mohammadali amoozegar

Lake Urmia, after experiencing rapid volume growth over the past few years, almost dried up in the fall of 2023. Consecutive droughts, agricultural water consumption and dam construction on the rivers feeding Lake Urmia play a significant role in reducing its water volume. In this regard, the aim of the present study is to investigate the microbiological changes created as a result of ecological changes in the highly saline lake of Urmia, which is one of the extreme regions inside Iran.

The required samples were obtained from Qalgachi area, which is located near Lake Urmia. In this research, by using the usual methods of culture, purification, biochemical and microbiological tests, four microbial species were identified and classified by PCR.

Among the four microbial species selected in this research, two species (KULC3, KULC4) were salt-loving and the other two (KULC1, KULC5) belonged to different non-salt-loving species, which probably represent changes in the salt-loving microflora of Lake Urmia.

The occurrence of ecological changes in extreme and closed environments such as Lake Urmia, causes the possibility of microbiological changes in line with environmental changes. The results of this research showed that the microorganisms that live as natural flora in a certain area are able to adapt to the new ecological conditions and harmonize with the new environmental conditions.

 Heavy metal pollution has increased worldwide. Bioremediation of toxic heavy metals in saline environments with conventional microbiological treatment processes is not feasible. Therefore, the use of halophilic and halotolerant bacteria need to be considered for the remediation of saline ecosystems. This study aimed to isolate and characterize toxic heavy metal-resistant and halophilic/halotolerant bacteria from the Lut desert.

 After sampling, halophilic/halotolerant bacteria were isolated on Moderate Halophilic media. Morphological and biochemical characterizations of isolates were carried out. Each isolate's heavy metal resistance was identified by an agar dilution method and the Minimum Inhibitory Concentrations (MIC ) of each heavy metal was determined. Then, sixteen strains were randomly selected and subjected to 16S rRNA gene identification.

 The least toxicities were found with selenite and arsenate on 74 selected isolates, while mercury exhibited the highest toxicity. The maximum MIC values of cadmium, copper, and  chromium were the same. Although, the MIC value of zinc was significantly less. The remarkable resistance toward lead, selenite, and arsenate was reported. Phylogenetic analysis revealed that most strains belong to the Bacillaceae family and Bacillus genus. 

Selected halophilic/halotolerant bacteria from the Lut desert had considerable  resistance to heavy metals. Therefore, these strains could be considered for further investigations of the mechanisms involved in heavy metal resistance of halophilic and halotolerant bacteria or for bioremediation of polluted saline environments.

Considering the critical conditions of Lake Urmia, identifying bacteria with the ability to live in extreme environments is valuable in terms of microbial applications and tolerance of the existing biological conditions, and it helps us to better understand the surrounding environment. In this study, the most abundant microbial branch in the soil samples obtained from three different heights of 10, 150 and 250 meters of Qale Kazem Khan Mountain, which is located on the shore of a very salty lake in Urmia, has been investigated.

The soil samples were collected to identify and classify Proteobacteria    subgroups using 16S rRNA sequencing using Next Generation Sequencing (NGS) as well as FLASH genetic software and UCHIME algorithm to identify the obtained sequences.

Altitude change affects the abundance of Alphaproteobacteria and Betaproteobacteria. The abundance percentage of Alphaproteobacteria has a direct relationship with altitude, while the abundance percentage of Betaproteobacteria increased with the decrease in altitude.

in the overview the percentage of Proteobacteria abundance the samples has an inverse relationship with the increase in height, whereas in the separate examination of the microbial groups, a significant relationship between the increase and decrease in abundance and the height of sampling is observed. Also, two unknown and unclassified genera in the  Deltaproteobacteria order were also identified which a very high frequency percentage (18-27%) among the data had related to the three samples.

Nayband Gulf is subjected to oil pollution due to the proximity to Assaluyeh industrial region. Prolonged exposure to contaminants affects the microbial population and shifts the population to the predominance of oil-degrading microbes. In this study, we  investigate the microbial diversity in Nayband Gulf waters and predict the genes involved in aromatic hydrocarbon degradation under aerobic and anaerobic conditions.

