Effect of mushroom polysaccharides and olive phenolic compounds on human carcinoma cells

Tese de mestrado. Biologia (Biologia Humana e Ambiente). Universidade de Lisboa, Faculdade de Ciências, 2012Hoje em dia, devido ao prolongamento da esperança média de vida, bem como o aumento das agressões sofridas pelo meio ambiente envolvente, o cancro é uma das doenças mais proeminentes no seculo XXI. Neoplasmas, conjuntos anormais de células cromossomicamente mutadas, levam ao crescimento relativamente autónomo de tecido danificado. As causas destas mutações variam entre internas - condições imunitárias, hormonais, heritabilidade - ou externas - como tabagismo, exposição a radiação ou agentes químicos infecciosos (Zaidman et al., 2005). As células neoplásicas caracterizam-se pela perda das suas funções especializadas e ganham por sua vez características biológicas tais como a produção de sinais de crescimento, inibição da apoptose, elevado potencial replicativo e a capacidade de invadir tecidos circundantes (Zaidman et al., 2005; Zong et al.,, 2012). A esta metastização dos tecidos está associada 90% da responsabilidade da morte por cancro (Zong et al.,, 2012). Apesar da eficiência dos fármacos gerados até hoje no combate ao cancro, o seu efeito tóxico causa na maioria dos casos um decréscimo acentuado na qualidade de vida dos doentes. Assim, torna-se importante descobrir novos agentes anti cancerigenos com efeitos tóxicos mais baixos (Cao et al., 2010) que possam ser utilizados em terapias complementares. Virámo-nos então de novo para as tradições mais antigas da medicina Chinesa e Mediterrânea. Polissacáridos são biopolímeros constituídos por várias unidades de monossacáridos ligados através de ligações glicosidícas, que podem apresentar diferentes conformações, não só nas suas unidades constituintes, mas também na conformação das suas ligações, atribuindo-lhes assim diversas funções biológicas. Estes estão presentes desde o armazenamento de energia (amido), formação de componentes estruturais (celulose), participantes na comunicação célula a célula, possuindo ainda papéis importantes no sistema imunitário, na fertilização, desenvolvimento, agregação plaquetária e prevenção de patogéneses (Zong et al., 2012). Desde a medicina ancestral chinesa que os cogumelos têm sido reportados como tendo propriedades imunomoduladoras - actuando como modificadores da resposta biológica - e possuindo propriedades antivirais, antimicrobiais, circulatórias e nas ultimas décadas anti cancerigenas. (Wasser, 2010). A descoberta do Lentinian, um polissacárido com propriedades anti cancerígenas, despoletou nos anos 60 a pesquisa que tem sido dedicada ate hoje ao campo dos polissacáridos (Cao et al., 2010). Ao longo do tempo, diversos polissacáridos produzidos por cogumelos, têm demonstrado largos efeitos inibidores em vários tipos de tumores como Sarcoma 180, carcinoma de Lewis e Yoshida Sarcoma (Zhang et al., 2007). Existem três mecanismos propostos de actuação destes polissacáridos: (1) actividade preventiva, (2) aumento da resposta imunitária do hospedeiro e (3) inibição directa quando em contacto com células cancerígenas (Zhang et al., 2007). Na sua maioria os cogumelos que possuem polissacáridos biologicamente activos pertencem ao grupo dos basidiomicetes contendo cerca de 700 espécies descritas (Wasser, 2002). O seu poder antioxidante também desempenha um papel fundamental contra o desenvolvimento cancerígeno. Anti oxidantes naturais encontrados em fruta, vegetais, cogumelos e outros recursos alimentares têm sido investigados para prevenção de doenças coronárias e outras como o cancro (Kozarski et al.,2012). Assim, na procura de compostos não tóxicos que possuíssem propriedades anticancerígenas investigou-se também um pouco dos efeitos que as folhas de oliveira possam ter no combate ao cancro. A oliveira (Olea europaea) é uma árvore da família das Oleaceae, (Zaid et al., 2012) com folhas alongadas, que se encontra ao longo de toda região Mediterrânea desde há mais de 7000 anos (Lalas et al., 2011). Ao longo da história as folhas de Olea europaea têm sido exploradas para a prevenção de hipertensão, carcinogénese, diabetes, arteroesclerose bem como outras doenças do foro mais comum (Bouallagui et al., 2011; Zaid et al., 2012). A folha de oliveira foi ainda utilizada ao longo da história como um meio de combate á malária (Lee et al., 2009) A incidência de cancro ao longo do mediterrâneo tem