Molecular Identification of Native Strain of Thraustochytrium 71-1 and Qualitative and Quantitative Determination of Produced Total Oil and its Squalene

Introduction:Squalene is a polyunsaturated hydrocarbon with six double bonds. Squalene has many applications in biofuel, cosmetic, medical and pharmaceutical industries. The common source of Squalene is shark liver oil that its consumption is limited. Thraustochytrium a genus of unicellular marine protist belong to the thraustochytrids family which is capable of producing high Squalene. Materials and methods: In this study, the qualitative and quantitative production of Squalene, oil and biomass was investigated in the native strain of Thraustochytrium 71-1 by TLC and HPLC. Molecular characterization of this strain was analyzed by 18srDNA gene analysis. Results: Results showed that the strain 71-1 belongs to the family of Thraustochytrids and the genus of Thraustochytrium. The results showed that the strain of Thraustochytrium 71-1 produced 4.12 and 1.25 gr/L, biomass and oil, respectively. Also, Squalene was produced as 74.6 mg/L in 4 days of incubation in GYP medium. Discussion and conclusion: In this research, the production of Squalene has been reported in the strain of the thraustochytrium marine for the first time in the Middle East. It is hoped that in future, the production of this substance could be increased by optimizing the culture medium and culture conditions of this strain to produce Squalene

Multifunctional polymeric nanoplatforms for brain diseases diagnosis, therapy and theranostics

The blood–brain barrier (BBB) acts as a barrier to prevent the central nervous system (CNS) from damage by substances that originate from the blood circulation. The BBB limits drug penetration into the brain and is one of the major clinical obstacles to the treatment of CNS diseases. Nanotechnology-based delivery systems have been tested for overcoming this barrier and releasing related drugs into the brain matrix. In this review, nanoparticles (NPs) from simple to developed delivery systems are discussed for the delivery of a drug to the brain. This review particularly focuses on polymeric nanomaterials that have been used for CNS treatment. Polymeric NPs such as polylactide (PLA), poly (D, L-lactide-co-glycolide) (PLGA), poly (ε-caprolactone) (PCL), poly (alkyl cyanoacrylate) (PACA), human serum albumin (HSA), gelatin, and chitosan are discussed in detail

Opium use and risk of mortality from digestive diseases: A prospective cohort study

Objectives:Opium use, particularly in low doses, is a common practice among adults in northeastern Iran. We aimed to investigate the association between opium use and subsequent mortality from disorders of the digestive tract.Methods:We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50,045 adults were enrolled during a 4-year period (2004-2008) and followed annually until December 2012, with a follow-up success rate of 99. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest.Results:In all, 8,487 (17) participants reported opium use, with a mean duration of 12.7 years. During the follow-up period 474 deaths from digestive diseases were reported (387 due to gastrointestinal cancers and 87 due to nonmalignant etiologies). Opium use was associated with an increased risk of death from any digestive disease (adjusted hazard ratio (HR)=1.55, 95 confidence interval (CI)=1.24-1.93). The association was dose dependent, with a HR of 2.21 (1.57-3.31) for the highest quintile of cumulative opium use vs. no use (P trend =0.037). The HRs (95 CI) for the associations between opium use and malignant and nonmalignant causes of digestive mortality were 1.38 (1.07-1.76) and 2.60 (1.57-4.31), respectively. Increased risks were seen both for smoking opium and for ingestion of opium.Conclusions:Long-term opium use, even in low doses, is associated with increased risk of death from both malignant and nonmalignant digestive diseases

Investigation and production of omega 3 oil rich in docosahexaenoic acid by native strain of Aurantiochytrium TA4

 Introduction: Omega 3 fatty acids play an important role in human health. Docosahexaenoic acid is the most important of polyunsaturated fatty acids that is supplied through the consumption of fish oil. Consequently, there is a need for new alternative sources like as single cell oils, because of possibility of heavy metal contamination in fish oil. Materials and methods: In this research, the samples were collected from mangrove forests in the Persian Gulf and Oman Sea. The strains of marine protist were isolated in GYP medium. Oil-producing strains were screened by fluorescence microscopy. Selected strain was identified by sequencing 18s rRNA gene and polyunsaturated fatty acids profile was determined by gas chromatography. Results: More than 20 marine protist strains were isolated. Triacylglycerol granules were detected in strain TA4 by orange fluorescent. Dyad, tetrad, octad cells and zoospore were observed in cell cycle. 18s rRNA gene sequence of this strain (1730 bp) was similar more than 97 % to Aurantiochytrium strain (Accession number: KJ938302). Its oil content is 46 % of CDW. The quantity of DHA, DPA and EPA fatty acids was 105, 46 and 26 mg per liter, respectively. Their contents were 16, 7 and 4 % of the total fatty acids, respectively. Discussion and conclusion: Thraustochytrids strains have a unique ability to produce polyunsaturated fatty acids, especially DHA and can be an alternative to these valuable compounds. These strains can be used for production of omega 3 oils due to their potential for production of DHA.&nbsp

Study of a Mathematical Model of Biocide Effect on a Biofilm Isolated from a Cooling System Using the Microtiter Plate