Phenol-chloroform method was performed for extracting DNA from the Nayband Gulf water sample. Extracted DNA sequencing was performed by new generation  sequencing technique. Then 16S rRNA gene-based amplicon sequencing was analyzed. Functional genes involved in the degradation of aromatic hydrocarbons under aerobic and anaerobic conditions were predicted from 16S rRNA gene sequences.

Our findings indicate that aromatic hydrocarbons contamination in Nayband Gulf water resulted in the enrichment of Oceanospirillales (24.67%), Cellvibrionales (28.95%), SAR11 clade (20.97%), Rhodobacterales (6.17%), Rhodospirillales (7.12%) and Flavobacteriales (5.50%).  Alphaproteobacteria (26.18%) and Gammaproteobacteria (42.23%) had the highest percentage. According to Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, the genes involved in degradation of naphthalene under anaerobic conditions were most abundant in the sample.

The results of this study showed that long-term exposure to oil pollution and oil spills affects the microbial population. The microbial population of Nayband Gulf region, due to its proximity to the South Pars oil & gas region and the entry of oil pollutants into the water, has caused the domination of petroleum hydrocarbons degrading bacteria.

Halophilic microorganisms have the potential to produce new biomolecules, including anti-cancer compounds, for medical applications. The purpose of this study was to evaluate the anti-cancer properties of pigments extracted from native Iranian halophilic Archaeon.

Pigment extract of Haloarcula sp. previously isolated and identified from Aran-Bidgol Lake was extracted. The effect of the extracted pigment on MDA-MB-468 breast cancer cell line was tested by MTT method and PI and FITC staining. Cells with different concentrations of pigment extract were incubated for 24, 48 and 72 hours. Finally, the expression of apoptotic genes, including BAX, CASP3, CASP7, CASP9, P21, P53, and SOX2, was examined by Real-Time PCR. Statistical analyses of the data were performed using the t-test and Repeated-Measures ANOVA.

Compared to untreated cells, the pigment extract inhibited the viability of MDA-MB-468 cells significantly after 48 hours at a concentration of 45.95 μg/ml (p*<0.05). In addition, the total population of early and late apoptotic cells (44.4%) increased in the studied cell line, which was associated with a
significant enhancement of the expression of the P53, BAX, CASP7, and CASP9 genes.

Halophilic archaea can be considered a suitable source of natural pigments with anti-cancer activity and potential benefits in chemotherapy.

Streptomyces is one of the most important prokaryotic microorganisms, and their secondary metabolites have high antimicrobial and cytotoxic properties. Three-quarters of the antibiotics known to be produced by these bacteria. As a result, finding new effective compounds from these microorganisms can be a way to treat cancer. The aim of this study was to isolate and screen halophilic or halotolent Streptomycetes from Garmsar salt cave soil that have the ability to produce metabolites with cytotoxic properties against human breast cancer cell line (MCF-7, IBRC C10082).

Isolation of Streptomyces from soil sample was done by serial dilution method and cultured on casein agar with 15% Nacl. The isolates were identified by microscopic and macroscopic examinations and the presence of diaminopalimic acid (DAP) in their cell wall. The cytotoxic effect was evaluated using MTT assay and 16SrRNA sequencing was performed to select selected streptomycetes.

Secondary metabolites of 2 Streptomyces showed a 50% reduction in the concentration of human breast cancer cells. Streptomyces sp.2 was 100% similar to Streptomyces koyangensis and Streptomyces sp.25 was 95.4% similar to Streptomyces tunisiensis.

The results of this study showed that Streptomyces sp.2 and Streptomyces sp.25 secondary metabolites had cytotoxic effect against MCF-7 human breast cancer cell line. The metabolite produced by them can be an option for further studies and provide more effective treatment with fewer side effects in the treatment of this disease.

