Publications by authors named "Yoshimitsu Uemura"

17 Publications

  • Page 1 of 1

Valorization of exo-microbial fermented coconut endosperm waste by black soldier fly larvae for simultaneous biodiesel and protein productions.

Environ Res 2020 06 2;185:109458. Epub 2020 Apr 2.

Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (Akuatrop) & Institute of Tropical Biodiversity and Sustainable Development (Bio-D Tropika), Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Terengganu, Malaysia; Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou, 450002, China. Electronic address:

The conventional practice in enhancing the larvae growths is by co-digesting the low-cost organic wastes with palatable feeds for black soldier fly larvae (BSFL). In circumventing the co-digestion practice, this study focused the employment of exo-microbes in a form of bacterial consortium powder to modify coconut endosperm waste (CEW) via fermentation process in enhancing the palatability of BSFL to accumulate more larval lipid and protein. Accordingly, the optimum fermentation condition was attained by inoculating 0.5 wt% of bacterial consortium powder into CEW for 14-21 days. The peaks of BSFL biomass gained and growth rate were initially attained whilst feeding the BSFL with optimum fermented CEW. These were primarily attributed by the lowest energy loss via metabolic cost, i.e., as high as 22% of ingested optimum fermented CEW was effectively bioconverted into BSFL biomass. The harvested BSFL biomass was then found containing about 40 wt% of lipid, yielding 98% of fatty acid methyl esters of biodiesel upon transesterification. Subsequently, the protein content was also analyzed to be 0.32 mg, measured from 20 harvested BSFL with a corrected-chitin of approximately 8%. Moreover, the waste reduction index which represents the BSFL valorization potentiality was recorded at 0.31 g/day 20 BSFL. The benefit of fermenting CEW was lastly unveiled, accentuating the presence of surplus acid-producing bacteria. Thus, it was propounded the carbohydrates in CEW were rapidly hydrolysed during fermentation, releasing substantial organic acids and other nutrients to incite the BSFL assimilation into lipid for biodiesel and protein productions simultaneously.
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http://dx.doi.org/10.1016/j.envres.2020.109458DOI Listing
June 2020

Flocculation of Chlorella vulgaris by shell waste-derived bioflocculants for biodiesel production: Process optimization, characterization and kinetic studies.

Sci Total Environ 2020 Feb 2;702:134995. Epub 2019 Nov 2.

Department of Chemical Process Engineering and Equipment, Faculty of Chemical Engineering, Ho Chi Minh City University of Technology, Ho Chi Minh City (VNU-HCM), 268 Ly Thuong Kiet St., District 10, HCMC, Viet Nam.

Flocculants are foreign particles that aggregate suspended microalgae cells and due to cost factor and toxicity, harvesting of microalgae biomass has shifted towards the use of bioflocculants. In this study, mild acid-extracted bioflocculants from waste chicken's eggshell and clam shell were used to harvest Chlorella vulgaris that was cultivated using chicken compost as nutrient source. It was found that a maximum of 99% flocculation efficiency can be attained at pH medium of 9.8 using 60 mg/L of hydrochloric acid-extracted chicken's eggshell bioflocculant at 50 °C of reaction temperature. On the other hand, 80 mg/L of hydrochloric acid-extracted clam shell bioflocculant was sufficient to recover C. vulgaris biomass at pH 9.8 and optimum temperature of 40 °C. The bioflocculants and bioflocs were characterized using microscopic, zeta potential, XRD, AAS and FT-IR analysis. The result revealed that calcium ions in the bioflocculants are the main contributor towards the flocculation of C. vulgaris, employing charge neutralization and sweeping as possible flocculation mechanisms. The kinetic parameters were best fitted pseudo-second order which resulted in R of 0.99 under optimal flocculation temperature. The results herein, disclosed the applicability of shell waste-derived bioflocculants for up-scaled microalgae harvesting for biodiesel production.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134995DOI Listing
February 2020

Tailoring the surface area and the acid-base properties of ZrO for biodiesel production from Nannochloropsis sp.

Sci Rep 2019 11 7;9(1):16223. Epub 2019 Nov 7.

Centre for Biofuel and Biochemical Research, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak, Malaysia.

