Concentrations Of Azide Research Articles

Evaluating the Lethal Dose (LD50) and Mutagenic Effects of Sodium Azide on Germination and Quality Traits in Two Varieties of Tomato (Solanum lycopersicum)

Study’s Excerpt Lethal dose (LD50) of sodium azide for two distinct tomato varieties, Beefsteak and San Marzano was quantified. The optimal mutagen doses that can be leveraged for enhancing quality traits in tomatoes is determined. Sodium azide has potential to improve crop resistance and productivity in tomato breeding programs. Full Abstract Sodium azide is a chemical mutagen that has been used to produce resistance in various susceptible crops to improve their yield and quality traits against harmful pathogens. The lethal dose and mutagenic effects of sodium azide on the germination percentage of two varieties of tomatoes (Beefsteak and San Marzano) were investigated with the aim of optimizing a suitable mutagen concentration with variability that could be exploited in the improvement of quality traits in Tomato plants. This study was carried out in the Green House at the Department of Biotechnology, Alex Ekwueme Federal University Ndufu-Alike, Ebonyi State (AE-FUNAI). The two varieties of tomato seeds were collected locally as fresh seeds from the taxonomic department and were treated with sodium azide at different concentrations of 0.0%, 0.2%, 0.4%, and 0.6% w/v. The seed was sown and monitored for 30 days with everyday documentation of germination percentage, survival percentage, and lethal dose. Statistical analysis using significant difference (LSD) at 95% probability level was employed to analyze the effects. The results obtained from this study show that there is a steady decrease in germination and survival percentage with increased concentration of sodium azide in both varieties of tomatoes when compared with the control. The lethal dose (LD50) was determined upon germination and survival of the tomato varieties. The highest LD50 was calculated by linear regression to be 0.950 for the beefsteak variety, which was significantly higher than 0.794 for the san marzano variety at 50% germination was recorded under treatment 0.6% NaN3. These concentrations are therefore considered as the LD50 values. Sodium azide via mutation at low concentrations improves some important quality traits of tomatoes.

Identification of Induced Chemical Mutants for Improving Yield and its Attributing Traits in Wheat (Triticum aestivum L.) against Changing Climate

Background: The enhancement of genetic traits in any crop relies on the existing variability within that particular crop. Through hybridization and traditional breeding methods, the variability within wheat crops has been nearly exhausted. Consequently, mutation breeding emerges as the sole viable and promising approach to introduce new variability for further improvements. Methods: An experiment was conducted during the Rabi seasons of 2020-21 (M1 generation) and 2021-22 (M2 generation) at the Crop Research Centre, Department of Genetics and Plant Breeding, ITM University Gwalior. The experiment assessed the impact of five different concentrations of Sodium Azide (0.02%, 0.03%, 0.04%, 0.05%, and 0.1%) and Hydroxyl Amine (0.2%, 0.3%, 0.4%, 0.5% and 0.6%), in addition to a control, on the wheat varieties MP-3382 and RVW-4106. It employed a randomized block design with three replications. Result: The findings revealed that Sodium Azide and Hydroxyl Amine, the most effective dosages were observed to be 0.1per cent and 0.4 per cent, respectively, in inducing genetic and phenotypic changes in seed quality parameters. Specifically, for the flag leaf area characteristic, the most effective concentrations were 0.03 per cent Sodium Azide and 0.4 percent Hydroxyl Amine. Plant height exhibited the greatest variability at 0.03 per cent Sodium Azide, 0.5 per cent Hydroxyl Amine and 0.1 percent Sodium Azide. A dosage of 0.5 per cent Hydroxyl Amine was found to be most effective in altering spike length. In terms of days to 50 per cent flowering, 0.05 per cent Sodium Azide was identified as the most effective dosage. From the study of traits in both the M1 and M2 generations, 12 mutants were confirmed, with seven validated for variety MP-3382 and five for variety RVW-4106.

Enhancing genetic variability in Trigonella species through sodium azide induction: morpho-physiological and chromosomal amelioration.