Application of oxygen releasing compounds (ORCs) is considered as a novel method in petroleum hydrocarbon remediation from groundwater. ORCs destroy chemically the contaminant by exposure to water which results in hydroxyl radical generation or biologically remove the pollution by biostimulation of the groundwater native microorganisms aerobically. In the present study, calcium peroxide (CaO2) nanoparticles were applied to supply the required oxygen for growth and activity of the native microorganisms to consume naphthalene (20 ppm) as a carbon source. Additionally, the effect of CaO2 content, temperature and pH on the performance of nanoparticles were investigated in the naphthalene removal. The results indicated that the microbial population was sharply increased in the presence of 400 mg/L of nanoparticles and at 30oC and the contaminant was completely removed after 20 days at neutral pH. Furthermore, naphthalene was 100% remediated from groundwater at pH 3, 7.4 and 12 after 2, 20 and 30 days, respectively. This proved the acceleration of chemical oxidation under the acidic condition. At 15 and 30 ± 0.5 oC the contaminant was removed from the media within 15 and 20 days respectively. Meanwhile, only 75% of contaminant was remediated from groundwater within 30 days at 4 ±0.5oC which was due to the reduction in the biological activity and the chemical reaction rate.

With the increased usage of nitrate fertilizers, the removal of their stable ionic and water-soluble end products is a challenge for human health. Several physicochemical methods have been examined for nitrate removal of water, but biological treatments are mostly preferred due to a higher efficiency and lower cost. To remove nitrogen from water, we investigated the potential of nitrate-reducing halophilic and halotolerant bacteria. A total of 50 strains from different saline and hypersaline environments of Iran, including the Incheboron wetland, Aran-Bidgol salt-lake, and Urmia endorheic salt-lake, were screened for nitrate reductase production. Among investigated bacteria, 60% and 19% of strains obtained from Urmia lake, and Incheboron wetland produced nitrate reductases, respectively. The nitrate reductase coding genes narG, and napA were analyzed in all strains with confirmed nitrate-reducing capacity. The napA gene was successfully amplified from a gram-negative halophilic strain, and the narG gene was detected in ten halophilic strains. Among nitrate-reducing isolates with the narG gene expression, the Kocuria rosea strain R3A34 showed the highest nitrate reductase production level. This strain was selected to optimize for its denitrifying activity. Results showed that 32°C, pH 7.0, NaCl 8% (w/v), and mannitol (as a carbon source) provide the optimal environmental conditions for the efficient production of nitrate reductase by the Kocuria rosea strain R3A34. As these are compatible with wastewaters conditions, this bacterium can be a proper candidate for bioremediation of wastewaters from nitrate pollutants.

Background & Aims:

 of the Study: Selenium is an essential nutritional material used for the important functions of the human body. The issue of the production of selenium nanoparticles (SeNPs) was investigated in various fields, such as anticancer, antioxidant, and antibacterial activities.

In order to study antibacterial activity, the nutrient broth medium containing synthesized SeNPs in six different concentrations (i.e., 100, 50, 25, and 12.5 µM) was evaluated on six pathogenic bacteria. Then, the growth curves were drawn as an antibacterial assay in six pathogenic bacteria. In addition, the antioxidant effect was examined by the 2, 2-Diphenyl-1-picrylhydrazyl method. The stock solution of SeNPs was mixed with culture media in six different concentrations (i.e., 0.001, 0.01, 0.1, 1, 10, and 100 μM) and exposed on MCF-7 and HT-29 cell lines; therefore, the anticancer effects of SeNPs were assayed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.

According to the obtained results, the most and least significant antibacterial effects of synthesized SeNPs were observed for Staphylococcus aureus (98%) and Klebsiella pneumonia (51.55%), respectively. The highest concentration of biosynthesized SeNPs can achieve a better outcome regarding the antioxidant activity. The growth of MCF-7 and HT-29 cancer cell lines were inhibited by synthesized SeNPs in a concentration of 100 µM

Consequently, the results of the present study showed that SeNPs synthesized from indigenous halophilic bacteria could display anticancer, antioxidant, and antibacterial activities. This progress can assist in the treatment of different diseases.

