Simultaneous bioreduction of tellurite and selenite by Yarrowia lipolytica, Trichosporon cutaneum, and their co-culture along with characterization of biosynthesized Te-Se nanoparticles.

BACKGROUND: Natural and anthropogenic activities, such as weathering of rocks and industrial processes, result in the release of toxic oxyanions such as selenium (Se) and tellurium (Te) into the environment. Due to the high toxicity of these compounds, their removal from the environment is vital. RESULTS: In this study, two yeast strains, Yarrowia lipolytica and Trichosporon cutaneum, were selected as the superior strains for the bioremediation of tellurium and selenium. The reduction analyses showed that exposure to selenite induced more detrimental effects on the strains compared to tellurite. In addition, co-reduction of pollutants displayed almost the same results in selenite reduction and more than ~ 20% higher tellurite reduction in 50 h, which shows that selenite triggered higher tellurite reduction in both strains. The selenite and tellurite kinetics of removal were consistent with the first-order model because of their inhibitory behavior. The result of several characterization experiments, such as FE-SEM (Field emission scanning electron microscopy), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and dispersive X-ray (EDX) on Te-Se nanoparticles (NPs) revealed that the separated Te-Se NPs were needle-like, spherical, and amorphous, consisted of Te-Se NPs ranging from 25 to 171 nm in size, and their surface was covered with different biomolecules. CONCLUSIONS: Remarkably, this work shows, for the first time, the simultaneous bioreduction of tellurite and selenite and the production of Te-Se NPs using yeast strains, indicating their potential in this area, which may be applied to the nanotechnology industry and environmental remediation.

Selenite bioreduction by a consortium of halophilic/halotolerant bacteria and/or yeasts in saline media.

Selenium oxyanions are released into environments by natural and anthropogenic activities and are present in agricultural and glass manufacturing wastewater in several locations worldwide. Excessive amounts of this metalloid have adverse effects on the health of living organisms. Halophilic and halotolerant microorganisms were selected for selenium oxyanions remediation due to presence of significant amount of salt in selenium-containing wastewater. Effects of aeration, carbon sources, competitive electron acceptors, and reductase inhibitors were investigated on SeO32- bio-removal. Additionally, NO3--containing wastewater were exploited to investigate SeO32- remediation in synthetic agricultural effluents. The results showed that the SeO32- removal extent is maximum in aerobic conditions with succinate as a carbon source. SO42- and PO43- do not significantly interfere with SeO32- reduction, while WO42- and TeO32- decrease the SeO32- removal percentage (up to 35 and 37%, respectively). Furthermore, NO3- had an adverse effect on SeO32- biotransformation by our consortia. All consortia reduced SeO32- in synthetic agricultural wastewaters with a 45-53% removal within 120 h. This study suggests that consortia of halophilic/halotolerant bacteria and yeasts could be applied to treat SeO32--contaminated drainage water. In addition, sulphates, and phosphates do not interfere with selenite bioreduction by these consortia, which makes them suitable candidates for the bioremediation of selenium-containing wastewater.

Biodegradation of high molecular weight hydrocarbons under saline condition by halotolerant Bacillus subtilis and its mixed cultures with Pseudomonas species.

Biodegradation of high-molecular-weight petroleum hydrocarbons in saline conditions appears to be complicated and requires further investigation. This study used heavy crude oil to enrich petroleum-degrading bacteria from oil-contaminated saline soils. Strain HG 01, with 100% sequence similarity to Bacillus subtilis, grew at a wide range of salinities and degraded 55.5 and 77.2% of 500 mg/l pyrene and 500 mg/l tetracosane, respectively, at 5% w/v NaCl. Additionally, a mixed-culture of HG 01 with Pseudomonas putida and Pseudomonas aeruginosa, named TMC, increased the yield of pyrene, and tetracosane degradation by about 20%. Replacing minimal medium with treated seawater (C/N/P adjusted to 100/10/1) enabled TMC to degrade more than 99% of pyrene and tetracosane, but TMC had lesser degradation in untreated seawater than in minimal medium. Also, the degradation kinetics of pyrene and tetracosane were fitted to a first-order model. Compared to B. subtilis, TMC increased pyrene and tetracosane's removal rate constant (K1) from 0.063 and 0.110 per day to 0.123 and 0.246 per day. TMC also increased the maximum specific growth rate of B. subtilis, P. putida, and P. aeruginosa, respectively, 45% higher in pyrene, 24.5% in tetracosane, and 123.4% and 95.4% higher in pyrene and tetracosane.

A topical gel of tea tree oil nanoemulsion containing adapalene versus adapalene marketed gel in patients with acne vulgaris: a randomized clinical trial.

