فهرست مطالب

Sciences, Islamic Republic of Iran - Volume:33 Issue: 3, Summer 2022
  • Volume:33 Issue: 3, Summer 2022
  • تاریخ انتشار: 1401/11/09
  • تعداد عناوین: 6
  • Zahra Etemadifar *, Maryam Moradi, Mohammad Rabbani Khorasgani, Sanaz Khashei Pages 205-211
    Application of metal-resistant plant growth-promoting bacteria is an efficient method for enhancing crop yields by improving biomass accumulation and plant tolerance to heavy metals. The present study aimed to isolate and characterize these bacteria from rhizosphere soil and root exudates of plants grown on agricultural soils contaminated with heavy metals. Plant growth-promoting properties of isolated strains were assayed by evaluating their abilities to solubilize insoluble phosphate, produce indole-3-acetic acid (IAA), and fix nitrogen. Resistance to metals toxicity and metal removal potential of the selected strains were investigated by MIC and MBC values determination and atomic absorption spectroscopy (AAS), respectively. Pantoea agglomeransexhibited the maximum solubilization of insoluble phosphate and IAA production. In the case of Cd2+, the highest MIC value belonged to Enterobacter ludwigi. Pseudomonas taiwanensis, P. agglomerans, and E. ludwigi exhibited the greatest MIC value (8mM) in the case of Pb2+. P. agglomerans and E. ludwigi showed the highest MBC of Pb2+(>120mM) and the greatest MBC of Cd2+ (30mM) belonged to P. agglomerans. Also, E. ludwigi exhibited the highest metal removal percentage for Pb2+ as 31.81% and Cd2+ as 37.58%. As results showed, these four isolated strains can be used as novel and efficient agents for improving plant growth, especially in heavy metals polluted agricultural soils.
    Keywords: Heavy metals removal, Nitrogen fixation, phosphate solubilizer, IAA production
  • Nastaran Rezaeepour, Sayyed Shahryar Rahpeyma, MohammadJavad Mehdipour Moghaddam, AliAsghar Karkhane, Bijan Bambai, Jamshid Raheb * Pages 213-225

    This study aimed to produce a recombinant version of glucose oxidase enzyme and introduce an economical method for enzyme immobilization. The pGAPZαA expression vector was utilized, which has a continuous expression and does not need an inducer and medium replacement. Enzyme immobilization was accomplished by adding WHWTYYW heptapeptide, which tends to bind to cellulosic and nitrocellulose surfaces, to bind the enzyme to the above-mentioned surfaces. In this study, the glucose oxidase (GOX)-encoding gene from Aspergillus niger ATCC 9029 was amplified by the polymerase chain reaction (PCR) and cloned into the pGAPZαA vector, and pGAPZαA/GOX was obtained as a control construct. On the other hand, a primer containing the heptapeptide sequence was designed, followed by adding the heptapeptide by the PCR technique to the end of the carboxyl in the GOX-encoding gene in the pGAPZαA/GOX construct and obtaining the pGAPZαA/GOX–heptapeptide construct. Both constructs were integrated into the Pichia pastoris genome by electroporation, and enzymatic activity and protein expression of the recombinant enzyme from both constructs underwent investigation. The amount of GOX production in the pGAPZαA/GOX wild-type construct and pGAPZαA/GOX with heptapeptide was estimated at 0.234 and 0.135 g/l, respectively. The stability of both constructs was evaluated on different surfaces and then compared as well. It was revealed that the enzyme with WHWTYYW heptapeptide has an increased affinity to bind in cellulose and nitrocellulose surfaces compared to the wild-type enzyme, while demonstrating no affinity for binding to the polyvinylidene fluoride paper.

    Keywords: Glucose Oxidase, Heptapeptide, pGAPZA, GOX, Pichia pastoris, Nitrucellulose
  • Hojjat Sadeghi-Aliabadi, Elham Jafari *, Fatemeh Sepahvand, Farshid Hassanzadeh Pages 227-232

