Displaying publications 1 - 20 of 50 in total

Abstract:
Sort:
  1. Primary recovery of a bacteriocin-like inhibitory substance derived from Pediococcus acidilactici Kp10 by an aqueous two-phase system
    Abbasiliasi S, Tan JS, Ibrahim TA, Kadkhodaei S, Ng HS, Vakhshiteh F, et al.
    Food Chem, 2014 May 15;151:93-100.
    PMID: 24423507 DOI: 10.1016/j.foodchem.2013.11.019
    A polymer-salt aqueous two-phase system (ATPS) consisting of polyethylene-glycol (PEG) with sodium citrate was developed for direct recovery of a bacteriocin-like inhibitory substance (BLIS) from a culture of Pediococcus acidilactici Kp10. The influences of phase composition, tie-line length (TLL), volume ratio (VR), crude sample loading, pH and sodium chloride (NaCl) on the partition behaviour of BLIS was investigated. Under optimum conditions of ATPS, the purification of BLIS was achieved at 26.5% PEG (8000)/11% sodium citrate with a TLL of 46.38% (w/w), VR of 1.8, and 1.8% crude load at pH 7 without the presence of NaCl. BLIS from P. acidilactici Kp10 was successfully purified by the ATPS up to 8.43-fold with a yield of 81.18%. Given that the operation of ATPS is simple, environmentally friendly and cost-effective, as it requires only salts and PEG, it may have potential for industrial applications in the recovery of BLIS from fermentation broth.
  2. Fulltext Extraction behaviors of aqueous PEG impregnated resin system in terms of impregnation stability and recovery via protein impregnated resin interactions on bovine serum albumin
    Abdul Aziz NFH, Abbasiliasi S, Abu Zarin M, Ng HS, Lan C, Tan JS
    PeerJ, 2021;9:e11920.
    PMID: 34963820 DOI: 10.7717/peerj.11920
    Background: Current advances in biotechnology have been looked at as alternative approaches towards the limited product recovery due to time- and cost-consuming drawbacks on the conventional purification methods. This study aimed to purify bovine serum albumin (BSA) as an exemplary target product using an aqueous impregnated resin system (AIRS). This method implies the concept of hydrophobicity of polymer that impregnated into the resins and driven by electrostatic attractions and hydrophilicity of aqueous salt solution to extract the target product.

    Methods: The extraction behaviors of impregnation in terms of stability and adsorption kinetics via protein-aqueous polymer impregnated resin were studied. Impregnation stability was determined by the leaching factor of polyethylene glycol (PEG). The major factors such as PEG molecular weights and concentration, pH of aqueous salt solution, extraction methods (sonication and agitation) and types of adsorbent material and concentration of aqueous salt phase influencing on partitioning of biomolecule were also investigated.

    Results: For impregnation stability, the leaching factor for Amberlite XAD4 did not exceed 1%. The scanning electron microscopy (SEM) image analysis of Amberlite XAD4 attributes the structural changes with impregnation of resins. For adsorption kinetics, Freundlich adsorption isotherm with the highest R2 value (0.95) gives an indication of favorable adsorption process. Performance of AIRS impregnated with 40% (w/w) of PEG 2000 was found better than aqueous-two phase system (ATPS) by yielding the highest recovery of BSA (53.72%). The outcomes of this study propound the scope for the application of AIRS in purification of biomolecules.

  3. Kinetic model derived from machine learning for accurate prediction of microalgal hydrogen production via conversion from low thermally pre-treated palm kernel expeller waste
    Ahmad Sobri MZ, Khoo KS, Sahrin NT, Ardo FM, Ansar S, Hossain MS, et al.
    Chemosphere, 2023 Oct;338:139526.