sido das mais baixas quando comparada com outras partes do mundo, principalmente quando nos referimos ao cancro da mama, do endométrio, próstata e leucemia. (Bouallagui et al., 2011; Zaid et al., 2012) Assim reunimos neste trabalho, o estudo dos efeitos de algumas espécies conhecidas (e outras menos conhecidas) de cogumelos, com o estudo dos efeitos de algumas variedades de oliveiras nacionais, na inibição do crescimento de células tumorais. Para isso, foram efectuados vários doseamentos de polissacáridos, proteínas, açucares e compostos fenólicos e foram aplicadas diversas amostras das espécies amostradas a quatro linhas de carcinoma humano: HeLa, carcinoma cervical, A549 carcinoma pulmonar; A431 carcinoma epidermóide e OE21 carcinoma esófagofaringeal. De entre os variados resultados obtidos, pudemos concluir que a aplicação de extra polissacáridos da estirpe Ganoderma carnosum revelou um alto teor inibitório, e que os intra polissacáridos de todas as estirpes amostradas mostraram uma capacidade antioxidativa acima de 50%. As folhas de oliveira por sua vez, foram também capazes de mostrar um potencial anti proliferativo das células tumorais bastante satisfatório. Acreditamos que nestes compostos podem estar presentes as condições para a sua aplicação como terapia complementar às terapias anticancerígenas existentes.Cancer is widely known nowadays as the disease of the century. Not only by the number of infected people worldwide but also by the amount of research dedicated to this field and its increasing success rate. Neoplasms, which are abnormal masses or colonies of cells produced by a relatively autonomous new growth of tissue, arise normally by the clonal expansion of a single cell that has undergone mutation in the chromosomal DNA, caused by a chemical, physical or biological agent (Zaidman et al., 2005). One of the most characterizing features of cancers, besides it’s ability to resist treatment, it’s his ability to metastasize and invade surrounding tissues, causing 90% of cancer deaths ( Zong et al., 2012). Although the efficiency of chemotherapy for the majority of cancers has improved over the last three decades, the drugs used in this treatment, contain high toxic effects that cause severe reduction in quality of life. Therefore, it is important to develop novel potent, but low toxic anti-cancer reagents, including natural products (Cao et al., 2010). The desire to find this new chemical drug as lead us to look back in time and to report to times of ancient Chinese and Mediterranean medicine, in order to encounter natural products that can in the future be developed as efficient co-chemotherapeutical agents. During this work we will test mushroom polysaccharides as well as olive leaves phenolic compounds, in human carcinoma cell lines, in order to discover more about their anti-tumor effects. Amongst our findings, extrapolysaccharides from Ganoderma lucidum were the most promising and all intrapolysaccharides were found to have a 50% rate of antioxidative power. Olive leaves were also very promising in the inibithion of human carcinoma cells in vitro

Développement d'une stratégie de modification du bois afin de limiter les variations dimensionnelles du produit lambris dans un contexte éco-responsable

Ce travail de thèse présente deux grands axes. Le premier axe, touche les traitements du bois dans le but principal de réduire les variations dimensionnelles et d’améliorer la résistance à l’attaque des champignons lignivores. Le second axe quant à lui, touche l’aspect environnemental du traitement acide citrique-glycérol. Ce dernier a pour but principal de démontrer que le prolongement de la durée de vie en service du produit lambris traité, compense les impacts environnementaux causés par ce traitement. Dans le premier axe, deux traitements ont été réalisés sur deux essences de pin (Pinus strobus L. et Pinus contorta D.). Un traitement à l’anhydride maléique et un autre traitement avec une solution d’acide citrique – glycérol brute (AC-G). Dans le premier cas, les effets de deux paramètres (la durée de séchage et la température d’estérification) sur les résultats des essais de stabilité dimensionnelle, de résistance à la dégradation fongique et de vieillissement accéléré ont été évalués. Trois niveaux de durée de séchage après imprégnation (12 h, 18 h et 24 h) et trois niveaux de température d’estérification (140 °C, 160 °C et 180 °C) ont été considérés. Dans