Genome sequence and probiotic potential of newly isolated Enterococcus durans strain MN187066.

Enterococci are commensals of the human intestinal tract. Their use as probiotics is supported by their ability to confer several health benefits and eliminate foodborne pathogens but is controversial due to the presence of virulence and antibiotic resistance traits. To use them as probiotics requires thorough research to establish their safety. Here, we sequenced the whole genome of a newly isolated Enterococcus durans MN187066 and used a suite of bioinformatics tools to analyze its beneficial probiotic traits as well as antimicrobial resistance and virulence genes. The whole genome had a length of 2 978 152 bp, and an average G + C content of 37.88%. The bopABCD genes involved in biofilm formation were annotated in the genome. However, further analysis showed that these genes are mostly helpful in strengthening their colonization and establishment in the gastrointestinal tract. Also, we identified secondary metabolite gene clusters and the bacteriocins Enterolysin A and Enterocin P. We also identified repUS15 and rep1 replicons and genes that were associated with antimicrobial resistance and virulence. Nevertheless, vancomycin resistance genes were not detected. Our results show that the Ent. durans strain MN187066 can be considered a nontoxigenic strain and produces beneficial metabolites that are critical for their success as probiotics.

Optimization of hyaluronic acid production and its cytotoxicity and degradability characteristics.

In the present study, culture conditions of Streptococcus equi was optimized through Box-Behnken experimental design for hyaluronic acid production. About 0.87 gL-1 of hyaluronic acid was produced under the determined conditions and optimal conditions were found as 38.42 °C, 24 hr and 250 rpm. The validity and practicability of this statistical optimization strategy were confirmed relation between predicted and experimental values. The hyaluronic acid obtained under optimal conditions was characterized. The effects of different conditions such as ultraviolet light, temperature and enzymatic degradation on hyaluronic acid produced under optimal conditions were determined. 118 °C for 32 min of autoclaved HA sample included 63.09 µg mL-1 of d-glucuronic acid, which is about two-fold of enzymatic effect. Cytotoxicity of hyaluronic acid on human dermal cells (HUVEC, HaCaT), L929 and THP-1 cells was studied. In vitro effect on pro or anti-inflammatory cytokine release of THP-1 cells was determined. Although it varies depending on the concentration, cytotoxicity of hyaluronic acid is between 5 and 30%. However, it varies depending on the concentration of hyaluronic acid, TNF-α release was not much increased compared to control study. Consequently, purification procedure is necessary to develop and it is worth developing the bacterial hyaluronic acid.

Production of an alkaline protease using Bacillus pumilus D3 without inactivation by SDS, its characterization and purification.

Abstract In this study, protease-producing capacity of Bacillus pumilus D3, isolated from hydrocarbon contaminated soil, was evaluated and optimized. Optimum growing conditions for B. pumilus D3 in terms of protease production were determined as 1% optimum inoculum size, 35 °C temperature, 11 pH and 48 h incubation time, respectively. Stability studies indicated that the mentioned protease was stable within the pH range of 7-10.5 and between 30 °C and 40 °C temperatures. Surprisingly, the activity of the enzyme increased in the presence of SDS with concentration up to 5 mM. The protease was concentrated 1.6-fold with ammonium sulfate precipitation and dialysis. At least six protein bands were obtained from dialysate by electrophoresis. Four clear protein bands with caseinolytic activity were detected by zymography. Dialysate was further purified by anion-exchange chromatography and the caseinolytic active fraction showed a single band between 29 and 36 kDa of reducing conditions.

Dye decolorization of magnetically retrievable formulation of laccase with amine-functionalized microparticles.

Laccase is an important enzyme used in many industries because of its multi-substrate catalyst. New immobilization agents are excellent tools for enhancing the abilities of this enzyme. In this study, immobilization of laccase on silica microparticles with NH2 (S-NH2) surface modification to use in dye removal applications was aimed. The yield of immobilization by this method was found to be 93.93 ± 2.86% under optimum conditions. In addition, this newly created immobilized enzyme was adapted to a decolorization application with 87.56 ± 1.60% efficiency. Silica microparticles with NH2 (S-NH2) surface modification were used for laccase immobilization and this immobilized laccase had quite good potential. Besides, Random Amplified Polymorphic DNA (RAPD) analysis in evaluating the toxicity of the decolorization process was utilized. After amplification with two RAPD primers, decreased toxicity of dye in this study was observed. This study showed that RAPD analysis in toxicity testing could be accepted as an alternative and practical method that this approach will contribute to the literature in terms of providing fast and reliable results. The use of amine-modified surface silica microparticles for laccase immobilization and RAPD for toxicity testing is a crucial aspect of our investigation.