    PMID: 37459926 DOI: 10.1016/j.chemosphere.2023.139526
    The depletion of fossil fuel sources and increase in energy demands have increased the need for a sustainable alternative energy source. The ability to produce hydrogen from microalgae is generating a lot of attention in both academia and industry. Due to complex production procedures, the commercial production of microalgal biohydrogen is not yet practical. Developing the most optimum microalgal hydrogen production process is also very laborious and expensive as proven from the experimental measurement. Therefore, this research project intended to analyse the random time series dataset collected during microalgal hydrogen productions while using various low thermally pre-treated palm kernel expeller (PKE) waste via machine learning (ML) approach. The analysis of collected dataset allowed the derivation of an enhanced kinetic model based on the Gompertz model amidst the dark fermentative hydrogen production that integrated thermal pre-treatment duration as a function within the model. The optimum microalgal hydrogen production attained with the enhanced kinetic model was 387.1 mL/g microalgae after 6 days with 1 h thermally pre-treated PKE waste at 90 °C. The enhanced model also had better accuracy (R2 = 0.9556) and net energy ratio (NER) value (0.71) than previous studies. Finally, the NER could be further improved to 0.91 when the microalgal culture was reused, heralding the potential application of ML in optimizing the microalgal hydrogen production process.
  4. Purification of β-mannanase derived from Bacillus subtilis ATCC 11774 using ionic liquid as adjuvant in aqueous two-phase system
    Aziz NFHA, Abbasiliasi S, Ng HS, Phapugrangkul P, Bakar MHA, Tam YJ, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2017 Jun 15;1055-1056:104-112.
    PMID: 28458127 DOI: 10.1016/j.jchromb.2017.04.029
    The partitioning of β-mannanase derived from Bacillus subtilis ATCC 11774 in aqueous two-phase system (ATPS) was studied. The ATPS containing different molecular weight of polyethylene glycol (PEG) and types of salt were employed in this study. The PEG/salt composition for the partitioning of β-mannanase was optimized using response surface methodology. The study demonstrated that ATPS consists of 25% (w/w) of PEG 6000 and 12.52% (w/w) of potassium citrate is the optimum composition for the purification of β-mannanase with a purification fold (PF) of 2.28 and partition coefficient (K) of 1.14. The study on influences of pH and crude loading showed that ATPS with pH 8.0 and 1.5% (w/w) of crude loading gave highest PF of 3.1. To enhance the partitioning of β-mannanase, four ionic liquids namely 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4), 1-butyl-3-methylimidazolium bromide ([Bmim]Br), 1-ethyl-3-methylimidazolium bromide ([Emim]Br) was added into the system as an adjuvant. The highest recovery yield (89.65%) was obtained with addition of 3% (w/w) of [Bmim]BF4. The SDS-PAGE analysis revealed that the β-mannanase was successfully recovered in the top phase of ATPS with the molecular size of 36.7kDa. Therefore, ATPS demonstrated a simple and efficient approach for recovery and purification of β-mannanase from fermentation broth in one single-step strategy.
  5. Remediation and recovery of Kariba weed as emerging contaminant in freshwater and shellfish aquaculture system via solvothermal liquefaction
    Azwar E, Mahari WAW, Liew RK, Ramlee MZ, Verma M, Chong WWF, et al.
    Sci Total Environ, 2023 Mar 08;876:162673.
    PMID: 36894104 DOI: 10.1016/j.scitotenv.2023.162673
    Fast growing Kariba weed causes major problems and pollution on freshwater and shellfish aquaculture systems by interfering with nutrient uptake of crops, restricting sunlight penetration, and decreasing water quality due to massive biomass of Kariba weed remnants. Solvothermal liquefaction is considered an emerging thermochemical technique to convert waste into high yield of value-added products. Solvothermal liquefaction (STL) of Kariba weed as an emerging contaminant was performed to investigate the effects of different types of solvents (ethanol and methanol) and Kariba weed mass loadings (2.5-10 % w/v) on treating and reducing the weed via conversion into potentially useful crude oil product and char. Up to 92.53 % of Kariba weed has been reduced via this technique. The optimal conditions for crude oil production were found to be at 5 % w/v of mass loading in methanol medium, resulting in a high heating value (HHV) of 34.66 MJ/kg and yield of 20.86 wt%, whereas the biochar production was found to be optimum at 7.5 % w/v of mass loading in methanol medium, resulting in 29.92 MJ/kg of HHV and 25.38 wt% of yield. The crude oil consisted of beneficial chemical compounds for biofuel production such as hexadecanoic acid, methyl ester (65.02 peak area %) and the biochar showed high carbon content (72.83 %). In conclusion, STL as a remediation for emerging Kariba weed is a feasible process for shellfish aquaculture waste treatment and biofuels production.