le second cas, après identification du meilleur catalyseur (HCl) et du meilleur ratio acide citrique – glycérol (3/1) pendant les essais préliminaires, les performances de ce traitement sur la stabilité dimensionnelle, la résistance à la pourriture fongique, la dureté de surface et l’adhérence des couches de revêtement de peinture sur la surface du substrat bois ont été analysées. Les résultats obtenus ont été appuyés par une suite d’analyses qualitatives et quantitatives pour mieux comprendre et expliquer. Les analyses qualitatives sont : (i) la spectroscopie infrarouge à transformée de Fourier (IRTF) et (ii) la microscopie électronique à balayage (MEB) tandis que la quantitative, l’analyse par perte de masse a été faite par pesée. Dans le second axe, une analyse des impacts environnementaux du traitement AC-G a été effectuée par le biais du logiciel SimaPro v8. La base de données Ecoinvent v3 et la méthode d’analyse d’impact Impact 2002+ ont été utilisées dans cette partie du travail de thèse. Sur la base des résultats du second traitement (AC-G) et des travaux disponibles dans la littérature, nous avons estimé, une durée de vie en service des lambris traités. Les différents scénarios de la durée de vie du lambris traité mis sur pied par rapport à celle offerte aujourd’hui par l’industrie, nous permettent de modéliser les impacts environnementaux du traitement. A cette fin, l’analyse de cycle de vie (ACV) a été utilisée comme outil de conception. En conclusion, les paramètres, durée de séchage et température d’estérification influencent les résultats obtenus dans le cas du traitement du bois à l’anhydride maléique. La combinaison 24 h de séchage et 180 °C, température d’estérification, représente les paramètres qui offrent les meilleurs résultats de stabilité dimensionnelle, de résistance à la dégradation fongique et de vieillissement accéléré. Le traitement AC-G améliore la stabilité dimensionnelle, la résistance à la dégradation fongique et la dureté de surface des échantillons. Cependant, le traitement réduit l’adhérence des couches de peinture. Les impacts environnementaux produits par le traitement AC-G sont majoritairement liés à la consommation de la ressource énergie (électricité). Le traitement prolonge la durée de vie en service du lambris traité et il a été mis en évidence que le scénario de durée de vie qui permettrait que le lambris traité puisse se présenter comme un produit à faible impact environnemental par rapport au lambris non traité est celui d’une durée de vie de 55 ans.The work presented in this thesis is divided in two research tracks. The first axis regards the wood treatment. The aim of that work, was to reduce dimensional variation and to improve the resistance to fungal decay. The work of the second track presents the environmental impact of the citric acid-glycerol treatment. The purpose was to demonstrate that, enhancement of the service life expectancy of the siding product compensates the environmental impacts of this treatment. In the first axis, two treatments were considered, one with maleic anhydride and the second with citric acid and glycerol mixture. For the first treatment, the effects of two parameters, drying time and esterification temperature were analysed and different performance tests were performed. These tests were: dimensional stability, decay and accelerate aging. Three drying times (12 h, 18 h and 24 h) and three levels of esterification temperature (140 °C, 160 °C and 180 °C) were examined. For the second treatment, after identification, during the preliminary test, of the best catalyst, hydrochloric acid (HCl), the best ratio treatment was identified (3/1). Dimensional stability, decay, hardness and pull-off tests were performed. For a better understanding of the obtained results, qualitative analyses were performed. These were Fourier transform infrared spectroscopy (FTIR) and scanning electronic microscopy (SEM) analysis. Weight loss analysis was also performed as a quantitative analysis. In the second axis, the environment impact of citric acid and glycerol mixture treatment was evaluated by SimaPro software v8. Ecoinvent data base and Impact2002+ impact method were also used in this part of the study. Based on the results of the second treatment (citric acid and glycerol mixture) and the literature research, service life expectancy of siding wood treated was estimated. Different scenarios defined on the