Isolation and identification of diazinon degrading bacteria from fresh water: a case study on the sediments of Lake Parishan in Iran

Diazinon is an organophosphate insecticide which is widely used in various industries. It is known as an important causative of water pollution which eventually redound death of aquatic animals. Today microorganisms are considered as a best choice to reduce environmental pollution. This study was done to identify diazinon degrading bacteria from sediments of Lake Parishan (IRAN) and to evaluate their degrading rate as well. Sampling was done from the surface sediments of Lake Parishan and its surrounding farms during summer, autumn and winter, then incubated in liquid salt medium containing diazinon for 20 days at 35°C. After growing, bacteria were transferred to solid saline medium. They were identified using biochemical tests; thereafter in order to evaluate their ability in degrading of diazinon, diagnostic tests were performed. Result showed that bacteria Pseudomonas, staphylococcus, Bacillus, Corynebacterium, Acinetobacter, Alcaligenes, Serattia, Salmonella, Citrobacter and Providencia are able to degrade diazinon. Among them Pseudomonas was the strongest in summer and winter, while Citrobacter was the most preferable bacterium in fall. It was also detected that combined population of Gram positive and Gram negative bacteria together are able to degrade diazinon faster. Therefore, the present study confirmed the application of bacteria for reducing diazinon pollution in waters considering their ease and economical application

The Effects of NaCl Stress on the Physiological and Oxidative Situation of Maize (Zea mayz L.) Plants in Hydroponic Culture

Abstract: The effects of NaCl salinity on biomass, Malondialdehyde (MDA), peroxidase (POD), Catalase (CAT), Na + , K + , Ca 2+ and proline in Zea mays L. seedlings were investigated under hydroponic condition. Seedlings were subjected to NaCl stress (0, 50, 100, 150 and 200 mM) for 14 days. A completely randomized design with four replicates for each treatment was used. Salinity stress affected on the growth and caused a reduction in root and shoot biomass. NaCl treatment caused a significant increase in root MDA content. NaCl at 100 mM and higher increased also the shoot MDA content significantly. Catalase activity of leaf was significantly increased at 100, 150 and 200 mM NaCl in comparison with the control. Peroxidase activity in leaf started to significant increase with the rise of NaCl content at 150 and 200 mM. The leaf Na + content, root and shoot proline concentrations increased with the increase in salinity stress. The leaf K + and Ca 2+ amounts were significantly decreased with the rise of salinity stress in comparison with control

Terminal flower 1(TFL1) homolog genes in monocots.

Terminal flower1 (TFL1) is a key gene in charge of flowering time in Arabidopsis thaliana. It belongs to a family of phosphatidyl ethanolamine binding protein domain (PEBP). The main issues addressed in this paper are current advances in TFL1 homologs isolated from the monocot plants include rice (Oryza sativa) and ryegrass (Lolium perenne). Taking advantage of previous studies of cloning, in this review we have evaluated function of these genes in regulating flowering time as well as the effect of altered expression of these genes. It will then discuss or address places or parts of these plants where these genes express. Additionally, structural and functional relationships between them are compared

Function and expression pattern of Terminal Flower 1 (TFL1) homolog genes in dicot plants.

Terminal floweringl (TPLI) is a key gene in charge of flowering time inArabz'dopsz's thaliana. During the past decade, genetic studies have found out several TFL] like genes in dicot plants. The main issues addressed in this paper are current advances in TFL] homologs isolated from different dicot species and their function in flowering. Taking advantage of previous studies of cloning, in this paper we have evaluated function of these genes in regulating flowering time. It will then go on to place or parts of plants in where these genes express. Moreover, similarity and differences between them and other known genes, have been compared

Assessment of Organochlorine Pesticide Residues in Water, Sediments and Fish from Lake Tashk, Iran

