Chalerm Ruangviriyachai

A new pyoverdin from Pseudomonas aeruginosa R

Abstract From a Pseudom onas aeruginosa hospital isolate a new pyoverdin was isolated. It is identical with that of Pseudomonas aeruginosa strain R except that in the peptide chain L-Gln is missing.

Optimised separation procedures for the simultaneous assay of three plant hormones in liquid biofertilisers

INTRODUCTION The overuse of petrochemical-based synthetic fertilisers has caused detrimental effects to soil, water supplies, foods and animal health. This, in addition to increased awareness of organic farming, has generated considerable interest in the evaluation of renewable biofertilisers. OBJECTIVE The three objectives of the current research were: (1) to evaluate and optimise a solid phase extraction procedure for extraction of three plant hormones, IAA, GA(3) and ABA from two model biofertilisers produced from coconut shells and pineapple peels; (2) to develop an HPLC analysis procedure for the simultaneous separation and quantification of three plant hormones (IAA, GA(3) and ABA); and (3) to evaluate the changes in three plant hormones levels at four different fermentation time periods and varying number of general bacteria, lactic acid bacteria and yeast. RESULT An optimised procedure for sample preparation, separation and simultaneous analysis of three plant hormones [indole-3-acetic acid (IAA), gibberellic acid (GA(3)) and abscisic acid (ABA)] produced in liquid biofertilisers was developed. This method involves sample cleanup using a Sep-pack OasisMAX cartridge containing mixed-mode anion-exchange and reverse-phase sorbents that provided optimum recovery of 85.6, 91.9 and 94.3%, respectively, for the three hormones, IAA, GA(3), and ABA. Baseline separation of three hormones was achieved using mobile phase consisting of 1% acetic acid and acetonitrile (75:25, v/v) at pH 4.0. The amounts of hormones produced in liquid biofertilisers were influenced by fruit types, fermentation time and total number of general bacteria, lactic acid bacteria and yeasts. The quantities of three plant hormones produced during fermentation correlated well with the total number of microorganisms present in the liquid biofertilisers. CONCLUSION A simple and rapid sample preparation procedure followed by RP-HPLC with UV detection was optimised and developed for simultaneous quantification and identification of three plant hormones namely, IAA, GA(3) and ABA in the liquid biofertilisers. This procedure allows quantification of the three plant hormones in their natural states without any prior derivatisation step. The results presented illustrate that the contents of the three plant hormones depended on the type of fruit wastes, fermentation time and the number of microorganisms found in liquid biofertilisers. This method can be extended to determine the quantity of three hormones in other matrices. This assay procedure will aid in the development of liquid biofertilisers, a valuable alternative fertilisers to promote plant growth. This process will help farmers to reduce production cost and pollution problems.

Improvement of cassava stem hydrolysis by two-stage chemical pretreatment for high yield cellulosic ethanol production

We used sodium chlorite followed by sodium hydroxide as a two-stage pretreatment of cassava stem for removal of lignin and hemicellulose to obtain a substrate with high cellulose content prior to hydrolysis. Response surface methodology was applied to determine the optimum hydrolysis conditions of two-stage pretreated cassava stem. After pretreatment, the cellulose content of cassava stem increased from 42.10% to 86.45%, concomitant with decreases in lignin (87.59%) and hemicellulose (78.18%) content. Acid hydrolysis of two-stage pretreated cassava stem under optimum conditions allowed obtaining a hydrolyzate rich in reducing sugar, with a yields up to 67.37%. Conversely, inhibitors were detected at very low concentrations. The fermentation of the hydrolyzate resulted in an ethanol yield of 22.58 g/100 g substrate corresponding to a theoretical ethanol yield of 84.41%. The results demonstrate that two-stage pretreatment is effective for improving cellulose hydrolyzability, resulting in high fermentable sugar and low fermentation inhibitor concentrations.

Structure proposal for a new pyoverdin from a Thai Pseudomonas putida strain1

From a Thai Pseudomonas putida strain a pyoverdin was isolated whose primary structure was deduced from its mass spectrometric fragmentation pattern. It belongs to the smallest representatives of this group of siderophores comprising only six amino acids.

Effect of agglomerated NiMo HZSM-5 catalyst for the hydrocracking reaction of Jatropha curcas oil

ABSTRACT Catalytic hydrocracking of Jatropha curcas oil over ZSM-5-supported catalyst was carried out to produce biofuels. The agglomerated catalyst was successfully prepared by a simple technique and characterized using several techniques. The hydrocracking reactions were studied in a batch reactor at 400°C under initial H2 atmosphere for 2 h reaction using 1 wt% catalyst loading. The effect of agglomerated catalysts on the yield of liquid fuels and hydrocarbon number distribution was discussed. The results showed that the hydrocarbon distribution largely changed depending on the type of catalyst. The powder catalysts seem selectively to produce hydrocarbon in the diesel range (C12–C22), whereas gasoline (C5–C12) and kerosene (C8–C16) had high formation after agglomerated catalyst was used. For agglomerated NiMo ZSM-5 catalyst, hydrocracking of Jatropha curcas oil produced more hydrocarbons in the gasoline range (about 43.23% in liquid fuels).

A bone-based catalyst for biodiesel production from waste cooking oil

ABSTRACT Biodiesel production via transesterification of waste cooking oil (WCO) with methanol using waste chicken bone-derived catalyst was investigated. The calcium carbonate content in the waste chicken bone was converted to calcium oxide (CaO) at a calcinations temperature of 800°C. The catalysts were prepared by calcination at 300–800°C for 5 h and catalyst characterization was carried out by X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) surface area measurement. CaO was used as catalyst for biodiesel production. The results of the optimization imply that the catalyst concentration of 3.0 wt%, methanol to oil ratio of 3:1, and reaction temperature of 80°C for 3 h provide the maximum values of yield in methyl ester production. Reusability of the catalyst from calcined waste chicken bone was studied for four times, with a good yield.