Bifunctional heterogeneous catalysts have a great potential to overcome the shortcomings of homogeneous and enzymatic catalysts and simplify the biodiesel production processes using low-grade, high-free-fatty-acid feedstock. In this study, we developed ZrO-based bifunctional heterogeneous catalysts for simultaneous esterification and transesterification of microalgae to biodiesel. To avoid the disadvantage of the low surface area of ZrO, the catalysts were prepared via a surfactant-assisted sol-gel method, followed by hydrothermal treatments. The response surface methodology central composite design was employed to investigate various factors, like the surfactant/Zr molar ratio, pH, aging time, and temperature on the ZrO surface area. The data were statistically analyzed to predict the optimal combination of factors, and further experiments were conducted for verification. BiO was supported on ZrO via the incipient wetness impregnation method. The catalysts were characterized by a variety of techniques, which disclosed that the surfactant-assisted ZrO nanoparticles possess higher surface area, better acid-base properties, and well-formed pore structures than bare ZrO. The highest yield of fatty acid methyl esters (73.21%) was achieved using BiO/ZrO, and the catalytic activity of the developed catalysts was linearly correlated with the total densities of the acidic and basic sites. The mechanism of the simultaneous reactions was also discussed.
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http://dx.doi.org/10.1038/s41598-019-52771-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838316PMC
November 2019

Impact of various microalgal-bacterial populations on municipal wastewater bioremediation and its energy feasibility for lipid-based biofuel production.

J Environ Manage 2019 Nov 13;249:109384. Epub 2019 Aug 13.

Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak Darul Ridzuan, Malaysia; Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak Darul Ridzuan, Malaysia. Electronic address:

The microalgal-bacterial co-cultivation was adopted as an alternative in making microbial-based biofuel production to be more feasible in considering the economic and environmental prospects. Accordingly, the microalgal-bacterial symbiotic relationship was exploited to enhance the microbial biomass yield, while bioremediating the nitrogen-rich municipal wastewater. An optimized inoculation ratio of microalgae and activated sludge (AS:MA) was predetermined and further optimization was performed in terms of different increment ratios to enhance the bioremediation process. The nitrogen removal was found accelerating with the increase of the increment ratios of inoculated AS:MA, though all the increment ratios had recorded a near complete total nitrogen removal (94-95%). In light of treatment efficiency and lipid production, the increment ratio of 0.5 was hailed as the best microbial population size in accounting the total nitrogen removal efficiency of 94.45%, while not compromising the lipid production of 0.241 g/L. Moreover, the cultures in municipal wastewater had attained higher biomass and lipid productions of 1.42 g/L and 0.242 g/L, respectively, as compared with the synthetic wastewater which were only 1.12 g/L (biomass yield) and 0.175 g/L (lipid yield). This was possibly due to the presence of trace elements which had contributed to the increase of biomass yield; thus, higher lipid attainability from the microalgal-bacterial culture. This synergistic microalgal-bacterial approach had been proven to be effective in treating wastewater, while also producing useful biomass for eventual lipid production with comparable net energy ratio (NER) value of 0.27, obtained from the life-cycle analysis (LCA) studies. Thereby, contributing towards long-term sustainability and possible commercialization of microbial-based biofuel production.
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http://dx.doi.org/10.1016/j.jenvman.2019.109384DOI Listing
November 2019

Sustainable green pretreatment approach to biomass-to-energy conversion using natural hydro-low-transition-temperature mixtures.

Bioresour Technol 2018 Aug 12;261:361-369. Epub 2018 Apr 12.

Department of Applied Chemistry and Biochemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.

Natural hydro-low-transition-temperature mixtures (NH-LTTMs) tend to be the most favorable next-generation green solvents for biomass pretreatment, as they are cheap and environmental friendly. The amount of water bound into the NH-LTTMs greatly affected their thermal stability, whereby the highest thermal stability was observed with the water content of 7.6 wt%. It is worth noting that, the highest molar transition energy of NH-LTTMs (47.57 kcal mol), which indicated the highest solubility, was optimized with the molar ratio of hydrogen bond donor (HBD)-hydrogen bond acceptor (HBA)-water (2:4:3) at a temperature of 60 °C. Hydrogen bonding networks of the NH-LTTMs, which led to the dissolution of biomass, were confirmed by the alteration in the peaks of the involved bonds and resonance signal to lower field through FTIR and H NMR spectra, respectively. The components evidenced in high-resolution mass spectra of extracted lignin showed its high potential to be valorized into useful fuels and chemicals.
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http://dx.doi.org/10.1016/j.biortech.2018.04.039DOI Listing
August 2018

Thermogravimetric analysis and kinetic modeling of low-transition-temperature mixtures pretreated oil palm empty fruit bunch for possible maximum yield of pyrolysis oil.

