxyethylene sorbitan monooleate, added to the assay medium for various "bacteriocins" from mycobacteria. Because M. diernhoferi ATCC 19340 (indicator strain for smegmatocin) is highly susceptible to oleic acid and smegmatocin requires Tween 80 for manifestation of its anti-M. diernhoferi activity, it is likely that smegmatocin-mediated antimicrobial action is caused by oleic acid generated by hydrolysis of Tween 80 by the inherent esterase action of smegmatocin. Other mycobacteriocins from rapidly growing mycobacteria also have inherent esterase activity against Tween 80 and require Tween 80 for expression of antimycobacterial action. Smegmatocin was found to hydrolyze various polyoxyethylene (sorbitan) fatty acyl esters but not sorbitan monooleate and glyceryl esters. 相似文献
2.
Truncated HP1 lacking a functional chromodomain induces heterochromatinization upon in vivo targeting 总被引:2,自引:2,他引:0
Brink MC van der Velden Y de Leeuw W Mateos-Langerak J Belmont AS van Driel R Verschure PJ 《Histochemistry and cell biology》2006,125(1-2):53-61
Packaging of the eukaryotic genome into higher order chromatin structures is tightly related to gene expression. Pericentromeric
heterochromatin is typified by accumulations of heterochromatin protein 1 (HP1), methylation of histone H3 at lysine 9 (MeH3K9)
and global histone deacetylation. HP1 interacts with chromatin by binding to MeH3K9 through the chromodomain (CD). HP1 dimerizes
with itself and binds a variety of proteins through its chromoshadow domain. We have analyzed at the single cell level whether
HP1 lacking its functional CD is able to induce heterochromatinization in vivo. We used a lac-operator array-based system
in mammalian cells to target EGFP-lac repressor tagged truncated HP1α and HP1β to a lac operator containing gene-amplified
chromosome region in living cells. After targeting truncated HP1α or HP1β we observe enhanced tri-MeH3K9 and recruitment of
endogenous HP1α and HP1β to the chromosome region. We show that CD-less HP1α can induce chromatin condensation, whereas the
effect of truncated HP1β is less pronounced. Our results demonstrate that after lac repressor-mediated targeting, HP1α and
HP1β without a functional CD are able to induce heterochromatinization. 相似文献
3.
Formulation Development and Bioavailability Evaluation of a Self-Nanoemulsified Drug Delivery System of Oleanolic Acid 总被引:1,自引:0,他引:1
Jia Xi Qi Chang Chak K. Chan Zhao Yu Meng Geng Nan Wang Jia Bei Sun Yi Tao Wang Henry H. Y. Tong Ying Zheng 《AAPS PharmSciTech》2009,10(1):172-182
This study aims to formulate and evaluate bioavailability of a self-nanoemulsified drug delivery system (SNEDDS) of a poorly
water-soluble herbal active component oleanolic acid (OA) for oral delivery. Solubility of OA under different systems was
determined for excipient selection purpose. Four formulations, where OA was fixed at the concentration of 20 mg/g, were prepared
utilizing Sefsol 218 as oil phase, Cremophor EL and Labrasol as primary surfactants, and Transcutol P as cosurfactant. Pseudo-ternary
phase diagrams were constructed to identify self-emulsification regions for the rational design of SNEDDS formulations. Sefsol
218 was found to provide the highest solubility among all medium-chained oils screened. Efficient self-emulsification was
observed for the systems composing of Cremophor EL and Labrasol. The surfactant to cosurfactant ratio greatly affected the
droplet size of the nanoemulsion. Based on the outcomes in dissolution profiles, stability data, and particle size profiles,
three optimized formulations were selected: Sefsol 218/Cremophor EL/Labrasol (50:25:25, w/w), Sefsol 218/Cremophor EL/Labrasol/Transcutol P (50:20:20:10, w/w), and Sefsol 218/Cremophor EL/Labrasol/Transcutol P (50:17.5:17.5:15, w/w). Based on the conventional dissolution method, a remarkable increase in dissolution was observed for the SNEDDS when compared
with the commercial tablet. The oral absorption of OA from SNEDDS showed a 2.4-fold increase in relative bioavailability compared
with that of the tablet (p < 0.05), and an increased mean retention time of OA in rat plasma was also observed compared with that of the tablet (p < 0.01). These results suggest the potential use of SNEDDS to improve dissolution and oral bioavailability for poorly water-soluble
triterpenoids such as OA. 相似文献
4.
