During recent decades the increasing in petrochemical industries around the world has been accompanied with varies products. With regard to high volume of water consumption in this industry, a large amount of wastewater is produced that contain, high ammonium content. Nitrogenous compounds can cause environmental problems including reduction in dissolved oxygen, eutrophication, odor and ammonium toxicity. The aim of this present study was reduction of ammonium in the wastewater of ammonia production unite of Razi petrochemical industry using hetrotrophic nitrification and aerobic denitrification and also achieving bacterial consortium with the most ammonium reduction activity. For this purpose, wastewater sampling was done during two stages and its chemical factors including BOD5, COD, DO, ammonium and nitrate was measured. Following enrichment and bacterial isolation, the potential of each isolate for ammonia and nitrate reduction was evaluated in different concentrations of ammonia. Then these isolates were used in consortium and their activity was assessed with 1, 5 and 10% inoculum with 100 mg/L ammonium concentration. Following determining the optimum inoculum percentage, the activity of consortium was optimized using Box-Benhken method. As a result, the BOD5 and COD from unite 2 was more than the unite 3. Furthermore the ammonium and nitrate unite 2 wastewater was also more than unit 3. From ten bacterial isolate Pseudomonas guguanensis and Pseudomonas entomophilia had the most ammonia and nitrate reduction during 24h with 93.2 and 89.2% activity, respectively with ammonia and nitrate elimination rates as 1.554 mg/h and 3.716 mg/h respectively. The most ammonia reduction by bacterial consortium was achieved at 100 mg/L ammonia in synthetic wastewater at 1% inoculum, with 96.3% yield at 24h and 4.0125 mg/h elimination rate. Following optimization of environmental factors, 10 optimized points was suggested by Design expert v10x (Software). For which pH 9, C/N ratio as 5:1, sodium acetate as carbon source in 31.7 ˚C and 120 rpm were the optimum conditions for ammonia elimination (94.3 mg/L) and nitrate production (7.94 mg/L) and nitrite production (2.9 mg/L). It can be suggested that the isolates of this study can be applied as consortium for simultaneously ammonia reduction from wastewater. Further studies are needed to evaluate the efficiency of bacterial consortium for treatment of wastewater.

One of the main problems in oil industry is contaminants of drilling cuts and heavy metals. Hence this, several researches have been made in order to reduce the environmental damages caused by these wastes and among the different proposed methods, biological methods have been considered more importantly. The aim of this study was isolation and identification of heavy metal resistant bacteria from drilling muds that be able to degrade petroleum hydrocarbons. For this purpose, samples were prepared from four drilling stations in Azadegan oil field (Fath drilling stations, No.26 and 81) and Mansouri oil field (Fath drilling stations, No. 62 and 87). Three samples were harvested from each station and totally 12 samples were prepared. Following samples inoculation in MMSM and then enrichment in Mueller-Hinton broth and Mueller-Hinton agar, bacterial isolation was done.The tolerance of isolates to different concentrations of Ni,Cd,Cu,Hg,Cr,Ba and Zn was assessed. The most resistant isolates were selected and identified based on 16S rRNA sequeneing, Furthermore, the optimum growth condition including temperature,PH,nitrogen source and tolerance to salinity were also investigated.As a result of the study 10 heavy metal resistant bacterial isolates were found that from them. four bacterial isolates were selected .The selected isolates were identified as Halomonas meridiana strain 2, Bacillus safensis strain 3, Staphylocaccuss pasteuri strain 9, Bacillus cereus strain 12. The optimum condition for Halomonas meridiana strain 2 growth was 25ºC, pH 8, urea as nitrogen source and 5% NaCl tolerance. In case of, Bacillus safensis strain 3 best growth was happened at 25ºC, pH 8, urea as nitrogen source and tolerate 10% NaCl. Staphylocaccuss pasteuri strain 9 did not tolerate salinity and showed best growth at 37ºC, pH 7 and urea as nitrogen source. Finally, Bacillus cereus strain 12 was able to growth at 5 % NaCl, 37ºC, pH 8 and ammonium nitrate as nitrogen source. Based on the obtained results in this study it can be concluded that it is possible that through application of these bacterial isolates environmental pollution due to petroleum hydrocarbons and heavy metals, be reduced.