Dechlorination of chlorinated compounds by Trametes versicolor ATCC 200801 crude laccase and quantitative structure-activity relationship of toxicity.

Chlorinated compounds constitute an important class of xenobiotics. Crude laccase was produced using Trametes versicolor ATCC (200801) in potato dextrose broth, with wheat bran as an inducing medium, and its ability to dechlorinate eight compounds was determined. The compounds were 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, heptachlor and pentachlorophenol. A range of parameters for the dechlorination of some compounds was tested, including incubation period, pH, initial substrate concentration, temperature, and enzyme quantity. The oxygen consumption was determined during each dechlorination process, under pre-determined optimum conditions. The changes in chemical structure of the compounds were also determined, by using FTIR analysis, following dechlorination of test chlorophenolics. Strong interactions were found to lead to the reactivity of hydroxyl groups in some cases and chlorine atoms were released from the benzene ring. The changes in compound toxicity were monitored before and after enzymatic treatment, using Microtox. Quantitative structure-activity relationships for the toxicity of the chlorinated compounds were developed. Consequently, the toxic activity of the test compounds was controlled by electrophilic index and electronic properties.

Sequential treatment of olive oil mill wastewater with adsorption and biological and photo-Fenton oxidation.

Olive oil mill wastewater (OMWW), a recalcitrant pollutant, has features including high phenolic content and dark color; thereby, several chemical or physical treatments or biological processes were not able to remediate it. In this study, the treatment efficiencies of three treatments, including adsorption, biological application, and photo-Fenton oxidation were sequentially evaluated for OMWW. Adsorption, biological treatment, and photo-Fenton caused decreasing phenolic contents of 48.69 %, 59.40 %, and 95 %, respectively. However, after three sequential treatments were performed, higher reduction percentages in phenolic (total 99 %) and organic contents (90 %) were observed. Although the studied fungus has not induced significant color reduction, photo-Fenton oxidation was considered to be an attractive solution, especially for color reduction. Besides, toxicity of OMWW treatment was significantly reduced.

Biosorption of acidic textile dyestuffs from aqueous solution by Paecilomyces sp. isolated from acidic mine drainage.

Removal of textile dyestuffs from aqueous solution by biosorption onto a dead fungal biomass isolated from acidic mine drainage in the Çanakkale Region of Turkey was investigated. The fungus was found to be a promising biosorbent and identified as Paecilomyces sp. The optimal conditions for bioremediation were as follows: pH, 2.0; initial dyestuff concentration, 50 mg l(-1) for Reactive Yellow 85 and Reactive Orange 12, and 75 mg l(-1) for Reactive Black 8; biomass dosage, 2 g l(-1) for Reactive Yellow 85, 3 g l(-1) for Reactive Orange 12, 4 g l(-1) for Reactive Black 8; temperature, 25 °C; and agitation rate, 100 rpm. Zeta potential measurements indicated an electrostatic interaction between the binding sites and dye anions. Fourier transform infrared spectroscopy showed that amine, hydroxyl, carbonyl, and amide bonds were involved in the dyestuff biosorption. A toxicity investigation was also carried out before and after the biosorption process. These results showed that the toxicities for the reactive dyestuffs in aqueous solutions after biosorption studies decreased. The Freundlich and Langmuir adsorption models were used for the mathematical description of the biosorption equilibrium, and isotherm constants were evaluated for each dyestuff. Equilibrium data of biosorption of RY85 and RO12 dyestuffs fitted well to both models at the studied concentration and temperature.

Decolorization potential of some reactive dyes with crude laccase and laccase-mediated system.