Cyclodextrins are cyclic α-1,4-glucans that are produced from starch or starch derivates using cyclodextrin glycosyltransferase
(CGTase). The most common forms are α-, β-, and γ-cyclodextrins. This mini-review focuses on the enzymatic production, unique
properties, and applications of γ-cyclodextrin as well as its difference with α- and β-cyclodextrins. As all known wild-type
CGTases produce a mixture of α-, β-, and γ-cyclodextrins, the obtaining of a CGTase predominantly producing γ-cyclodextrin
is discussed. Recently, more economic production processes for γ-cyclodextrin have been developed using improved γ-CGTases
and appropriate complexing agents. Compared with α- and β-cyclodextrins, γ-cyclodextrin has a larger internal cavity, higher
water solubility, and more bioavailability, so it has wider applications in many industries, especially in the food and pharmaceutical
industries. 相似文献
5.
Yareli Rojas-AguirreIvan Castillo David J. HernándezBenjamín Nogueda-Torres Adrián Márquez-NavarroJuan C. Villalobos Francisco Sánchez-BartézLuvia Sánchez-Torres Isabel Gracia-MoraRafael Castillo Francisco Hernández-Luis 《Carbohydrate polymers》2012,87(1):471-479
The molecular interactions of 5,6-dichloro-2-(trifluoromethyl)-1H-benzimidazole (G2), an antiprotozoa with poor aqueous solubility, with 2-hydroxypropyl-α-cyclodextrin (HPαCD), methyl-β-cyclodextrin (MβCD) and 2-hydroxypropyl-β-cyclodextrin (HPβCD) were examined. The aqueous solubility enhancement by cyclodextrins (CDs) was evidenced in phase-solubility diagrams, and the stoichiometry of G2/CD systems was determined by Job's plots. Two-dimensional NMR spectroscopic data revealed that a different mode of interaction took place between G2 and CDs in solution. With HPαCD, a non-inclusion complex was generated. In the case of MβCD, a typical host-guest system was obtained and with HPβCD a partial inclusion complex through the narrow side of the macrocycle was formed. ESI-mass spectrometric data confirmed the stoichiometry and mode of interaction of these systems in solution. Solid-state characterization (scanning calorimetry and powder X-ray diffraction) supported the inclusion complex formation. The leishmanicidal activity, trypanocidal activity and non-toxic profile of G2/MβCD showed the advantages of using this inclusion complex to promote the biological assays extension of G2. 相似文献
6.
Francini K.J. Yatsu Letícia S. Koester Ivana Lula Joel J. Passos Rubén Sinisterra Valquiria L. Bassani 《Carbohydrate polymers》2013
In the present study we evaluated the complexation of daidzein/genistein/glycitein, present in an isoflavone enriched fraction (IEF), with β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin (HPβCD). Based on the increased solubility and higher complexation efficiency, IEF and HPβCD solid complexes were prepared by kneading, freeze-drying, co-evaporation, spray-drying and microwave. The solid complexes were characterized using Fourier transformed-infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and nuclear magnetic resonance spectroscopy, and the isoflavone content and solubility were determined by liquid chromatography. The results suggest that the isoflavones daidzein, genistein and glycitein may be externally associated to HPβCD as well as that isoflavones/HPβCD inclusion complexes are formed through the insertion of B-ring into the cyclodextrin cavity. Except for the freeze-dried IEF/HPβCD solid complex, all complexes showed similar content and solubility. In conclusion, the three isoflavones showed to be able to simultaneously complex with HPβCD. 相似文献
7.
Complexation of celecoxib with hydroxypropyl β-cyclodextrin (HPβCD) in the presence and absence of 3 hydrophilic polymers—polyvinyl
pyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC), and polyethylene glycol (PEG)—was investigated with an objective
of evaluating the effect of hydrophilic polymers on the complexation and solubilizing efficiencies of HPβCD and on the dissolution
rate of celecoxib from the HPβCD complexes. The phase solubility studies indicated the formation of celecoxib-HPβCD inclusion
complexes at a 1∶1M ratio in solution in both the presence and the absence of hydrophilic polymers. The complexes formed were
quite stable. Addition of hydrophilic polymers markedly enhanced the complexation and solubilizing efficiencies of HPβCD.