Synthesis and catalytic performance of bimetallic NiMo- and NiW-ZSM-5/MCM-41 composites for production of liquid biofuels

Abstract This work presents a synthesis of bimetallic NiMo and NiW modified ZSM-5/MCM-41 composites and their heterogeneous catalytic conversion of crude palm oil (CPO) to biofuels. The ZSM-5/MCM-41 composites were synthesized through a self-assembly of cetyltrimethylammonium bromide (CTAB) surfactant with silica-alumina from ZSM-5 zeolite, prepared from natural kaolin by the hydrothermal technique. Subsequently, the synthesized composites were deposited with bimetallic NiMo and NiW by impregnation method. The obtained catalysts presented a micro-mesoporous structure, confirmed by XRD, SEM, TEM, EDX, NH3-TPD, XRF and N2 adsorption-desorption measurements. The results of CPO conversion demonstrate that the catalytic activity of the synthesized catalysts decreases in the series of NiMo-ZSM-5/MCM-41 > NiW-ZSM-5/MCM-41 > Ni-ZSM-5/MCM-41 > Mo-ZSM-5/MCM-41 > W-ZSM-5/MCM-41 > NiMo-ZSM-5 > NiW-ZSM-5 > ZSM-5/MCM-41 > ZSM-5 > MCM-41. It was found that the bimetallic NiMo- and NiW-ZSM-5/MCM-41 catalysts give higher yields of liquid hydrocarbons than other catalysts at a given conversion. Types of hydrocarbon in liquid products, identified by simulated distillation gas chromatography-flame ionization detector (SimDis GC-FID), are gasoline (150–200°C; C5–12), kerosene (250-300°C; C5–20) and diesel (350°C; C7–20). Moreover, the conversion of CPO to biofuel products using the NiMo- and NiW-ZSM-5/MCM-41 catalysts offers no statistically significant difference (P> 0.05) at 95% confidence level, evaluated by SPSS analysis.

Optimization of biodiesel production from waste cooking oil using waste bone as a catalyst

ABSTRACT This work determined the association between several parameters of biodiesel production from waste cooking oil (WCO) using waste bovine bone (WBB) as catalyst to achieve a high conversion to fatty acid methyl ester (%FAME). The effect of three independent variables was used as the optimum condition using response surface methodology (RSM) for maximizing the %FAME. The RSM analysis showed that the ratio of MeOH to oil (mol/mol), catalyst amount (%wt), and time of reaction have the maximum effects on the transform to FAME. Moreover, the coefficient of determination (R2) for regression equations was 99.19%. Probability value (P < 0.05) demonstrated a very good significance for the regression model. The optimal values of variables were MeOH/WCO ratio of 15.49:1 mol/mol, weight of catalyst as 6.42 wt%, and reaction time of 128.67 min. Under the optimum conditions, %FAME reached 97.59%. RSM was confirmed to sufficiently describe the range of the transesterification parameters studied and provide a statistically accurate estimate of the best transform to FAME using WBB as the catalyst.

Enhanced liquid biofuel production from crude palm oil over synthesized NiMoW-ZSM-5/MCM-41 catalyst

ABSTRACT Micro-mesoporous ZSM-5/MCM-41 composites were prepared and then loaded with varied contents of NiMoW by the wet impregnation method. The hydrocracking conversion of crude palm oil to liquid biofuels with the prepared catalysts was carried out in a batch reactor at 400°C for 2 h. ZSM-5/MCM-41 composite exhibited 51.00% conversion with a yield of 9.23% gasoline, 20.60% kerosene, and 21.17% diesel. Upon loading of NiMoW, the catalysts exhibited an improved conversion (≥ 62.60%) and a reduced formation of coke, which resulted from combined properties of ZSM-5 with MCM-41 and the presence of dispersed NiMoW. The contents of impregnated metals also affected the performance of catalysts. Using ANOVA analysis (p < 0.05), we found that 8:8:8 wt.% NiMoW-ZSM-5/MCM-41 catalyst was suitable for the production of biofuels, when considering the efficiency and cost-effectiveness.

Jet fuel production from palm oil by catalytic hydrocracking using a Ni-Mo/HY catalyst

ABSTRACT Catalytic hydrocracking of palm oil over zeolites of HY supporting Ni and Mo (Ni–Mo/HY) catalysts was carried out to produce jet fuels. A Box–Behnken Design (BBD) followed by the Response Surface Methodology (RSM) with 17 runs was used to assess the significance of three factors: reaction temperature (°C), weight of the catalyst (%wt) used, and the reaction time (minute) required to achieve the optimum percentage of jet fuel (%jet fuel). The coefficients of determination (R2) for regression equations were 99.51%. The probability value (p < 0.05) demonstrated a very good significance for the regression model. The optimal values of variables were reaction temperature (418.85°C), the weight of the catalyst (3.16 wt%), and reaction time (119.37 min). Under the optimum conditions, % jet fuel reached 36.60%. The RSM was confirmed to sufficiently describe the range of convert palm oil into jet fuel parameters studied and provide a statistically accurate estimate of the best transform to jet fuel using Ni–Mo/HY as the catalyst. The physicochemical properties of the jet fuel were produced within the ASTM D7566 standard for jet fuel. The results proved that palm oil can be utilized as an alternative energy resource.