In this study, the levels of organochlorine (OC) pesticide residues in Lake Tashk have been investigated using water, sediment and fish (carp) samples as a case study to find out the extent of pesticide contamination and accumulation in the lake. Six OC pesticides namely DDT, DDE, lindane, endosulfan, heptachlor and chlordane were analyzed in four sites at four seasons. Water samples were processed using a liquid–liquid extraction technique and gas chromatograph equipped with electron capture detector (GC-ECD). Soxhlet extraction was used for fish and sediment samples followed by clean up and gas chromatograph. DDE was the predominant residue in all the samples analyzed, at the mean concentrations of 0.075 ppb, 8.750 ppb and 4.446 ppb in water, sediment and fish samples, respectively. The lowest levels of OC pesticides were related to heptachlor and chlordane which none of them were found in water samples. Gonban and Midstream sites had the highest and the lowest concentrations of OC pesticides, respectively

Amylase activity of aquatic actinomycetes isolated from the sediments of mangrove forests in south of Iran

In this study amylase producing actinomycetes were isolated from the sediments of mangrove forests in the south of Iran and the rate of amylase activity was measured. The samples of sediments were collected from one hundred different places in mangrove forests of the south of Iran. Collected samples were diluted then they were purified on the starch (casein agar) culture and Woodruff. After that they were examined in terms of amylase production on agar–starch culture. The activity of the produced amylase by the isolated aquatic actinomycetes was measured by dinitrosalicylic acid (DNS) method. The results showed that aquatic actinomycetes were isolated from 86 per 100 places in spring (86%) and from 61 per 100 places in summer (61%). The highest rates of producing enzyme were related to isolated samples in spring (62.97 U/ml). Biochemical and Bergey’s book tests showed that the most isolated aquatic actinomycetes belonged to Streptomyces genus. As regards this, it is economical and easy to isolate the aquatic actinomycetes which produce amylase that is used in different industries in Iran from the sediments of mangrove forests of the south of Iran. So the isolated strains in this study can be suitable candidates for amylase production after genetic manipulation

COMPARISON OF FREQUENCY ANILINE DEGRADING BACTERIA IN THE SOIL AROUND SHIRAZ REFINERY IN SUMMER AND AUTUMN

ABSTRACT Aniline is one of the serious hazardous materials for life due to toxicity and carcinogenic effects. It is widely distributed in the soil and surrounding environment. Microbial degradation is one of the main mechanisms to remove it from environment. The aim of this research is to detect the indigenous aniline resistance bacteria from soil around Shiraz Refinery (Iran) and compare these for the term of two seasons in order to select the most powerful aniline resistant bacteria for bioremediation and clean a polluted soil. Sampling from the soil around Shiraz Refinery was done during summer and autumn and cultured in a medium containing 0.1 g/l aniline. Isolated bacteria were identified using the standard methods, these are known to be: Delftia acidovorans, Enterobacter ludwigii, Raoultella planticola, Alcaligenes faecalis, Serratia marcescens, Microbacterium barkeri, Pseudomonas acidovorans, Erwinia sp., Rhodococcus sp. Findings showed all of these bacteria were able to degrade aniline from the soil around Shiraz refinery and Delftia acidovorans and Rhodococcus sp. which was found during both time periods, had the highest ability to eliminate aniline

Association of IRGM (rs1000113 C/T) Genetic Polymorphism with the Incidence of Acute Rejection in Iranian Liver Transplanted Patients

Background & Objective: Autophagy has been shown to be involved in organ transplantation. IRGM (human immunity-related GTPase) has a crucial role in autophagy complex activation and ROS and microorganism elimination during graft rejection. We examined the association between rs1000113 C/T genetic polymorphism of IRGM and the risk of liver rejection in liver transplanted patients. Materials & Methods: The present study included 100 healthy people and 100 patients with liver disease that led to liver transplantation. Fifty patients were diagnosed with histologically proven acute liver rejection and the other 50 without any rejection. Both groups were matched for sex and age. To determine variants of rs1000113 C/T genetic polymorphism of IRGM, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used. Results: A significant association was observed between liver rejection and rs1000113 C/T genetic polymorphism of IRGM (TC: p-value=0.0098, OR=2.93 CI=1.2-7.22) and (CC: p-value=0.0098, OR=0.34 CI=0.138 -0.83). Also, a significant association was observed between this polymorphism and allelic frequency in liver rejection patients. (T: p-value=0.027, OR=2.14 CI=1.027-4.57) and (C: p-value= 0.027, OR=0.46 CI=0.218 -0.97). No significant difference was found in rs1000113 C/T genetic polymorphism of IRGM, sex, blood group, and underlying disease among the healthy groups and liver transplanted patients. Conclusions: The data suggest that the rs1000113 C/T genetic polymorphism of IRGM, an autophagy-related polymorphic locus, influences liver rejection in liver transplanted patients, with the possible involvement of autophagy in transplantation. Recipients with TC genotype for IRGM are more likely to develop liver rejection compared to those with CC genotype