Solid inclusion complexes of celecoxib-HPβCD were prepared in 1∶1 and 1∶2 ratios by the kneading method, with and without
the addition of hydrophilic polymers. The solubility and dissolution rate of celecoxib were significantly improved by complexation
with HPβCD. The celecoxib-HPβCD (1∶2) inclusion complex yielded a 36.57-fold increase in the dissolution rate of celecoxib.
The addition of hydrophilic polymers also markedly enhanced the dissolution rate of celecoxib from HPβCD complexes: a 72.60-,
61.25-, and 39.15-fold increase was observed with PVP, HPMC, and PEG, respectively. Differential scanning calorimetry and
X-ray diffractometry indicated stronger drug amorphization and entrapment in HPβCD because of the combined action of HPβCD
and the hydrophilic polymers.
Published: September 29, 2006 相似文献
8.
Rose, Michael J., Jr. (Veterans Administration Hospital, Washington, D.C.), Stephen A. Aron, and Bernard W. Janicki. Effect of various nonionic surfactants on growth of Escherichia coli. J. Bacteriol. 91:1863-1868. 1966.-Escherichia coli cultivated in media containing 0.5, 1.0, 2.0, or 4.0% concentrations of surface-active polyoxyethylene derivatives of formaldehyde polymers of octyl phenol (Triton WR-1339; Macrocyclon) or of sorbitan mono-fatty acid esters (Tween 20, 40, 60, and 80) exhibited significantly retarded growth only at the highest concentration. To determine the mechanism of bacteriostasis, certain derivatives and compounds related to the surfactants were investigated. Experiments with compounds related to the Triton-type agents demonstrated that incorporation of monomeric substances (Triton X-205, X-305, Igepal CA-730, or Dowfax 9N20) into the medium at a concentration of 4.0% did not inhibit the growth of E. coli. It was concluded that the formaldehyde polymer was essential for growth inhibition by the polyoxyethylene derivatives of octyl phenol. The inhibitory activity of the Tween compounds, in contrast, appeared to result from the unesterified fatty acids which contaminate the commercial preparations. Polyol (60), the sorbitan polyoxyethylene derivative of Tween 60 and the basic structural unit of all the Tween-type compounds, and a Tween 80 preparation which was purified by extraction of the unesterified oleic acid, were not inhibitory. Moreover, the amount of free oleic acid present as a contaminant of Tween 80 was found to be sufficient to cause significant growth inhibition. These results and the observation that E. coli does not appear to hydrolyze the esterified fatty acid of Tween 80 led to the conclusion that growth inhibition obtained with various Tween compounds probaby is a function of their respective fatty acid contaminants. 相似文献
9.
The effects of ethanol, acetone, dimethylsulfoxide (DMSO), polyoxyethylene sorbitan monooleate (Tween 80), polyoxyethylene sorbitan monolaurate (Tween 20), Triton X-100, and carboxymethyl cellulose (CMC) on the kinetics of biphenyl 4-hydroxylase of rabbit liver microsomes were investigated in an attempt to find a substrate-solubilizing or suspending agent (carrier) which was itself a non-effector of the mixed-function oxidase. The effects of these carriers on the activities of NADPH-cytochrome P-450 reductase, NADPH-cytochrome c reductase, and cytochrome P-450 content were also investigated.Ethanol and DMSO inhibited biphenyl 4-hydroxylase and NADPH-cytochrome P-450 reductase. Acetone inhibited the hydroxylase uncompetitively at concentrations which appeared to stimulate NADPH-cytochrome P-450 reductase. All of the detergents inhibited biphenyl 4-hydroxylase although only Triton X-100 markedly affected the reduction of cytochrome P-450. The interaction of Tween 80 with the hydroxylase gave rise to non-linear Lineweaver-Burk plots although at high concentrations of biphenyl or low concentrations of the detergent the inhibition appeared to be competitive.Biphenyl caused a 2–3-fold stimulation of NADPH-cytochrome P-450 reductase, but in the presence of Tween 80 the stimulation was absent. Since V of biphenyl 4-hydroxylase in the presence of Tween 80 was not significantly different from V in its absence it would appear that the reduction of cytochrome P-450 was not ratelimiting.Of all the carriers studied only CMC was without effect on all aspects of microsomal electron transport investigated. As far as biphenyl 4-hydroxylase is concerned, CMC appears to be the most suitable substrate carrier. 相似文献
10.
