Bioconversion of starch to maltooligosaccharides (MOS) by the reaction of maltogenic amylase

Maltogenic amylase is one of the significant enzymes in oligosaccharides synthesis. Its ability to utilise multiple substrates and catalyse hydrolysis and transglycosylation reactions simultaneously makes it a unique biocatalyst. The catalysis could be exploited in many ways to obtain oligosaccharides of different lengths and various modified sugars. Nonetheless, one of the major drawbacks of substrate hydrolysis to produce oligosaccharides is the low production of MOS with higher degree of polymerisation. To address this issue, reaction parameter optimisation was performed via one-factor-at-a-time (OFAT) approach on the production of MOS from soluble starch hydrolysis using maltogenic amylase from Bacillus lehensis G1 (MAG1). Optimisation of MAG1 loading, soluble starch loading, temperature, time and pH resulted in the production of 84.87 mg/g MOS with polymerisation degree of 3 to 7 compared to that of 51.60 mg/g obtained before the optimisation process, which recorded 1.64-fold increment. Among all parameters, soluble starch loading gave the most significant impact on the MOS production as the reaction equilibrium is highly affected by substrate concentration. The occurrence of MOS with polymerisation degree of 4 and above, which resulted from starch hydrolysis further confirms the endo-type of MAG1. Because starch is an abundant and inexpensive source of carbohydrate in the world, this study provides a cost-effective MOS production process which is highly relevant for industry

Biochemical and physical characterization of immobilized Candida rugosa lipase on metal oxide hybrid support

Enzyme immobilization on inorganic materials is gaining more attention with the potential characteristics of high-surface-area-to-volume ratios, increasing the efficiency of enzyme loading on the support. Metal oxide hybrid support was prepared by a wetness impregnation of five metal precursors, including CaO, CuO, MgO, NiO, and ZnO, on Al2O3 and used as a support for the immobilization of Candida rugosa lipase (CRL) by adsorption. Maximum activity recovery (70.6%) and immobilization efficiency (63.2%) were obtained after optimization of five parameters using response surface methodology (RSM) by Box–Behnken design (BBD). The biochemical properties of immobilized CRL showed high thermostability up to 70 °C and a wide range in pH stability (pH 4–10). TGA-DTA and FTIR analysis were conducted, verifying thermo-decomposition of lipase and the presence of an amide bond. FESEM-EDX showed the homogeneous distribution and high dispersion of magnesium and CRL on MgO-Al2O3, while a nitrogen adsorption–desorption study confirmed MgO-Al2O3 as a mesoporous material. CRL/MgO-Al2O3 can be reused for up to 12 cycles and it demonstrated high tolerance in solvents (ethanol, isopropanol, methanol, and tert-butanol) compared to free CRL

Enzymatic conversion strategies of starch to maltooligosaccharides by maltogenic amylase and cyclodextrin glucanotransferase

Recently, the application of emulsion liquid membrane (ELM) process as an alternative technology for solute separation is highlighted due to the simple operation of simultaneous extraction and stripping process. The most important aspects for a successful ELM process are liquid membrane formulation and emulsion stability. This study was carried out to investigate the liquid membrane formulation for the reduction of chromium (VI) to chromium (III) from electroplating wastewater using continuous ELM process (CELM). Liquid membrane system comprises of three liquid phases which are external (electroplating wastewater), organic liquid membrane and internal phase. Liquid membrane and internal phase were emulsified and dispersed into the external phase to be treated. The experimental work consisted of four major parts which were ELM component formulation, stability study of ELM in batch process, screening of parameters and optimization of chromium removal efficiency by response surface methodology (RSM) in continuous operation process and recovery of the chromium at optimum process conditions. The results show that the favourable conditions for liquid membrane formulation are 0.04 M TOMAC as a carrier, palm oil as a diluent and 0.1 M thiourea in 0.1 M sulfuric acid as a stripping agent. The best condition of stable water-in-oil (W/O) emulsion was obtained at 7000 rpm of homogenizer speed, 5% (w/v) Span 80 as surfactant and 1 minute of emulsifying time. Meanwhile, the most stable water-in-oil-in-water (W/O/W) emulsion obtained during the continuous process operation was at 350 rpm agitation speed, pH<5 of external phase and 1 to 5 of treat ratio. The optimization results by RSM show that 99% of chromium was extracted at 2.83 minutes of retention time, 342 rpm rotational speed and 1 to 5 of treat ratio. As a conclusion, about 81% of less-toxic chromium (III) has been recovered into the internal phase using 2.0 M thiourea in 2.0 M sulfuric acid as the stripping agent. The favourable process condition of the formulated membrane study was satisfactory and is suitable to treat wastewater as low as 20 ppm up to 200 ppm of chromium concentrations. This study reveals that CELM is a simple process and practical technology to remove chromium (VI) from industrial wastewater while solving the environmental problem simultaneously.In nature, Bacillus lehensis G1 utilizes extracellular cyclodextrin glucanotransferase (CGTase) to degrade starch into cyclodextrins (CDs). This is followed by hydrolysis of CDs by intracellular maltogenic amylase (MAG1) into glucose, maltose and maltooligosaccharides (MOS). The MOS are potential prebiotic for human consumption. In industries, amylases are used to produce MOS from starch. However, the conversion of starch directly to MOS using MAG1 has several limitations such as low specificity towards starch compared to ß-cyclodextrin (ß-CD) and low productivity of MOS. In order to overcome these drawbacks, two strategies involving optimization of reaction parameters using statistical method and synergism of enzyme mixture approach, were applied. In this study, the optimization of enzymatic reaction parameters for enhanced MOS production by MAG1 using soluble starch as a substrate was performed. In the first strategy, the effects of reaction parameters (enzyme loading, substrate loading, temperature, reaction time and pH) on MOS yield was investigated using one-factor-at-a-time (OFAT) method and 25-1 fractional factorial design. Based on the 25-1 fractional factorial design results, three parameters namely substrate loading, reaction time and pH were found to have a significant effect and was used in central composite design under response surface methodology (RSM). The MOS production was successfully optimized by the RSM. Under the optimized conditions (0.25 % (w / v) of substrate loading, 0.5 h of reaction time and pH 7.45) by RSM, the MOS yield was 107.29 mg / g of substrate which was 1.3-fold higher compared to the value after OFAT analysis which was only 84.87 mg / g of substrate. In the second strategy, the synergistic effect of MAG1 and CGTase for improving the MOS production process had also been studied using two different approaches which were asynchronous and synchronous methods. For the asynchronous method, the cyclization and hydrolysis reaction of CGTase and MAG1, were carried out in two separated steps respectively. Whereas, for the synchronous method, the two enzymes were added simultaneously and became a one-pot enzymatic reaction. The results from the studies conducted show the capability of the synchronous method was capable to convert the soluble starch (1.5 % (w / v)) into MOS with higher yield than the asynchronous method. The optimum conditions were obtained when MAG1 loading to CGTase loading in 3 U: 7 U ratio, with the reaction temperature of 40 ºC and pH 7.0. Based on these optimum conditions, the total yield of MOS attained was 307.86 mg / g of substrate after 2 h, which was 2.1-fold higher than the asynchronous method (146.78 mg / g) and 2.9-fold higher compared to the reaction of MAG1 alone. The used of CGTase and MAG1 synchronously enable the direct conversion of soluble starch to higher yield of MOS

