Exploiting xylan as sugar donor for the synthesis of an antiproliferative xyloside using an enzyme cascade

Abstract Background Currently, industrial societies are seeking for green alternatives to conventional chemical synthesis. This demand has merged with the efforts to convert lignocellulosic biomass into value-added products. In this context, xylan, as one of main components of lignocellulose, has emerged as a raw material with high potential for advancing towards a sustainable economy. Results In this study, the recombinant endoxylanase rXynM from the ascomycete Talaromyces amestolkiae has been heterologously expressed in Pichia pastoris and used as one of the catalysts of an enzyme cascade developed to synthesize the antiproliferative 2-(6-hydroxynaphthyl) β-d-xylopyranoside, by transglycosylation of 2,6-dihydroxynaphthalene. The approach combines the use of two fungal xylanolytic enzymes, rXynM and the β-xylosidase rBxTW1 from the same fungus, with the cost-effective substrate xylan. The reaction conditions for the cascade were optimized by a Central Composite Design. Maximal productions of 0.59 and 0.38 g/L were reached using beechwood xylan and birchwood xylan, respectively. For comparison, xylans from other sources were tested in the same reaction, suggesting that a specific optimization is required for each xylan variety. The results obtained using this enzyme cascade and xylan were similar or better to those previously reported for a single catalyst and xylobiose, an expensive sugar donor. Conclusions Beechwood and birchwood xylan, two polysaccharides easily available from biomass, were used in a novel enzyme cascade to synthetize an antiproliferative agent. The approach represents a green alternative to the conventional chemical synthesis of 2-(6-hydroxynaphthyl) β-d-xylopyranoside using a cost-effective substrate. The work highlights the role of xylan as a raw material for producing value-added products and the potential of fungal xylanolytic enzymes in the biomass conversion.

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β-Galactosidases from a Sequence-Based Metagenome: Cloning, Expression, Purification and Characterization

Microorganisms ◽

10.3390/microorganisms9010055 ◽

2020 ◽

Vol 9 (1) ◽

pp. 55

Author(s):

María Florencia Eberhardt ◽

José Matías Irazoqui ◽

Ariel Fernando Amadio

Keyword(s):

Bacterial Species ◽

Value Added ◽

Raw Material ◽

Activity Levels ◽

Treatment Technology ◽

Catalytic Domains ◽

Stabilization Ponds ◽

Cazy Database ◽

Genes Encoding ◽

Value Added Products

Stabilization ponds are a common treatment technology for wastewater generated by dairy industries. Large proportions of cheese whey are thrown into these ponds, creating an environmental problem because of the large volume produced and the high biological and chemical oxygen demands. Due to its composition, mainly lactose and proteins, it can be considered as a raw material for value-added products, through physicochemical or enzymatic treatments. β-Galactosidases (EC 3.2.1.23) are lactose modifying enzymes that can transform lactose in free monomers, glucose and galactose, or galactooligosacharides. Here, the identification of novel genes encoding β-galactosidases, identified via whole-genome shotgun sequencing of the metagenome of dairy industries stabilization ponds is reported. The genes were selected based on the conservation of catalytic domains, comparing against the CAZy database, and focusing on families with β-galactosidases activity (GH1, GH2 and GH42). A total of 394 candidate genes were found, all belonging to bacterial species. From these candidates, 12 were selected to be cloned and expressed. A total of six enzymes were expressed, and five cleaved efficiently ortho-nitrophenyl-β-galactoside and lactose. The activity levels of one of these novel β-galactosidase was higher than other enzymes reported from functional metagenomics screening and higher than the only enzyme reported from sequence-based metagenomics. A group of novel mesophilic β-galactosidases from diary stabilization ponds’ metagenomes was successfully identified, cloned and expressed. These novel enzymes provide alternatives for the production of value-added products from dairy industries’ by-products.