Plant breeding, aimed at enhancing desired traits, depends on genetic diversity. Mutation breeding is a powerful method of rapidly expanding genetic diversity, facilitating crop improvement, and ensuring food security. In a recent study, researchers evaluated the genetic variability of Trigonella species using different doses of sodium azide (SA) (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) through morphological, physiological, and cytogenetic studies. Morphological variations were observed in cotyledonary leaves, vegetative leaves, and overall plant growth and habit. Several quantitative parameters, such as plant height, fertile branches per plant, pods per plant (or clusters), seeds per pod, and seed yield, increased when treated with 0.2% and 0.4% SA compared to the control. Furthermore, the total chlorophyll content and carotenoids increased in the sample treated with 0.2% SA over the control but decreased with higher concentrations. Scanning electron microscopy revealed that stomatal aperture and seed dimensions increased at lower concentrations of sodium azide treatment. The study found a positive correlation between the different parameters studied in the Trigonella species, as indicated by high r-values. Based on their findings, it was concluded that the genotype of fenugreek can be improved by using 0.2% and 0.4% concentrations of sodium azide. However, the evaluation of observed variants in successive generations is a critical and necessary process to validate their potential as keystones for crop genetic improvements.

Determination of lethal dose (LD50) and sensitivity of fenugreek (Trigonella foenum-graecum) to sodium azide for induction of mutation

The present experiment was conducted in the year 2021 at Sri Karan Narendra Agriculture University, Jobner, Rajasthan, to determine the optimum dose (LD50) and duration of the chemical mutagen treatment for the induction of desirable mutation. A set of 100 pre-soaked fenugreek seeds were treated with 12 different concentrations of sodium azide, viz. 0.3 mM, 0.6 mM, 1 mM, 2 mM, 3 mM, 4 mM, 5 mM, 6 mM, 7 mM, 8 mM, 9 mM and 10 mM for three different durations, viz. 3 h, 6 h and 9 h. Results showed that a dose-dependent decreasing tendency was observed in germination percentage, survival percentage, root length and shoot length with increasing concentration and duration of sodium azide treatment. Almost all the mutagenic treatments resulted in decrease in germination percentage, survival percentage and seedling height (root and shoot length) with increasing concentrations and duration of mutagen in laboratory conditions. Also, the LD50 value was observed as an 8 mM sodium azide concentration for 6 h in fenugreek. The mutagen treatments given at 9 h duration were detrimental for fenugreek. They cannot be used for mutation induction as they are utterly lethal after a 3 mM sodium azide concentration. So, lower treatments of mutagens have influenced less biological damage and would be suitable for inducing desirable mutations.

Generating Stable Nitrogen Bubble Layers on Poly(methyl methacrylate) Films by Photolysis of 2-Azidoanthracene.

2-Azidoanthracene (2N3-AN) can act as a photochemical source of N2 gas when dissolved in an optically transparent polymer such as poly(methyl methacrylate) (PMMA). Irradiation at 365 or 405 nm of a 150 μm-thick polymer film submerged in water causes the rapid appearance of a surface layer of bubbles. The rapid appearance of surface bubbles cannot be explained by normal diffusion of N2 through the polymer and likely results from internal gas pressure buildup during the reaction. For an azide concentration of 0.1 M and a light intensity of 140 mW/cm2, the yield of gas bubbles is calculated to be approximately 40%. The dynamics of bubble growth depend on the surface morphology, light intensity, and 2N3-AN concentration. A combination of nanoscale surface roughness, high azide concentration, and high light intensity is required to attain the threshold N2 gas density necessary for rapid, high-yield bubble formation. The N2 bubbles adhered to the PMMA surface and survived for days under water. The ability to generate stable gas bubbles "on demand" using light permits the demonstration of photoinduced flotation and patterned bubble arrays.

