Ternary biogenic silica/magnetite/graphene oxide composite for the hyperactivation of Candida rugosa lipase in the esterification production of ethyl valerate

Oil palm leaves (OPL) silica (SiO2) can replace the energy-intensive, commercially produced SiO2. Moreover, the agronomically sourced biogenic SiO2 is more biocompatible and cost-effective enzyme support, which properties could be improved by the addition of magnetite (Fe3O4) and graphene oxide (GO) to yield better ternary support to immobilize enzymes, i.e., Candida rugosa lipase (CRL). This study aimed to optimize the Candida rugosa lipase (CRL immobilization onto the ternary OPL-silica-magnetite (Fe3O4)-GO (SiO2/Fe3O4/GO) support, for use as biocatalyst for ethyl valerate (EV) production. Notably, this is the first study detailing the CRL/SiO2/Fe3O4/GO biocatalyst preparation for rapid and high yield production of ethyl valerate (EV). AFM and FESEM micrographs revealed globules of CRL covalently bound to GL-A-SiO2/Fe3O4/GO; similar to Raman and UV–spectroscopy results. FTIR spectra revealed amide bonds at 3478 cm–1 and 1640 cm–1 from covalent interactions between CRL and GL-A-SiO2/Fe3O4/GO. Optimum immobilization conditions were 4% (v/v) glutaraldehyde, 8 mg/mL CRL, at 16 h stirring in 150 mM NaCl at 30 °C, offering 24.78 ± 0.26 mg/g protein (specific activity = 65.24 ± 0.88 U/g). The CRL/SiO2/Fe3O4/GO yielded 77.43 ± 1.04 % of EV compared to free CRL (48.75 ± 0.70 %), verifying the suitability of SiO2/Fe3O4/GO to hyperactivate and stabilize CRL for satisfactory EV production

Assessment of fatty acid composition and response surface optimization of ultrasonic-assisted extraction of phenolic compounds from Pouteria campechiana pulp

Pouteria campechiana (PC) pulp was analyzed for its fatty acid composition. Fourteen different kinds of fatty acids were found with the major fatty acids viz. palmitic acid (C16:0), oleic acid (C18:1), myristic acid (C14:0) and linolenic acid (C18:2), making up approximately 73.8 % of the total fatty acid content (TPC). An ultrasonic-assisted extraction (UAE) of the polyphenolic bioactive components in PC pulp powder were statistically optimized using the Central Composite Design (CCD). Factors that gave maximized TPC in the crude extract of PC pulp powder were assessed for factors, ratio of ethanol:water, extraction temperature and extraction time. The established optimum conditions of the CCD model with R2 = 0.8833 were within the studied range and agreed well with the predicted values. Under an optimized condition [30 min, 35 °C and ratio of ethanol:water, 60:40 (%, v/v)], the highest TPC was 1162.80 mg GAE/100 g in comparison to the predicted 1115.06 mg GAE/100 g. High Performance Liquid Chromatography confirmed that gallic acid and its derivatives were the major components, comprising a ?0.03 % (w/w) of the PC pulp crude extract. Pertinently, a high recovery value in the HPLC validation data (109.84 %, R2 = 0.9995) suggests the method was accurate

Optimization of Endoglucanase Synthesis by Trichoderma harzianum via Taguchi Approach

The oil palm biomass produced by plantations and mills in Malaysia is the largest contributor to the nation’s agro-waste, with the oil palm leaves (OPL) topping the list. Nevertheless, the surplus of OPL might have applicability as the substrate for cultivating lignocellulolytic bio-degraders. Ipso facto, this study employed raw OPL as the carbon source for cultivating Trichoderma harzianum under solid-state fermentation (SSF). Optimization of the SSF process using the Taguchi orthogonal design to produce endoglucanase (CMCase) successfully established the optimal fermentation conditions as the following: 7.00 × 108 spore/g inoculum size, 50% moisture content, pH 12 Mandel’s medium, with 3-day incubation at 40°C. The crude enzyme cocktail exhibited the corresponding maximum activity of 417.49 U/g CMCase. The enzymatic activities were significantly affected by factors, moisture content, inoculum size, and initial pH (p-value < 0.05). In short, the high extracellular CMCase activity of the T. harzianum crude enzyme cocktail may prove valuable in accelerating the saccharification of cellulose for biofuel-and nanocellulose production

Nanocellulose and nanoclay as reinforcement materials in polymer composites: a review

The advancement of nanotechnology has opened a new opportunity to develop nanocomposites using nanocellulose (NC) and nanoclay (NCl). Researchers have regarded these nanocomposites as promising substitutes for conventional polymers because of their characteristic and useful features, which include exceptional strength and stiffness, low weight, and low environmental impact. These features of NC and NCl explain their multifarious applications across many sectors. Here we review NC and NCl as well as various reinforced polymer composites that are made up of either of the two nanomaterials. The structural and physicochemical properties of NC and NCl are highlighted, along with the mechanical behavior and thermal properties of NC. Current nanomaterial hybrid biopolymers for the production of novel high-performance polymer nanocomposites are also discussed with respect to their mechanical properties