Bioresour Technol 2018 May 31;255:189-197. Epub 2018 Jan 31.

Department of Applied Chemistry and Biochemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.

The impacts of low-transition-temperature mixtures (LTTMs) pretreatment on thermal decomposition and kinetics of empty fruit bunch (EFB) were investigated by thermogravimetric analysis. EFB was pretreated with the LTTMs under different duration of pretreatment which enabled various degrees of alteration to their structure. The TG-DTG curves showed that LTTMs pretreatment on EFB shifted the temperature and rate of decomposition to higher values. The EFB pretreated with sucrose and choline chloride-based LTTMs had attained the highest mass loss of volatile matter (78.69% and 75.71%) after 18 h of pretreatment. For monosodium glutamate-based LTTMs, the 24 h pretreated EFB had achieved the maximum mass loss (76.1%). Based on the Coats-Redfern integral method, the LTTMs pretreatment led to an increase in activation energy of the thermal decomposition of EFB from 80.00 to 82.82-94.80 kJ/mol. The activation energy was mainly affected by the demineralization and alteration in cellulose crystallinity after LTTMs pretreatment.
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http://dx.doi.org/10.1016/j.biortech.2018.01.132DOI Listing
May 2018

Optimization and kinetic study of ultrasonic assisted esterification process from rubber seed oil.

Bioresour Technol 2018 Jan 12;247:51-57. Epub 2017 Sep 12.

Chemical Engineering Department, Biomass Processing Laboratory, Center of Biofuel and Biochemical Research (CBBR), Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610 Seri Iskandar, Perak, Malaysia.

Recently, rubber seed oil (RSO) has been considered as a promising potential oil source for biodiesel production. However, RSO is a non-edible feedstock with a significant high free fatty acid (FFA) content which has an adverse impact on the process of biodiesel production. In this study, ultrasonic-assisted esterification process was conducted as a pre-treatment step to reduce the high FFA content of RSO from 40.14% to 0.75%. Response surface methodology (RSM) using central composite design (CCD) was applied to the design of experiments (DOE) and the optimization of esterification process. The result showed that methanol to oil molar ratio was the most influential factor for FFA reduction whereas the effect of amount of catalyst and the reaction were both insignificant. The kinetic study revealed that the activation energy and the frequency factor of the process are 52.577kJ/mol and 3.53×10min, respectively.
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http://dx.doi.org/10.1016/j.biortech.2017.09.075DOI Listing
January 2018

Choline chloride (ChCl) and monosodium glutamate (MSG)-based green solvents from optimized cactus malic acid for biomass delignification.

Bioresour Technol 2017 Nov 10;244(Pt 1):941-948. Epub 2017 Aug 10.

Department of Applied Chemistry and Biochemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.

This work aimed to develop an efficient microwave-hydrothermal (MH) extraction of malic acid from abundant natural cactus as hydrogen bond donor (HBD) whereby the concentration was optimized using response surface methodology. The ideal process conditions were found to be at a solvent-to-feed ratio of 0.008, 120°C and 20min with 1.0g of oxidant, HO. Next generation environment-friendly solvents, low transition temperature mixtures (LTTMs) were synthesized from cactus malic acid with choline chloride (ChCl) and monosodium glutamate (MSG) as hydrogen bond acceptors (HBAs). The hydrogen-bonding interactions between the starting materials were determined. The efficiency of the LTTMs in removing lignin from oil palm biomass residues, empty fruit bunch (EFB) was also evaluated. The removal of amorphous hemicellulose and lignin after the pretreatment process resulted in an enhanced digestibility and thermal degradability of biomass.
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http://dx.doi.org/10.1016/j.biortech.2017.08.043DOI Listing
November 2017

Torrefaction of empty fruit bunches under biomass combustion gas atmosphere.