Adapalene is used for treatment of acne vulgaris, a common dermatological disease. Nano-based carriers have been developed to improve solubility and bioavailability of adapalene and other acne treatment drugs. In our previous report, tea tree oil nanoemulsion containing adapalene gel (TTO NE + ADA Gel) showed appropriate physical and biological properties such as stability, viscosity, pH, size, morphology and biocompatibility in an animal model. The present study was designed to assess efficacy and safety of the TTO NE + ADA Gel in comparison with 0.1% adapalene marketed gel (ADA Marketed Gel). A total of 100 patients were randomized to receive TTO NE + ADA Gel or ADA Marketed Gel, once daily at night, for 12 weeks. Analysis for efficacy was conducted by acne lesion count (total, inflammatory and non-inflammatory) and acne severity index at weeks 4, 8 and 12 using generalized estimating equation along with the safety assessments in each measurement for assessing dryness, erythema, burning sensation and irritation. Significantly better reduction in total, inflammatory, and non-inflammatory acne lesions were reported for TTO NE + ADA Gel as compared to the ADA Marketed Gel overall and on each measurement occasion (p value < 0.001 for all). Mean acne severity index also reduced with TTO NE + ADA Gel significantly in comparison with ADA Marketed Gel (p value < 0.001). Dryness was the most common adverse effect reported in both groups and it was higher in TTO NE + ADA Gel group. In conclusion, TTO NE + ADA Gel compared to ADA Marketed Gel appears more effective in the treatment of acne vulgaris, with no important change in adverse effects.

Intra tester reliability of sympathetic skin responses in subjects with primary palmar hyperhidrosis.

BACKGROUND: Primary palmar hyperhidrosis (PPH) is a disorder related to sympathetic dysfunction. Iontophoresis can be used to reduce sweating rate. Sympathetic skin response (SSR) is commonly used to evaluate the sympathetic system. However, scarce evidence exists about the reliability of SSR parameters. OBJECTIVE: To assess the relative and absolute reliability of SSR before and after the application of iontophoresis with aluminum chloride hexahydrate (ACH) gel or tap water in subjects with PPH. METHODS: Twenty subjects were randomized to receive either iontophoresis with ACH gel or tap water. Three SSRs (amplitude and latency) with 5 s intervals from both hands in both groups were recorded before and after the application of iontophoresis for 30 min. Reliability of amplitude and latency of the SSR was assessed using intraclass correlation coefficient (ICC) with 95% confidence intervals, standard error of measurement (SEM), and minimal detectable change (MDC). RESULTS: Amplitudes and latencies of SSR showed good to excellent test-retest reliability for ICC in both groups before iontophoresis. Except for right hand latency which was moderate (0.5-0.75). After iontophoresis, the ACH gel group still showed good to excellent agreement for SSR parameters, while the reliability of SSR parameters in the tap water group was reduced. CONCLUSION: Subjects with PPH showed high intra-rater reliability for SSR parameters which was maintained after ACH gel iontophoresis and decreased after tap water iontophoresis. It seems that media used for iontophoresis or the state of media (gel vs liquid) may affect the reliability of SSR. Further research is recommended.

LED Photo-polymerization, a Novel Strategy for Triggered Release Liposomes.

LED light is used for many medical and cosmetic applications such as phototherapy and skin rejuvenation. Such physical methods can be combined with drug therapy, such as LED-responsive drug delivery system, the subject of present investigation. To perform this investigation, a nanoliposome composed of DPPC, DSPE-PEG2000, and DC8,9PC, was prepared as LED-sensitive systems. Calcein was loaded in the liposomes as a fluorescent probe for drug release studies. Different LED wavelengths (blue, green and red) were used for triggering release of calcein from nanoliposome. Indoor daylight, darkness, and sunlight were applied as controls. Results showed that liposomes do not release their cargo in darkness, but they released it in response to indoor daylight, sunlight and LEDs, with the blue light showing the highest effect. Results also showed that release of calcein was sensitive to wavelength. Our results reveal potential of LED-sensitive liposomes for medical and cosmetic applications and that such system can be combined with phototherapy. Such concomitant therapies can increase medical/cosmetic effects and decrease adverse reactions to phototherapy.

Evaluation of heavy petroleum degradation using bacterial-fungal mixed cultures.

The use of potent microbial mixed cultures is a promising method for the bioremediation of recalcitrant compounds. In this study, eight molds, three yeasts, and four bacterial isolates were screened from an aged oil-polluted area. An oil degradation assay with various combinations including Bacterial Mixed Culture (BMC), Fungal Mixed Culture (FMC), Fungal-Bacterial Mixed Culture (TMC), and Sequential Fungal-Bacterial Mixed Culture (SMC) was investigated. The results indicated that the SMC culture had the highest yield of degradation (65.96%) in comparison with the degradation yields of TMC, FMC and BMC, which were 59.04%, 56.64%, and 47.56%, respectively. The degradation of saturates, aromatics, resins, and asphaltenes in the crude oil found using the Iatroscan system were, as follows: 64.21%, and 67.63% for aromatics, 72.90%, and 73.59% for saturates, and 53.88% and 58.25% for resins with respect to the TMC and SMC cultures as the superior mixed cultures. The growth rates of yeasts, molds, and bacteria in the TMC and SMC cultures were compared for further evaluation of the role of each microorganism in the degradation. Our findings support the use of mixed cultures in the bioremediation of recalcitrant petroleum pollution.