Ana Figueiras Jorge M. G. Sarraguça Alberto A. C. C. Pais Rui A. Carvalho J. Francisco Veiga 《AAPS PharmSciTech》2010,11(1):233-240
In this study, we investigate how the effect of l-arginine (ARG) and cyclodextrins upon omeprazole (OME) stability and solubility. The effect of the presence of ARG on the
apparent stability constants (K1:1) of the inclusion complexes formed between OME and each cyclodextrin, β-cyclodextrin (βCD), and methyl-β-cyclodextrin (MβCD)
is studied by phase solubility diagrams and nuclear magnetic resonance (NMR) spectroscopy. The interaction of OME with those
cyclodextrins, in the presence of ARG, is characterized using NMR spectroscopy and molecular dynamics simulations. ARG significantly
increases the drug solubility and complex stability, in comparison to inclusion complexes formed in its absence. The effect
is more pronounced for the OME:βCD complex. ARG also contributes to a larger stability of OME when free in aqueous solution.
The combination of ARG with cyclodextrins can represent an important tool to develop stable drug formulations. 相似文献
11.
The purpose of this study was to investigate the effect of cyclodextrins (CDs) on aqueous solubility, stability, and in vitro corneal permeability of delta-8-tetrahydrocannabinol (Δ8-THC). Phase solubility of Δ8-THC was studied in the presence of 2-hydroxypropyl-β-cyclodextrin (HPβCD), randomly methylated-β-cyclodextrin (RMβCD) and
sulfobutyl ether-β-cyclodextrin sodium salt (SβCD). Stability of Δ8-THC in 5% w/v aqueous CD solutions, as a function of pH, was studied following standard protocols. In vitro corneal permeation of Δ8-THC (with and without CDs) across excised rabbit cornea was also determined. Phase-solubility profile of Δ8-THC in the presence of both HPβCD and RMβCD was of the AP type, whereas, with SβCD an AL type was apparent. Aqueous solubility of Δ8-THC increased to 1.65, 2.4, and 0.64 mg/mL in the presence of 25% w/v HPβCD, RMβCD, and SβCD, respectively. Significant degradation of Δ8-THC was not observed within the study period at the pH values studied, except for at pH 1.2. Transcorneal permeation of Δ8-THC was dramatically improved in the presence of CDs. The results demonstrate that CDs significantly increase aqueous solubility,
stability, and transcorneal permeation of Δ8-THC. Thus, topical ophthalmic formulations containing Δ8-THC and modified beta CDs may show markedly improved ocular bioavailability. 相似文献
12.
Marcílio S. S. Cunha-Filho Bruno Dacunha-Marinho Juan J. Torres-Labandeira Ramón Martínez-Pacheco Mariana Landin 《AAPS PharmSciTech》2007,8(3):E68-E77
The purpose of this research was to explore the utility of β cyclodextrin (βCD) and β cyclodextrin derivatives (hydroxypropyl-β-cyclodextrin
[HPβCD], sulfobutylether-β-CD [SB\CD], and a randomly methylated-β-CD [RMβCD]) to form inclusion complexes with the antitumoral
drug, β-lapachone (βLAP), in order to overcome the problem of its poor water solubility. RMβCD presented the highest efficiency
for βLAP solubilization and was selected to develop solid-state binary systems. Differential scanning calorimetry (DSC), X-ray
powder diffractometry (XRPD), Fourier transform infrared (FTIR) and optical and scanning electron microscopy results suggest
the formation of inclusion complexes by both freeze-drying and kneading techniques with a dramatic improvement in drug dissolution
efficiency at 20-minute dissolution efficiency (DE20-minute 67.15% and 88.22%, respectively) against the drug (DE20-minute 27.11%) or the βCD/drug physical mixture (DE20-minute 27.22%). However, the kneading method gives a highly crystalline material that together with the adequate drug dissolution
profile make it the best procedure in obtaining inclusion complexes of RMβCD/βLAP convenient for different applications of
βLAP.
Published: July 27, 2007 相似文献
13.
Randall K Cheng SW Kotchevar AT 《In vitro cellular & developmental biology. Animal》2011,47(9):631-639
Solubilizing agents are routinely added when investigating the biotransformation of lipophilic substrates using hepatic microsomes.