Bioresour Technol 2017 Nov 13;243:107-117. Epub 2017 Jun 13.

Department of Mechanical Engineering, Yamaguchi University, Tokiwa-dai, Ube, Yamaguchi 755-8611, Japan.

Torrefaction of oil palm empty fruit bunches (EFB) under combustion gas atmosphere was conducted in a batch reactor at 473, 523 and 573K in order to investigate the effect of real combustion gas on torrefaction behavior. The solid mass yield of torrefaction in combustion gas was smaller than that of torrefaction in nitrogen. This may be attributed to the decomposition enhancement effect by oxygen and carbon dioxide in combustion gas. Under combustion gas atmosphere, the solid yield for torrefaction of EFB became smaller as the temperature increased. The representative products of combustion gas torrefaction were carbon dioxide and carbon monoxide (gas phase) and water, phenol and acetic acid (liquid phase). By comparing torrefaction in combustion gas with torrefaction in nitrogen gas, it was found that combustion gas can be utilized as torrefaction gas to save energy and inert gas.
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http://dx.doi.org/10.1016/j.biortech.2017.06.057DOI Listing
November 2017

Ionic liquids toxicity on fresh water microalgae, Scenedesmus quadricauda, Chlorella vulgaris &Botryococcus braunii; selection criterion for use in a two-phase partitioning bioreactor (TPPBR).

Chemosphere 2017 Oct 12;184:642-651. Epub 2017 Jun 12.

Department of Chemistry, Universite de Savoie Le Bourget-du-Lac, LCME/CISM Campus Scientifique Le Bourget-du-Lac, FR 73376, France.

A promising method of Carbon dioxide (CO) valorization is to use green microalgae photosynthesis to process biofuel. Two Phase Partitioning Bioreactors (TPPBR) offer the possibility to use non-aqueous phase liquids (NAPL) to enhance CO solubility; thus making CO available to maximize algae growth. This requires relatively less toxic hydrophobic Ionic Liquids (ILs) that comprise a new class of ionic compounds with remarkable physicochemical properties and thus qualifies them as NAPL candidates. This paper concerns the synthesis of ILs with octyl and butyl chains as well as different cations containing aromatic (imidazolium, pyridinium) and non-aromatic (piperidinum, pyrrolidinium) rings for CO absorption studies. The authors measured their respective toxicity levels on microalgae species, specifically, Scenedesmus quadricauda, Chlorella vulgaris and Botryococcus braunii. Results revealed that octyl-based ILs were more toxic than butyl-based analogues. Such was the case for bmim-PF6 at double saturation with an absorbance of 0.11, compared to Omim-PF6 at 0.17, bmim-NTf2 at 0.02, and Omim-NTf2 at 0.14, respectively. CO uptake results for ILs bearing octyl-based chains compared to the butyl analog were 54% (nCO/nIL) (i.e., moles of CO moles of IL) and 38% (nCO/nIL), respectively. Conclusively, 1-butyl-1-methylpiperidinium absorbed 13% (nCO/nIL) and appeared the least toxic, having an absorbance of 0.25 at 688 nm (double saturation at 7 d) compared to 1-butyl-3-methylimidazolium, which showed the highest toxicity with zero absorbance. Accordingly, these findings suggest that 1-butyl-1-methylpiperidinium is capable of transporting CO to a system containing green microalgae without causing significant harm; thus allowing its use in TPPBR technology.
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http://dx.doi.org/10.1016/j.chemosphere.2017.06.037DOI Listing
October 2017

Process simulation and techno economic analysis of renewable diesel production via catalytic decarboxylation of rubber seed oil - A case study in Malaysia.

J Environ Manage 2017 Dec 27;203(Pt 3):950-961. Epub 2017 May 27.

Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia. Electronic address:

This work describes the economic feasibility of hydroprocessed diesel fuel production via catalytic decarboxylation of rubber seed oil in Malaysia. A comprehensive techno-economic assessment is developed using Aspen HYSYS V8.0 software for process modelling and economic cost estimates. The profitability profile and minimum fuels selling price of this synthetic fuels production using rubber seed oil as biomass feedstock are assessed under a set of assumptions for what can be plausibly be achieved in 10-years framework. In this study, renewable diesel processing facility is modelled to be capable of processing 65,000 L of inedible oil per day and producing a total of 20 million litre of renewable diesel product per annual with assumed annual operational days of 347. With the forecasted renewable diesel retail price of 3.64 RM per kg, the pioneering renewable diesel project investment offers an assuring return of investment of 12.1% and net return as high as 1.35 million RM. Sensitivity analysis conducted showed that renewable diesel production cost is most sensitive to rubber seed oil price and hydrogen gas price, reflecting on the relative importance of feedstock prices in the overall profitability profile.
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http://dx.doi.org/10.1016/j.jenvman.2017.05.053DOI Listing
December 2017

Lipid for biodiesel production from attached growth Chlorella vulgaris biomass cultivating in fluidized bed bioreactor packed with polyurethane foam material.

Bioresour Technol 2017 Sep 4;239:127-136. Epub 2017 May 4.

Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak Darul Ridzuan, Malaysia.

The potential to grow attached microalgae Chlorella vulgaris in fluidized bed bioreactor was materialized in this study, targeting to ease the harvesting process prior to biodiesel production. The proposed thermodynamic mechanism and physical property assessment of various support materials verified polyurethane to be suitable material favouring the spontaneous adhesion by microalgae cells. The 1-L bioreactor packed with only 2.4% (v/v) of 1.00-mL polyurethane foam cubes could achieve the highest attached growth microalgae biomass and lipid weights of 812±122 and 376±37mg, respectively, in comparison with other cube sizes. The maturity of attached growth microalgae biomass for harvesting could also be determined from the growth trend of suspended microalgae biomass. Analysis of FAME composition revealed that the harvested microalgae biomass was dominated by C16-C18 (>60%) and mixture of saturated and mono-unsaturated fatty acids (>65%), satiating the biodiesel standard with adequate cold flow property and oxidative stability.
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http://dx.doi.org/10.1016/j.biortech.2017.04.118DOI Listing
September 2017

Characterization of natural low transition temperature mixtures (LTTMs): Green solvents for biomass delignification.

Bioresour Technol 2016 Jan 1;199:258-264. Epub 2015 Aug 1.

Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan. Electronic address:

The aim of this work was to characterize the natural low transition temperature mixtures (LTTMs) as promising green solvents for biomass pretreatment with the critical characteristics of cheap, biodegradable and renewable, which overcome the limitations of ionic liquids (ILs). The LTTMs were derived from inexpensive commercially available hydrogen bond acceptor (HBA) and l-malic acid as the hydrogen bond donor (HBD) in distinct molar ratios of starting materials and water. The peaks involved in the H-bonding shifted and became broader for the OH groups. The thermal properties of the LTTMs were not affected by water while the biopolymers solubility capacity of LTTMs was improved with the increased molar ratio of water and treatment temperature. The pretreatment of oil palm biomass was consistence with the screening on solubility of biopolymers. This work provides a cost-effective alternative to utilize microwave hydrothermal extracted green solvents such as malic acid from natural fruits and plants.
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http://dx.doi.org/10.1016/j.biortech.2015.07.103DOI Listing
January 2016

Flocculation behavior and mechanism of bioflocculant produced by Aspergillus flavus.

J Environ Manage 2015 Mar 2;150:466-471. Epub 2015 Jan 2.

Department of Civil and Water Resources Engineering, University of Maiduguri, P.M.B 1069, Maiduguri, Borno State, Nigeria.

In this study, the flocculation behavior and mechanism of a cation-independent bioflocculant IH-7 produced by Aspergillus flavus were investigated. Results showed 91.6% was the lowest flocculating rate recorded by IH-7 (0.5 mg L(-1)) at pH range 4-8. Moreover, IH-7 showed better flocculation performance than polyaluminum chloride (PAC) at a wide range of flocculant concentration (0.06-25 mg L(-1)), temperature (5-45 °C) and salinity (10-60% w/w). The current study found that cation addition did not significantly enhance the flocculating rate and IH-7 is a positively charged bioflocculant. These findings suggest that charge neutralization is the main flocculation mechanism of IH-7 bioflocculant. IH-7 was significantly used to flocculate different types of suspended solids such as activated carbons, kaolin clays, soil solids and yeast cells.
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http://dx.doi.org/10.1016/j.jenvman.2014.12.035DOI Listing
March 2015

Production of a bioflocculant from Aspergillus niger using palm oil mill effluent as carbon source.