Biosurfactant production by Mucor circinelloides on waste frying oil and possible uses in crude oil remediation.

Biosurfactants are biocompatible surface active agents which many microorganisms produce. This study investigated the production of biosurfactants by Mucor circinelloides. The effects of different factors on biosurfactant production, including carbon sources and concentrations, nitrogen sources, and iron (II) concentration, were studied and the optimum condition determined. Finally, the strain's ability to remove the crude oil and its relationship with biosurfactant production was evaluated. The results showed that M. circinelloides could reduce the surface tension of the culture medium to 26.6 mN/m and create a clear zone of 12.9 cm diameter in an oil-spreading test. The maximum surface tension reduction was recorded 3 days after incubation. The optimum condition for biosurfactant production was achieved in the presence of 8% waste frying oil as a carbon source, 2 g/L yeast extract as a nitrogen source, and 0.01 mM FeSO4. M. circinelloides could consume 8% waste frying oil in 5 days of incubation, and 87.6% crude oil in 12 days of incubation. A direct correlation was observed between oil degradation and surface tension reduction in the first 3 days of fungal growth. The results showed that the waste frying oil could be recommended as an inexpensive oily waste substance for biosurfactant production, and M. circinelloides could have the potential to treat waste frying oil. According to the results, the produced crude biosurfactant or fungal strain could be directly used for the mycoremediation of crude oil contamination in oil fields.

Assessing the biodegradation of polycyclic aromatic hydrocarbons and laccase production by new fungus Trematophoma sp. UTMC 5003.

Environmental pollution caused by petroleum compounds has become a global concern. The aim of this study was to evaluate the indigenous fungal isolates in Iran for biodegradation of crude oil pollutants. In order to isolate fungal strains, the soil samples were enriched in minimal salts medium (MSM) with 1% crude oil and then the crude oil degradation was measured by total petroleum hydrocarbon (TPH) assay. The degradation of hydrocarbons compounds was also analysed by FT-IR and HPLC, and the activity of peroxidase enzyme and biosurfactant production were also measured. We isolated 40 fungal strains and selected the isolate G-05 with 70% degradation ability of petroleum hydrocarbons as a premium isolate after 15 days. Residual crude oil analysis with FT-IR spectrophotometry and HPLC showed that G-05 is able to degrade 90 and 100% of aliphatic compounds and some polycyclic aromatic hydrocarbons (PAH), respectively. Evaluation of enzymatic activity showed that this isolate can produce 4 U L-1 of Laccase enzyme for oil removal; it is capable of producing biosurfactant and reducing the surface tension of the medium to 25.95 ± 0.1 m Nm-1. This strain was identified as a member of Trematophoma genus and the obtained results showed that this strain is a highly potent strain in bioremediation of soils contaminated by crude oil.

Synergistic Effect of Sarocladium sp. and Cryptococcus sp. Co-Culture on Crude Oil Biodegradation and Biosurfactant Production.

This study was conducted to evaluate the co-culture ability of two yeast (Sarocladium sp. and Cryptococcus sp.) isolates as compared to their individual cultures in surfactant production and oil degradation. The results showed that individual culture of each strain was capable of producing surfactant, degrading oil, and pyrene; also, a synergistic effect was observed when a co-culture was applied. Oil removal and biomass production were 28 and 35% higher in the co-culture than in individual cultures, respectively. To investigate the synergistic effects of mix culture on oil degradation, the surface tension, emulsification activity (EA), and cell surface hydrophobicity of individual and co-culture were studied. A comparison between the produced biosurfactant and chemical surfactants showed that individual culture of each yeast strain could reduce the surface tension like SDS and about 10% better than Tween 80. The results showed that the microbial consortium could reduce the surface tension more, by 10 and 20%, than SDS and Tween 80, respectively. Both individual cultures of Sarocladium sp. and Cryptococcus sp. showed good emulsification activity (0.329 and 0.412, respectively) when compared with a non-inoculated medium. Emulsification activity measurement for the two yeast mix cultures showed an excellent 33 and 67% increase as compared to the individual culture of Sarocladium sp. and Cryptococcus sp., respectively. The cell surface hydrophobicity of Sarocladium sp. and Cryptococcus sp. increased (38 and 85%) when the cells were treated with pyrene as a hydrophobic substrate for four generations. Finally, a 40% increase for pyrene degradation was measured in a co-culture of the two yeast mix culture. According to the results of the present study, the co-culture system exhibited better performance and this study will enhance the understanding of the synergistic effects of yeast co-culture on oil degradation.