  6. An integration study of microalgae bioactive retention: From microalgae biomass to microalgae bioactives nanoparticle
    Cai Y, Lim HR, Khoo KS, Ng HS, Cai Y, Wang J, et al.
    Food Chem Toxicol, 2021 Dec;158:112607.
    PMID: 34653554 DOI: 10.1016/j.fct.2021.112607
    Microalgae metabolites include biologically active compounds with therapeutic effects such as anticancer, anti-inflammatory and immunomodulation effects. One of the most recent focuses is on utilizing microalgae lipid-based biologically active compounds in food applications. However, most microalgae biological active compounds in their natural forms have common drawbacks like low solubility, low physicochemical stability and strong susceptibility to degradation, which significantly limits their application in foods, therefore, it is important to find solutions to retain their functional properties. In the present work, a comprehensive review on multi-product biorefinery was carried out from upstream processing stage to downstream processing stage, and identify critical processes and factors that impact bioactive material acquisition and retention. Furthermore, since nanoencapsulation technology emerges as an effective solution for microalgae nutraceutical product's retention, this work also focus on the nanoparticle perspective and comprehensively reviews the current nanoencapsulation solutions of the microalgae bioactive extract products. The aim is to depict advances in the formulations of microalage bioactive nanoparticles and provide a critical analysis of the reported nanoparticle formation. Overall, through the investigation of microalgae from biomass to bioactive nanoparticles, we aim to facilitate microalgae nutraceuticals incorporation as high value-added ingredients in more functional food that can improve human health.
  7. Exploring the additive bio-agent impacts upon ectoine production by Halomonas salina DSM5928T using corn steep liquor and soybean hydrolysate as nutrient supplement
    Chen PW, Cui ZY, Ng HS, Chi-Wei Lan J
    J Biosci Bioeng, 2020 Aug;130(2):195-199.
    PMID: 32370929 DOI: 10.1016/j.jbiosc.2020.03.011
    Ectoine production using inexpensive and renewable biomass resources has attracted great interest among the researchers due to the low yields of ectoine in current fermentation approaches that complicate the large-scale production of ectoine. In this study, ectoine was produced from corn steep liquor (CSL) and soybean hydrolysate (SH) in replacement to yeast extract as the nitrogen sources for the fermentation process. To enhance the bacterial growth and ectoine production, biotin was added to the Halomonas salina fermentation media. In addition, the effects addition of surfactants such as Tween 80 and saponin on the ectoine production were also investigated. Results showed that both the CSL and SH can be used as the nitrogen source substitutes in the fermentation media. Higher amount of ectoine (1781.9 mg L-1) was produced in shake flask culture with SH-containing media as compared to CSL-containing media. A total of 2537.0 mg L-1 of ectoine was produced at pH 7 when SH-containing media was applied in the 2 L batch fermentation. Moreover, highest amount of ectoine (1802.0 mg L-1) was recorded in the SH-containing shake flask culture with addition of 0.2 μm mL-1 biotin. This study demonstrated the efficacy of industrial waste as the nutrient supplement for the fermentation of ectoine production.
  8. Fulltext Mangosteen xanthone γ-mangostin exerts lowering blood glucose effect with potentiating insulin sensitivity through the mediation of AMPK/PPARγ
    Chen SP, Lin SR, Chen TH, Ng HS, Yim HS, Leong MK, et al.
