Enzymatic Synthesis of Oleyl Oleate, a Liquid Wax Ester, in a Stirred Tank Reactor

High performance enzymatic synthesis of oleyl oleate, a liquid wax ester was successfully synthesized via enzymatic esterification reaction of oleic acid and oley alcohol. Immobilised Candida antartica lipase B (Novozym 435) was used as biocatalyst. The study was divided into four parts which are the optimisation of reaction synthesis at different scales, the reactor study in term of mixing efficiency, the stability of immobilised enzyme and the analysis and characterization of the product of the reaction. Preliminary synthesis of oleyl oleate was carried out in a small scale reaction with a total volume of 3.5 mL using screw-capped vials. Optimisation reaction study via conventional method of varying one parameter at-a-time approach was carried out. A high percentage conversion yield of >90% was achieved at optimum reaction time of 5 min, reaction temperature of 40-6O0C1 molar ratio of substrates (oleyl alcoholloleic acid) of 2:1, amount of enzyme of 0.4 g and organic solvents of Log P23.5 at fixed agitation speed of 150 rpm. Investigation in larger scale production of oleyl oleate was performed using 2 L stirred tank reactor (STR). The reaction was scaled-up to 300X with a total volume of 1.05 L. A high percentage conversion of oleyl oleate was achieved of >95% by conventional experiment method at reaction time of 30 min, agitation speed of 400 rpm, reaction temperature of 45-50°C, molar ratio of substrate (oleyl alcoholloleic acid) of 2:l and amount of enzyme of 90 g. The reaction synthesis was further optimised by response surface method (RSM) based on five-level, three-variable central composite rotatable design (CCRD) to evaluate the interactive effects of important parameters in larger scale processing. Generally, simultaneously increasing amount of enzyme, agitation speed and reaction temperature would improved the yields. A high percentage conversion of 97.4% was achieved under the optimum condition, which compared well with the maximum predicted value of 97.7%. In order to improve the production and productivity of oleyl oleate to the highest amount that can be produced in a 2 L STR, the reaction was synthesized in a solvent-free system. Maximum scaling-up of substrate concentration that can be achieved in the reactor vessel was 900X as compared to 300X previously. The production and productivity of oleyl oleate were successfully improved from 295.39 g/L/h to 705.76 g1Uh and 31 0.16 glh to 952.78 glh, respectively. Reactor study on the performance of 2 L STR as a mixing device was evaluated to improve the mixing efficiency. The rheological property of the reaction mixture exhibited Newtonian behaviour. Rushton turbine impeller showed better performance in degree of mixing, as compared to AL Hydrofoil impeller whereby a high Reynolds number of >lo4 was achieved at 400 rpm, which exhibit a turbulent flow pattern. There was significant effect to the mixing improvement on the enzyme particles distribution by using a 2 impellers system with spacing of 30 mm. The enzyme showed high stability against heat as shown by the high percentage conversion of wax ester. Novozym 435 retained its synthetic activity up to 9 uses and 4 uses in screw-capped vials and STR, respectively. The effect of shear forces due to the mechanical agitation speed on the enzyme morphology was determined by scanning electron microscope (SEM). Although small rupture on the surface of enzyme was observed when increasing the agitation speed, the enzyme activity was very high even at high agitation speed.Analysis of product was evaluated by spectroscopy method of Fourier transform-infrared spectroscopy (FT-IR) and gas chromatography-mass spectroscopy (GC-MS) to identify the product obtained. Characteristics of oleyl oleate were also examined, which include iodine value, saponification value, acid value and ester value. Solubility of oleyl oleate in methanol and ethanol was comparatively lower as compared to the solubility at higher chain length of alcohols. This compound seems compatible in most of oils and stable even after heating up to 90°C and overnight storage at room temperature

Theoretical investigations of β-tricalcium

Beta-tri-calcium phosphate (β-TCP) materials have gained a great deal of research considerations in biomaterial area due to their excellent biocompatibility and identical chemical compositions to the natural teeth and bones. Therefore, the β-TCP compound can be used as coatings, cement and composites as well as biocompatible ceramics for medical and dental applications. Electronic and optical properties for β-TCP compound have been investigated using density functional theory (DFT). For the calculations, we used full potential linear augmented plane wave method (FPLAPW), within three types of approximations along with local density approximations (LDA), generalized gradient approximations (GGA) and Modified Becke-Johnson (mBJ) to get the effect of the exchange and correlation in our calculations to get an accurate results. The computed band gap values for (β-TCP) compound using LDA, GGA, and mBJ-GGA approximations are 5.5 eV, 5.9 eV and 6.8 eV respectively. This is also predicted that the chemical bonding in this compound is a kind of combination of covalent and ionic character that is in a line with the experimental findings. The optical parameter, static dielectric constant ε1(0) reaches the values of 3.23681 (eV) at 0 GPa for the β-TCP compound. The obtained results are of vital nature for rising the quality of the electronic and optical properties of this material, and provide more evidence to fabricate novel Beta-Tri-calcium phosphate biomaterials for medical and dental applications

Isolation and identification of amylolytic bacteria from ragi

Ragi is a traditional dry starter culture frequently used in many fermented food products in Asian countries. Ragi contains starch that can be degraded by amylases provided by bacteria and other microorganisms during fermentation in producing fermented foods. This study was carried out to isolate bacteria from ragi and to screen for their ability to hydrolyse starch. Seven bacterial colonies were isolated from ragi, with three samples showing starch hydrolysis activity. Two of the starchdegrading bacterial isolates were identified using partial 16S rRNA gene sequencing as Bacillus licheniformis with 97% and 98% similarity, and one sample identified as a lactic acid bacteria, Enterococcus faecium (98%). Isolation and identification of these bacteria from ragi can provide a promising source of amylase that can be further studied and manipulated for the development of starter culture and to improve the quality of traditional ragi-based fermented food products

Green synthesis of lauryl palmitate via lipase-catalyzed reaction

Enzyme catalysis is most attractive for the synthesis of fine organic compounds, which are difficult to prepare and to handle by conventional means. In this work, green synthesis of lauryl palmitate, a wax ester was successfully carried out by lipase-catalyzed esterification of palmitic acid and lauryl alcohol. In this study, commercial immobilized lipase from Candida antartica (Novozym 435) was used as biocatalyst. The effect of various reaction parameters were optimized to obtain a high yield of wax esters. The optimum condition to produce lauryl palmitate was at reaction time (RT); 10 min, temperature (T); 40°C, amount of enzyme (E); 0.4 g, molar ratio of substrate (N); 2:1 and organic solvents of log P>3.5. The product was then subjected to characterize using Fourier-transform infrared spectroscopy (FT-IR) and Gas chromatography spectroscopy (GC) to ensure the purity of product obtained. Analysis of yield showed that at optimum condition, lauryl palmitate was produced in short time with high purity, >90%

Identifying Business Potential for Small and Medium-Sized Enterprises (SMEs) Based on Developmental Plans in Penang, Malaysia

This study aims to identify the business potential possibilities for small and medium-sized enterprises (SMEs) and explore the ways in which such businesses and state, regional and national economic development planning may interact. Drawing insights from Penang’s development plans and/or blueprints, this paper generates a typology of such plans and maps them accordingly in terms of economic sector. In capturing the national and state development plan and/or policies for its economic progress, research methodology through a content analysis was done by referring to the documents issued by Penang and national agencies The strategies will help equip a way forward for SMEs to grow in response to these development plans. By participating in the main economic sectors this strategy will directly bring benefits for SMEs’ as they will be able to have wider access to markets, including government programs and incentives. When SMEs align their business model with what an economy is trying to achieve policy-wise, this endeavor will to a certain extent mitigate the common challenges that hinder SMEs’ growth

Identification of bacteria associated with Holothuria (Mertensiothuria) leucospilota from Pangkor Island