Azo dyes are the most widely used synthetic colorants in the textile, food, pharmaceutical, cosmetic, and other industries, accounting for nearly 70% of all dyestuffs consumed. Recently, much research attention has been paid to efficient monitoring of these hazardous chemicals and their related metabolites because of their potentially harmful effect on environmental issues. In contrast to the complex and expensive instrumental procedures, the detection system based on the quantum dots (QDs) with the superior optochemical properties provides a new era in the pollution sensing and prevention.

We have developed a QD-enzyme hybrid system to probe methyl red (MR) in aqueous solutions using a fluorescence quenching procedure.

The azoreductase enzyme catalyzed the reduction of azo group in MR, which can efficiently decrease the Förster resonance energy transfer between the QDs and MR molecules. The correlation between the QDs photoluminescence recovery and MR enzymatic decolorization at the neutral phosphate buffer permitted the creation of a fluorescence quenching-based sensor. The synthesized biosensor can be used for the accurate detection of MR in a linear calibration over MR concentrations of 5-84 μM, with the limit of detection of 0.5 μM in response time of three minutes.

Our findings revealed that this fluorometric sensor has the potential to be successfully applied for monitoring a wide linear range of MR concentration with the relative standard deviation of 4% rather than the other method.

Survey of bacterial community structure in hypersaline ecosystems and identification of novel halophilic species can be very important from biotechnological and ecological aspects. In this study, we survey bacterial community structure in sediments from saline wetland in south of Halghe Dare hills as one of the hypersaline ecosystems in Alborz province.

This cross-sectional study was performed by sampling from saline wetland in south of Halghe Dare hills in June 2018. Isolation of heterotrophic bacteria was conducted using R2A agar medium. After differentiation of isolates based on morphological and biochemical characteristics, identification and phylogenetic relationships analysis of selected isolates were performed by 16S rRNA gene sequencing and analysis using NCBI databases and bioinformatics softwares. The Illumina next-generation sequencing was also applied to survey bacterial diversity by cultivation-independent method.

Isolates included 13 species belonging to 8 genera including Bacillus (31.25%), Halomonas 25%, Gracilibacillus (12.50%), Virgibacillus (6.25%), Streptomyces (6.25%), Nitratireductor (6.25%), staphylococcus (6.25%) and Planococcus (6.25%). Illumina sequencing showed that Aneurinibacillus migulanus and Paenibacillus polymyxa were dominant species insoil sample.

The results showed that the microbial population of the studied wetland is similar to the community of the wetlands reported in other parts of the world and dominated by halotolerant and halophilic species. Presence of various bacterial species and some probable novel taxonomic groups in saline wetland in south of Halghe Dare hills presents a new genetic and microbial source for future studies.

Nowadays plant endophytic bacteria have found diverse and useful applications in biotechnology; therefore, much attention has been paid to the isolation, identification, and evaluation of these microorganisms. Since the sterilizing plant tissue surfaces from epiphytic bacteria is difficulty, the efficacy of three different screening methods for endophytic bacteria including 1- HClO sterilization, 2- Periodic sterilization (modified tyndallization) and 3- Triton X100 and HClO sterilization, was evaluated in this study. The modified Tyndallization is an innovative method used in this study to appropriately remove the internal spores of epiphytic bacteria, considered to be an obstacle to the isolation of endophytes. Most of the endophytic bacteria were isolated from dicotyledons and leaves. Endophytic bacteria were also studied for the production of different hydrolase enzymes, whereas the protease enzyme was produced in a wide range of endophytic bacteria in greater quantities than other enzymes. The EndoA strain was molecularly identified and found to be 100% similar to Bacillus halotolerans.

Aquatic saline ecosystems are suitable environments for isolation of microorganisms with high diversity and widely used biotechnology features. The pectinase enzyme is one of the most important commercial enzymes with high potential in food and pharmaceutical industries. Therefore, the discovery of microorganisms with new characteristics has always been a focus of research. As such, a pectinase producing actinomycete Streptomyces coelicoflavus GIAL86 was isolated from Meyghan Salt Lake of Arak located in Markazi Province of Iran. This strain was screened among 35 isolates of halotolerant actinomycetes with the highest production of pectinase enzymes. It was also found that production of pectate lyase, pectin esterase and polygalacturonase increased simultaneously with the logarithmic growth of the strain and its maximum production is at the time of stationary phase beginning. Also, some actinomycete strains with more pectinase activity were identified by molecular identification and their phylogenic relationships were investigated.