    Biomed Pharmacother, 2021 Dec;144:112333.
    PMID: 34678724 DOI: 10.1016/j.biopha.2021.112333
    Diabetes mellitus (DM) is concomitant with significant morbidity and mortality and its prevalence is accumulative in worldwide. The conventional antidiabetic agents are known to mitigate the symptoms of diabetes; however, they may also cause side and adverse effects. There is an imperative necessity to conduct preclinical and clinical trials for the discovery of alternative therapeutic agents that can overcome the drawbacks of current synthetic antidiabetic drugs. This study aimed to investigate the efficacy of lowering blood glucose and underlined mechanism of γ-mangostin, mangosteen (Garcinia mangostana) xanthones. The results showed γ-Mangostin had a antihyperglycemic ability in short (2 h)- and long-term (28 days) administrations to diet-induced diabetic mice. The long-term administration of γ-mangostin attenuated fasting blood glucose of diabetic mice and exhibited no hepatotoxicity and nephrotoxicity. Moreover, AMPK, PPARγ, α-amylase, and α-glucosidase were found to be the potential targets for simulating binds with γ-mangostin after molecular docking. To validate the docking results, the inhibitory potency of γ-mangostin againstα-amylase/α-glucosidase was higher than Acarbose via enzymatic assay. Interestingly, an allosteric relationship between γ-mangostin and insulin was also found in the glucose uptake of VSMC, FL83B, C2C12, and 3T3-L1 cells. Taken together, the results showed that γ-mangostin exerts anti-hyperglycemic activity through promoting glucose uptake and reducing saccharide digestion by inhibition of α-amylase/α-glucosidase with insulin sensitization, suggesting that γ-mangostin could be a new clue for drug discovery and development to treat diabetes.
  9. Advances in production of bioplastics by microalgae using food waste hydrolysate and wastewater: A review
    Chong JWR, Khoo KS, Yew GY, Leong WH, Lim JW, Lam MK, et al.
    Bioresour Technol, 2021 Dec;342:125947.
    PMID: 34563823 DOI: 10.1016/j.biortech.2021.125947
    Microalgae have emerged as an effective dual strategy for bio-valorisation of food processing wastewater and food waste hydrolysate which favours microalgae cultivation into producing value-added by products mainly lipids, carbohydrates, and proteins to the advantages of bioplastic production. Moreover, various microalgae have successfully removed high amount of organic pollutants from food processing wastewater prior discharging into the environment. Innovation of microalgae cultivating in food processing wastewater greatly reduced the cost of wastewater treatment compared to conventional approach in terms of lower carbon emissions, energy consumption, and chemical usage while producing microalgae biomass which can benefit low-cost fertilizer and bioplastic applications. The study on several microalgae species has all successfully grown on food waste hydrolysates showing high exponential growth rate and biomass production rich in proteins, lipids, carbohydrates, and fatty acids. Multiple techniques have been implemented for the extraction of food wastes to be incorporate into the bioplastic production.
  10. Recent development in the production strategies of microbial carotenoids
    Foong LC, Loh CWL, Ng HS, Lan JC
    World J Microbiol Biotechnol, 2021 Jan 04;37(1):12.
    PMID: 33392834 DOI: 10.1007/s11274-020-02967-3
    Carotenoids are a diverse group of lipid-soluble pigments that exhibit potent biological activities such as antioxidant, anti-inflammatory, and provitamin A activities. The potent health benefits of carotenoids result in the surge in the market demands for carotenoids, especially natural carotenoids from sustainable sources. Microbial carotenoids have attracted considerable interests for many industrial applications because of the low costs and ease of scaling-up with shorter production time. There is a growing interest in the search of new and sustainable microbial sources and cost-efficient production strategies following the high economical values and vast commercial applications of carotenoids. This article presents a review on the industrial production strategies of microbial carotenoids from microalgae, fungi, and bacteria sources. The industrial significance of the mass production of microbial carotenoids is also discussed. The structure, classification, and biosynthesis pathway of the carotenoids are also presented in this review.