Holothuria (Mertensiothuria) leucospilota is the most abundant sea cucumber species in Malaysia. This study aimed to identify bacteria isolated from the external and internal body parts of H. leucospilota collected from the coastal water of Pangkor Island, Perak, Malaysia. A total of 26 bacterial samples were isolated using streak plate method from eight body parts of two fresh H. leucospilota specimens and from the surrounding surface sediments and seawater. Identification of the bacterial isolates was based on microscopic examination, 16S rDNA amplification and phylogenetic analysis using the neighbour-joining method. Three genera of bacteria were identified namely Vibrio, Bacillus, and Acinetobacter. The genus Vibrio was found to be the main bacterial group associated with the H. leucospilota specimens from Pangkor Island

Optimization of lipase-catalyzed synthesis of palm amino acid surfactant using response surface methodology (RSM)

Amino acid surfactants are high-value surfactants which have excellent emulsifying characteristics and minimal toxicity to the living body. Enzymatic synthesis of palm kernel amino acid surfactant was optimized by response surface methodology (RSM) using palm kernel olein (PKO) and l(+)-lysine catalyzed by Lipozyme RM IM. The reaction was performed in batch mode stirred tank reactor (STR) with one multi-bladed impeller. A central composite rotatable design (CCRD) was employed to evaluate the interactive effects of various parameters. The parameters were temperature (A): (40.00–70.00 °C), impeller speed (B): (100.00–400.00 rpm), substrates ratio (C): (1.00–4.00 mmol) and enzyme amount (D): (5.00–8.00 g). The optimum condition derived via RSM at fixed reaction time of 24 h was temperature; 47.50 °C, impeller speed; 323.96 rpm, substrates ratio; 3.25 mmol and enzyme amount; 7.25 g. The experimental yield was 89.03% under the optimum condition, which compared well with the maximum predicted value of 93.77%

Determinants of Effective Financial Risk Management in Small Business: A Theoretical Framework

This paper aims to develop a theoretical model of potential determinants of effective financial risk management in small business. In achieving this objective, the methodology used includes library search and analyzing previous literature review on the subject of financial risk management and small business especially in Malaysia case study. The significant variables are namely the leadership, training programs, use of technology, entrepreneurship orientation (EO) and accounting information. This paper also hopes to strengthen the body of knowledge on how financial risk management helps small business towards success, besides to act as a reference for empirical research

Are sukuk debt or equity? A classification of sukuk by regulatory bodies and credit rating agencies / Rafisah Mat Radzi and Nurul Aini Muhamed.

Sukuk (Islamic bonds) are the Shariah (Islamic law) instrument that serves as an alternative to conventional bonds that are used in the modern capital market. In theory, sukuk represent a form of equity as they represent certificates conferring ownership to holders of an asset or pool of assets or claim to its cash flows. In practice, they have become known as Islamic bonds with their investors holding debt. Following the question of whether sukuk are debt or equity, this paper aims to classify sukuk from the perspective of regulatory bodies and credit rating agencies. Furthermore, to what extent the innovations in this Islamic instrument make it differ substantially from conventional bonds in practice will be examined

Protein produced by Bacillus subtilis ATCC21332 in the presence of Cymbopogon flexuosus essential oil

Proteins levels produced by bacteria may be increased in stressful surroundings, such as in the presence of antibiotics. It appears that many antimicrobial agents or antibiotics, when used at low concentrations, have in common the ability to activate or repress gene transcription, which is distinct from their inhibitory effect. There have been comparatively few studies on the potential of antibiotics or natural compounds in nature as a specific chemical signal that can trigger a variety of biological functions. Therefore, this study was focusing on the effect of essential oil from Cymbopogon flexuosus in regulating proteins production by Bacillus subtilis ATCC21332. The Minimum Inhibition Concentration (MIC) of the C. flexuosus essential oil on B. subtilis was determined by using microdilution assay, resulting 1.76mg/ml. The bacteria cells were further exposed to the C. flexuosus essential oil at concentration of 0.01 MIC for 72 h. The proteins were then isolated and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Proteins profile showed that a band with approximate size of 30 kDa was appeared for the treated bacteria with C. flexuosus essential oil. Thus, B. subtilis ATCC21332 in stressful condition with the presence of C. flexuosus essential oils at low concentration could induce the protein production. The isolated protein also showed antimicrobial activity against selected Gram-positive and Gram-negative bacteria