Bioresour Technol 2014 Nov 19;171:66-70. Epub 2014 Aug 19.

Biomass Processing Lab, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak, Malaysia.

This study evaluated the potential of bioflocculant production from Aspergillus niger using palm oil mill effluent (POME) as carbon source. The bioflocculant named PM-5 produced by A. niger showed a good flocculating capability and flocculating rate of 76.8% to kaolin suspension could be achieved at 60 h of culture time. Glutamic acid was the most favorable nitrogen source for A. niger in bioflocculant production at pH 6 and temperature 35 °C. The chemical composition of purified PM-5 was mainly carbohydrate and protein with 66.8% and 31.4%, respectively. Results showed the novel bioflocculant (PM-5) had high potential to treat river water from colloids and 63% of turbidity removal with the present of Ca(2+) ion.
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http://dx.doi.org/10.1016/j.biortech.2014.08.038DOI Listing
November 2014

Production of biodiesel fuel from canola oil with dimethyl carbonate using an active sodium methoxide catalyst prepared by crystallization.

Bioresour Technol 2014 Jul 18;163:360-3. Epub 2014 Apr 18.

Center for Biofuel and Biochemical Research, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, Malaysia.

In this study, a novel method for the production of biodiesel under mild conditions using fine particles of sodium methoxide formed in dimethyl carbonate (DMC) is proposed. Biodiesel is generally produced from vegetable oils by the transesterification of triglycerides with methanol. However, this reaction produces glycerol as a byproduct, and raw materials are not effectively utilized. Transesterification with DMC has recently been studied because glycerol is not formed in the process. Although solid-state sodium methoxide has been reported to be inactive for this reaction, the catalytic activity dramatically increased with the preparation of fine catalyst powders by crystallization. The transesterification of canola oil with DMC was studied using this catalyst for the preparation of biodiesel. A conversion greater than 96% was obtained at 65°C for 2h with a 3:1M ratio of DMC and oil and 2.0 wt% catalyst.
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http://dx.doi.org/10.1016/j.biortech.2014.04.030DOI Listing
July 2014

Hot-compressed-water decomposed products from bamboo manifest a selective cytotoxicity against acute lymphoblastic leukemia cells.

Toxicol In Vitro 2004 Dec;18(6):765-71

Kagoshima Prefecture Institute of Industrial Technology, 1445-1 Oda Hayato-cho, Aira, Kagoshima 899-5105, Japan.

We examined the effect of hot-compressed-water (HCW) extracted and fractionated bamboo products (named as fractions A and B) on the viability of human cultured cell lines, derived from leukemia patients and human peripheral blood lymphocytes, obtained from normal adults. Fraction A was composed of xylose, xylooligosaccharides and water-soluble lignin, determined by high-performance anion exchange chromatography and spectrophotometry. Fraction B was composed of glucose and celooligosaccharides. It was found that Fraction B expressed a negligible cytotoxic effect against leukemia cells, while Fraction A reduced markedly (in a dose-dependent manner) the viability of leukemia cell lines, derived from acute lymphoblastic leukemia (ALL)--Jurkat and MOLT-4. Fraction A did not influence the viability of leukemia cells, derived from myelogenous leukemia (ML-2) or lymphoma (SupT-1), as well as the viability of normal lymphocytes. Furthermore, microscopic examination of ALL-derived cells treated with Fraction A showed typical apoptotic morphological changes such as a condensation of nucleus and membrane blebing, as well as phosphatidylserine (PSer) exposure on the cell surface. The effect of decomposed products of commercially available xylan against ALL-derived Jurkat cells was significantly lower than that of Fraction A. These results suggest that the cytotoxic effect of Fraction A may be attributed to apoptosis, induced by xylooligosaccharides and it is specific for ALL-derived cells. We speculate that the water-soluble lignin is an important factor, potentiating the cytotoxic effect of xylan in HCW-extracts from bamboo.
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http://dx.doi.org/10.1016/j.tiv.2004.03.011DOI Listing
December 2004
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