  11. Fulltext The correlation between cytopenia and esophageal varices in patients with liver cirrhosis
    Gue CS, Yap CK, Ng HS
    Med J Malaysia, 2004 Dec;59(5):604-8.
    PMID: 15889562
    This retrospective study analysed the case records of 200 patients in the Department of Gastroenterology, Singapore General Hospital from February 2000 to January 2001 who had liver cirrhosis and underwent gastroscopy for the detection of varices. The aim of this study was to determine any relationship between leucopenia, thrombocytopenia and the occurrence of esophageal varices in a cirrhotic population. Our results showed that the diagnostic yield of varices grade 2 and 3 was 6.3% if platelet count was > 150,000/mm3, 25% if platelet count was 100,000 to 150,000/mm3, 38.9% if platelet count was 50,000-99,000/mm3 and 100% if platelet count was <50,000/mm3. Similarly, the diagnostic yield of varices grade 2 and 3 was 19.4% if total white count was > 4,000/mm3, 66.7% if total white count was 3,000- 4,000/mm3 and 94.8% if total white count was < 3,000/mm5. We conclude that thrombocytopenia and leucopenia can be used to stratify risk for occurrence of esophageal varices in cirrhotic patients and gastroscopy will have a high yield for varices when platelet count is < 150,000/mm3 or total white is < 4,000/mm.
  12. Utilizing adsorption of wood and its derivatives as an emerging strategy for the treatment of heavy metal-contaminated wastewater
    Jiang J, Shi Y, Ma NL, Ye H, Verma M, Ng HS, et al.
    Environ Pollut, 2024 Jan 01;340(Pt 1):122830.
    PMID: 37918773 DOI: 10.1016/j.envpol.2023.122830
    The rapid development of the industrial sector has resulted in tremendous economic growth. However, this growth has also presented environmental challenges, specifically due to the substantial sewage generated and its contribution to the early warning of global water resource depletion. Large concentrations of poisonous heavy metals, including cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and nickel (Ni), are found in industrial effluent. Therefore, various studies are currently underway to provide effective solutions to alleviate heavy metal ion pollution in sewage. One emerging strategy for sewage pollution remediation is adsorption using wood and its derivatives. This approach is gaining popularity due to the porous structure, excellent mechanical properties, and easy chemical modification of wood. Recent studies have focused on removing heavy metal ions from sewage, summarising and analysing different technical principles, affecting factors, and mainstream chemical modification methods on wood. Furthermore, this work provides insight into potential future development direction for enhanced adsorption of heavy metal ions using wood and its derivatives in wastewater treatment. Overall, this review aims to raise awareness of environmental pollution caused by heavy metals in sewage and promote green environmental protection, low-carbon energy-saving, and sustainable solutions for sewage heavy metal treatment.
  13. Fulltext Curcumin Metabolite Tetrahydrocurcumin in the Treatment of Eye Diseases
    Kao YW, Hsu SK, Chen JY, Lin IL, Chen KJ, Lee PY, et al.
    Int J Mol Sci, 2020 Dec 28;22(1).
    PMID: 33379248 DOI: 10.3390/ijms22010212
    Curcumin is one of the most valuable natural products due to its pharmacological activities. However, the low bioavailability of curcumin has long been a problem for its medicinal use. Large studies have been conducted to improve the use of curcumin; among these studies, curcumin metabolites have become a relatively new research focus over the past few years. Additionally, accumulating evidence suggests that curcumin or curcuminoid metabolites have similar or better biological activity than the precursor of curcumin. Recent studies focus on the protective role of plasma tetrahydrocurcumin (THC), a main metabolite of curcumin, against tumors and chronic inflammatory diseases. Nevertheless, studies of THC in eye diseases have not yet been conducted. Since ophthalmic conditions play a crucial role in worldwide public health, the prevention and treatment of ophthalmic diseases are of great concern. Therefore, the present study investigated the antioxidative, anti-inflammatory, antiangiogenic, and neuroprotective effects of THC on four major ocular diseases: age-related cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). While this study aimed to show curcumin as a promising potential solution for eye conditions and discusses the involved mechanistic pathways, further work is required for the clinical application of curcumin.
