Effect of structural changes of lignocelluloses material upon pre-treatment using green solvents

The Malaysia Biomass strategy 2020 stated that the key step of biofuel production from biomass lies on the pretreatment process. Conventional ‘pre-treatment’ methods are ‘non-green” and costly. The recent green and cost-effective biomass pretreatment is using new generation of Ionic Liquids also known as Deep Eutectic Solvents (DESs). DESs are made of renewable components are cheaper, greener and the process synthesis are easier. Thus, the present paper concerns with the preparation of various combination of DES and to study the effect of DESs pretreatment process on microcrystalline cellulose (MCC), a model substrate. The crystalline structural changes were studied using using X-ray Diffraction Methods, Fourier Transformed Infrared Spectroscopy (FTIR) and surface area and pore size analysis. Results showed reduction of crystalline structure of MCC treated with the DESs and increment of surface area and pore size of MCC after pre-treatment process. These results indicated the DES has successfully converted the lignocelluloses material in the form suitable for hydrolysis and conversion to simple sugar

Screening and production of polyhydroxybutyrate (PHB) by bacterial strains isolated from rhizosphere soil of groundnut plants

Polyhydroxybutyrate (PHB) otherwise known as bioplastics are biodegradable materials that are accumulated in various microorganisms to serve as carbon and energy reservoirs and regarded as an attractive alternative to petroleum-derived plastics. Although research has been conducted on isolation of PHB-producing microorganisms from different ecological environments, few studies have been carried out on isolation of potential PHB-producing microorganisms from rhizosphere environment of groundnut plants, Arachis hypogaea which can be regarded as a good environment for the isolation of potential PHB-producing microorganisms. In the present study, a total of twenty-one (21) bacterial strains were primarily screened and isolated from rhizosphere soil of a groundnut plant. Four bacterial isolates with maximum PHB-producing potential upon screening using submerged fermentation were selected for further studies. The fermentation pattern of PHB production was studied using different nutrient sources. The influence of agitation on PHB production was also studied. Mannitol stimulated maximum (6.076a mg/mL) PHB production by Bacillus sp. 1; KNO3 used as a limiting nutrient induced best (5.728a mg/mL) PHB production by Citrobacter sp. and MgSO4.7H2O supported maximum (5.972a mg/mL) PHB production in Enterococcus sp. A low agitation speed of 150 rpm was found to support best (5.802a mg/mL) PHB production by Bacillus sp.1. Findings from this study indicated that the isolated bacterial strains have high PHB- producing potential. The need to explore other environment harbouring microbial strains with high PHB-producing potential is paramount to the discovery of bioplastics with improved properties for potential industrial applications

VIRTUAL SEARCHING OF DUMMYTEMPLATE FOR SINENSETIN BASED ON 2D MOLECULAR SIMILARITY USING CHEMDB TOOL

Sinensetin-like molecules have been searched virtually to find a dummy template for Molecular Imprinted Polymer (MIP) synthesis. The aim of this study is to find a novel adsorbent for Solid Phase Extraction (SPE) of sinensetin based on tailored method using dummy template. Virtual searching was done using ChemDS online c6emical database containing 5 million commercially available chemicals. Sinensetin as target was converted into SMILES code then it was run with threshold of molecular similarity score of 0.5. There were 90 chemical structures given as the output mainly flavone analogue, three flavonols and several non-flavonoidcompounds. The suggested results are three dummy templates that derived from luteolin (flavon) or quercetin (flavonol) with slight alteration by methoxylationprocess

VIRTUAL SEARCHING OF DUMMY TEMPLATE FOR SINENSETIN BASED ON 2D MOLECULAR SIMILARITY USING CHEMDB TOOL

Sinensetin-like molecules have been searched virtually to find a dummy template for Molecular Imprinted Polymer (MIP) synthesis. The aim of this study is to find a novel adsorbent for Solid Phase Extraction (SPE) of sinensetin based on tailored method using dummy template. Virtual searching was done using ChemDB online chemical database containing 5 million commercially available chemicals. Sinensetin as target was converted into SMILES code then it was run with threshold of molecular similarity score of 0.5. There were 90 chemical structures given as the output mainly flavone analogue, three flavonols and several non-flavonoid compounds. The suggested results are three dummy templates that derived from luteolin (flavon) or quercetin (flavonol) with slight alteration by methoxylation process

