Medium chain fatty acids (MCFA) production through anaerobic fermentation using Clostridium kluyveri: Effect of ethanol and acetate

Medium-chain fatty acids (MCFA) are saturated monocarboxylic acids and can be used as antimicrobials, corrosion inhibitors, precursors in biodiesel, and bioplastic production. In the present study, MCFA production was evaluated with acetate and ethanol using the bacteria Clostridium kluyveri. Effects of substrate, electron donor, and methane inhibitor on MCFA production were evaluated. Bacteria successfully converted the ethanol and acetate to butyrate (C4), caproate (C6), and caprylate (C8) by chain elongation process. The highest concentrations of butyrate (4.6 g/l), caproate (3.2 g/l), and caprylate (0.5 g/l) were obtained under methane inhibition conditions than other conditions. The productions of butyrate and caproate were 1.6 and 1.48 times higher under methane inhibition conditions, respectively. Results denoted that the bacteria C. kluyveri can be used for conversion of acetate and ethanol into useful products like butyrate and caproate

Biodegradation of aliphatic and aromatic hydrocarbons using the filamentous fungus Penicillium sp. CHY-2 and characterization of its manganese peroxidase activity

The aim of this work was to study the potential of the non-lignolytic filamentous fungus Penicillium sp. CHY-2, isolated from Antarctic soil, for the biodegradation of eight different aliphatic and aromatic hydrocarbons such as octane, decane, dodecane, ethylbenzene, butylbenzene, naphthalene, acenaphthene, and benzo[a]pyrene. Among all the compounds, CHY-2 showed the highest level of degradation for decane (49.0%), followed by butylbenzene (42.0%) and dodecane (33.0%), and lower levels of degradation for naphthalene (15.0%), acenaphthene (10.0%), octane (8.0%), ethylbenzene (4.0%), and benzo[a]pyrene (2.0%) at 20 °C. The addition of carbon sources such as glucose (5 g L−1) and Tween-80 (5 g L−1) enhanced decane degradation by about 1.8-fold and 1.61-fold respectively at 20 °C. The metabolites produced during the degradation of decane were identified by gas chromatography-mass spectrometry (GC-MS). Furthermore, the enzyme manganese peroxidase (MnP) from CHY-2 was purified. MnP was found to consist of monomers with a molecular mass of 36 kDa. The purified MnP had an optimum pH of 5.0 and temperature of 30 °C. The Km and Vmax values of MnP towards Mn2+ were 1.31 μM and 185.19 μM min−1 respectively. These results indicated that the strain CHY-2 can be used for the degradation of hydrocarbons and could have promising applications in treatment of hydrocarbon contaminated sites

Biodegradation of toxic organic compounds using a newly isolated Bacillus sp. CYR2

The objective of this study was to isolate a new bacterium and investigate its ability for degradation of various toxic organic compounds. Based on 16S rRNA gene sequence and phylogenetic analysis, the isolated strain was identified as Bacillus sp. CYR2. Degradation of various toxic compounds and growth of CYR2 strain were evaluated with 2 and 4% inoculum sizes. All the experiments were conducted for 6 days, flasks were incubated at 30oC under 180 rpm. Among the 2 and 4% inoculum sizes, bacteria showed highest growth and toxic compounds degradation at 4% inoculum size. Especially, compared to 2% inoculum size, growth of the strain CYR2 at 4% inoculum size was increased by 15.1 folds with 4-secondarybutylphenol, 9.1 folds with phenol, and 5.4 folds with 4-tertiary-butylphenol. Strain CYR2 at 4% inoculum size showed highest removal of phenol (84 ± 5%), followed by 4-tertiary-butylphenol (66 ± 3%), 4-secondary-butylphenol (63 ± 5%) and 4-nonylphenol (57 ± 6%). Compared with 2% inoculum size, degradation ability of strain CYR2 with 4% inoculum size was enhanced by 3.45 times with 4-tertiary-octylphenol, and 2.53 times with 4-tertiarybutylphenol. Our results indicated that the newly isolated Bacillus sp. CYR2 can be used for in situ bioremediation of phenol and alkylphenols contaminated water

Strength recovery of concrete exposed to freezing-thawing by self-healing of cementitious materials using synthetic fiber

In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol(PVA) fibers with polar OH-groups, as well as improved self-healing for cracks that are larger than 0.1 mm in width, posing concerns of CO2 gas and Cl-penetration, were observed. Also, CO3 2-reacts with Ca2+ in the concrete crack, resulting in the precipitation of a carbonate compound, CaCO3. Based on this, it is deemed possible for the recovery of effective water tightness and strength recovery through effective freezing-thawing resistance to be made from cracks that are larger than 0.1mm in width. In addition, it was determined that, as for the most suitable self-healing conditions in the inside and surface of the cracks, calcium hydroxide (Ca(OH)2) solution with CO2 micro-bubble was more effective in promoting the self-healing capability than water with CO2 micro-bubble. Copyright © 2017 VBRI Press

Human error control in the collaborative workflow modeling tool based on GEMS model