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Optimization of a pretreatment and hydrolysis process for the efficient recovery of recycled sugars and unknown compounds from agricultural sweet sorghum bagasse stem pith solid waste

PeerJ ◽

10.7717/peerj.6186 ◽

2019 ◽

Vol 6 ◽

pp. e6186 ◽

Cited By ~ 2

Author(s):

Ting-Ting Jiang ◽

Yan Liang ◽

Xiang Zhou ◽

Zi-Wei Shi ◽

Zhi-Jun Xin

Keyword(s):

Solid Waste ◽

Sweet Sorghum ◽

Agricultural Waste ◽

Value Added ◽

Raw Material ◽

Alkali Concentration ◽

Sweet Sorghum Bagasse ◽

Amorphous Cellulose ◽

Sorghum Bagasse ◽

Value Added Products

Background Sweet sorghum bagasse (SSB), comprising both a dermal layer and pith, is a solid waste generated by agricultural activities. Open burning was previously used to treat agricultural solid waste but is harmful to the environment and human health. Recent reports showed that certain techniques can convert this agricultural waste into valuable products. While SSB has been considered an attractive raw material for sugar extraction and the production of value-added products, the pith root in the SSB can be difficult to process. Therefore, it is necessary to pretreat bagasse before conventional hydrolysis. Methods A thorough analysis and comparison of various pretreatment methods were conducted based on physicochemical and microscopic approaches. The responses of agricultural SSB stem pith with different particle sizes to pretreatment temperature, acid and alkali concentration and enzyme dosage were investigated to determine the optimal pretreatment. The integrated methods are beneficial to the utilization of carbohydrate-based and unknown compounds in agricultural solid waste. Results Acid (1.5−4.5%, v/v) and alkali (5−8%, w/v) reagents were used to collect cellulose from different meshes of pith at 25–100 °C. The results showed that the use of 100 mesh pith soaked in 8% (w/v) NaOH solution at 100 °C resulted in 32.47% ± 0.01% solid recovery. Follow-up fermentation with 3% (v/v) acid and 6.5% (w/v) alkali at 50 °C for enzymolysis was performed with the optimal enzyme ratio. An analysis of the surface topography and porosity before and after pretreatment showed that both the pore size of the pith and the amount of exposed cellulose increased as the mesh size increased. Interestingly, various compounds, including 42 compounds previously known to be present and 13 compounds not previously known to be present, were detected in the pretreatment liquid, while 10 types of monosaccharides, including D-glucose, D-xylose and D-arabinose, were found in the enzymatic solution. The total monosaccharide content of the pith was 149.48 ± 0.3 mg/g dry matter. Discussion An integrated technique for obtaining value-added products from sweet sorghum pith is presented in this work. Based on this technique, lignin and hemicellulose were effectively broken down, amorphous cellulose was obtained and all sugars in the sweet sorghum pith were hydrolysed into monosaccharides. A total of 42 compounds previously found in these materials, including alcohol, ester, acid, alkene, aldehyde ketone, alkene, phenolic and benzene ring compounds, were detected in the pretreatment pith. In addition, several compounds that had not been previously observed in these materials were found in the pretreatment solution. These findings will improve the transformation of lignocellulosic biomass into sugar to create a high-value-added coproduct during the integrated process and to maximize the potential utilization of agricultural waste in current biorefinery processing.

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Design of a Synthetic Enzyme Cascade for the in vitro Fixation of a C1 Carbon Source to a Functional C4 Sugar

Green Chemistry ◽

10.1039/d1gc02226a ◽

2021 ◽

Author(s):

Samed Güner ◽

Vanessa Wegat ◽

André Pick ◽

Volker Sieber

Keyword(s):

Carbon Dioxide ◽

Carbon Source ◽

Greenhouse Gas ◽

Value Added ◽

Waste Stream ◽

Enzyme Cascade ◽

Sustainable Future ◽

Value Added Products

Realizing a sustainable future requires intensifying the waste stream conversion, such as converting the greenhouse gas carbon dioxide into value-added products. In this paper, we focus on utilizing formaldehyde as...

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Whey Utilization: Sustainable Uses and Environmental Approach

Food Technology and Biotechnology ◽

10.17113/10.17113/ftb.59.02.21.6968 ◽

2021 ◽

Vol 59 (2) ◽

Author(s):

Elizabeta Zandona ◽

Marijana Blažić ◽

Anet Režek Jambrak

Keyword(s):

Whey Proteins ◽

Organic Matter Content ◽

Value Added ◽

Edible Films ◽

Matter Content ◽

Raw Material ◽

Sustainable Utilization ◽

The Past ◽

Food Applications ◽

Value Added Products

The dairy industry produces large amounts of whey as a by- product or co-product, which has led to considerable environmental problems due to its high organic matter content. Over the past decades, possibilities of more environmentally and economically efficient whey utilisation have been studied, primarily to convert unwanted end products into a valuable raw material. Sustainable whey management is mostly oriented to biotechnological and food applications for the development of value-added products such as whey powders, whey proteins, functional food and beverages, edible films and coatings, lactic acid and other biochemicals, bioplastic, biofuels and similar valuable bioproducts. This paper provides an overview of the sustainable utilization of whey and its constituents, considering new refining approaches and integrated processes to covert whey, or lactose and whey proteins to high value-added whey-based products.