Stimulating Genetic Variability on Growth And Yield of Okra (Abelmoschus esculentus) Using Sodium Azide

As interest in mutant breeding grows, so does the amount of study being done on employing mutagens to induce mutations for genetic variety. As a result, breeders' only means of producing variety is through mutation breeding. An experiment was conducted to induce genetic variability using sodium azide on varieties of okra (Ablemoschus esculentus). Okra seeds were treated with different sodium azide concentrations (0mM, 2mM, 4mM, and 6mM). The research was carried out at the Department of Agronomy Federal University Dutsin-ma. The objectives of the research were to evaluate the effect of sodium azide (NaN3) on the growth and yield of okra, identify the mutagen that induces beneficial mutation with minimum lethality, select the variety of okra that produce the best mutants in terms of yield and agronomic traits. The pre-soaking of okra seed in distilled water, treatment with mutagen, seed germination test, and germination percentage were done in the laboratory. The treated and the control seeds were planted in nylon bags on the field. Each treatment was in three replications. The field layout was Completely Randomized design (CRD). The result revealed that plots treated with 2mM, 4mM, and 6mM of sodium azide recorded decreased growth, yield, and yield components with an increase in concentrations of the mutagens in okra varieties studied in comparison with untreated plots. However, treatment with 2mM and 4mM performed better than those treated with 6mM. Therefore, treatment with a low concentration of Sodium Azide is recommended for the okra varieties used in this research

Secretory Production of the Hericium erinaceus Laccase from Saccharomyces cerevisiae.

Mushroom laccases play a crucial role in lignin depolymerization, one of the most critical challenges in lignin utilization. Importantly, laccases can utilize a wide range of substrates, such as toxicants and antibiotics. This study isolated a novel laccase, named HeLac4c, from endophytic white-rot fungi Hericium erinaceus mushrooms. The cDNAs for this enzyme were 1569 bp in length and encoded a protein of 523 amino acids, including a 20 amino-acid signal peptide. Active extracellular production of glycosylated laccases from Saccharomyces cerevisiae was successfully achieved by selecting an optimal translational fusion partner. We observed that 5 and 10 mM Ca2+, Zn2+, and K+ increased laccase activity, whereas 5 mM Fe2+ and Al3+ inhibited laccase activity. The laccase activity was inhibited by the addition of low concentrations of sodium azide and L-cysteine. The optimal pH for the 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt was 4.4. Guaiacylglycerol-β-guaiacyl ether, a lignin model compound, was polymerized by the HeLac4c enzyme. These results indicated that HeLac4c is a novel oxidase biocatalyst for the bioconversion of lignin into value-added products for environmental biotechnological applications.

Analytical Validation of Two Assays for Equine Ceruloplasmin Ferroxidase Activity Assessment.

Ceruloplasmin (Cp) assessment in biological samples exploits the oxidase activity of this enzyme against several substrates, such as p-phenylenediamine (p-P), o-dianisidine (o-D) and, most recently, ammonium iron(II) sulfate (AIS). Once developed in humans, these assays are often used in veterinary medicine without appropriately optimizing in the animal species of interest. In this study, two assays using AIS and o-D as substrates have been compared and validated for Cp oxidase activity assessment in horse's plasma. The optimization of the assays was performed mainly by varying the buffer pH as well as the buffer and the substrate molar concentration. Under the best analytical conditions obtained, the horse blood serum samples were treated with sodium azide, a potent Cp inhibitor. In the o-D assay, 500 µM sodium azide treatment completely inhibits the enzymatic activity of Cp, whereas, using the AIS assay, a residual analytical signal was still present even at the highest (2000 µM) sodium azide concentration. Even though the analytical values obtained from these methods are well correlated, the enzymatic activity values significantly differ when expressed in Units L-1. A disagreement between these assays has also been detected with the Bland-Altman plot, showing a progressive discrepancy between methods with increasing analytical values.

Mutagenic effect of hydroxyl amine and sodium azide on the performance of tomato (Solanum lycopersicum L.)