Khouzestan province has approximately 33 % of surface water resources of Iran. Karoon river is the most important river in Iran that provides the water need for drinking and industries of many villages and cities including Ahvaz. Its pollution is one of the most problems. Surveys show that agricultural drainage is one of the main pollution resources for this river. Furthermore, industrial, hospital and municipal wastewaters also pollute this river. As a result of pouring hospital and even house sewages in to this river can enter antibiotics in to water and hence cause antibiotic resistance in bacterial inhabitants of this river. The aim of this study was to assess the seasonal changes of microorganisms in Karoon river.
For this purpose, sampling was done from 5 selected stations at 4 seasons. Following culturing of water samples on nutrient agar, colony count was performed and the isolates were identified based on biochemical and morphological tests. Antibiotic resistance of isolates against 8 common antibiotics (penicillin, cefixime, gentamicin, trimethoprim-sulfamethoxazole, cefalexine, erythromycin, tetracyline and ciprofloxine) was evaluated according to the standards Kirby-Bauer disc diffusion method. Furthermore, the sensitivity of isolates to different concentrations of Hg (0.01 gr/ml , 0.03 gr/ml and 0.05 gr/ml) was investigated. As a result, different bacterial species, mainly from enterobacteriaceae and also Pseudomonas aeruginosa were identified. Some of isolates were resistant to several antibiotics. All of isolates were sensitive to Hg. The worst water quality was found in summer while winter showed the best water quality. The possible reason can be due to reducing water volume, tribes migration and recreational activities in summer season and increasing rain and dilution of pollutants in winter season. Based on the results of this study it can be concluded that the microbial pollution of Karoon river has variation that is depend to the season and geographical station and it is necessary that continuous sampling is performed and pollutions is measured. These in formations can be useful for bacterial infections control and preventing epidemics.
 

One of the main problems in the oil industry is the emulsion breaking or demulsification of undesirable water in oil emulsions which produced in the various stages of extraction, transportation and refining of crude oil. These emulsions cause many problems, most notably cause damages to refinery’s equipment and facilities, reducing the quality and quantity of crude oil and environmental pollution which happen by improper disposal of them into the environment. The chemical demulsification with demulsifiers one of the most widely used method for removing of these emulsions which has some disadvantages such as high toxicity, non-biodegradablity and causing secondary pollution in the environment. After revealing the harmful effects of chemical demulsifiers on the environment searching for eco-friendly demulsifiers has become such a serious challenge in this field. One of the appropriate options for replacement the chemical method of demulsification is the biological demulsification with biodemulsifiers which have advantages such as biocompatibility. The aim of this study was isolation and identification of biodemulsifier-producing bacteria from crude oil contaminated environments and production of biocompatible biodemulsifiers. Ten demulsifying bacterial isolates were isolated from crude oil wastes (sludge and sediment), drain, crude oil and oil contaminated soils of Abadan refinery. After enrichment and screening of these isolates with Mueller- Hinton broth and MMSM medium, respectively they were purified by serial culturing on Muller-Hinton agar. The demulsifying activity of these isolates was evaluated through demulsification test and qualitative methods for demulsification evaluation and according to these tests, 5 best isolates were selected for further analysis. These isolates were identified by sequencing of 16S rRNA gene as Stenotrophomonas maltophilia strain 7 with 97.14±2% demulsification ratio, Delftia tsuruhatensis strain 3 with 95.71±1% demulsification ratio, Pseudomonas stutzeri strain 19 with 92.85±3% demulsification ratio, Alcaligenes aquatilis strain 22 with 85.71±3% demulsification ratio and Alcaligenes faecalis strain 20 with 71.43±1% demulsification ratio. Optimization of the growth conditions of isolates and determination the location of their biodemulsifiers showed that optimized conditions for bacterial growth by Stenotrophomonas maltophilia strain 7 were 35˚C, pH 7 and ammonium nitrate as a nitrogen source and its biodemulsifier is cell-bound; in case of Delftia tsuruhatensis strain 3 were 35˚C, pH 7 and sodium nitrate as a nitrogen source and its biodemulsifier is cell-bound; in case of Pseudomonas stutzeri strain 19 were 35˚C, pH 7 and ammonium nitrate as a nitrogen source and its biodemulsifier is extracellular; in case of Alcaligenes aquatilis strain 22 were 35˚C, pH 7 and ammonium nitrate as a nitrogen source and its biodemulsifier is both extracellular and cell-bound; in case of Alcaligenes faecalis strain 20 were 40˚C, pH 7 and sodium nitrate as a nitrogen source and its biodemulsifier is extracelluar. Using microbial consortium of best 5 isolates for breaking of water in oil emulsion showed that microbial consortium has negative effect on demulsification performance of the isolates. The demulsification ratio that was measured in this state was 35.71±2 which in compared with individual demulsification performances of the isolates is a low performance. Based on these results it can be concluded that these isolates are a good biodemulsifier producers and they have great performance on demulsifying water in oil emulsion so they can be used for industrial water in oil emulsion breaking.

