73 research outputs found
Complete dissipation of 2,4,6-trinitrotoluene by in-vessel composting
We demonstrate complete removal of 2,4,6-trinitrotoluene (TNT) in 15 days using an in-vessel composting system, which is amended with TNT-degrading bacteria strains. A mixture of TNT, food waste, manure, wood chips, soil and TNT-degrading bacteria consortium are co-composted for 15 days in an aerobic environment. Variations in the TNT degradation rates are assessed when composting reactors are operated at different carbon/nitrogen ratios (C/N), aeration rates, TNT concentrations and TNT-degrading bacteria inoculum loads. Changes in TNT concentrations are measured using high performance liquid chromatography, and C/N are determined using elemental analysis every 5 days. Temperature and moisture of the system are measured every 6 hours. Optimum TNT degradation performance is achieved by combining C/N of 20/1 and a 5 L min(-1) aeration rate. Complete removal is achieved for TNT concentrations of 2, 10, and 100 g kg(-1) in 15 days by the help of Citrobacter murliniae STE10, Achromobacter spanius STE11, Kluyvera cryocrescens STE12, and Enterobacter amnigenus STE13 bacteria strains. The final products of composting are used to cultivate four different plant seedlings for 10 weeks and showed no toxic effect, which is promising for the potential agricultural use of TNT-contaminated lands after remediation
Antioxidant response of Chlamydomonas reinhardtii grown under different element regimes
Elibol Cakmak, Zeynep/0000-0002-6772-5570; Cakmak, Turgay/0000-0002-4953-8384WOS: 000357326500006Nutrient stress is one of the most favorable ways of increasing neutral lipid and high value-added output production by microalgae. However, little is known about the level of the oxidative damage caused by nutrient stress for obtaining an optimal stress level for maximum production of specific molecules. In this study, the antioxidant response of Chlamydomonas reinhardtii grown under element deprivation (nitrogen, sulfur, phosphorus and magnesium) and supplementation (nitrogen and zinc) was investigated. All element regimes caused a decrease in growth, which was most pronounced under N deprivation. Element deprivation and Zn supplementation caused significant increases in H2O2 and lipid peroxidation levels of C.reinhardtii. Decrease in total chlorophyll level was followed by an increase of total carotenoid levels in C.reinhardtii under N and S deprivation while both increased under N supplementation. Confocal imaging of live cells revealed dramatic changes of cell shape and production of neutral lipid bodies accompanied by a decrease of chlorophyll clusters. Antioxidant capacity of cells decreased under N, S and P deprivation while it increased under N and Zn supplementation. Fluctuation of antioxidant enzyme activities in C.reinhardtii grown under different element regimes refers to different metabolic sources of reactive oxygen species production triggered by a specific element absence or overabundance.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112Y029]This study was supported by a grant from the Scientific and Technological Research Council of Turkey (Project# 112Y029)
Complete dissipation of 2,4,6-trinitrotoluene by in-vessel composting
We demonstrate complete removal of 2,4,6-trinitrotoluene (TNT) in 15
days using an in-vessel composting system, which is amended with
TNT-degrading bacteria strains. A mixture of TNT, food waste, manure,
wood chips, soil and TNT-degrading bacteria consortium are co-composted
for 15 days in an aerobic environment. Variations in the TNT degradation
rates are assessed when composting reactors are operated at different
carbon/nitrogen ratios (C/N), aeration rates, TNT concentrations and
TNT-degrading bacteria inoculum loads. Changes in TNT concentrations are
measured using high performance liquid chromatography, and C/N are
determined using elemental analysis every 5 days. Temperature and
moisture of the system are measured every 6 hours. Optimum TNT
degradation performance is achieved by combining C/N of 20/1 and a 5 L
min(-1) aeration rate. Complete removal is achieved for TNT
concentrations of 2, 10, and 100 g kg(-1) in 15 days by the help of
Citrobacter murliniae STE10, Achromobacter spanius STE11, Kluyvera
cryocrescens STE12, and Enterobacter amnigenus STE13 bacteria strains.
The final products of composting are used to cultivate four different
plant seedlings for 10 weeks and showed no toxic effect, which is
promising for the potential agricultural use of TNT-contaminated lands
after remediation
Induction of triacylglycerol production in Chlamydomonas reinhardtii: Comparative analysis of different element regimes
Elibol Cakmak, Zeynep/0000-0002-6772-5570; Olmez, Tolga Tarkan/0000-0002-8818-4507; Cakmak, Turgay/0000-0002-4953-8384WOS: 000334828000053PubMed: 24472680In this study, impacts of different element absence (nitrogen, sulfur, phosphorus and magnesium) and supplementation (nitrogen and zinc) on element uptake and triacylglycerol production was followed in wild type Chlamydomonas reinhardtii CC-124 strain. Macro- and microelement composition of C. reinhardtii greatly differed under element regimes studied. In particular, heavy metal quotas of the microalgae increased strikingly under zinc supplementation. Growth was suppressed, cell biovolume, carbohydrate, total neutral lipid and triacylglycerol levels increased when microalgae were incubated under these element regimes. Most of the intracellular space was occupied by lipid bodies under all nutrient starvations, as observed by confocal microscopy and transmission electron micrographs. Results suggest that sulfur, magnesium and phosphorus deprivations are superior to nitrogen deprivation for the induction triacylglycerol production in C. reinhardtii. On the other hand, FAME profiles of the nitrogen, sulfur and phosphorus deprived cells were found to meet the requirements of international standards for biodiesel. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112Y029]; Turkish Ministry of Agriculture and Rural Affairs General Directorate of Agricultural ResearchGida Tarim Ve Hayvancilik Bakanligi [TAGEM-10/AR-GE/26]; [BAP 2011/04]This study was supported by grants from the Scientific and Technological Research Council of Turkey (Project # 112Y029), Turkish Ministry of Agriculture and Rural Affairs General Directorate of Agricultural Research (TAGEM-10/AR-GE/26) and a research fund appropriated to Kirikkale University (BAP 2011/04). Authors thank Alper D. Ozkan for technical assistance and critical reading of the manuscript
Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.