Tomato, an important vegetable crop due to its utility as raw, cooked and processed form of food, requires improved cultivar with high nutrition and yield to meet out global demand in changing agro-climatic conditions. The mutagenesis is one of the most important techniques to create genetic variability and identification of economically important traits towards the crop improvement. Therefore, the mutagenic effect of various concentrations of hydroxyl amine and sodium azide were studied on tomato var. PKM 1 for the qualitative and quantitative traits of economic importance. The seeds of tomato were obtained from Ryoth’s Depot Kurnool, Andhra Pradesh, India and treated with the different concentrations of sodium azide (SA) and hydroxyl amine (HA) 2 mM, 3 mM, 4 mM, 5 mM and 0.1, 0.15%, 0.2, 0.25%, respectively) for four hours. Study on germination per cent, seedling height, root length and pollen viability was carried out in lab and for growth parameters. M1 generation was grown in the field. The mutagens hydroxyl amine (0.1%) and sodium azide (2 Mm), showed least reduction in parameters and with increase the concentration of both chemicals, decline was noted. Highly significant differences were observed in the treatments with respect to the studied traits (seed germination, seedling survival, seedling height, root length, pollen viability, leaves per seedling and height at maturity, branches per plant and fruits per plant. The present study concluded that mutagens had detrimental effects along with creating variability. Hence, hydroxyl amine (0.1%) and sodium azide (2 Mm) could be utilized to induce variability for the improvement of tomato.

ASSESSMENT OF VARIATIONS IN CATHARANTHUS ROSEUS L. INDUCED BY GAMMA RAYS AND SODIUM AZIDE USING RAPD MARKERS

The study of genetic variations in Catharanthus roseus L. induced by gamma rays and sodium azide using RAPD markers transpired in 2021–2022 at the Department of Biology, University of Kufa, Iraq. The seeds of two cultivars of Catharanthus roseus L., i.e., victory pure white and local (pink variety), received two doses of gamma rays (50 and 75 Gray) and four sodium azide concentrations (0.2%, 0.4%, 0.6%, and 0.8%). Non-treated seeds of both cultivars also served as a control for comparison. Evaluating the effects obtained through the exposure of C. roseus seeds to gamma rays and sodium azide employed DNA markers, including 16 primers used in applying RAPDs. DNA extraction, accomplished from fresh apical leaves, underwent molecular markers application. RAPD markers could detect the generation of genetic variation induced by gamma rays and sodium azide treatments through the appearance of polymorphic bands. Using 16 RAPD primers, the largest molecular size was 2,543 bp produced by primer OPB-17, with the lowest 114 bp produced by primer OPC-08. The highest number of main and polymorphic bands was 18 and 10, respectively, in primer OPA-10. The highest number of monomorphic bands was eight in primer OPX-17, which affected its ability to give the lowest value for polymorphism. The highest number of amplified bands was 78 bands in primer OPC-09. Primer OPA-10 provided the highest number of polymorphic and unique bands, as well as, the highest values for discrimination and primer efficiency. Primer OPC-09, with seven treatments resulting in a unique fingerprint, is superior to all other primers.

Ceruloplasmin Interferes with the Assessment of Blood Lipid Hydroperoxide Content in Small Ruminants.

Simple and inexpensive analytical methods for assessing redox balance in biological matrixes are widely used in animal and human diagnostics. Two of them, reactive oxygen metabolites (ROMs) and total oxidant status (TOS), evaluate the lipid hydroperoxide (LOOH) content of the sample and are based on iron-mediated mechanisms. However, these tests provide uncorrelated results. In this study, we compared these two tests in the blood serum of goat kids and lambs, together with an evaluation of ceruloplasmin (CP) oxidase activity. No significant correlation was found between ROMs and TOS, or between TOS and CP oxidase activity, in either species. Conversely, ROMs and CP oxidase activity were highly correlated in both kid and lamb samples (p < 0.001). A significant progressive reduction in the analytical signal in the ROMs assay was observed when sodium azide, an effective CP inhibitor, was added to the samples before the assay (p < 0.001). This decrease was related to sodium azide concentration (p < 0.01) and was not found when sodium azide was added at the same concentrations in the TOS assay. These findings suggest that ROMs, unlike TOS, may be affected by CP, which interferes with LOOH detection in blood samples.