Bacterial colonization on metal surfaces and their metabolic activities lead to biocorrosion. In fact, any agent removing the biofilm or decreasing its thickness is capable of preventing biocorrosion. Biocides make up one such agent. These agents can control bacterial biofilms, remove these structures, or kill cells within them. The object of this research is to study the thermodynamic model of biocide penetration into the biofilm using the microtiter plate test. First, the biofilm bacteria were isolated to form a mix- bacterial biofilm. The biocide effect on the mix-biofilm was then determined using the microtiter plate test. Results from this test were compared with those from a thermodynamic model and it was revealed that the effects of oxidizing biocides such as sodium hypochlorite and hydrogen peroxide are in good agreement with the results from the model. The results indicated that increased biocide concentration leads to the removal of the biofilm or to the kill-off of the cells within it. However, in the case of non-oxidizing biocides such as sulfathiazol, glutaraldehyde, and alkyl dimethyl ammonium chloride, the efficiency results did not agree well with the results from the thermodynamic model such that increased biocide concentration did not remove the biofilm nor did it kill off the cells within i

Novel strains of Bacillus cereus Wah1 and Enterobacter cloacae Wkh with high potential for production of siderophores

Introduction: Siderophores are relatively low-weight molecules (500 to 1000 Dalton), which are produced by many microorganisms as the chelating ligands of iron under iron deficiency. Plants can absorb the siderophore-iron complex to meet their needs for iron. The aim of this study was isolation and identification of siderophore producing bacteria. Materials and methods: In this study, we used liquid chrome azurol S (CAS) assay for the isolation of siderophore producing plant growth promoting rhizobacteria (PGPRs). Then, different kinds of the produced siderophores by the best strains were determined using overlaid chrome azurol S (O-CAS) assay. Finally, two best siderophores producing strains were identified using the 16S rDNA gene sequencing analysis. Results: The results showed that 69.3 percent of the isolated bacteria could produce siderophores. The lowest and highst levels of siderophores belonged to the strains Cke1 (17.58 percent siderophore unit) and Wah1 (97.76 percent siderophore unit) respectively. Based on the O-CAS assay method, these strains produced catchol and hydroxamat types of siderophores. Two strains Wah1 and Wkh were identified using 16S rDNA gene sequencing analysis as Bacillus cereus and Enterobacter cloacae, respectively. Discussion and conclusion: Wah1 and Wkh produced more siderophores (as siderophore unit) than other strains, which were studied using the same method until now. Therefore, they could be valuable strains to study their potential as biological fertilizers and plant protection against the soil born pathogens

Preparation of protein-loaded PLGA-PVP blend nanoparticles by nanoprecipitation method: entrapment, Initial burst and drug release kinetic studies

Objective(s):Despite of wide range applications of polymeric nanoparticles in protein delivery, there are some problems for the field of protein entrapment, initial burst and controlled release profile.   Materials and Methods: In this study, we investigated the influence of some changes in PLGA nanoparticles formulation to improve the initial and controlled release profile. Selected parameters were: pluronic F127, polysorbate 80 as surfactant, pH of inner aqueous phase, L/G ratio of PLGA polymer, volume of inner aqueous phase and addition of polyvinylpyrrolidone as an excipient. FITC-HSA was used as a model hydrophilic drug. The nanoparticles were prepared by nanoprecipitation.   Results:  Initial release of FITC-HSA from PLGA-tween 80 nanoparticles (opt-4, 61%) was faster than control (PLGA-pluronic) after 2.30 h of incubation. Results showed that decrease in pH of inner aqueous phase to pI of protein can decrease IBR but the release profile of protein is the same as control. Release profile with three phases including a) initial burst b) plateau and c) final release phase was observed when we changed volume of inner aqueous phase and L/G ratio in formulation. Co-entrapment of HSA with PVP and pluronic reduced the IBR and controlled release profile in opt-19. Encapsulation efficiency was more than 97% and nanoparticles size and zeta potentials were mono-modal and -18.99 mV, respectively.   Conclusion:  In this research, we optimized a process for preparation of PLGA-PVP-pluronic nanoparticles of diameter less than 300 nm using nanoprecipitation method. This formulation showed a decreased initial burst and long lasting controlled release profile for FITC-HSA as a model drug for proteins

Tea drinking habits and oesophageal cancer in a high risk area in northern Iran: population based case-control study.

OBJECTIVE: To investigate the association between tea drinking habits in Golestan province, northern Iran, and risk of oesophageal squamous cell carcinoma. DESIGN: Population based case-control study. In addition, patterns of tea drinking and temperature at which tea was drunk were measured among healthy participants in a cohort study. SETTING: Golestan province, northern Iran, an area with a high incidence of oesophageal squamous cell carcinoma. PARTICIPANTS: 300 histologically proved cases of oesophageal squamous cell carcinoma and 571 matched neighbourhood controls in the case-control study and 48 582 participants in the cohort study. MAIN OUTCOME MEASURE: Odds ratio of oesophageal squamous cell carcinoma associated with drinking hot tea. RESULTS: Nearly all (98%) of the cohort participants drank black tea regularly, with a mean volume consumed of over one litre a day. 39.0% of participants drank their tea at temperatures less than 60 degrees C, 38.9% at 60-64 degrees C, and 22.0% at 65 degrees C or higher. A moderate agreement was found between reported tea drinking temperature and actual temperature measurements (weighted kappa 0.49). The results of the case-control study showed that compared with drinking lukewarm or warm tea, drinking hot tea (odds ratio 2.07, 95% confidence interval 1.28 to 3.35) or very hot tea (8.16, 3.93 to 16.9) was associated with an increased risk of oesophageal cancer. Likewise, compared with drinking tea four or more minutes after being poured, drinking tea 2-3 minutes after pouring (2.49, 1.62 to 3.83) or less than two minutes after pouring (5.41, 2.63 to 11.1) was associated with a significantly increased risk. A strong agreement was found between responses to the questions on temperature at which tea was drunk and interval from tea being poured to being drunk (weighted kappa 0.68). CONCLUSION: Drinking hot tea, a habit common in Golestan province, was strongly associated with a higher risk of oesophageal cancer