Business process should support the execution of collaboration process with agility and flexibility through the integration of enterprise inner or outer application and human resources from the collaborative workflow view.Although the dependency of enterprise activities to the automated system has been increasing, human role is as important as ever.In the workflow modelling this human role is emphasized and the structure to control human error by analysing decision-making itself is needed.Also, through the collaboration of activities agile and effective communication should be constructed, eventually by the combination and coordination of activities to the aimed process the product quality should be improved.This paper classifies human errors can be occurred in collaborative workflow by applying GEMS(Generic Error Modelling System) to control them, and suggests human error control method through hybrid based modelling as well.On this base collaborative workflow modeling tool is designed and implemented. Using this modelling methodology it is possible to workflow modeling could be supported considering human characteristics has a tendency of human error to be controlled

Production of poly-3-hydroxybutyrate (P3HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) from synthetic wastewater using Hydrogenophaga palleronii

In the present study, synthetic wastewater (SW) was used for production of poly-3-hydroxybutyrate (P3HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) using the bacteria Hydrogenophaga palleronii. SW at various volatile fatty acids concentrations (5–60 g/l) was evaluated for the growth and biopolymer production using H. palleronii. Substrate degradation was analyzed using total organic carbon (TOC) analyzer and high pressure liquid chromatography (HPLC). H. palleronii showed highest and lowest removal of TOC at 5 g/l (88 ± 4%) and 60 g/l (15 ± 6%) respectively. Among all the concentrations evaluated, bacteria showed highest biopolymer production with 20 g/l (63 ± 5%), followed by 30 g/l (58 ± 3%) and 40 g/l (56 ± 2%). Lowest biopolymer production was observed at 5 g/l concentration (21 ± 3%). Structure, molecular weight, and thermal properties of the produced biopolymer were analyzed. These results denoted that the strain H. palleronii can be used for degradation of high concentration of volatile fatty acids persistent in wastewaters and their subsequent conversion into useable biopolymers

Isolation and characterization of a biosurfactant-producing heavy metal resistant Rahnella sp. RM isolated from chromium-contaminated soil

Objective of the study was to isolate heavy metal resistant bacteria from chromium-contaminated subsurface soil and investigate biosurfactant production and heavy metal bioremediation. Based on 16S rRNA gene sequence and phylogenetic analysis, the isolate was identified as Rahnella sp. RM. The biosurfactant production by heavy metal resistant Rahnella sp. RM was optimized using Box- Behnken design (BBD). The maximum emulsification activity was obtained 66% at 6% soybean meal in pH 7.0 and 33.5°C. The biosurfactant was characterized using Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). The highest metal removal rates using the biosurfactant were found 74.3, 72.5, and 70.1%, respectively, at the 100 mg/L amended flasks at 48 h. This study indicated the biosurfactant from heavy metal resistant Rahnella sp. RM could be used as a potential tool to remediate the metals in contaminated environments

Polyhydroxyalkanoates (PHA) production from synthetic waste using Pseudomonas pseudoflava : PHA synthase enzyme activity analysis from P. pseudoflava and P. palleronii

Synthetic wastewater (SW) at various carbon concentrations (5–60 g/l) were evaluated for polyhydroxyalkanoates (PHA) production using the bacteria Pseudomonas pseudoflava. Bacteria showed highest PHA production with 20 g/l (57 ± 5%), and highest carbon removal at 5 g/l (74 ± 6%) concentrations respectively. Structure, molecular weight, and thermal properties of the produced PHA were evaluated using various analytical techniques. Bacteria produced homo-polymer [poly-3-hydroxybutyrate (P3HB)] when only acetate was used as carbon source; and it produced co-polymer [poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV)] by addition of co-substrate propionate. PHA synthase, the enzyme which produce PHA was extracted from two bacterial strains i.e., P. pseudoflava and P. palleronii and its molecular weight was analysed using SDS-PAGE. Protein concentration, and PHA synthase enzyme activity of P. pseudoflava and P. palleronii was carried out using spectrophotometer. Results denoted that P. pseudoflava can be used for degradation of organic carbon persistent in wastewaters and their subsequent conversion into PHA

Controlling the Magnetic Anisotropy of the van der Waals Ferromagnet Fe3GeTe2 through Hole Doping.

Identifying material parameters affecting properties of ferromagnets is key to optimized materials that are better suited for spintronics. Magnetic anisotropy is of particular importance in van der Waals magnets, since it not only influences magnetic and spin transport properties, but also is essential to stabilizing magnetic order in the two-dimensional limit. Here, we report that hole doping effectively modulates the magnetic anisotropy of a van der Waals ferromagnet and explore the physical origin of this effect. Fe3-xGeTe2 nanoflakes show a significant suppression of the magnetic anisotropy with hole doping. Electronic structure measurements and calculations reveal that the chemical potential shift associated with hole doping is responsible for the reduced magnetic anisotropy by decreasing the energy gain from the spin-orbit induced band splitting. Our findings provide an understanding of the intricate connection between electronic structures and magnetic properties in two-dimensional magnets and propose a method to engineer magnetic properties through doping

Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum

During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics