Effects of pH, glucose and iron sulfate concentration on the yield of biohydrogen by Clostridium butyricum EB6

A local bacterial isolate from palm oil mill effluent (POME) sludge, identified as Clostridium butyricum EB6, was used for biohydrogen production. Optimization of biohydrogen production was performed via statistical analysis, namely response surface methodology (RSM), with respect to pH, glucose and iron concentration. The results show that pH, glucose concentration and iron concentration significantly influenced the biohydrogen gas production individually, interactively and quadratically (P < 0.05). The center composite design (CCD) results indicated that pH 5.6, 15.7 g/L glucose and 0.39 g/L FeSO₄ were the optimal conditions for biohydrogen production, yielding 2.2 mol H₂/mol glucose. In confirmation of the experimental model, t-test results showed that curve fitted to the experimental data had a high confidence level, at 95% with t = 2.225. Based on the results of this study, optimization of the culture conditions for C. butyricum EB6 significantly increased the production of biohydrogen.     

A comparative study on the energy policies in Japan and Malaysia in fulfilling their nations’ obligations towards the Kyoto Protocol

Global warming and the associated changes in the world climate pattern have been accepted world wide as the gravest threat to humanity in the 20th century. To mitigate the impacts of global warming, the Kyoto Protocol was established in 1997 with the objective of reducing global greenhouse gases (GHGs) emission, in particular carbon dioxide (CO₂), by 5.2% below 1990 levels. Developed nations that ratified the Protocol are committed to GHG reduction targets while developing nations are encouraged to reduce GHG emissions on a voluntary basis. Since most of the GHGs emissions come from the energy sector, energy policy plays an important role in fulfilling the Kyoto Protocol obligations. This year marks the beginning of the commitment period for the 2012 Kyoto Protocol. In this case, it would be worthwhile to compare the energy policies in Malaysia and Japan as these nations move towards fulfilling their obligations towards the Kyoto Protocol; bearing in mind that both countries ratified the Protocol, but that Japan commits a reduction target of 6% while Malaysia bears no obligation. Based on the comparison, recommendations were made on how a developing nation like Malaysia could adopt the policies implemented in Japan to suit local conditions and contribute significantly to GHG reduction.     

Biodiesel from cotton seed oil and its effect on engine performance and exhaust emissions

The use of biodiesel is rapidly expanding around the world, making it imperative to fully understand the impacts of biodiesel on the diesel engine combustion process and pollutant formation. Biodiesel is known as the mono-alkyl-esters of long chain fatty acids derived from renewable feedstocks, such as, vegetable oils or animal fats, for use in compression ignition engines. Different parameters for the optimization of biodiesel production were investigated in the first phase of this study, while in the next phase of the study performance test of a diesel engine with neat diesel fuel and biodiesel mixtures were carried out. Biodiesel was made by the well known transesterification process. Cottonseed oil (CSO) was selected for biodiesel production. Cottonseed is non-edible oil, thus food versus fuel conflict will not arise if this is used for biodiesel production. The transesterification results showed that with the variation of catalyst, methanol or ethanol, variation of biodiesel production was realized. However, the optimum conditions for biodiesel production are suggested in this paper. A maximum of 77% biodiesel was produced with 20% methanol in presence of 0.5% sodium hydroxide. The engine experimental results showed that exhaust emissions including carbon monoxide (CO) particulate matter (PM) and smoke emissions were reduced for all biodiesel mixtures. However, a slight increase in oxides of nitrogen (NO_x) emission was experienced for biodiesel mixtures.     

Piezoresistive cantilever array sensor for consolidated bioprocess monitoring

Cellulolytic microbes occur in diverse natural niches and are being screened for industrial modification and utility. A microbe for consolidated bioprocessing (CBP) development can rapidly degrade pure cellulose and then ferment the resulting sugars into fuels. To identify and screen for novel microbes for CBP, we have developed a piezoresistive cantilever array sensor which is capable of simultaneous monitoring of glucose and ethanol concentration changes in a phosphate buffer solution. 4‐mercaptophenylboronic acid and polyethyleneglycol‐thiol are employed to functionalize each piezoresistive cantilever for glucose and ethanol sensing, respectively. Successful concentration measurements of glucose and ethanol with minimal interferences are obtained with our cantilever array sensor. SCANNING 31: 204–210, 2009. © 2009 Wiley Periodicals, Inc.     