  Hemicelluloses are one of the most abundant natural resources and are becoming of increasing interest and importance due to their potential role as renewable and sustainable energy sources. Xylan is a major component of hemicellulose and is the second most abundant polysaccharide in plant cell walls. Xylan consists of a linear backbone of β-1,4-linked D-xylopyranosyl units, which are substituted with different side chains with ، D-galactose، glucuronic، acetic، ρ-coumaryl and ferulic residues. α-L-Arabinofuranosidase (α-L-Afase ; EC 3.2.1.55) catalyzes the hydrolysis of L-arabinosyl linkages attached to the β-1,4-linked D-xylopyranosyl backbone. Recently, α-L-arabinofuranosidases have received increased attention primarily due to their role in the degradation of lignocelluloses as well as their positive effect on the activity of other enzymes acting on lignocelluloses. α-L-Arabinofuranosidases have potential applications in several biotechnological processes, such as improvement of animal feedstock digestibility, production of bio-ethanol, effective in the treatment of diabetes, paper pulp delignification and juice clarification. The aim of this study was to isolation of arabinofuranosidase producing bacteria from environmental samples. A total of 54 soil samples were prepared. Xylan degrading bacteria were identified by CRX agar (xylan-congo red Medium). Due to enzymatic hydrolysis of xylan-Congo red complex in CRX agar, xylanolitic bacteria formed a clear zone in a red background. 61 clonies were isolated from 54 samples that from these,53 clonies had the ability to degerade xylan. Then AFase- producing clonies were screened using fluorogenic substrate, 4-methylumbelliferyl α-L-arabinofuranoside (αMUA) and by observing fluorescence under UV light. 53 clonies had ability to degerade xylan, from these 9 strains were identified as α-L-Afase producing. Finally, based on the maximum light intensity produced by UV radiation and measuring the enzyme produced using 4-Nitophenyl-α-L-arabinofuranoside, 5 isolates were selected as the best strains. Isolates were identified using biochemical tests and sequencing of the 16S rRNA. Enzyme assay and optimization of enzyme production conditions were conducted using ρ-Nitrophenyl-α-L-arabinofuranoside (ρNPAF). Growth curve of these isolates was obtained in different pH and temperatures. The production of enzyme in optimal condition was also investigated. The selected isolates(H-5، 7-A،6-A, 7-B، S2-10 B) where identified as Brevibacillus , Bacillus sp.، Bacillus subtilis, Bacillus stratosphericus and Bacillus sp. respectivly. Molecular weigth of the produced enzyme by these isolates was approximately 40KD. Bacillus subtilis strain 6-A and Bacillus s.p. strain S2-10 B had maximum growth at 37℃ and pH 7. Brevibacillus s.p. strain H-5, Bacillus s.p. strain 7-A, Bacillus stratosphericus strain 7-B had maximum growth in 30℃. Optimal pH for Brevibacillus s.p. strain H-5, Bacillus s.p strain 7-A and Bacillus stratosphericus strain 7-B where 7, 6 and 8 respectivly. Enzyme activity of the Brevibacillus s.p. strain H-5 was 0.944 U/ml, Bacillus s.p. strain 7-A was 0.953 U/ml, Bacillus subtilis strain 6-A was 0.957 U/ml , Bacillus s.p. strain S2-10 B was 0.948 U/ml and Bacillus stratosphericus strain 7-B was 0.960 U/ml and that among them, Bacillus stratosphericus strain 7-B had maximum enzyme production