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A Review on Bioconversion of Agro-Industrial Wastes to Industrially Important Enzymes

Bioengineering ◽

10.3390/bioengineering5040093 ◽

2018 ◽

Vol 5 (4) ◽

pp. 93 ◽

Cited By ~ 21

Author(s):

Rajeev Ravindran ◽

Shady Hassan ◽

Gwilym Williams ◽

Amit Jaiswal

Keyword(s):

Solid Phase ◽

Agricultural Waste ◽

Large Fraction ◽

Value Added ◽

Industrial Wastes ◽

Raw Material ◽

Corn Cob ◽

Phase Culture ◽

Commercially Important ◽

Value Added Products

Agro-industrial waste is highly nutritious in nature and facilitates microbial growth. Most agricultural wastes are lignocellulosic in nature; a large fraction of it is composed of carbohydrates. Agricultural residues can thus be used for the production of various value-added products, such as industrially important enzymes. Agro-industrial wastes, such as sugar cane bagasse, corn cob and rice bran, have been widely investigated via different fermentation strategies for the production of enzymes. Solid-state fermentation holds much potential compared with submerged fermentation methods for the utilization of agro-based wastes for enzyme production. This is because the physical–chemical nature of many lignocellulosic substrates naturally lends itself to solid phase culture, and thereby represents a means to reap the acknowledged potential of this fermentation method. Recent studies have shown that pretreatment technologies can greatly enhance enzyme yields by several fold. This article gives an overview of how agricultural waste can be productively harnessed as a raw material for fermentation. Furthermore, a detailed analysis of studies conducted in the production of different commercially important enzymes using lignocellulosic food waste has been provided.

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Eco-friendly laminated strand lumber from date palm rachis

Drvna industrija ◽

10.5552/drvind.2019.1843 ◽

2019 ◽

Vol 70 (4) ◽

pp. 359-367

Author(s):

Masoud Shafie ◽

Hamid Zarea-Hosseinabadi

Keyword(s):

Mechanical Properties ◽

Design Of Experiments ◽

Date Palm ◽

Value Added ◽

Cost Effective ◽

Strength Properties ◽

Taguchi Design ◽

Raw Material ◽

Taguchi Design Of Experiments ◽

Product Thickness

This study was performed to use date palm rachis, as a low value bio-waste, in the manufacture of a high value added eco-friendly structural composite lumber. Taguchi design of experiments was applied to analyse the effect of raw material and product parameters on the mechanical properties of laminated strand lumber from date palm rachis. The results indicate that the composite exhibits similar or superior strength properties compared to solid lumber and engineered products from wood or other lignocellulosic material for building sector. Taguchi design of experiments was assessed as a powerful and cost effective technique to obtain optimal levels for maximizing the mechanical properties of the environmentally-friendly composite. Maximum values for the mechanical properties of date palm rachis-based LSL were obtained from a combination of 20 mm product thickness, 10 % resin content, 4mm strand thickness, and 850 kg/m3 product density. Product thickness with an 81.3 % contribution and strand thickness with an 80 % contribution have the highest effects on the flatwise stiffness and compression strength perpendicular to grain, respectively.

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Preparation of Pyrrhotite from Ammonium Jarosite and Estimation of Activation Energy in Reducing Atmosphere

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2018-0149 ◽

2019 ◽

Vol 17 (9) ◽

Author(s):

Xiaoling Ma ◽

Hongbin Tan ◽

Faqin Dong ◽

Bowen Li ◽

Jinfeng Liu ◽

...