  14. Recent development of unconventional aqueous biphasic system: characteristics, mechanisms and applications
    Kee PE, Ng TC, Lan JC, Ng HS
    Crit Rev Biotechnol, 2020 Jun;40(4):555-569.
    PMID: 32283954 DOI: 10.1080/07388551.2020.1747388
    Aqueous biphasic system (ABS) is widely used in the recovery, extraction, purification and separation of proteins, enzymes, nucleic acids and antibodies. The ABS with high water content and low interfacial tension offers a biocompatible environment for the recovery of labile biomolecules. Process integration can be achieved using ABS by incorporating multiple-steps of purification, concentration and purification of biomolecules in a single-step operation which often results in high product recovery yield and purity. Conventional ABS is usually formed by aqueous solutions of two polymers or a polymer and a salt above a critical concentration. The high viscosity of polymer-based ABS causes slow phase separation and hinders the mass transfer of biomolecules, whereas polymer/salt ABS is characterized by high ionic strength resulting in the loss of bioactivity of recovered biomolecules. These limitations have encouraged the development of novel ABS which is more cost-effective for various biotechnological applications. This review discusses the characteristics and mechanisms of several types of emerging unconventional ABS using phase-forming components such as hyperbranched polymers, special salts, surfactants, magnetic fields, the addition of nanoparticles and incorporation of various solvent. Moreover, several novel applications of ABS for different separation purposes such as microfluidic-based ABS, ABS bioreactors, application of ABS as an analytical tool, and ABS micropatterning are discussed in this review. In the last section of this review, a comprehensive summary of process integration using ABS for extractive fermentations, bioconversion, crystallization and precipitation is also supplemented for the comprehensive review of various types and applications of ABS in recent years.
  15. Efficiency of Ionic Liquids-Based Aqueous Two-phase Electrophoresis for Partition of Cytochrome c
    Kee PE, Lan JC, Yim HS, Tan JS, Chow YH, Ng HS
    Appl Biochem Biotechnol, 2020 May;191(1):376-386.
    PMID: 31907777 DOI: 10.1007/s12010-019-03202-y
    Cytochrome c is a small water-soluble protein that is abundantly found in the mitochondrial intermembrane space of microorganism, plants and mammalians. Ionic liquids (ILs)-based aqueous two-phase electrophoresis system (ATPES) was introduced in this study to investigate the partition efficiency of cytochrome c to facilitate subsequent development of two-phase electrophoresis for the separation of cytochrome c from microbial fermentation. The 1-Hexyl-3-methylimidazolium bromide, (C6mim)Br and potassium citrate salt were selected as the phase-forming components. Effects of phase composition; position of electrodes; pH and addition of neutral salt on the partition efficiency of cytochrome c in the ATPES were evaluated. Highest partition coefficient (K = 179.12 ± 0.82) and yield of cytochrome c in top phase (YT = 99.63% ± 0.00) were recorded with IL/salt ATPES composed of 30% (w/w) (C6mim)Br and 20% (w/w) potassium citrate salt of pH 7 and 3.0% (w/w) NaCl addition with anode at the bottom phase and cathode at the top phase. The SDS-PAGE profile revealed that cytochrome c with a molecular weight of 12 kDa was preferably partitioned to the IL-rich top phase. Present findings suggested that the single-step ATPES is a potential separation approach for the recovery of cytochrome c from microbial fermentation. Graphical Abstract.
  16. Fulltext Evaluation of Aqueous Biphasic Electrophoresis System Based on Halide-Free Ionic Liquids for Direct Recovery of Keratinase
    Kee PE, Yim HS, Kondo A, Lan JC, Ng HS
    Mar Drugs, 2021 Aug 17;19(8).