Fibrin is the main protein component of a blood clot. But because of pathtophysiologycal disorders, the fibrin hydrolysis is not complete and hence, thrombosis disorders, such as a myocardial infarction and cardiovascular diseases, can occur. Fibrinolysin hydrolyzes fibrin and remove blood clot from blood vessels. Available fibrinolytic druges are expensive and have side effects such as short half-life, allergiy, etc. The aim of this study was identification of fibrinolysin-producing bacteria from different environmental isolate. After initial assay of the blood clot lysis, casein hydrolysis and fibrinolysis on human plasma plate, from total 79 bacterial isolates 44 bacterial had the ability to digest blood clot 37 were positive casein and 33 isolates had halo, one on fibrin hydrolysis From these 33 isolates, five best isolates were selected. Growth curve of these five isolates was obtained in different pH and temperatures. Optimum enzyme production condition was also studied. Activity of produced fibrinolytic enzymes were also studied at different temperature, pH and different protease treatments. These isolates were identified by sequencing of 16S rRNA gene. Finally, five isolates were identified as Alcaligenes sp. strain NK4, Alcaligenes faecalis strain NK7, Alcaligenes faecalis strain NK26, Bacillus mycoides strain NK28 and Bacillus mycoides strain NK30. Optimized conditions for bacterial growth by Alcaligenes faecalis strain NK26 were 43˚C, pH 7; in case of Alcaligenes faecalis strain NK7, 30˚C, pH 6 ; in case of Bacillus mycoides strain NK30, 30˚C, pH 8 ; in case of Alcaligenes sp. strain NK4 30˚C, pH 7 and for Bacillus mycoides strain NK28 were 37˚C, pH6. The best condition for fibrinolytic enzyme stability of faecalis strain NK26 was 60˚C and pH 7, for faecalis strain NK7, 60˚C and pH8. For mycoides strain 30, 60˚C and pH8. For Pseudomonas sp. strain NK4 60˚C, pH 8 and for mycoides strain NK28 were 80˚C, pH8. Finally, based on these results it can be concluded that these isolates are good condition for fibrinolysin production and can be also used for food processing

Discharge of hazardous pollutants of industries to the water is an environmental problem that effective treatment of waste water is necessity. Spent caustic is a waste from Refineries and Petrochemicals plants which is difficult to treat and dispose of due to its noxious properties. Spent caustic has high chemical oxygen demand (COD) and this is not accepted in waste water treatment out fall. There are different ways to handling spent caustic containing bioremediation that is the way to oxidize of organic compounds in waste and consequently to reduce COD
The present research demonstrates potential of the biological treatment of petrochemical spent caustic under aerobic conditions by bacteria. For isolation of indigenous resident bacteria from spent caustic, waste water sample with organic compounds as the only carbon source was inoculated in mineral salts medium at pH 7.5 and incubated in 30 ºC for 48 hours. Two isolated AK1 and AK2 were identified with molecular analysis of the 16S rRNA gene and biochemical characteristics. On the basis of analysis, AK1 is a strain of Pseudomonas benzenivorans and AK2 is a strain of Rhodococcus globerulus. To survey COD reduction of spent caustic waste by those bacteria, their growth conditions was considered by pH, temperature, time and concentration. After treating no bacteria no diluted waste sample under optimum conditions of pH between 7-7.5 and temperature 30 ºC, reduction of COD was observed 52.4 and 52.5 percent in average for AK1 and AK2 respectively. These results can be expressed using indigenous resident bacteria is appropriate choice to remove organic pollutants of petrochemical wastes and prevent environmental hazardous
 

Methicillin Resistant Staphylococcus aureus(MRSA) is a major human pathogen with high mortality. Presence of many virulence factors in this organism helps high pathogenesis ability. Resistance to methicillin in MRSA is due to the acquisition of mecA gene.This gene is located on the mobile genomic island that is named staphylococcal cassette chromosome mec(SCCmec). SCCmec elements are classified into 11 main types of I to XI. panton valentine leukocidin is a leukotoxin that is encoded by pvl gene. PVL is known to cause severe skin ,soft tissue infection and necrotizing pneumonia.The aim of this study was to investigate mecA , pvl genes and SCCmec typing of Staphylococcus aureus strains isolated from clinical samples in Ahvaz Razi teaching hospital