For highly lipophilic compounds, the concentration of solvent or surfactant necessary for dissolution can be detrimental to
enzyme activity. This study evaluates the effect of 12 surfactants on microsomal metabolism and the ability of the same surfactants
to improve the aqueous solubility of the pentabrominated diphenyl ether BDE-100, a lipophilic environmental contaminant previously
found to be recalcitrant to in vitro metabolism. Of the surfactants investigated, Cremophor EL and Tween 80 displayed the
best combination of increased BDE-100 solubility and minimal inhibition of microsomal metabolism. However, a comparison of
the in vitro metabolism products of BDE-100 in the presence of the two surfactants revealed varying amounts of metabolites
depending on the surfactant used. 相似文献
14.
Sateeshkumar Sathigari Gurkishan Chadha Y-H. Phillip Lee Nydeia Wright Daniel L. Parsons Vijay K. Rangari Oladiran Fasina R. Jayachandra Babu 《AAPS PharmSciTech》2009,10(1):81-87
Efavirenz (EFV) is an oral antihuman immunodeficiency virus type 1 drug with extremely poor aqueous solubility. Thus, its
gastrointestinal absorption is limited by the dissolution rate of the drug. The objective of this study was to characterize
the inclusion complexes of EFV with β-cyclodextrin (β-CD), hydroxypropyl β-CD (HPβCD), and randomly methylated β-CD (RMβCD)
to improve the solubility and dissolution of EFV. The inclusion complexation of EFV with cyclodextrins in the liquid state
was characterized by phase solubility studies. The solid-state characterization of various EFV and CD systems was performed
by X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy analyses. Dissolution studies were
carried out in distilled water using US Pharmacopeia dissolution rate testing equipment. Phase solubility studies provided
an AL-type solubility diagram for β-CD and AP-type solubility diagram for HPβCD and RMβCD. The phase solubility data enabled calculating stability constants (K
s) for EFV-βCD, EFV-HPβCD, and EFV-RMβCD systems which were 288, 469, and 1,073 M−1, respectively. The physical and kneaded mixtures of EFV with CDs generally provided higher dissolution of EFV as expected.
The dissolution of EFV was substantially higher with HPβCD and RMβCD inclusion complexes prepared by the freeze drying method.
Thus, complexation with HPβCD and RMβCD could possibly improve the dissolution rate-limited absorption of EFV. 相似文献
15.
Michikatsu Sato Machiko Watanabe Hiroto Nagano Yoshiaki Yagi 《Biotechnology letters》1994,16(7):703-708
A simple and specific recovery method for α-cyclodextrin (α-CD) was developed by employing co-digestion of CD reaction mixtures
with CGTase fromBacillus ohbensis and α-glucosidase. The combination of CGTase fromB. ohbensis and α-glucosidase, such as α-amylase, β-amylase, or glucoamylase was examined for the selective degradation of β-and γ-CD
in the CD reaction mixture formed by CGTase fromB. macerans. The co-digestion of the CD mixture with Taka-amylase and the CGTase resulted in α-CD and maltodextrins, the combination
with β-amylase resulted in α-CD and maltose, and that with glucoamylase resulted in α-CD and glucose. The conditions of selective
degradation of β- and γ-CD by co-digestion with the CGTase and glucoamylase were optimized as follows: the incubation pH,
5.5; incubation temperature, 50°C; CGTase concentration, 15 u/g of substrate; glucoamylase, 10 u/g of substrate; substrate
concentration, 10% (w/v); the incubation time was fixed for 18 hr from the stand point of operation convenience.
Most part of the content was presented in poster session at the 7th International Cyclodextrin Symposium, Tokyo, April 1994. 相似文献
16.
Tatyana Avramova Dimitrina Spassova Sava Mutafov Svetlana Momchilova Lilyana Boyadjieva Boryana Damyanova Blaga Angelova 《World journal of microbiology & biotechnology》2010,26(6):1009-1014
Studied is the effect of the non-ionic surfactant Tween 80 on the microbial transformation of 4-androstene-3,17-dione into
its 9α-hydroxy-derivative by resting Rhodococcus sp. cells. The surfactant was applied in the cultivation medium as an additional source of carbon, in the transformation
reaction medium as a mediator of the steroid substrate solubility or was used for permeabilization of the glucose grown Rhodococcus sp. cells. Special attention is paid to the fact that Tween 80 accelerates the 9α-steroid hydroxylation reaction carried
out by glucose-grown cells. When the surfactant was applied as a supplementary source of carbon, the rate of the steroid hydroxylation
reaction was significantly lower. In addition, the kinetics of the transformation process changed into a linear one thus indicating
a very slow, if any, product degradation. The fatty acid profile, cell surface hydrophobicity as well as cell ultrastructure
observed by scanning and transmission electron microscopy in the Tween 80- and glucose-grown Rhodococcus sp. cells are compared and related with their 9α-hydroxylating activity. 相似文献
17.
