Intraparticle convection, diffusion and reaction of substrate in porous slab catalysts for zero order reaction

Diffusion-reaction problem in a porous solid catalyst is important in the design and analysis of heterogeneous phase reactors and has been extensively studies. However, the effect of intraparticle convection on the substrate transport inside the solid has been scantly reported in the literature, though intraparticle convection plays significant role in enhancing the substrate transport inside the porous catalyst. This becomes more significant especially in the case of immobilized biocatalysts applications with limited reactant solubility, such as oxygen in aqueous phase, typically encountered in aerobic fermentation and biodegradation. Though earlier works have reported on the effect of intraparticle convection on the nutrient transport in porous solid catalysts, there remain gaps and unexplored aspects of this problem. This research investigates the effect of intraparticle convection for the case of zero order reaction in slab geometry. The convection effect is represented in term of intraparticle Peclet Number in the differential equation obtained as a result of mass balance for the nutrient transport inside the solid catalyst. The effect of intraparticle flow on the intrapraticle nutrient transport is studied by solving the resulting differential equation for the concentration profile inside the solid which in turn is used to calculate the effectiveness factor of the catalyst. The exact solutions for the zero order reactions is obtained following the analytical approach. The numerical solution using an explicit finite difference scheme is used to validate our analytical results. The analytical and the numerical solutions almost superimpose each other which proves that our analytical solution is correct. The results show that the convection enhances the rate of nutrients transport inside the porous solid. With the increasing value of Intraparticle Peclet Number, the substrate penetrates deeper into the solid in the direction of the flow

Screening of β-glucoside kinase directed evolution library to form a sulfur-phosphorus bond

Glycoscience is a field that explores the structures and functions of glycans promising great advances in an array of applications. The objective of this research is to form a sulfur-phosphorus bond at the position 6’ of the sugar involved in many biological processes. A directed evolution strategy was adopted with error-prone PCR technique to create random mutagenesis of recombinant plasmid library of the β-glucoside kinase (βglk) recloned into a pTrcHisB plasmid and transformed into Escherichia coli. Following the creation of libraries, high throughput screening by 96-well microplate using fluorescent activated cell sorting (FACS) techniques were carried out. Positive clones were selected, sequenced for identification and enzyme expression and characterization were carried out

Temperature effect on expression of soluble Endoglucanase I from Fusarium oxysporum using E. coli Lemo21:DE3

Formation of inclusion bodies especially when expressing eukaryotic recombinant proteins in prokaryotic host such as E. coli is a challenge. Ability to express soluble proteins in E.coli will enable us to utilize all the benefits of E.coli as a host mainly the short doubling time. As few reports indicates that temperature influences the expression of recombinant proteins, this study aims to observe its effect on solubility of endoglucanase I. The optimum temperature for expressing endoglucanase I from Fusarium oxysporum using Lemo21:DE3 as a host is reported here

Bioprospecting novel cellulose-degrading enzymes from pome metagenomic DNA libraries by enrichment strategy

Green technology is the environment-friendly way to protect the Earth’s natural resources and the environment we inhabit. The functionalmetagenomic approach has proven to be a powerful tool to identify novel biocatalysts indispensables in green technology of biofuel production from plant’s biomass through metagenomic DNA library construction and high-throughput screening. Culture enrichment strategies are additional pre-screening methods to provide an attractive mean of enhancing the screening hit rate. In this work metagenomic DNA libraries were made from Malaysian palm oil mill effluent (POME) microorganisms after culture enrichment experiment based on natural selection principle. Metagenomic DNA was extracted from both enriched and non-enriched cultures and cloned to pCC1FOS fosmid and transformed into EPI300™-T1RE. coli.Qualitative and quantitative analysis of metagenomic DNA and recombinant clones are provided to confirm the efficiency of enrichment strategy

Potential inhibitors of α-glucosidase and α-amylase enzymes from locally available fruit wastes by solid state fermentation