    PMID: 34436302 DOI: 10.3390/md19080463
    Aqueous biphasic electrophoresis system (ABES) incorporates electric fields into the biphasic system to separate the target biomolecules from crude feedstock. Ionic liquid (IL) is regarded as an excellent candidate as the phase-forming components for ABES because of the great electrical conductivity, which can promote the electromigration of biomolecules in ABES, and thereby enhances the separation efficiency of the target biomolecules from crude feedstock. The application of electric fields to the conventional biphasic system expedites the phase settling time of the biphasic system, which eases the subsequent scaling-up steps and reduces the overall processing time of the recovery process. Alkyl sulphate-based IL is a green and economical halide-free surfactant when compared to the other halide-containing IL. The feasibility of halide-free IL-based ABES to recover Kytococcus sedentarius TWHK01 keratinase was studied. Optimum partition coefficient (Ke = 7.53 ± 0.35) and yield (YT = 80.36% ± 0.71) were recorded with IL-ABES comprised of 15.0% (w/w) [EMIM][ESO4], 20.0% (w/w) sodium carbonate and 15% (w/w) crude feedstock. Selectivity (S) of 5.75 ± 0.27 was obtained with the IL-ABES operated at operation time of 5 min with 10 V voltage supplied. Halide-free IL is proven to be a potential phase-forming component of IL-ABES for large-scale recovery of keratinase.
  17. Insect biorefinery: A circular economy concept for biowaste conversion to value-added products
    Kee PE, Cheng YS, Chang JS, Yim HS, Tan JCY, Lam SS, et al.
    Environ Res, 2023 Mar 15;221:115284.
    PMID: 36640934 DOI: 10.1016/j.envres.2023.115284
    With rapid growing world population and increasing demand for natural resources, the production of sufficient food, feed for protein and fat sources and sustainable energy presents a food insecurity challenge globally. Insect biorefinery is a concept of using insect as a tool to convert biomass waste into energy and other beneficial products with concomitant remediation of the organic components. The exploitation of insects and its bioproducts have becoming more popular in recent years. This review article presents a summary of the current trend of insect-based industry and the potential organic wastes for insect bioconversion and biorefinery. Numerous biotechnological products obtained from insect biorefinery such as biofertilizer, animal feeds, edible foods, biopolymer, bioenzymes and biodiesel are discussed in the subsequent sections. Insect biorefinery serves as a promising sustainable approach for waste management while producing valuable bioproducts feasible to achieve circular bioeconomy.
  18. Expression of His-tagged NADPH-dependent acetoacetyl-CoA reductase in recombinant Escherichia coli BL-21(DE3)
    Kee PE, Chiang YC, Ng HS, Lan JC
    J Biosci Bioeng, 2023 Oct;136(4):312-319.
    PMID: 37500302 DOI: 10.1016/j.jbiosc.2023.07.001
    Poly-3-hydroxybutyrate (P(3HB)), a member of the polyhydroxyalkanoate (PHA) family, is a biodegradable polyester with diverse industrial applications. NADPH-dependent acetoacetyl-CoA reductase (phaB) is the enzyme which plays an essential role in P(3HB) synthesis by catalyzing the conversion of the intermediates. The expression of phaB enzyme using the recombinant Escherichia coli BL-21(DE3) and the purification of the synthesized enzyme were studied. The pET-B3 plasmid harbouring the phaB gene derived from Ralstonia eutropha H16, was driven by the lac promoter in E. coli BL-21(DE3). The enzyme was expressed with different induction time, temperatures and cell age. Results showed that the cell age of 4 h, induction time of 12 h at 37°C were identified as the optimal conditions for the enzyme reductase expression. A specific activity of 0.151 U mg-1 protein and total protein concentration of 0.518 mg mg-1 of dry cell weight (DCW) were attained. Affinity chromatography was performed to purify the His-tagged phaB enzyme, in which enhanced the specific activity (14.44 U mg-1) and purification fold (38-fold), despite relative low yield (44.6%) of the enzyme was obtained. The purified phaB showed an optimal enzyme activity at 30°C and pH 8.0. The findings provide an alternative for the synthesis of the reductase enzyme which can be used in the industrial-scale production of the biodegradable polymers.