Cell immobilization for cyclodextrin production: Mini review

Cell immobilization has been applied in various industries, including chemical manufacturing, food, pharmaceutical, and textile. Recently, innovations in cell immobilization techniques and support materials have been put forward for application in high value-added chemical biosynthesis, such as cyclodextrin (CD). The techniques, support materials, and process parameters of cell immobilization play important roles in achieving high CD yield. This review should help one choose the correct cell immobilization technique and support for a CD biosynthesis setup. Previously, CD biosynthesis utilized free cells, even though they present difficulties such as the low product yield, cell lysis, unstable plasmid, and non-reusable cells. This review highlights how the problems that arise from free-cell bioreactors could be mitigated by cell immobilization. The process conditions of cell immobilization for CD production are also presented

Biochemical and Physical Characterization of Immobilized Candida rugosa Lipase on Metal Oxide Hybrid Support

Enzyme immobilization on inorganic materials is gaining more attention with the potential characteristics of high-surface-area-to-volume ratios, increasing the efficiency of enzyme loading on the support. Metal oxide hybrid support was prepared by a wetness impregnation of five metal precursors, including CaO, CuO, MgO, NiO, and ZnO, on Al2O3 and used as a support for the immobilization of Candida rugosa lipase (CRL) by adsorption. Maximum activity recovery (70.6%) and immobilization efficiency (63.2%) were obtained after optimization of five parameters using response surface methodology (RSM) by Box&ndash;Behnken design (BBD). The biochemical properties of immobilized CRL showed high thermostability up to 70 &deg;C and a wide range in pH stability (pH 4&ndash;10). TGA-DTA and FTIR analysis were conducted, verifying thermo-decomposition of lipase and the presence of an amide bond. FESEM-EDX showed the homogeneous distribution and high dispersion of magnesium and CRL on MgO-Al2O3, while a nitrogen adsorption&ndash;desorption study confirmed MgO-Al2O3 as a mesoporous material. CRL/MgO-Al2O3 can be reused for up to 12 cycles and it demonstrated high tolerance in solvents (ethanol, isopropanol, methanol, and tert-butanol) compared to free CRL

WILDLIFE EX-SITU CONSERVATION : FORENSICS, BIOBANKING, ZOONOTIC DISEASES AND CAPTIVE BREEDING

Wildlife ex-situ conservation is a complete process of securing populations outside natural habitats. Tools like captive breeding, population genetics, artificial insemination and many others are key elements in this conservation practice. This book compiles all the advancements in ex-situ conservation via the application of forensics, captive breeding, molecular genetics, disease control and husbandry management by the Department of Wildlife and National Parks (PERHILITAN) Peninsular Malaysia. A very precise and comprehensive explanation of each component is presented in this book. Those components include An Overview of ExSitu Conservation; Wildlife Forensics for Combating Wildlife Crime; Wildlife Biobanking; Wildlife Disease Surveillance; Wildlife Conservation; Wildlife Rescue, Rehabilitation and Release; Wildlife Husbandry Management and Way Forward of PERHILITAN’s ultimate goal in ex-situ conservation. All the information generated in this book will be valuable guidance for wildlife conservationists, policymakers, stakeholders and scholars. The authors of this book comprise a team with extensive experience and a wide range of skills, which make them highly qualified to publish the first-ever book on Ex-Situ Conservation in Peninsular Malaysia