Material and Methods: This cross sectional study was done on 100 Staphylococcus aureus strains collected from clinical samples in Ahvaz Razi hospital during 9 months period (2014-2015). Antimicrobial susceptibility testing were determined by agar disc diffiusion method according to Clinical and Laboratory Standards Institute(CLSI) guideline. Detection of mecA ,pvl genes and determination of SCCmec typing were done using Multiplex-PCR
Results:The rate of mecA and pvl genes was 58% and 4% in order. The majority of MRSA isolates (77.5%) were belonged to wound samples. All MRSA isolates were resistant to cefoxitin and most susceptibility were seen to vancomycin and then chloramphenicol. SCCmec type III was the most prevalent type(22.41%) among MRSA isolates. The other types consist: II(15.51%), V(10.34%), I(8.62%), IVb(6.89%). 5.16 percentage of MRSA isolates had multibands and 31.03% were non typeable.The isolates that have pvl gene were belonged to V and IVb SCCmec type ,therefore they belonged to CA-MRSA

Conclusions: The present finding from this study indicated high prevalence rate of MRSA strains in this zone. We find 5 SCCmec types(I-V) that is shown wide variaty types in this zone.Furthermore high rate of SCCmec type III that reflects a widespread of MRSA strains with multidrugs resistance. This subject can be a serious warning to physician and infection control units in health care systems. For safe use of antibiotics and continuous surviellance of MRSA infections and developing the strategies for control of MRSA strains with multidrug resistance. Regarding to the high frequency of pvl gene in MRSA strains, also to severe and lethal diseases caused by these bacteria, early diagnosis and proper treatment must be considered for the prevention of disease progress
 

Tannins are natural and water-soluble polyphenols that bind proteins and cause to become indigestible. Tannin acyl hydrolase (EC.3.1.1.20) is a key enzyme that hydrolyse ester bonds in hydrolysable tannin. The aim of this study was isolation tannase producing bacteria from environmental resources. For this purpose, samples were collected from wheat farm, peat, cattle and sheep feces, decayed date byproduct, decayed leaves of eucalyptus, rhizospheres of palm, cypress and acacia, tea waste and olive waste. After enrichment and cultivation on screening medium containing tannin and enzyme assay, growth curve of these selected isolates was obtained in different pH and temperatures. The effect of pH, temperature, nitrogen sources and different agricultural substrates were investigated on production of enzyme. Stability of produced tannase was also investigated at different temperature, pH and protease treatments. Enzyme unit was also calculated. Finally these isolates were identified based on biochemical tests and sequencing of 16S rRNA gene. As a result, 43 bacterial isolates with a halo zone around colony were performed that after their cultivation in liquid special medium and evaluating of enzyme activity, 20 isolates had potential of tannase production. From these 20 isolates, three isolates were identified as Klebsiella pneumoniae strain RG, Enterobacter cloacae starin RF and Pseudomonas solanaceanum strain RP. Optimized conditions for tannase production by K. pneumoniae strain RG were 30˚C, pH 5.5, ammonium sulfate and oak grain mill in 48 h incubation. In case of P. solanaceanum strain RP, 37˚C, pH 7, ammonium sulfate and oak grain mill in 48 h incubation were optimum conditions while optimum parameters for E. cloacae starin RF were 37˚C, pH 5.5, Sodium nitrate and peel as substrate in 48 h incubation .Tannase enzyme of K. pneumoniae had the best activity in 30˚C and pH 5.5 with enzyme unit and protein content as 45 U/ml and 0.223 mg/ml, respectively. Tannase obtained from P. solanaceanum strain RP had the best activity at 65˚C and pH 5.5 with enzyme unit and protein content as 35 U/ml and 0.085 mg/ml, respectively. Tannase enzyme of E. cloacae had the best activity at 55˚C and pH 7 and had enzyme unit and protein content as 42.3 U/ml and 0.233 mg/ml, respectively. Finally, based on these results it can be concluded that these isolates are potent tannase producers. These isolates can be good candidates for biological production of tannase and also bioremediation of wastes containing tannin and also tannin removal from animal feed.