Operational stability, regenerability, and thermodynamics studies on biogenic silica/magnetite/graphene oxide nanocomposite-activated candida rugosa lipase

Inorganic biopolymer-based nanocomposites are useful for stabilizing lipases for enhanced catalytic performance and easy separation. Herein, we report the operational stability, regenerability, and thermodynamics studies of the ternary biogenic silica/magnetite/graphene oxide nanocomposite (SiO2 /Fe3 O4 /GO) as a support for Candida rugosa lipase (CRL). The X-ray photo-electron spectroscopy (XPS), X-ray diffraction (XRD), field-electron scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM), and nitrogen adsorption/desorption data on the support and biocatalyst corroborated their successful fabrication. XPS revealed the Fe3 O4 adopted Fe2+ and Fe3+ oxidation states, while XRD data of GO yielded a peak at 2θ = 11.67◦, with the SiO2 /Fe3 O4 /GO revealing a high surface area (≈261 m2 /g). The fourier transform infrared (FTIR) spectra affirmed the successful fabricated supports and catalyst. The half-life and thermodynamic parameters of the superparamagnetic immobilized CRL (CRL/SiO2 /Fe3 O4 /GO) improved over the free CRL. The microwave-regenerated CRL/SiO2 /Fe3 O4 /GO (≈82%) exhibited higher catalytic activity than ultrasonic-regenerated (≈71%) ones. Lower activation (Ea) and higher deactivation en-ergies (Ed) were also noted for the CRL/SiO2 /Fe3 O4 /GO (13.87 kJ/mol, 32.32 kJ/mol) than free CRL (15.26 kJ/mol, 27.60 kJ/mol). A peak at 4.28 min in the gas chromatograph-flame ionization detection (GC-FID) chromatogram of the purified ethyl valerate supported the unique six types of 14 hydrogen atoms of the ester (CAS: 539-82-2) in the proton nuclear magnetic resonance (1 H-NMR) data. The results collectively demonstrated the suitability of SiO2 /Fe3 O4 /GO in stabilizing CRL for improved operational stability and thermodynamics and permitted biocatalyst regenerability

Development of nanoemulsion incorporated with Hibiscus sabdariffa for cosmeceutical application

Hibiscus sabdariffa (HS) has been reported to possess a crucial content of bioactive compounds, such as phenolic acids and flavonoids, therefore, HS was recognized as a source of antioxidants. Due to that, the development of nanoemulsion incorporated with HS appears promising for cosmeceutical application. This study is focused on the formulation of oil-inwater (O/W) nanoemulsions of HS to enhance the bioaccessibility of its active compounds. The influences of hydrophiliclipophilic balance (HLB) value of surfactant and grapeseed oil (GSO) to olive oil (OO) ratio on the droplet size, zeta potential, PDI and stability of the nanoemulsions were investigated. The results showed that the smallest particle size was obtained at 145.9 nm with PDI = 0.388 and zeta-potential = -41.1 mV in the systems prepared using HLB value of 12 and 2:1 ratio of GSO to OO. Then the selected nanoemulsion which based on the lowest particle size (NE-F6, GSO:OO = 2:1, and HLB = 12) showed good stability over time and temperature without no phase separation, creaming or cracking was spotted. The pH value of the NE-F6 was obtained at 5.2

Development of nanoemulsion incorporated with Hibiscus sabdariffa for cosmeceutical application

Hibiscus sabdariffa (HS) has been reported to possess a crucial content of bioactive compounds, such as phenolic acids and flavonoids, therefore, HS was recognized as a source of antioxidants. Due to that, the development of nanoemulsion incorporated with HS appears promising for cosmeceutical application. This study is focused on the formulation of oil-inwater (O/W) nanoemulsions of HS to enhance the bioaccessibility of its active compounds. The influences of hydrophiliclipophilic balance (HLB) value of surfactant and grapeseed oil (GSO) to olive oil (OO) ratio on the droplet size, zeta potential, PDI and stability of the nanoemulsions were investigated. The results showed that the smallest particle size was obtained at 145.9 nm with PDI = 0.388 and zeta-potential = -41.1 mV in the systems prepared using HLB value of 12 and 2:1 ratio of GSO to OO. Then the selected nanoemulsion which based on the lowest particle size (NE-F6, GSO:OO = 2:1, and HLB = 12) showed good stability over time and temperature without no phase separation, creaming or cracking was spotted. The pH value of the NE-F6 was obtained at 5.2

In silico analysis of a putative dehalogenase from the genome of halophilic bacterium Halomonas smyrnensis AAD6T