Promising Anticancer Activity of [Bis(1,8-quinolato)palladium (II)] Alone and in Combination

Due to similar coordination chemistry of palladium and platinum, a large number of palladium compounds as well have been investigated for their anticancer activity. In the present study, we describe synthesis, characterization, and anticancer activity of palladium complex [Bis(1,8-quinolato)palladium (II)], coded as NH3 against seven different cancer cell lines. NH3 is found to have higher antitumor activity than cisplatin against both parent ovarian A2780 cell line and cisplatin-resistant cell lines. Also, NH3 has the lower IC₅₀ value in HT-29 colorectal cancer cell line. The higher antitumor activity of NH3 is due to the presence of bulky 8-Hydroxyquinoline ligand, thus reducing its reactivity. Proteomic study has identified significantly expressed proteins which have been validated through bioinformatics. NH3 has been found to be less toxic than cisplatin at 2.5 mg/kg and 5 mg/kg dosages on mice models. Binary combinations of NH3 with curcumin and epigallocatechin gallate (EGCG) have demonstrated dose and sequence-dependent synergism in ovarian and colorectal cancer models. All of the preclinical studies indicate promising therapeutic potential of NH3 [Bis(1,8-quinolato)palladium (II)] as an anticancer drug.     

Application of factorial design in optimization of anion exchange resin based methylation of vegetable oil and fats

A simple, rapid and fairly selective method for the preparation of fatty acid methyl esters (FAMEs) based on anion exchange resin Amberlite IRA-904 catalyzed transesterification of vegetable oil/fat with iodomethane has been described. The vegetable oil and animal fats used were sunflower oil, palm oil, vanaspati (hydrogenated vegetable oil), olive oil, tallow and butter. A Plackett–Burman factorial experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The effects of five different variables amount of resin, strength of sodium hydroxide, volume of iodomethane, heating time and temperature of thermostatic water bath, on the yield of fatty acid methyl esters (FAMEs) have been investigated. From these studies, certain variable showed up as significant, and they were optimized by a using 2³ + star central composite design, which involved 16 experiments. The best conditions for transesterification reaction were as follows: amount of resin 2 g, strength of sodium hydroxide 0.25 N, volume of iodomethane 400 µl, heating time 2 min at 70 °C. A standard IUPAC method was used to prepare FAMEs from vegetable oil/fats for comparative purpose. Finally samples of oil/fat obtained from both methods were analysed by Gas liquid chromatography. Analytical results for the FAMEs by resin based proposed method, and conventional IUPAC method showed a good agreement, thus indicating the possibility of using Amberlite IRA-904 based transesterification instead of intensive treatments inherent with the conventional time-consuming methods.

Industrial relevance

Fatty acids are the main components of edible oil and fats, therefore determination of fatty acid composition is so far one of the important parameters for quality evaluation and nutritional value determination of edible oil and fats. The analysis of fatty acid is usually carried out by Gas liquid chromatography (GLC) after conversion of volatile fatty acid methyl esters (FAME) although other ester may be prepared for specific purpose.The endeavor of present work was to improve the FAMEs preparation method, proposing the development of anion exchange resin Amberlite IRA-904 based transesterification of edible oil/fat with iodomethane as alkylating reagent. The present method besides being rapid and reproducible avoids the use of classical saponification, washing of esters and solvent extraction step.     

Shrinkage of Food Materials During Drying: Current Status and Challenges

The structural heterogeneities of fruits and vegetables intensify the complexity to comprehend the interrelated physicochemical changes that occur during drying. Shrinkage of food materials during drying is a common physical phenomenon which affects the textural quality and taste of the dried product. The shrinkage of food material depends on many factors including material characteristics, microstructure, mechanical properties, and process conditions. Understanding the effect of these influencing factors on deformation of fruits and vegetables during drying is crucial to obtain better‐quality product. The majority of the previous studies regarding shrinkage are either experimental or empirical; however, such studies cannot provide a realistic understanding of the physical phenomena behind the material shrinkage. In contrast, theoretical modeling can provide better insights into the shrinkage that accompanies simultaneous heat and mass transfer during drying. However, limited studies have been conducted on the theoretical modeling of shrinkage of fruits and vegetables. Therefore, the main aim of this paper is to critically review the existing theoretical shrinkage models and present a framework for a theoretical model for the shrinkage mechanism. This paper also describes the effect of different drying conditions on material shrinkage. Discussions on how the diverse characteristics of fruits and vegetables affect shrinkage propagation is presented. Moreover, a comprehensive review of formulation techniques of shrinking models and their results are also presented. Finally, the challenges in developing a physics‐based shrinkage model are discussed.