Halophilic archaea are known as the novel producers of natural products and their supernatant metabolites could have cytotoxic effects on cancer cells. In the present study, we screened the anticancer potential of supernatant metabolites from eight native haloarchaeal strains obtained from a culture collection in Iran. Five human cancer cell lines including breast, lung, prostate and also human fibroblast cells as the normal control were used in the present study. Moreover, to evaluate the anti-tumor effect of the selected supernatant, inhibition of sphere formation and tumor development was assessed in-vitro and in-vivo, respectively. Among all strains, supernatant metabolites from Halobacterium salinarum IBRC M10715 had the most potent cytotoxic effect on prostate cancer cell lines (IC50 = 0.5 mg/mL) without any effects on normal cells. It significantly increased both early and late apoptosis (about 11% and 9%, respectively) in the androgen-dependent PC3 cell line, reduced sphere formation ability of DU145 and PC3 cells with down-regulation of SOX2 gene expression. Furthermore, our results revealed that tumors developed in nude mice significantly shrank post intratumor injection of metabolites of the haloarchaeal strain. In conclusion, we suggested here for the first time that supernatant metabolites from Halobacterium salinarum IBRC M10715 could be a novel component against prostate cancer in-vitro and in-vivo with remarkable reduction in stem-like properties of tumor.

Pectinase or pectinolytic enzymes are complex enzymes which include pectin methyl esterase (EC.3.1.1.11), pectin lyase (EC.4.2.2.2) and polygalacturonase (EC.3.3.1.15) which degrade pectin in the cell wall of plant cells. These enzymes have many industrial applications that some of them are active in extreme condition regarding to temperature, pH and salt concentration. In this study, the bacteria with an ability to produce pectinase enzyme in salty condition were identified and the corresponding gene was analyzed.
Strains from Urmia, Inche boron and Gomeshan Ponds were inoculated in the media containing pectin precursors. By analyzing the clear zones around the colonies based on I2/KI indicator, the positive strains were selected. Quantification of enzyme activity on all three types of pectinase was carried out by spectrophotometry. In order to molecularly screen the bacterium contained pectinase gene, the bacterium genome was amplified using appropriate primers.
Seventeen positive strains for pectinase (10 from Gomeshan Lake, 6 from Inche Boron Lake and 1 from where Urmia Lake) were identified among 130 studied samples. According to size of clear zone of enzyme activity in the qualitative test, activity level of all three pectinase enzymes in R2S25 strain of Inche Boron Lake was measured and the growth curve was obtained. Molecular study showed that all strains contain desired gene segment.
Discussion and Quantitative evaluation showed that production and activity of pectinase enzyme in R2S25 strain increased simultaneously with increasing the growth of selected strain in logarithmic phase. Molecular study also showed that the genuses of Martelella, Aeromocrobium, Planococcus, Marinobacter, Virgibacillus, Kocuria and Micrococcus contain the pectinase gene

Given the high diversity, biotechnological applications and the effective role of bacteria in making and maintaining the ecosystem balance; biodiversity research are very important. Meanwhile, the halophilic bacteria and archaea have been considered because of their biotechnological importance and specific ecological condition. In this study, we investigated the diversity of heterotrophic bacteria and archaea of Namakdan cave in Qeshm Island.
This cross-sectional study was carried out by sampling from Qeshm Namakdan cave in November 2013. The diversity of the cave heterotrophic aerobic bacteria was analyzed using the culture method. Halophilic and halotolerant bacteria and Archaea under aerobic conditions were isolated by MGM and Marine agar media, respectively. Isolates were separated according to morphological differences, and primary biochemical features. Finally, 16s rRNA sequencing was performed for 32 isolates.
Among 172 isolates 16S rRNA sequencing was carried out for 27 strains. Phylogenetic analysis placed archaea in the euryarchaeota division and Halococcus, Haloferax, Haloarcula, Halogeometricum genus branches and bacteria in Firmicutes and Bacteroides divisions and in Aliifodinibius, Paenibacillus, Aquibacillus, Paraliobacillus, and Bacillus genus branches. Among the sequenced isolates, 11 isolates showed less than 89.7% similarity to the standard species, which is considered as a borderline point to present new microbial species.
Placing the identified isolates in different phylogenetic divisions and genus branches demonstrates the wide microbial diversity of Qeshm Namakdan cave ecosystem. Presenting native microorganisms in new species and genera from unique ecosystems by introducing new genetic content provides access to new native genes and pathways.