With regard to the occurrence of fungal infections and the emergence of resistant species, finding new antifungal compounds seems inevitable. So, various sources are screened for this purpose which bacteria, especially Bacillus species are good candidates for industrial production of antifungal agents. Bacillus spp. are grown quickly and easily cultured to produce different metabolites. The aim of this study was to find Bacillus species from environmental resources with antifungal activity. For this purpose, different samples from wheat and barely farms, cattle and sheep faeces, rhizosphere of palms, acacia and eucalyptus, beekeeping soil, sediment of karoon river, saline soil, olive waste were collected. following heat treatment of samples, Bacillus species were isolated by culturing in nutrient broth and nutrient agar medium. The Isolates were cultured in TSB and anti-fungal and anti-bacterial effects of their supernatants were determined by disc diffusion method against fungal. MIC and MFC indices of the selected strains were obtained against two fungal pathogens. Growth curve of these isolates was obtained in different pH and temperatures. The effect of pH, temperature, carbon and nitrogen sources were investigated on production of antibiotic by these isolates. Stability of produced antibiotics were also studied at different temperature and under protease treatments. These isolates were identified by biochemical tests and sequencing of 16S rRNA gene. As a result of this study, Forty isolates from Bacillus genus were isolated which Twenty of them were effective against Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Penicillium sp., Fusarium sp. and Rhodotorulla sp. Three isolates these from Twenty isolates (SF1، SB15 و SK26) that have significant antifungal effects on a wide range of fungi were selected. which SF1 had equal MIC and MFC. So, this strain can be considered as a fungicide. Finally, two isolates were identified as Bacillus cereus strain SB15 and Bacillus cereus strain SF1 and one isolates was identified as Bacillus toyonensis strain SK26. Optimized conditions for antibiotic production by Bacillus cereus strain SB15 and Bacillus cereus strain SF1 were 37˚C, pH 7 and 48 h incubation and for Bacillus toyonensis strain SK26 were 30˚C, pH 5.5 and 48 h incubation. Antibiotics produced in all three isolates were resistant to proteases. Based on the obtained results it can be concluded these bacillus strains have prope potential of antibiotic production and can be used for industrial or pharmaceutical purposes

 Phosphorus (P), after nitrogen is the major limiting factor in plant growth owing to its low bioavailability in soils. Considerable amounts of phosphorus fertilizers following their application in soil became unavailable for plants due to their complex formation with Ca and Mg in calcerous soils or with Al and Fe in acidic solils. One suitable approach is use of biologic potential of soil and phosphate solubilizing location. These species through secretion of organic and inorganic acids and also phosphatase enzyme cause dissolution of mineral phosphates and also hydrolysis of organic phosphate, in soil. The aim of this study was isolation of phosphate solubilizing bacteria from different fields such as wheat, barely, bean, cabbage, sunflower, clover farms, garlic and brine pool. After an enrichment step and cultivation on screening medium containing tricalcium ¬phosphate as the sole phosphorus source, 100 bacterial isolates with a halozone were obtained from which 27 isolates were selected based on the phosphate solubilization index and efficiency. The amount of release phosphorous in special broth medium was evaluated by ascorbic acid method. Four most potent isolates were selected and growth curve of them was obtained in different pH and temperatures. The effect of pH, temperature, various carbon sources, various nitrogen sources and incubation time were investigated on phosphate solubilization activity of these four isolates. These isolates were identified by biochemical tests and sequencing of 16S rRNA gene. As a resulte these isolates were identified as Raoultella terrigenia, Pseudomonas protegens, Pseudomonas fluorescens and Enterobacter cloacae. Optimized conditions for phosphate solubilization by Raoultella terrigenia were 30˚C, pH 5.5, glucose, yeast extract-(NH4)2SO4 and 5 day incubation; in case of Pseudomonas protegens were 30˚C, pH 5.5, glucose, urea and 3 day incubation; in case of Pseudomonas fluorescens were 30˚C, pH 7, glucose, urea and 5 day incubation and for Enterobacter cloacae were 25˚C, pH 7, glucose, yeast extract-(NH4)2SO4 and 5 day incubation. Finally, based on these results it can be concluded that these isolates are potent phosphate solubilizing agent that can be used as bio-fertilizer and industrial purposes such as extracting phosphorus from phosphate rock.