Triclosan is an antimicrobial agent and a persistent pollutant. The
biodegradation of triclosan is dependent on many variables including the
biodegradation organism and the environmental conditions. Here, we
evaluated the triclosan degradation potential of two fungi strains,
Rhodotorula mucilaginosa and Penicillium sp., and the rate of its
turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed
less susceptibility to triclosan when grown in minimal salt medium. In
order to further evaluate the effects of environmental conditions on
triclosan degradation, three different culture conditions including
original thermal power plant wastewater, T6 nutrimedia and ammonium
mineral salts medium were used. The maximum triclosan degradation yield
was 48\% for R. mucilaginosa and 82\% for Penicillium sp. at 2.7 mg/L
triclosan concentration. Biodegradation experiments revealed that
Penicillium sp. was more tolerant to triclosan. Scanning electron
microscopy micrographs also showed the morphological changes of fungus
when cells were treated with triclosan. Overall, these fungi strains
could be used as effective microorganisms in active uptake (degradation)
and passive uptake (sorption) of triclosan and their efficiency can be
increased by optimizing the culture conditions
PRE-TREATMENT OF FULVIC ACID PLAYS A STIMULANT ROLE IN PROTECTION OF SOYBEAN (GLYCINE MAX L.) LEAVES AGAINST HEAT AND SALT STRESS
The purpose of this study was to illuminate the effects of fulvic acid
in plants' stress signaling pathway. 2.0 mg/l fulvic acid was sprayed on
soybean leaves for 3 days at 12 h intervals, followed by treatment of
150 mM NaCl or exposed to heat stress at 35 degrees C for 2 h over 2
days. Pre-treatment with fulvic acid increased the relative water
content (RWC), antioxidant enzyme, isoenzyme activities (SOD, APX, GST),
as well as alleviated the stress-induced oxidative damage by decreasing
the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA). In
addition, the application of fulvic acid under salt stress induced
rubisco expression only at 12 h, while it induced the expression of
cytochrome c oxidase at 6 h and 12 h. On the other hand, fulvic acid
under heat stress induced significant expression of both rubisco and
cytochrome c oxidase at 6 h and 12 h. However, under high salinity
conditions, fulvic acid suppressed the transcript levels of Hsp70, while
it induced increases in Hsp70 levels under heat treatment at 6 h. As a
result, in this study, fulvic acid played the role of a regulator and
stimulant in stress response of soybean leaves
Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography
In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95–98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation
Oligonucleotide Delivery with Cell Surface Binding and Cell Penetrating Peptide Amphiphile Nanospheres
A drug delivery system designed specifically for oligonucleotide
therapeutics can ameliorate the problems associated with the in vivo
delivery of these molecules. The internalization of free oligonudeotides
is challenging, and cytotoxicity is the main obstacle for current
transfection vehicles. To develop nontoxic delivery vehicles for
efficient transfection of oligonudeotides, we designed a self-assembling
peptide amphiphile (PA) nanosphere delivery system decorated with cell
penetrating peptides (CPPs) containing multiple arginine residues (R-4
and R-8), and a cell surface binding peptide (KRSR), and report the
efficiency of this system in delivering G-3129, a Bcl-2 antisense
oligonucleotide (AON). PA/AON (peptide amphiphile/antisense
oligonucleotide) complexes were characterized with regards to their size
and secondary structure, and their cellular internalization efficiencies
were evaluated. The effect of the number of arginine residues on the
cellular internalization was investigated by both flow cytometry and
confocal imaging, and the results revealed that uptake efficiency
improved as the number of arginines in the sequence increased. The
combined effect of cell penetration and surface binding property on the
cellular internalization and its uptake mechanism was also evaluated by
mixing R-8-PA and KRSR-PA. R-8 and R-8/KRSR decorated PAs were found to
drastically increase the internalization of AONs compared to
nonbioactive PA control. Overall, the KRSR-decorated self-assembled PA
nanospheres were demonstrated to be noncytotoxic delivery vectors with
high transfection rates and may serve as a promising delivery system for
AONs
Antioxidant ?-tocopherol/?-cyclodextrin-inclusion complex encapsulated poly(lactic acid) electrospun nanofibrous web for food packaging
- …