Isolation of Halophilic and Halotolerant Microorganisms from the Bakhtegan Lake and the Effect of Physicochemical Factors on Their Frequency

The lake in the protected Bakhtegan zone is the shelter to wildlife and very important from an ecological and environmental viewpoint. The lake has a unique diversity in terms of Halophilic and Halotolerant bacteria. Based on our experiments, from among the six genera of Halobacteriaceae, only the four Halobacterium, Haloarcula, Halococcus, and Haloferax genera were isolated, the greatest frequency (mean: 54%) belonging to Halobacterium and the least frequency (mean: 4%) belonging to Haloferax among the isolated genera. The Halotolerant bacteria isolated included Pseudomonas sp., Flavobacterium sp., Micrococcus sp. and Bacillus sp. genera. The greatest number of Halotolerant bacteria isolated from the lake water was Pseudomonas (mean: 72%). Furthermore, the number of total coliforms was greater than the number of fecal coliforms. Statistical analysis revealed that Halophilic and Halotolerant colonies had the same mean numbers only at Tashk and Gomban sampling sites but that the mean numbers obtained at Dehzir sampling site was significantly different from those obtained at the former two. It was also found that increasing salt concentration and pH level increased the number of halophilic colonies while increased levels of dissolved oxygen decreased their numbers. Salt concentration, pH level, and DO level had similar effects on the number of total and fecal coliform colonies

Isolation and identification of PHA producing bacteria from oil contaminanted soils in Masjed Soleiman and optimization of producing conditions

Introduction: Polyhydroxyalkanoate (PHA) is counted biodegradable polymer, produced by bacteria, which is employed instead of petrochemical plastics, to reduce environment pollution. The purpose of this study is the isolation and identification of the PHA producing bacteria in Masjed-Soleiman oil fields, determination of PHA produced by the bacteria, determine the optimal conditions of temperature, pH, concentration and type of carbon and nitrogen sources on the level of PHA synthesis and the use of waste oil as a cheap substrate of carbon for the synthesis of PHA by isolated bacteria. Materials and methods: At first 9 samples of soil contaminated with crude oil, from 9 points at 4 well sites in Masjed-Soleiman oil field were taken. The initial screening was done by MSM at the temperature of 28 °C. Isolates from the view point of producing PHA, were confirmed, by using Sudan black stain and were identified by using phenotypical tests and 16S rRNA sequence determination. Also, optimization of temperature, pH, carbon and nitrogen sources were made for bacteria growth. Results: In this study eleven isolates were identified as PHA producers and among them the highest range belongs to MIS-1 strain by the range of 58.522 percent of the cellular dry waight, wich produces the maximum PHA. This isolate is recognized as the species of pseudomonas aeroginosa according to the phenotypic tests and sequence analysis of 16S rRNA with 95 % similarity. In addition, the results of optimization tests showed that, the isolates in the temperature of 37 °C, pH7, glucose as the source of carbon and ammonium sulphate as the source of nitrogen and finally, concentration of 10 g/lit of the carbon source and 0.5 g/lit of nitrogen source, the highest range of PHA was synthesized. Discussion and conclusion: The results of this research show that the soil polluted with crude oil of Masjed- Soleiman oil field, in long term and also due to high rate of carbon, provides a suitable environment for screening of beneficial bacteria such as PHA producing bacteria