Today, discovery and production of new antimicrobial drugs has been emphasized due to the growing of antimicrobial resistance. The purpose of this study was to screen out antimicrobial producing bacteria among halophilic or halotolerant Gram-positive endospore-forming bacteria isolated from different areas of Iran.
62 strains were isolated from salin lakes of Iran, endospore-forming ability was evaluated and further identification of strains was done using 16S rRNA gene sequencing. Screening test was performed using two-layer agar diffusion method in which the indicator strains, Bacillus cereus (ATCC 14579) and Escherichia coli, (PTCC 1330) were inoculated in the seed layer. Finally, the production of antimicrobial active agent during a period of 7 days was studied followed by evaluating the effect of base-layer agar concentration on the dissemination of antibacterial metabolite.
Isolates WT6, R4A19 produced an agent(s) which inhibited the growth of both B.cereuse and E.Coli. The inhibition zone against only E.Coli was observed when R4A20 strain had been cultured in the base layer, while four non-bacillus strains (R4S2, LbS2, RF1 and WT19) could inhibit the growth of B.cereuse. The antibacterial compound production of WT6 against Bacillus cereuse and E.Coli reached to its optimumm leved after 3 and 4 days respectively, while R4A20 produced the active substance, optimally, after 5 days. No significant difference effect on diameter of zone inhibition was observed among various base-layer agar concentrations.
Halophile or halotolerant endospore-forming bacteria isolated from different areas of Iran possess a potential to be considered as interesting microorganisms for further antimicrobial research studies.

Since Babagorgorfountain in the Ghorveh city of Kurdistan province is located in the arsenic belt of Iran, to raise awareness about the quality of drinking water from this fountain the concentration of arsenic and other heavy metals as well as other physicochemical parameters were investigated to protect the public health. In this study, water samples were collected from Babagorgorfountain. Arsenic in the water was measured by field and laboratory methods. Its concentration was estimated to be more than 500 ppb in a field method and 596 ppb in a SDDC method with absorbance measurements at 520 nm. The SDDC method can measure arsenic species separately and the concentration of arsenite and arsenate were found to be 239 and 357 ppb, respectively. Other physiochemicalparameters and heavy metals in the fountain water were evaluated according to standard methods. According to the World Health Organization guidelines the maximum safe level of arsenic in drinking water is 10 ppb. The concentration of arsenic in this fountain’s water is estimated at 60 times the limit and therefore its use is very dangerous for public health.

Organophosphorus pesticides are used extensively in agriculture. Most of them are released into the environment and have harmful effects on the health of ecosystems, wildlife and humans. Due to the increase of the salinity in the agriculture, especially drainage waters and the need for cleaning and reuse of the water due to water shortages, there is an increased demand for new treatment techniques. Bioremediation is the efficient and environmentally friendly way and can be used to remove these contaminants.
Halophilic bacteria that have the ability to use organophosphorus pesticide chlorpyrifos as the sole source of carbon, were isolated through targeted enrichment. Based on the higher growth and tolerance in the presence of the pesticide, one isolate was selected. The ability of the selected strain to degrade chlorpyrifos was examined by gas chromatography-mass spectrometry analysis. The strain was identified by molecular method. To determine the optimal growth conditions, as an indicator of optimal pesticide removal, factors such as temperature, pH, concentration of salt and chlorpyrifos in the presence of pesticide (sole source of carbon) were examined.
The selected isolatenamed CDB5 showed 25.23% removal of chlorpyrifos in the basic conditions without addition of growth factors in 10 days. The molecular identification revealed that this halophilic strain belongs to the genus Halomonas sp. Investigation of the effect of factors in the presence of chlorpyrifos as the sole source of carbon showed that the strain has the highest growth at temperature 35℃, pH7, salt concentration of 10% and the chlorpyrifos concentration of 600 mg/l.
Discussion and Halophilic bacteria due to compatibility with the salty condition, can be a good option for the removal of organophosphorus pesticides in the contaminated salty environments.