    Thieno[2,3-b]pyridine, a bicyclic heterocyclic, possesses various advantageous biological properties, including a cytotoxic effect. This study synthesized thieno pyridine scaffold derivatives with position 2 modifications. The reaction between 2-chloronicotinonitrile and methyl thioglycolate produced methyl amino thieno pyridine carboxylate 1. As a result of hydrazinolysis, methyl amino thieno pyridine carbohydrazide 2 was synthesized as a key compound for preparing final derivatives. The reaction of compound 2 with phthalic anhydride yielded thieno pyridine-phthalimide. The 1,3,4-oxadiazole scaffolds were synthesized in two steps. During the initial reaction of compound 2 with aroyle chloride derivatives, the corresponding intercessor was cyclized to oxadiazole in the presence of phosphoryl chloride. Compound 2 was subsequently cyclized in boiling glacial acetic acid to produce a pyridine-pyrazole derivative. MTT assay was utilized to assess the cytotoxic activity against two cell lines. Except for compound 6, the final compounds exhibited IC50 values <50 µM against both cell lines. Lipophilic compounds 4 and 5 exhibited significant cytotoxic effects compared to other compounds.

    Keywords: Thieno pyridine, Anticancer activity, Oxadiazole, Phthalimide
  • Farzaneh Sheikhshoaii, Samieh Fozooni *, Hooshang Hamidian Pages 233-243
    The primary interest of researchers from biology, physics, medicine, chemistry, industry, and material science towards nanotechnology is the most upgrading of production methods, especially those that are cleaner and simpler. This work investigates a new Balangu-based nanocomposite made from Balangu, polyurethane, iron oxide (Fe3O4) and silver sulfide (Ag2S) nanoparticles. The bio-nanocomposite was prepared by the synthesis of Fe3O4 and Ag2S nanoparticles on the Balangu matrix. Balangu is a natural and abundant, renewable polysaccharide, safe to use, non-toxic, hydrophilic, and biodegradable polymer. A mixture of Balangu/Fe3O4/Ag2S nanocomposite hydrogel and ethylene glycol was stirred at ambient temperature. After 2h, diphenyl methane diisocyanate was added and refluxed. The resulted product was filtered and washed thrice with deionized water. Subsequently, Balangu/Fe3O4/Ag2S/polyurethane nanocomposite was obtained by drying in the oven. This research was aimed at investigating the potential of this nanocomposite in drug delivery systems. Balangu/Fe3O4/Ag2S/polyurethane nanocomposite was synthesized using various Ag2S nanoparticle contents. The resulted bio-nanocomposite was evaluated by FT-IR, XRD, SEM, and TGA techniques. In vitro drug release experiments were performed to assess the efficacy of the developed nanocomposite in the controlled drug delivery systems. The Balangu/Fe3O4/Ag2S/polyurethane nanocomposite containing 0.01 M AgNO3 exhibited longer and better controlled drug release.
    Keywords: Balangu, Magnetic nanocomposite, drug delivery, Swelling, Ag2S
  • Adetunji Adeniji *, Olumide Ajani, Theophilus Adagunodo, James Agbolade, Ayomide Ayeni Pages 245-257
    Dar-Zarrouk criteria were used to explore a study region in southwestern Nigeria that was covered by a crystalline groundwater basement complex to illustrate the possibility for groundwater protection. This was accomplished by determining if the research area's protective potentials were predominantly low, weak, moderate, or good. The study's protective potential was calculated using physical subsoil layer data such as apparent resistivity and layer thickness values. For vertical electrical probes, the Schlumberger electrode array arrangement was employed, and twenty probe locations were defined depending on the spread allowed and subsurface depth. The Dar-Zarrouk parameters revealed that there was 70% evidence of poor/weak groundwater protection potential within the study area, implying that the availability of profitable groundwater quality within the study area is envisaging a tragic development due to contaminating activities that could percolate from the topsoil to the subsoil in the near future. As a result, frequent assessment of adequate water quality development and standards is recommended within the environment for the safe use of groundwater resources.
    Keywords: Geophysical investigation, Dar-Zarrouk parameters, Groundwater quality, Groundwater Contamination, Leachate percolation
  • SRINIVASA BOYAPATI *, Ramkiran U, Kantam RRL Pages 259-266
    The Probability model of a quality characteristic is assumed to follow the linear failure rate distribution. Control charts based on the extreme values of each subgroup are constructed. The control chart constants depend on the probability model of the extreme order statistics of each subgroup and the size of the subgroup. Accordingly, the proposed chart is known as extreme value chart. The technique of analysis of the means for a skewed population is applied with respect to linear failure rate distribution. The results are illustrated by example on live data.
    Keywords: Analysis of means (ANOM), Statistical quality control (SQC), Average run length (ARL), Linear failure rate distribution (LFRD)