In shaken cultures ofPhanerochœte chrysosporium, different Tweens gave rise to similar and high lignin peroxidase (LiP) activities. The polyoxyethylene-sorbitan (POE-S)
moieties isolated from Tweens gave rise to somewhat lower LiP activities, whereas fatty acids isolated from Tweens gave rise
to much lower LiP activities than parent Tweens. LiP activity appeared 3 d after addition of Tween 80 if this was added within
the first 4 d after inoculation. Of the three chemical moieties contained in Tweens,i.e., fatty acids, sorbitan, and polyoxyethylene (POE), only the latter one significantly stimulated the LiP activity of the culture.
The stimulatory effect of POE on the LiP activity increased till its molar mass of approx. 1 kDa, then it levelled off. The
quantity of POE in the culture decreased with time. Tween 80, its POE-S moiety and POEs seem to enhance LiP production and
not only their release. 相似文献
18.
Carolina Jullian Constanza Cifuentes Muriel Alfaro Sebastián Miranda Germán Barriga Claudio Olea-Azar 《Bioorganic & medicinal chemistry》2010,18(14):5025-5031
The inclusion complexes of Luteolin (LU) with cyclodextrins (CDs) including β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD) and dimethyl-β-cyclodextrin (DMβCD), Scheme 1, have been investigated using the method of steady-state fluorescence. The stoichiometric ratio of the three complexes was found to be 1:1 and the stability constants (K) were estimated from spectrofluorometric titrations, as well as the thermodynamic parameters. Maximum inclusion ability was obtained in the case of HPβCD followed by DMβCD and βCD. Moreover, 1H NMR and 2D NMR were carried out, revealing that LU has different form of inclusion which is in agreement with molecular modeling studies. These models confirm that when LU–βCD and LU–DMβCD complexes are formed, the B-ring is oriented toward the primary rim; however, for LU–HPβCD complex this ring is oriented toward the secondary rim. The ESR results showed that the antioxidant activity of luteolin was the order LU–HPβCD > LU–DMβCD > LU–βCD > LU, hence the LU-complexes behave are better antioxidants than luteolin free. 相似文献
19.
Concentrated cell suspensions of Lactobacillus bulgaricus prepared from cells grown in semisynthetic media were frozen in liquid nitrogen. After storage for 24 hr, the cell suspensions were found to have decreased colony counts and acid-producing capacity in milk. The amount of loss varied among the different strains tested. The addition of known cryoprotective agents to cell suspensions of the most labile strain before freezing provided little or no protection to the cells. However, storage stability of all strains investigated was improved by supplementing the growth medium with Tween 80 (polyoxyethylene sorbitan monooleate). The concentration of Tween 80 necessary for maximal storage stability varied among strains. 相似文献
20.
Carolina P. Dahmer Allison Rutter Barbara A. Zeeb 《International journal of phytoremediation》2018,20(6):523-529
Point Pelee National Park (PPNP) is highly contaminated with dichlorodiphenyltrichloroethane (DDT) due to the historical use of this persistent organochlorine pesticide. Hydroxypropyl-β-cyclodextrin (HPβCD) has previously been investigated for its role in the remediation of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). In the present study, HPβCD's ability to promote DDT microbial degradation, enhance DDT phytoextraction by two native grasses (Schizachyrium scoparium and Panicum virgatum), and increase DDT bioavailability to redworms (Eisenia fetida) was investigated. Using a range of HPβCD concentrations (2.5% to 10%), it was determined that it did not promote DDT microbial degradation in PPNP soils, however, it was able enhance the DDT phytoextraction ability of S. scoparium plants due to the increased water solubility of DDT. Although HPβCD application to PPNP soil did not increase DDT bioavailability to redworms, its enhanced solubility allowed it to move through the soil column, and hence groundwater contamination is a possibility. Due to this important issue, in situ use of HPβCD to remediate DDT contamination is not recommended unless measures are in place to mitigate movement into groundwater. 相似文献