Diatoms are a potent source of polyunsaturated fatty acids. This study was conducted for screening a Naviculoid diatom strains from the southern Caspian Sea with analyzing its lipid production and accumulation potentials. The isolate was identified as Navicula salinicola strain IBRC-M 5083 based on micro-morphological characterization and analysis of 18S rRNA genomic region. Navicula salinicola were cultured in the f/2 medium under both normal and prolonged culture (21 days) conditions. Total lipid percentages of this strain were found to be 31.83% under normal condition and 43.72±1.4% in prolonged culture respectively on the basis of their dry cell weight (DCW). Also, the oil droplets were detected in 21 days’ cells as shown by Sudan Black B staining experiments. Furthermore, the main fatty acids were found by Gas Chromatography analyses of this strain under prolonged condition to be Eicosapentaenoic acid (25.58%TFA). Such oil accumulation capabilities seem to be promising for performing further studies on this strain as a source of Omega-3 in aquafeed, pharmaceutical and biofuel industries.

Azo dyes are the biggest group of colors. One of the special characteristic of this group of dye is the presence of double bonds of Nitrogen (N=N). Several studies reported biodecolorization using microorganisms, so far. However, it is for the first time to our knowledge that decolorization by halophilic archaea have been reported.
Among the 15 strains of archaea isolated from Qeshm saline cave and 7 type strains from Iranian biological resource center, 2 strains showed high ability in decolorization of azo dye. Effects of different factors including pH (5-9), temperature (30-50 °C), various salt concentrations (12.5-30%), different concentrations of dye (400-5000 mg/L), different carbon sources and several nitrogen sources and agitation have been measured after 4 days of incubation in static condition. Moreover, the toxicity tolerance of halo archaeal strains to dye, growth and decolorization rates were studied. Statistical significance was assessed by ANOVA Tukey’s multiple comparison test.
Strain A with 99.1 % similarity to Halogeometricum borinquense and strain B with 99.4 % similarity to Haloferax mediterranei were the best decolorizing strains. Both strains had their highest decolorization rate in the presence of NaCl (15-17.5 %), pH 7, microaerophilic condition and yeast extract as nitrogen source. Halogeometricum borinquense showed higher decolorization rate in the presence of saccharose and glucose as carbon sources at 45 oC temperature and for Haloferax mediterranei temperature of 40 oC and propionic acid as carbon source were best decolorizing conditions. These strains were able to decolorize dyes at 1000 mg/L concentration and tolerate dye concentrations to the highest level of 5000 mg/L.
Discussion and In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

Chemolithotrophic bacteria have an important role in the biogeochemical cycle in natural ecosystems. For instance, the oxidative part of the sulfur cycle is handled by sulfur-oxidizing bacteria. Moreover, these bacteria have an important role in various industrial fields including bioleaching. The aim of this study was isolation and identification of chemolithotrophic sulfur-oxidizing bacteria from the Namakdan cave Qeshm, Iran.
In this cross-sectional study, after sampling from the Namakdan cave in Qeshm and transferring the samples (salt, water, and sediment) to the lab, sample inoculation into enrichment media was carried out with three concentrations of NaCl. Following pH and temperature measurement, samples were transferred into solid and two-phase media. Further characterization of the isolates was performed using 16S rRNA gene amplification. Further analysis was performed to characterize the autotrophic or heterotrophic features of the isolates. Biomass was examined using classical turbidity method.
Totally, 39 strains were isolated from samples, based on differences in primary features such as colony form or growth rate. A total of 5 isolates were selected for further studies. Phylogenetic analysis showed that these isolates belong to Halothiobacillus genus.
Due to 30% salinity and neutral pH of this cave, isolation of chemolithotrophic sulfur-oxidizing bacteria was limited to few genera. Chemolithotrophic bacteria have longer growth time in comparison to heterotrophic ones, increasing generation time to 30 days.