A therapeutic approach for treating diabetes is to decrease thepost-prandial hyperglycaemia. This is done by retarding the absorption of glucose through the inhibition of carbohydrate hydrolyzing enzymes, α-amylase and α-glucosidase, in the digestive tract. Inhibition of both enzymes helps to reduce the glucose level in the blood of a diabetic patient. This study was aimed to investigate the production of α-glucosidase and α-amylase inhibitors from local fruit wastes (honeydew skin, banana peel, and pineapple skin) using solid state fermentation. Each of the fruit wastes was fermented with three different types of white rot fungus Phenarochaete chrysosporium (PC), Panus tigrinus M609RQY (M6) and RO209RQY (RO2) for 7 days. Sampling was carried out starting from day 4 to day 7 to determine the enzyme inhibition activity. The samples were extracted using water prior to enzyme analysis. Most of the fruit samples showed varying degree of percentage inhibition activity depending on the sampling time. Extract of fermented banana peels with RO2 on day 4 showed the higher α-glucosidase inhibition (56.57 ± 0.32 %), followed by honeydew extract fermented with the same fungus on the same day (39.68 ± 0.05 %). Extracts of each fruit waste sample fermented with PC showed the least α-glucosidase inhibition (below 15 %). Meanwhile for α-amylase inhibition activity, the extract from fermented honeydew skins with PC on day 7 showed the highest inhibition activity i.e. 98.29 ± 0.63%. The least inhibition activity (43.37 ± 0.54 %) was observed in the extract from honeydew skins fermented with M6 on day 5. All positive results showed that fruit wastes could be the alternative sources for antidiabetic agent especially for α-amylase and α-glucosidase inhibitors. (14) (PDF) Potential Inhibitors of Alpha-Glucosidase and Alpha-Amylase Enzymes From Locally Available Fruit Wastes by Solid State Fermentation. Available from: https://www.researchgate.net/publication/334987630_Potential_Inhibitors_of_Alpha-Glucosidase_and_Alpha-Amylase_Enzymes_From_Locally_Available_Fruit_Wastes_by_Solid_State_Fermentation#fullTextFileContent [accessed Jul 07 2020]

Potential inhibitors of α-glucosidase and α-amylase enzymes from local fruit waste by solid state fermentation

One therapeutic approach for treating diabetes is to decrease the post-prandial hyperglycaemia. This is done by retarding the absorption of glucose through the inhibition of the carbohydrate hydrolyzing enzymes, α- amylase and α-glucosidase, in the digestive tract. Inhibition of both enzymes will help to reduce glucose level in the blood of diabetic patient. This study was aimed to investigate the production of α-glucosidase and α- amylase inhibitors from local fruit wastes (honeydew skin, banana peel, and pineapple skin) using solid state fermentation. Each of the fruit waste was fermented with three different types of white rot fungus (Phenarochaete chrysosporium (P.chrysosporium), Panus tigrinus MQR609 (M6) and RO2) for 7 days. Sampling was done starting from day 4 to day 7 to determine enzyme inhibition activity. The samples were extracted using water prior to enzyme analysis. Most of the fruit samples showed varying degrees of percentage inhibition activity depending on the sampling time. Extract of fermented banana peels with RO2 on day 4 showed higher potential of α-glucosidase inhibition (56.57±0.32%). Followed with honeydew extract fermented with the same fungus on the same day showed 39.68±0.05%. Extracts of each fruit wastes sample fermented with P.chrysosporium showed least potential of α-glucosidase inhibition (below 15%). While for α- amylase inhibition activity the extract from fermented honeydew skins with P.chrysosporium on day 7 showed the highest potential inhibition activity 98.29±0.63%. The least potential inhibition activity occurred in extract from honeydew skins fermented with M6 on day 5 showed 43.37±0.54%. All the positive result showed that fruit waste can be alternatives sources for antidiabetic agent especially for α-amylase and α- glucosidase inhibitors