Abatement of Inhibitors in Recycled Process Water from Biomass Fermentations Relieves Inhibition of a Saccharomyces cerevisiae Pentose Phosphate Pathway Mutant

Understanding the nature of fermentation inhibition in biomass hydrolysates and recycled fermentation process water is important for conversion of biomass to fuels and chemicals. This study used three mutants disrupted in genes important for tolerance to either oxidative stress, salinity, or osmolarity to ferment biomass hydrolysates in a xylose-fermenting Saccharomyces cerevisiae background. The S. cerevisiaeZWF1 mutant with heightened sensitivity to fermentation inhibitors was unable to ferment corn stover dilute-acid hydrolysate without conditioning of hydrolysate using a fungal strain, Coniochaeta ligniaria, to consume inhibitors. Growth of two other strains, a salt-sensitive HAL4 mutant and a GPD1 mutant sensitive to osmotic stress, was not negatively affected in hydrolysate compared to the parent xylose-metabolizing strain. In recycled fermentation process water, inhibition of the ZWF1 mutant could again be remediated by biological abatement, and no effect on growth was observed for any of the mutants compared to the parent strain.

AKTIVITAS ANTIBAKTERI EKSTRAK PERASAN DAUN MENGKUDU (Morinda citrifolia L.) TERHADAP Escherichia coli SECARA IN VITRO

Noni juice can inhibit the growth of Escherichia coli bacteria. Noni juice extraction needs concentration to extract so that the preparation is more stable in the storage process. The purpose of this study was to determine the antibacterial activity and the amount of the minimum inhibitory concentration of noni juice extract from E. coli bacteria in vitro. This type of experimental research with a completely randomized one-way design. The extract was obtained by concentrating the Noni leaf extract. Extract quality control parameters include organoleptic, yield, drying shrinkage, and qualitative tests of flavonoid and anthraquinone compounds. Antibacterial activity test using the disc diffusion method with an extract concentration of 1.56%; 3.12%; 6.25%; 12.5%; and 25% with 3 replications. Positive control of amoxicillin and negative control of distilled water. Inhibition is known from the zone formed around the paper disc. The data obtained were statistically analyzed using Kruskall Wallis followed by Mann Whitney with a 95% confidence level. The results showed that the variation in the concentration of the noni juice extract had a significant effect (p <0.05). The biggest inhibitory zone was seen at 25% concentration of 10.16 mm and included in the strong category. The minimum inhibitory power was produced at a concentration of 3.12% at 2.50 mm with a weak treatment category.

Spatially-resolved investigation of the water inhibition of methane oxidation over palladium

Pd/Al2O3 catalysts are known to be active for low temperature methane oxidation reactions, however it has been shown that gases normally associated with methane gas streams (H2O, CO2, H2S) can have an inhibitory effect on the total oxidation reaction.

Process water inhibition method for hydraulic testing

Since any hydro-testing is closely related to storage of the tested metal products, the first stage of any hydro-testing is to clean the inner surface of the metal product from either preservative or corrosion products that appeared during storage. Nowadays, we widely use polymers and polymer-based materials for cleaning metals and alloys surfaces of corrosion products. Such agents must satisfy the following requirements: firstly, firmly bind pollution and oxidized forms of metals, preventing surface passivation; secondly, be easily removed from the surface after cleaning; thirdly, components of the cleaning composition should not cause surface oxidation. However, these cleaning methods may not be suitable for hydro-testing due to possible formation of highly toxic waste water, so we often use methods of simultaneous washing with safer soda and citric acid under high pressure, followed by purging with dry air. The paper studies aqueous solutions of N-M-1 corrosion inhibitor mixed with alkali as a corrosion suppressing method in hydraulic tests before commissioning of any product pipelines in order to reduce concentration of a toxic inhibitor in inhibited water. The experiment had two focuses: to assess effectiveness of a new mixture in terms of corrosion inhibition during product pipelines commissioning and to assess toxicity of the mixture using an acid test on two testing objects from two different systematic groups. We proved that, without losing its corrosion inhibition effectiveness in hydro-testing, the mixture can be safely dumped in sewer systems, being preliminarily acidified to acceptable pH values, thanks to lowered N-M-1 concentration. Apart from that, we identified a synergistic effect of N-M-1 corrosion inhibitor acting with NaOH alkali.

KINETIC MODELING OF SERIES REACTION CH4-CH3OH-DME WITH CuO-ZnO/gamma-Al2O3 CATALYST

A kinetic model was proposed for the synthesis of methane to be dimethyl ether (DME) in one reaction step from (CH4 + O2) and (CH3OH) to dimethyl ether using kinetic CuO-ZnO /gAl2O3 catalyst parameters. The bifunctional catalyst of the series kinetic reaction model according to the experimental results obtained under isothermal conditions in a pipe flow reactor under various operating conditions: 225-325 ° C; 10 bar gauge; Residence time, 16-57.0 (g Catalyst) hour (mole CH4) -1. An important step for modeling is the synthesis of methanol from (CH4 + O2) and the synthesis of (CH3OH to DME) is methanol dehydration (very fast), and water-shifting and CO2 (equilibrium) reactions. The effects of water inhibition and CO2 were also taken into account in the synthesis of methanol and the formation of hydrocarbons. The dehydration advantage of methanol can achieve higher yields above 60 % methanol that was converted to DME and the remaining 5% methanol if (CH4 + O2) comes in at 10 bar gauge and 375 ° C. At higher temperatures produces CO2 and H2O. Methane-methanol-DME series reaction model follows single-order gas phase reaction to methane and methanol with k1 = 0.195 minutes-1 and k2 = 0.115 minutes-1 The time and maximum concentration occurs in the formation of methanol constituents 9.5 minutes and 0.44 mole

Water adsorbancy of high surface area layered double hydroxides (AMO-LDHs)

Water adsorbancy of high surface area layered double hydroxides in different relative humidity was investigated. High water inhibition can be achieved via surface modification of LDHs with stearic acid via acid–base reaction.