Determination of the effective of chemical mutagenesis using sodium azide to improvement of vegetative growth and flowering characteristics in Helichrysum bracteatum L. plant

This study were carried out on Helichrysum bracteatum L. plant at the Experimental nursery of the Ornamental Hort. Dept., Fac. Agric., Cairo Univ., Giza, Egypt, during the two successive seasons (2014/15 and 2015/16). The aim of this study was to investigate the effect of on some vegetative and flowering parameters and anatomical structure of leaves and flowers. Seeds of H. bracteatum L. were exposed to four concentrations of (0.05, 0.1, 0.2 and 0.3%) of sodium azide (NaN3) solution for six hours; one set of seeds was kept without sodium azide treatment (untreated) to act as control. The obtained data revealed that the low concentration of sodium azide (SA) increased plant height, number of leaves/ plant, stem diameter (cm) number of flowers, flowers fresh weight (g)/plant and flowers dry weight (g)/plant in M1 and M2. The ratio of chlorophyll (a and b) showed a markedly decrease as a result of increasing sodium azide concentrations. On contrary, in case of carotenoids showed a markedly increase as a result of decreasing sodium azide concentrations. Were obtained on many morphological mutants in flowers through two generations. Some parameters of anatomical structure of leaves and flowers and to confirm the stability of some of the mutations were obtained during the second generations.

Development of source material for pea breeding through chemical mutagenesis and evaluation of its genetic diversity using SSR markers

Background. Pea (Pisum sativum L.) is a valuable leguminous crop of worldwide importance. The main problem of modern plant breeding is a decrease in the genetic diversity of crops, including pea. One of the ways to increase genetic polymorphism is the use of chemically induced mutagenesis. Sodium azide (NaN3) is a highly effective chemical mutagen successfully used in mutation breeding to increase the productivity of cultivated plants and enrich them with new useful traits. We used it to obtain new pea breeding material.Materials and methods. Experiments were carried out to obtain pea mutants using sodium azide at the concentrations of 1, 5 and 10 mM and the exposure time of 3 and 9 h. Molecular genetic polymorphism of the М2 plants and the original cultivar was assessed using 10 SSR markers from the microsatellite genomic library (Agrogene®, France).Results. Optimal concentrations of sodium azide and the duration of seed treatment with it were identified: 1–5 mM for 3 h. Sixteen mutant populations were obtained; in ten of them a change in the leaf type was found. An analysis of the yield structure components revealed a significant superiority (p &lt; 0.05) over the initial cultivar ‘Pamyati Khangildina’ in the mutant populations No. 1, No. 5, No. 9, No. 10, No. 15 and No. 16 in the number of seeds per pod, No. 9 and No. 16 in the weight of 1000 seeds, and No. 16 in the weight of seeds per plant. A dendrogram constructed on the basis of the SSR analysis data showed the degree of differences between the M2 populations of pea plants and the initial cultivar ‘Pamyati Khangildina’.Conclusion. The obtained mutant populations are planned to be used in pea breeding as sources of high seed numbers in pods, seed yield, seed weight per plant, and large seed size. A microsatellite analysis with 10 SSR markers revealed differences among the M2 mutant populations at the genetic level and made it possible to identify them.

A case series of suicides by sodium azide ingestion

To investigate the involvement of sodium azide in 13 forensic apparent suicides. Cases with suspicion of an intentional sodium azide ingestion confirmed by blood analysis were included. All blood samples were collected at the scene by the forensic physician. In six cases, the blood was femoral blood, in the other cases the origin was unknown. Nine blood samples were preserved with sodium fluoride and heparin or oxalate as anticoagulant, four contained EDTA as anticoagulant. The cases were screened for the presence of alcohol, drugs of abuse and medicines in blood. Azide in blood was identified and quantified after derivatization with pentafluorobenzylbromide (PFBBr) using GC-MS. In some cases other biological matrices were available for analysis as well. Thirteen cases were included (male/female: 2/11; age range: 27–86 years). Most bodies were found in their homes. Two victims were found in the garden needing resuscitation and eventually died in the hospital. In almost all cases, a small container labeled with sodium azide was found at the scene and the total dose in the container, if classified, varied from 2 to 3 gram. In three cases, a forensic autopsy was performed and the pathologist found no anatomical cause of death. Toxicological analysis for the presence of alcohol, drugs of abuse and medicines resulted in no indications for a toxicological cause of death. In all cases, medicines were found, especially analgesics, opioids and anti-emetics. Alcohol was detected in three cases. The median azide blood concentration was 17 mg/L (interquartile range: 13.5–20.5 mg/L). Azide was measured in other biological matrices in four cases showing higher azide concentrations in vitreous humor and lower azide concentrations in heart blood and urine compared to the blood obtained by the forensic physician. Median concentrations in vitreous humor, heart blood and urine were 26, 8 and 7 mg/L, respectively. In 11 cases, very high concentrations of azide were found in the blood (13 to 26 mg/L), corresponding with concentrations that were measured in persons who died after apparent intentional ingestion of sodium azide. In two cases, no toxicologically relevant results were found, except for azide. However, the measured azide concentrations were lower (about 1 mg/L), possibly due to degradation as a consequence of prolonged unsuitable storage prior to arrival at the institute. Unfortunately, no other biological matrices were available. These victims were found together and a container with label of sodium azide was found near them. The mentioned dose on the label of 3 gram is higher than earlier reported lethal doses of 700 mg. Higher azide concentrations in vitreous humor suggest good permeation and postmortem stability. It was concluded that the high concentration of azide can explain the death in 11 of our cases. In 2 cases, death by an azide overdose cannot be concluded but also cannot be excluded. Although femoral blood is the specimen of choice, vitreous humor is a good alternative when suspecting an azide overdose.

Effect of Sodium Azide on Yield and its Components in Bread Wheat (Triticum aestivum L.).

&lt;b&gt;Background and Objective:&lt;/b&gt; The wheat crop is considered one of the most important crops globally, especially in Egypt. It has great nutritional importance, so it was necessary to increase productivity and any genetic improvement depends on the presence of many genetic differences so that breeders can achieve this. This study aimed to use chemical mutagenic (sodium azide) to obtain the desired genetic differences in two wheat cultivars. &lt;b&gt;Materials and Methods:&lt;/b&gt; Two types of bread Sids 12 and Giza 164 were treated with different concentrations of sodium azide (NaN&lt;sub&gt;3&lt;/sub&gt;) (1000, 2000, 3000, 4000, 5000 and 6000 ppm). &lt;b&gt;Results:&lt;/b&gt; The highest grain/plant 78.91 g was obtained from Sis12 and 62.96 g from Giza 164 compared to the control 42.57 and 40.24 g for Sids 12 and Giza 164, respectively. Also from the results obtained, the relationship of yield was positive and significant with both grain/spike, spikelet's no./spike spikes no./plant and height/plant. On the contrary, it was negative and significant with a 1000-grain weight (-0.433). &lt;b&gt;Conclusion:&lt;/b&gt; The two treatments (1000 and 2000 ppm) were the best in the Sids 12, while (1000 and 5000 ppm) were the best treatments in the Giza 164.

Induction of Genetic Variability in Pusa Jwala and Pusa Sadabahar (Capsicum annuum L.) through Mutation via Sodium Azide and Hydroxyl Amine

The present study was carried out to determine the mutagenic effect of Sodium Azide and hydroxyl amine on the morphological features of Pusa Jwala and Pusa Sadabahar (Capsicum annuum L.) in M2 generation. Seed were pre-soaked in distilled water for 6hrs and later treated with different concentration w/v (0.1, 0.15, 0.20, 0.25) of sodium azide and hydroxyl amine mutagens for 6hrs. The experiment was planted Randomized block design, replicated three times. Observation on growth parameters of M2 mutants of Pusa Jwala and Pusa Sadabahar shown significant variation on the plant height, germination, primary secondary branches, length of fruit, test weight of seed, number of fruits per plant, days to first flower mortality and survival. Most of the parameters decreased with increase in concentration of sodium azide. The result of study shown that sodium azide significantly affects plant height, germination and days to first flowering. Sodium Azide is more effective as compared to the Hydroxyl Amine in inducing genetic variability. Keywords: Chilli, Mutant, Sodium Azide, Hydroxyl Amine, Pusa Jwala, Pusa Sadabahar, Variability