Morphological change of lignocellulosic biomass upon retreatment with deep eutectic solvents (DESS)

Deep Eutectic Solvents (DESs) has emerged as new type of Ionic liquids which exhibit similar characteristic with the conventional ILs but with additional advantages. Unlike conventional ILs, DESs are made from renewable, cheaper and greener components. Besides, the process synthesis is relatively easier. In light o the wide application of the conventional ILs in the pretreatment of lignocelluloses, it is interesting to study the application of DESs for degrading biomass. For this purpose, MCC (microcrystalline cellulose) structure was used as a model cellulose/substrate to study the structural change of the substrate using DESs. This is achieved by using Thermal Gravitational Analysis (TGA) and Xray Diffraction Methods. Results showed a great reduction of crystalline structure of MCC treated with the DESs. In addition, the effect of structural change was also studied using the real biomass pretreated with DESs. The work was carried out using Scanning Electron Microscopy (SEM) as tool to analyze the structural changes in the Rice Husk treated with DESs

Deep eutectic solvents-halophilic cellulase system: An efficient route for in situ saccharification of lignocellulose

Pre-treatment of lignocellulosic biomass is essential for the cost-effective saccharification process to produce fermentable sugars. In this study, Deep Eutectic Solvents (DESs) and halophilic cellulase system were used as a new green and cost-effective approach for lignocellulose hydrolysis. The stability and compatibility between DES and halophilic cellulase for lignocellulose hydrolysis were investigated by monitoring the stability of halophilic cellulase in the occurrence of different concentrations of DESs. It was found that halophilic cellulase showed higher stability in the occurrence of 10–20% (v/v) DES. It has been noticed that 20% of DESs, enhanced 2–3 folds in the release of glucose. The compatibility of the DES-halophilic cellulase system has been further evaluated and improved the saccharification efficiency even at high solid loadings. Using the system , saccharification of the rice husk produced three folds of glucose higher than the untreated sample. The yield was estimated to be higher than 1 mM of glucose using the halophilic cellulase -DES system with the hydrolysis for 36 h. DESs-halophilic cellulase system offers a good alternative compared to the available lignocelluloses pre-treatment method in terms of cost, environmental an

Applicability evaluation of deep eutectic solvents–cellulase system for lignocellulose hydrolysis

Deep Eutectic Solvents (DESs) have recently emerged as a new generation of ionic liquids for lignocellulose pretreatment. However, DESs contain salt components which tend to inactivate cellulase in the subsequent saccharification process. To alleviate this problem, it is necessary to evaluate the applicability of the DESs–Cellulase system. This was accomplished in the present study by first studying the stability of cellulase in the presence of selected DESs followed by applicability evaluation based on glucose production, energy consumption and kinetic performance. Results showed that the cellulase was able to retain more than 90% of its original activity in the presence of 10% (v/v) for glycerol based DES (GLY) and ethylene glycol based DES (EG). Furthermore, both DESs system exhibited higher glucose percentage enhancement and lower energy consumption as compared to diluted alkali system. Among the two DESs studied, EG showed comparatively better kinetic performance

Improvement of halophilic cellulase production from locally isolated fungal strain

Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett–Burman design and the Face Centered Central Composite Design (FCCCD). Plackett–Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4Æ7H2O, NaCl, MgSO4Æ7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization

Potential halophilic cellulases for in situ enzymatic saccharification of ionic liquids pretreated lignocelluloses

Ionic liquids (ILs) have been used as an alternative green solvent for lignocelluloses pretreatment. However, being a salt, ILs exhibit an inhibitory effect on cellulases activity, thus making the subsequent saccharification inefficient. The aim of the present study is to produce salt-tolerant cellulases, with the rationale that the enzyme also tolerant to the presence of ILs. The enzyme was produced from a locally isolated halophilic strain and was characterized and assessed for its tolerance to different types of ionic liquids. The results showed that halophilic cellulases produced from Aspergillus terreus UniMAP AA-6 exhibited higher tolerance to ILs and enhanced thermo stability in the presence of high saline conditions

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]