In this study, decolorization of dyestuffs, such as Reactive Red 198, Rem Blue RR, Dylon Navy 17, Rem Red RR, and Rem Yellow RR was studied using laccase and laccase-mediated system. The laccases are known to have an important potential for remediation of pollutants. Among these dyestuffs, decolorization of Rem Blue RR and Dylon Navy 17 was performed with crude laccase under optimized conditions. Vanillin was selected as laccase mediator after screening six different compounds with Rem Yellow RR, Reactive Red 198, and Rem Red RR as substrates. However, Rem Yellow RR was not decolorized by either laccase or laccase-mediated system. It is observed that the culture supernatant contained high laccase activity after treatment with catalase that was responsible for the decolorization. Besides, culture supernatant with high laccase activity as enzyme source was treated with catalase; in this way, the hypothesis that laccase was the enzyme responsible for decolorization was supported. The Rem Blue RR was decolorized with 64.84% under the optimum conditions and Dylon Navy 17 with 75.43% with crude laccase. However, using the laccase and vanillin, the decolorization of Reactive Red 198 and Rem Red RR was found to be 62% and 68%, respectively. Our study demonstrated that the decolorization abilities of laccase and/or laccase mediator systems were based on the types of mediator, the dye structure, and the standard experimental conditions. Also, the electrochemical behaviors of some samples were studied. The redox potentials of these samples were determined using cyclic voltammetry on glassy carbon electrode in phosphate buffer (pH 6) solution.

New fungal biomasses for cyanide biodegradation.

Cyanide, a hazardous substance, is released into the environment as a result of natural processes of various industrial activities which is a toxic pollutant according to Environmental Protection Agency. In nature, some microorganisms are responsible for the degradation of cyanide, but there is only limited information about the degradation characteristics of Basidiomycetes for cyanide. The aim of the present study is to determine cyanide degradation characteristics in some Basidiomycetes strains including Polyporus arcularius (T 438), Schizophyllum commune (T 701), Clavariadelphus truncatus (T 192), Pleurotus eryngii (M 102), Ganoderma applanatum (M 105), Trametes versicolor (D 22), Cerrena unicolor (D 30), Schizophyllum commune (D 35) and Ganoderma lucidum (D 33). The cyanide degradation activities of P. arcularius S. commune and G. lucidum were found to be more than that of the other fungi examined. The parameters including incubation time, amount of biomass, initial cyanide concentration, temperature, pH and agitation rate were optimized for the selected three potential fungal strains. The maximum cyanide degradation was obtained after 48 h of incubation at 30°C by P. arcularius (T 438). The optimum pH and agitation rate were measured as 10.5 and 150 rev/min, respectively. The amount of biomass was found as 3.0 g for the maximum cyanide biodegradation with an initial cyanide concentration of 100mg/L. In this study, agar was chosen entrapment agent for the immobilization of effective biomass. We suggested that P. arcularius (T 438) could be effective in the treatment of contaminated sites with cyanide due to capability of degrading cyanide.

Enhancement with inducers of lacasse production by some strains and application of enzyme to dechlorination of 2, 4, 5-trichlorophenol

Lacasse is one of the extracellular enzymes excreted from white and brown rot fungi, which is involved in ligninolysis. In the present study, the effects of the addition of lacasse inducers to the medium on enhancement of enzyme production under conditions of submerged fermentation were researched. At first, a culture medium was selected suitable for lacasse production. To increase the production of lacasse using different inducers and to examine the ability of dechlorination, this article focuses on screen lacasse activity of 21 basidiomycetes isolates grown in five culture media. All inducers evaluated influenced lacasse activity positively except for gallic acid, mannitol, and malt extract for studied isolates. Our findings showed that lacasse activity of Trametes versicolor ATCC (200801) when it was induced with wheat bran reached up to 29.08 U ml-1 and was examined the ability of dechlorination of 2, 4, 5-trichlorophenol (2,4,5-TCP). The parameters including pH, initial substrate concentration, amount of enzyme, period of reaction, and temperature were tested for dechlorination process. Correlation between oxygen consumption and dechlorination processes under the determined optimum conditions was analyzed. Toxicity of 2, 4, 5-TCP before and after enzymatic treatment was evaluated by Microtox test. The results demonstrated that toxicity of intermediates formed 2, 4, 5-TCP did not change.