Characterization of Mutant Aspergillus niger and the Impact on Certain Plants

Aspergillus niger is a dangerous pathogen for many plants. It is a major cause of the destruction, rotting and decomposition of plant tissues. Toxicity caused by A. niger can be inhibited by mutation decreasing the destructive effect on plants. An 18S rDNA molecular tool was used to identify A. niger strains. Sodium azide (NaN3) is a chemical mutagen that disturbs fungal enzymatic activity and causes microbial production of cellulose-degrading enzymes, decreasing mycotoxin production. Different concentrations of sodium azide were used to treat A. niger (30, 40 and 50 µM). The study was designed on two levels: the first level concerned the mutant A. niger’s mode of action: the higher the mutagen concentration, the lower the growth diameter and spore counts. The mutant A. niger’s total proteins and flavonoids were reduced when compared to control. RAPD-PCR showed genetic variation in the genetic content of mutant fungi compared to control resulting in a polymorphism percentage of 78.56%. The second level included the effect of these mutants on two plants (onion and maize). The greater the increase in mutant concentration, the greater the increase in the plants’ morphological and physiological behavior. In conclusion, mutation reduced fungal activity and strengthened plant resistance.

Bacterial Deterioration in the Limestone Minaret of Prince Muhammad and Suggested Treatment Methods, Akhmim, Egypt

El-Amir Muhammad’s minaret in Akhmim, Sohag, Egypt, is constructed of limestone and has been exposed to many factors of damage as a result of the high levels of ground water. Limestone is strongly affected by ground water, especially when being impure. The current work discusses the results of analytical techniques including chemical testing to determine the types of soluble salts through optical microscopy, electronic scanning electron microscope with an X-ray energy dispersion system (ESEM) to study and determine the causes of rapid degradation. Microbial weathering phenomena toward limestone were also studied. Different bacteria and fungi were isolated from outdoors and indoors of air and limestone of the building of which Bacillus cereus OK447647, B. subtilis OK447648, Serratia marcescens OK447650, Pseudomonasoryzihabitans OK447649, Aspergillus flavus, A. niger, Penicillium chrysogenum and Cladosporium cladosporoids were the most representative. B. cereus OK447647 and B. subtilis OK447648 have shown ability for calcium carbonate dissolving. The minimal inhibitory concentrations (MICs) of sodium azide were investigated against the growth of microbial isolates. Sodium azide at 100 ppm was found to be the best treatment for bacterial isolates although it had no significant effect against fungi.

Response of Local and Roma Tomato Varieties to (0.2mM) Concentration of Sodium Azide (NaN3) in Dry Season

Response of Local and Roma Tomato Varieties to (0.2mM) Concentration of Sodium Azide (NaN3) in Dry Season

Experimental and theoretical studies into the hydroxyl radical mediated transformation of propylparaben to methylparaben in the presence of dissolved organic matter surrogate

Dissolved humic and biogenic substances might be present in the aphotic zone and contribute to the fate of parabens in natural aquatic ecosystem under the fluctuation of water multi-parameters. Through the combination of batch tests with quantum chemical calculation, hydroxyl radical (•OH) mediated degradation of propylparaben (PP) to methylparaben (MP) has been confirmed in the present study. The interaction of dissolved oxygen with environmental relevant concentration of humic acid (HA), algal and bacterial cell lysis leads to a slow production of •OH. Aqueous PP undergoes a mild removal process with the pseudo-first order rate constant (10−7, s−1) higher at 7.43 in HA than at 3.30-4.89 in biogenic cell lysis. PP removal is correlated with the aromaticity of DOM surrogate and the produced •OH concentration, which could be enhanced by the increase of light intensity and DO other than HA. The •OH mediated process on PP removal has been confirmed by the linearly inhibited effect of tert-butanol while totally inhibited effects of higher concentration of sodium azide and co-existent chemical (17β-estradiol). Based on the detection of byproduct MP, two possible reaction pathways, •OH attacking at β-carbon (path-β) and terminal γ-carbon (path-γ) of the propyl side chain of PP, are proposed. Through the analysis of thermal and kinetics parameters, the •OH initiated H-abstraction and the resulting C-C bond cleavage leading to the formation of MP and acetaldehyde in path-β is confirmed to be the dominant reaction mechanism. Considering the universal occurrence of parabens and these DOM surrogates, this mild removal process has special implications for the self-purification of organic pollutants in natural aquatic ecosystems, especially in DOM-rich matrices in the aphotic zone.