Amongst the methods that remove heavy metals from environment, biosorption approaches have received increased attention because of their environmentally friendly and cost-effective feature, as well as their superior performances.
In the present study, we investigated the ability of a surface-engineered Escherichia coli, carrying the cyanobacterial metallothionein on the cell surface, in the removal of Ca (II) from solution under different experimental conditions. The biosorption process was optimized using central composite design. In parallel, the kinetics of metal biosorption was studied, and the rate constants of different kinetic models were calculated.
Cadmium biosorption is followed by the second-order kinetics. Freundlich and Langmuir equations were used to analyze sorption data; characteristic parameters were determined for each adsorption isotherm. The biosorption process was optimized using the central composite design. The optimal cadmium sorption capacity (284.69 nmol/mg biomass) was obtained at 40°C (pH 8) and a biomass dosage of 10 mg. The influence of two elutants, EDTA and CaCl2, was also assessed on metal recovery. Approximately, 68.58% and 56.54% of the adsorbed cadmium were removed by EDTA and CaCl2 during desorption, respectively. The Fourier transform infrared spectrophotometer (FTIR) analysis indicated that carboxyl, amino, phosphoryl, thiol, and hydroxyl are the main chemical groups involved in the cadmium bioadsorption process.
Results from this study implied that chemical adsorption on the heterogeneous surface of E. coli E and optimization of adsorption parameters provides a highly efficient bioadsorbent.

Dischargeing hazardous pollutants of oil and gas industries such as spent caustic into the soil and water is an environmental concern for which biological treatment could offer a solution. To remove high levels of sulfur compounds in spent caustic waste, isolation of chemolithoautotrophic sulfur-oxidizing bacteria from Meighan wetland was considered in this study.
For isolation of chemolithoautotroph haloalkaliphile sulfur-oxidizing bacteria, alkaline sulfur-respiring medium with sodium thiosulfate as the sole electron and energy source and sodium carbonate/bicarbonate as carbon source were utilized. To confirm that the purified isolates are obligated autotroph, their growth on nutrient agar medium was surveyed and selected strains were identified based on 16S rRNA sequence analysis. The growth and activity of selected strain named EMA were optimized at various pHs and salt conditions by assessment of protein content and remained thiosulfate in the culture medium.
Following enrichment, 10 chemolithoautotrophic, haloalkaliphilic sulfur-oxidizing strains were isolated. 16S rRNA sequence analysis, showed that the strains belonged to the genus Thioalkalivibrio. The optimal growth and thiosulfate removal of the selected strain were obtained at pH 10 and 50 g/l of salt (sodium chloride or sodium sulfate). At higher salt concentrations, thiosulfate removal was higher in the presence of sodium sulfate, rather than sodium chloride.
Discussion and high sulfur removal activity of the isolated haloalkaliphilic Thioalkalivibrio strains in extreme conditions with these bacteria could be promising for the biotreatment of spent caustic.

Lipase is one of the most important hydrolytic enzymes widely used in various commercial activities such as food, dairy, pharmaceutical and detergent inducteries. In this experiment, Taguchi method was attempted as a powerful method to optimize the factors affecting enzyme production and to investigate the interactions among these factors and their optimum combination in Salinivibrio sp. SA2. The optimum conditions for pH, temperature, shaker's rpm, olive oil concentration and salt type turned out to be 8, 35 °C, 100 rpm, 2% and sodium chloride 1 M, respectively. Significant factors influencing on the lipase production proved to be pH, agitation and Salt type. The maximum lipase activity in optimum condition and at the 5% significance level (p