  19. Tropical Seaweeds as a Sustainable Resource Towards Circular Bioeconomy: Insights and Way Forward
    Kee PE, Phang SM, Lan JC, Tan JS, Khoo KS, Chang JS, et al.
    Mol Biotechnol, 2023 Nov 08.
    PMID: 37938536 DOI: 10.1007/s12033-023-00940-7
    Seaweeds are photosynthetic marine macroalgae known for their rapid biomass growth and their significant contributions to global food and feed production. Seaweeds play a crucial role in mitigating various environmental issues, including greenhouse gases, ocean acidification, hypoxia, and eutrophication. Tropical seaweeds are typically found in tropical and subtropical coastal zones with warmer water temperatures and abundant sunlight. These tropical seaweeds are rich sources of proteins, vitamins, minerals, fibers, polysaccharides, and bioactive compounds, contributing to their health-promoting properties and their diverse applications across a range of industries. The productivity, cultivability, nutritional quality, and edibility of tropical seaweeds have been well-documented. This review article begins with an introduction to the growth conditions of selected tropical seaweeds. Subsequently, the multifunctional properties of tropical seaweeds including antioxidant and anti-inflammatory, anti-coagulant, anti-carcinogenic and anti-proliferative, anti-viral, therapeutic and preventive properties were comprehensively evaluated. The potential application of tropical seaweeds as functional foods and feeds, as well as their contributions to sustainable cosmetics, bioenergy, and biofertilizer production were also highlighted. This review serves as a valuable resource for researchers involved in seaweed farming as it provides current knowledge and insights into the cultivation and utilization of seaweeds.
  20. Fulltext Nutrients for Prevention of Macular Degeneration and Eye-Related Diseases
    Khoo HE, Ng HS, Yap WS, Goh HJH, Yim HS
    Antioxidants (Basel), 2019 Apr 02;8(4).
    PMID: 30986936 DOI: 10.3390/antiox8040085
    The risk of macular degeneration can be reduced through the consumption of antioxidant-rich foods, supplements, and nutraceutical formulas. This review focuses on the antioxidants, vitamins, and minerals that have been reported for reducing the risk of macular degeneration and other eye-related diseases. Antioxidants including anthocyanins, carotenoids, flavonoids, and vitamins have been shown to reduce the risk of eye-related diseases. Anthocyanins extracted from berries are powerful antioxidants. Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin are anthocyanin aglycones detected in berries, currants, and other colored fruits and vegetables. β-Carotene, as well as xanthophyll lutein and zeaxanthin, have been reported to reduce the risk of macular degeneration. Flavonoids from plants help in the prevention of eye-related diseases through anti-inflammatory mechanisms. A combination of these antioxidants, vitamins, and minerals possess a synergistic effect on the prevention or risk reduction of macular degeneration. Formulas have been developed as dietary supplements to cater to the high demand from consumers and patients with eye problems. Many of the formulated dietary supplements that are sold in the market have been clinically proven for their efficacy to treat eye diseases. Although the bioactivities in the supplement capsules or tablets have been scientifically established for reducing risks of several diseases, which include macular degeneration and other eye-related diseases, knowledge on the right dosage, efficacy, and bioavailability of antioxidants, vitamins, and minerals is important for consumers. The information may help them make the best decision in choosing the right dietary supplements and nutraceuticals following the evidence-based recommended dosages and reference intakes for improving general health and preventing eye-related diseases. This review covers the potential causal factors involved in eye diseases, clinically proven treatments, and controversial findings on the antioxidants in the prevention of macular degeneration. Future studies should consider multiethnic and multicenter trials for eliminating potential bias in research.
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links