Comparative metagenomics reveals different hydrocarbon degradative abilities from enriched oil-drilling waste.

The oil drilling process generates large volumes of waste with inadequate treatments. Here, oil drilling waste (ODW) microbial communities demonstrate different hydrocarbon degradative abilities when exposed to distinct nutrient enrichments as revealed by comparative metagenomics. The ODW was enriched in Luria Broth (LBE) and Potato Dextrose (PDE) media to examine the structure and functional variations of microbial consortia. Two metagenomes were sequenced on Ion Torrent platform and analyzed using MG-RAST. The STAMP software was used to analyze statistically significant differences amongst different attributes of metagenomes. The microbial diversity presented in the different enrichments was distinct and heterogeneous. The metabolic pathways and enzymes were mainly related to the aerobic hydrocarbons degradation. Moreover, our results showed efficient biodegradation after 15 days of treatment for aliphatic hydrocarbons (C8-C33) and polycyclic aromatic hydrocarbons (PAHs), with a total of about 50.5% and 46.4% for LBE and 44.6% and 37.9% for PDE, respectively. The results obtained suggest the idea that the enzymatic apparatus have the potential to degrade petroleum compounds.

Improved enrichment and isolation of polycyclic aromatic hydrocarbons (PAH)-degrading microorganisms in soil using anthracene as a model PAH.

Lack of attention to soil and microbial characteristics that influence PAHs degradation has been a leading cause of failures in isolation of efficient PAH degraders and bioaugumentation processes with microbial consortia. This study compared the classic method of isolation of PAHs-degraders with a modified method employing a pre-enrichment respirometric analysis. The modified enrichment of PAH degrading microorganisms using in vitro microcosm resulted to reduced enrichment period and more efficient PAH-degrading microbial consortia. Results indicate that natural soils with strong heterotrophic microbial activity determined through pre-enrichment analysis, are better suited for the isolation of efficient PAH degrading microorganisms with significant reduction of the enrichment period.

Alpha-lipoic acid modifies oxidative stress parameters in sickle cell trait subjects and sickle cell patients.

BACKGROUND & AIMS: Oxidative stress plays a crucial role in the sickle cell disease. Alpha-lipoic acid (ALA) is a potent antioxidant that is employed in the treatment of several diseases. The objective of this study was to test the ALA effect in the sickle cell disease (SCD) treatment. METHODS: Sixty subjects were selected and divided into groups according to the hemoglobin profile: AA (normal), AS (SCD trait subject) and SS (SCD patient). Patients were randomized into a placebo-controlled trial and treated with either ALA (200 mg) or vehicle. Blood samples were collected before supplementation and after 3 months of treatment. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities and total antioxidant status (TAS) were evaluated as measure of antioxidant defense. Lipid and protein damages were quantified by malondialdehyde (MDA) and carbonyl assays, respectively. RESULTS: CAT activity significantly increased in the AS group after ALA treatment and GPx activity presented significant decrease in all groups. SOD activity was not different in any group. Data on MDA and carbonyl levels showed significant reduction in the AA group with ALA treatment. TAS decreased in the same group. CONCLUSION: ALA treatment protected AA individuals from oxidative damage to lipids and proteins. In SCD subjects, the dose applied was not effective to prevent the oxidative damage.

Microbial consortium bioaugmentation of a polycyclic aromatic hydrocarbons contaminated soil.

In this study we evaluated the capacity of a defined microbial consortium (five bacteria: Mycobacterium fortuitum, Bacillus cereus, Microbacterium sp., Gordonia polyisoprenivorans, Microbacteriaceae bacterium, Naphthalene-utilizing bacterium; and a fungus identified as Fusarium oxysporum) isolated from a PAHs contaminated landfarm site to degrade and mineralize different concentrations (0, 250, 500 and 1000 mg kg(-1)) of anthracene, phenanthrene and pyrene in soil. PAHs degradation and mineralization was evaluated by gas chromatography and respirometry, respectively. The microbial consortium degraded on average, 99%, 99% and 96% of the different concentrations of anthracene, phenanthrene and pyrene in the soil, in 70 days, respectively. This consortium mineralized 78%, on average, of the different concentrations of the 3 PAHs in soil after 70 days. Contrarily, the autochthonous soil microbial population showed no substantial mineralization of the PAHs. Bacterial and fungal isolates from the consortium, when inoculated separately to the soil, were less effective in anthracene mineralization compared to the consortium. This signifies synergistic promotion of PAHs mineralization by mixtures of the monoculture isolates (the microbial consortium).

Biodegradation of the herbicide glyphosate by filamentous fungi in platform shaker and batch bioreactor.

The biodegradation conducted by microorganisms on herbicide glyphosate (N-phosphonomethylglycine) was investigated. Five strains of filamentous fungi belonging to the Fusarium genre were grown on Czapeck medium without phosphorous and supplemented with the addition of glyphosate. The assays were conducted to determine the ability of use as a phosphorous source, the inhibition caused by presence of herbicide, and the biodegradation in shaker and bioreactor by Fusarium strains. It was observed that the herbicide did not show any negative effect on microrganisms by quantity of the biomass. Among the strains tested, no inhibition was noted by the addition of glyphosate even at a high concentration. All strains studied were able to biodegrade it and use the herbicide as a phosphorous source. The formation of consortium was not better than the strains tested in pure culture. The biodegradation in the bioreactor was better than in the shaker. However, there wasn't any influence on biodegradation rate by changing the amount of oxygen in the system.