Efficacy of fractional CO2 laser in treatment of atrophic scar of cutaneous leishmaniasis.

Cutaneous leishmaniasis is an endemic disease in Iran. Unfortunately, it can lead to unsightly atrophic scars with limited treatment options. Fractional CO2 laser is accepted for treatment of atrophic acne scars and recently has been used to treat cutaneous leishmaniasis, so we planned to use fractional CO2 laser on leishmaniasis scar. We conducted this study on 60 leishmaniasis scars on the face of 40 patients. The lesions were treated by a fractional CO2 laser with beam size of 120 µm, with energy of 50-90 mJ, and 50-100 spots/cm(2) density with two passes in three monthly sessions. Evaluation was done in the first and second months after the first treatment and 3 and 6 months after the last treatment. Digital photography was performed at each visit. Assessment of improvement rate by patient and physician was rated separately as follows: no improvement (0%), mild (<25%), moderate (25-50%), good (51-75%), and excellent (76-100%). Based on patients' opinion, in the first and second follow-up, 48.3 and 90% of them reported moderate to excellent healing, respectively (p < 0.001). In 3 and 6 months follow-up after the end of the experiment, most of the patients (88.3 and 95%, respectively) reported moderate to excellent healing of scars. Based on two observers' opinion, healing in the first follow-up in most of the patients (65%) was mild to moderate and 33% were reported as having no healing. In the second follow-up, only 5% of the patients were reported with no healing and 60% were reported as having moderate healing (p < 0.001). In 3 and 6 months follow-up, most of the patients (95 and 96.6%) were reported as having moderate to excellent healing (p = <0.001). Our results underlined the high efficacy of fractional CO2 laser for leishmaniasis scar. No significant adverse effects were noted.

Effect of essential oils, hydrating agents, and ethanol on hair removal efficiency of thioglycolates.

BACKGROUND: The required time for hair removal by chemical depilatories has always been a concern and depends on different parameters including permeation into the hair shaft. OBJECTIVES: In an attempt to improve this process, it was decided here to investigate the possibility of decreasing depilation time of thioglycolates, widely used depilatories, using penetration enhancers. METHODS: Urea, sodium dodecyl sulfate, dimethylsulfoxide (DMSO), ethanol (75 and 96%), NaCl, and peppermint and orange oils were used as penetration enhancers, and their effect on depilatory time of thioglycolates, represented as tear resistance time (TRT) of hair shaft under a constant tensile stress, was studied. The effects of temperature and hydration on TRT were also investigated. RESULTS: Results showed that ethanol (75%), DMSO, and peppermint oil (ethanolic solution) were able to significantly reduce TRT up to two times from about 6 to 3.5 min. Other enhancers were not able to change TRT. Results also revealed that increase in temperature from 20 to 37 °C reduces TRT by about 4 times. Hydration in boiling water also reduced TRT significantly about 1.5 times. CONCLUSIONS: Present results show that it is possible to reduce depilation time by penetration enhancers. Such improvement can increase users' compliance and might provide other advantages like decreased skin irritation.

Mechanistic analysis of drug release from theophylline pellets coated by films containing pectin, chitosan and Eudragit RS.

The objective of this study was to obtain detailed information on the mechanism of drug release from mixed-film of pectin-chitosan/Eudragit RS. Pellets (710-840 microm in diameter) containing 60% theophylline and 40% microcrystalline cellulose were prepared by extrusion-spheronization method. Eudragit L100-55 enteric coating capsules included film-coated pellets of theophylline in theoretical coating weight gains of 10, 15, and 20%, with pectin-chitosan complex contents of 5, 10, 15, and 20% for each level of weight gain were prepared and subjected to in vitro drug release. Drug release from this system showed a bimodal release profile characteristic with the drug release enhancement, being triggered (burst release) in the colonic medium. The reason for burst drug release may be due to the enzymatic degradation of pectin via pectinolytic enzymes in the simulated colonic medium. The mechanism of drug release from each formulation was evaluated in the terms of zero-order, first-order, Higuchi and Korsmeyer-Peppas models. It was observed that none of the enteric coating capsules showed any drug release in the simulated gastric medium (phase I). The analysis of release profiles showed that zero-order kinetics was found as the better fitting model for all formulations in the simulated small intestine (phase II) and it could be due to the pectin-chitosan swelling and subsequent formation of aqueous channels. In the colonic medium (phase III), due to degradation of pectin and its leaching from the mixed-film, there was a modification in drug release kinetics from swelling-controlled at phase II to anomalous at phase III. It also was found that both zero-order and Higuchi models contributed in colonic drug release from most of the formulations.