Keyword(s):

Activation Energy ◽

Value Added ◽

Cost Effective ◽

Raw Material ◽

Sulfuric Acid Production ◽

Reducing Atmosphere ◽

Heat Treated ◽

Simple Processing ◽

Oxide Phases ◽

Ammonium Jarosite

Abstract Ammonium jarosite sediment is a by-product of hydrometallurgical process used to extract zinc metal, which, which contains heavy metal ions and raises severe environmental concerns The transformation of jarosite sediment into high-value-added sulfide products through simple processing is a cost-effective and efficient strategy to overcome environmental and waste management issues. Herein, the influence of sulfur on thermal decomposition of ammonium jarosite is investigated in reducing atmosphere. The results reveal that the presence of sulfur promoted the decomposition of ammonium jarosite and szomolnokite and iron oxide phases have been observed after being heat treated at 300 °C. Moreover, after heat treatment at 700 °C, the decomposition of jarosite/sulfur mixture resulted in the formation of pyrrhotite phase, which can be used as a raw material for sulfuric acid production. Lastly, the activation energy of pyrrhotite formation has been estimated by using KAS equation and found to be 216.2 kJ/mol in reducing atmosphere.

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Current Status of Microalgae to Produce Biogas through Pretreatment of Lignocellulosic Waste in the Era of 21-Century

10.20944/preprints202008.0233.v1 ◽

2020 ◽

Author(s):

Ali Raza Ishaq ◽

Faiza Jabeen ◽

Maleeha Manzoor ◽

Tahira Younis ◽

Ayesha Noor ◽

...

Keyword(s):

Fossil Fuels ◽

Value Added ◽

Raw Material ◽

Current Status ◽

Fish Feed ◽

Potential Candidate ◽

Lignocellulosic Waste ◽

Major Drawback ◽

Lignocellulosic Feedstocks ◽

Value Added Products

Modern day civilization is dependent on energy generation by fossil fuels. But the major drawback of using fossil fuels is environmental pollution. Microalgae are potential candidate for production of various products of interest, such as proteins, mini food, pigments and triglycerides that can be converted into biofuels. Lignocellulosic feedstocks are the most abundantly available raw material of plants that can serve as a promising feedstock for cultivating bacteria, fungi, yeasts and microalgae to produce biofuels and other value-added products. Owing to the abundant availability of these low/no cost substrates, can be utilized as feedstocks for cultivating microalgae to generate biogas/biodiesel. Likewise, there is much room to exploit defatted algal biomass to be used as animal/fish feed and oil producing/accumulating genes knowledge in future to produce high and good quality biodiesel and biogas.

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Improving Mildew Resistance of Soy Meal by Nano-Ag/TiO2, Zinc Pyrithione and 4-Cumylphenol

Polymers ◽

10.3390/polym12010169 ◽

2020 ◽

Vol 12 (1) ◽

pp. 169 ◽

Cited By ~ 3

Author(s):

Wenping Li ◽

Mingsong Chen ◽

Yanchen Li ◽

Jingmeng Sun ◽

Yi Liu ◽

...

Keyword(s):

Soy Protein ◽

Cellular Structure ◽

Value Added ◽

Oil Industry ◽

Raw Material ◽

Zinc Pyrithione ◽

Mildew Resistance ◽

Soy Meal ◽

Mold Resistance ◽

Value Added Products

As a byproduct from the soybean oil industry, soy meal can be reproduced into value-added products to replace formaldehyde as a plywood adhesive. However, the use of soy meal has been limited by its poor antifungal and antiseptic properties. In this work, three kinds of material, namely nano-Ag/TiO2, zinc pyrithione, and 4-cumylphenol were applied to enhance the mildew resistance of soy meal via breakdown of the cellular structure of mildew. The fungi and mold resistance, morphology, thermal properties, and mechanism of the modified soy meal were evaluated. The success of the antifungal and antiseptic properties was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. The results indicated that all three kinds of material improved the fungi and mold resistance of soy meal, and sample B, which was modified with a compound of nano-Ag/TiO2 and zinc pyrithione, was the effective antifungal raw material for the soy-based adhesives. FTIR indicated that the great improvement of antifungal properties of soy meal modified with 4-cumylphenol might be caused by the reaction between COO– groups of soy protein. This research can help understand the effects of the chemical modification of nano-Ag/TiO2, zinc pyrithione, and 4-cumylphenol on soy meal, and the modified soy meal exhibits potential for utilization in the plywood adhesive industry.

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