Microbial-assisted removal of natural or synthetic pollutants is the prevailing green, low-cost technology to treat polluted environments. However, the challenge with enzyme-assisted bioremediation is the laborious nature of dehalogenase-producing microorganisms’ bioprospecting. This bottleneck could be circumvented by in-silico analysis of certain microorganisms’ whole-genome sequences to predict their protein functions and enzyme versatility for improved biotechnological applications. Herein, this study performed structural analysis on a dehalogenase (DehHsAAD6) from the genome of Halomonas smyrnensis AAD6 by molecular docking and molecular dynamic (MD) simulations. Other bioinformatics tools were also employed to identify substrate preference (haloacids and haloacetates) of the DehHsAAD6. The DehHsAAD6 preferentially degraded haloacids and haloacetates ( 3.2–4.8 kcal/ mol) and which formed three hydrogen bonds with Tyr12, Lys46, and Asp182. MD simulations data revealed the higher stability of DehHsAAD6-haloacid- (RMSD 0.22–0.3 nm) and DehHsAAD6-haloacetates (RMSF 0.05–0.14nm) complexes, with the DehHsAAD6-L-2CP complex being the most stable. The detail of molecular docking calculations ranked complexes with the lowest binding free energies as: DehHsAAD6-L-2CP complex ( 4.8 kcal/mol) ¼ DehHsAAD6-MCA ( 4.8 kcal/mol) < DehHsAAD6-TCA ( 4.5 kcal/mol) < DehHsAAD6-2,3-DCP ( 4.1 kcal/mol) < DehHsAAD6-D-2CP ( 3.9 kcal/mol) < DehHsAAD6-2,2-DCP ( 3.5 kcal/mol) < DehHsAAD6-3CP ( 3.2 kcal/mol). In a nutshell, the study findings offer valuable perceptions into the elucidation of possible reaction mechanisms of dehalogenases for extended substrate specificity and higher catalytic activity

Antioxidant Activity of Andrographolide from Andrographis paniculata leaf and Its Extraction Optimization by using Accelerated Solvent Extraction

Andrographis paniculata is widely used as a medicinal plant in many countries and andrographolide is the major bioactive compound extracted from A. paniculata leaf. This study purposely to optimize statistical andrographolide extraction using the accelerated solvent extraction (ASE) technique. The Box Behnken design (BBD) was chosen to determine the optimum ASE conditions for the extraction temperature (ºC), cycle number, and extraction time (min) to achieve the highest yield of andrographolide. The optimum ASE conditions were identified as: extraction temperature of 60 ºC, using 3 cycles and 5 min extraction time, with maximum conversion yield as high as 335.2 ± 0.2 mg/g determined by High Performance Liquid Chromatography (HPLC) with the squared correlation coefficients (R2) of 0.97. The findings revealed the ASE method significantly enhanced andrographolide extraction and agreed closely with the predicted value at 337.5 mg/g. Andrographolide was isolated by preparative HPLC technique. A. paniculata leaf extract and extracted andrographolide displayed moderate radical scavenging activity in 2, 2−Diphenyl−1−picrylhydrazyl hydrate (DPPH) assay with IC50 of 0.883 ± 1.597 mg/ml and 0.514 ± 0.285 mg/ml respectively as IC50 for ascorbic acid was 0.048 ± 0.004 mg/ml.  A. paniculata extract and andrographolide inhibited the tyrosinase enzyme with IC50 of 0.749 ± 0.293 μg/ml and IC50 of 2.441 ± 2.026 μg/ml indicated stronger tyrosinase inhibition abilities than kojic acid, IC50 of 19.985 ± 0.557 μg/ml. These results suggest that A. paniculata leaf extract and andrographolide have greater potential as sources of biochemical compounds that can be used as skin depigmentation solutions

Occurrence and identification of basidiomycetous fomitopsis species the causal agent of brown-rot in oil palm elaeis guineensis in Johor, Malaysia

Macro fungi belonging to the family “Polyporaceae†in the phylum Basidiomycota are among the commonplace causal agents of plant diseases. In the present study, we reported the molecular characterization of a macro fungi basidiomycetous brown-rot fungal phytopathogen Fomitopsis strain MM4. The fungal phytopathogen was identified and molecular characterized from the infected stem and tissue of oil palm (Elaeis guineensis) in Kulai, Johor. The 18SrRNA nucleotide sequence of the fungal pathogen strain MM4 showed 99% similarity with partial sequences of Antrodia serialis maintained in the genebank database. The pairwise multiple sequence alignment and phylogenetic analysis revealed that the fungus clustered into a single branch of a phylogenetic tree; hence the fungus was designated as Fomitopsis meliae (MM4). The pathogenicity test revealed significant differences (p ≤ 0.05) in disease severity caused by the characterized basidiomycetous brown-rot F. meliae fungal pathogen on oil palm seedlings and the pathogen was successfully re-isolated from infected samples. To the best of our knowledge, this is the first report of 18S rRNA F. meliae Basidiomycota brown-rot fungi infecting oil palm (Elaeis guineensis). The findings of this study thus support the diversity of pathogenic macro fungi affecting oil palm trees in Malaysia