basis of the service life expectancy estimated. For this aim, life cycle assessment (LCA) was used as design tool. The drying time and esterification temperature parameters affect the results obtained in the case of the first treatment. Better results in terms of dimensional stability and accelerated aging, were obtained for the samples dried for 24 h and esterified at 180 °C. The citric acid and glycerol mixture treatment improves wood dimensional stability. Decay and hardness were improved compared to untreated samples. For the pull-off test, the treatment was found to reduce coating adhesion on the wood surface. The environmental impacts of the treatment process were mainly linked to the energy consumption (electricity). Citric acid and glycerol mixture treatment improves the service life expectancy of siding and the scenario of life service that presents treated lodgepole pine wood siding as more ecofriendly than the untreated one corresponds to 55 years

Utilization of date palm tree fibres as biomass resources for developing sustainable composites for industrial applications

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.Petroleum based fibres are dominating our everyday usage of fibres, textiles, and composite development reaching an annual consumption of more than 50 million tons in 2020. Over the years, there has been a desperate need for sustainable alternatives; but unfortunately, the global production of natural fibres (NF) has reached a plateau due to the reliance on very few natural sources and lack of biodiversity. With the growing concern on climate change due to the pollution emitted from petroleum-based manufacturing products and their end life disposal, sustainable manufacturing of sustainable materials represents a primary concern for the construction industry. New technologies and materials are extensively investigated and proposed to meet sustainability guidelines imposed by governments and specifically the United Nations (UN). NF represent one of the most investigated renewable and sustainable materials. The date palm tree (DPT), Phoenix Dactylifera L., produces globally an approximate of 4.8 million tons (dry weight) where 3.6 million tons are produced in the MENA region only as by-products of pruning, regarded as agricultural waste, which are either landfilled or incinerated. This research investigates and develops novel methodologies to overcome the drawbacks of utilizing DPT by-products where DPT fibre (DPF) can be extracted from and utilized as a reinforcement in developing sustainable composites for industrial applications. An intensive literature review database was developed to highlight previous research work and investigations carried out to date on the utilization of DPF and their effect in developing sustainable composites and the drawbacks limiting their feasibility for upscaling and industrialization. This identified the problem statement in current research that must be addressed to distinguish the potential of DPF utilization and industrialization. Various surface modification treatments as well as their conditions (soaking time and duration) effect on the characteristics of DPF (surface morphology, chemical composition, chemical structure, and crystallinity) was investigated and evaluated to develop a more hydrophobic fibre that enhances the interfacial bonding when used as a reinforcement with various matrix systems (i.e., polymers and cementitious). DPF treated with sodium hydroxide (NaOH) solution, 6%, for 3 hours showed optimal results where an increase in tensile strength of the fibre by 147%. Scanning electron microscopy (SEM) images demonstrated the effectiveness of the surface treatment showing a more porous surface where the impurities and waxes were successfully removed. Furthermore, investigations, evaluation and prediction on the effect of DPF particle size distribution, density, diameter size (unsieved, ≥1,000 μm, 500 – 1,000 μm, 250 – 500 μm, 125 – 250 μm, and ≤125 μm) and loading content (10, 20, 30, 40 wt.% of matrix) on both the mechanical, physical, fungal resistance and disintegration properties of recycled thermoplastic, recycled polyvinyl chloride (RPVC), and biodegradable thermoplastic, polylactic acid (PLA), were evaluated. The hydrophilic nature of DPF contributed to an increase in thickness swelling (TS), moisture content (MC) and water absorption (WA) for both RPVC and PLA reinforced composites. TS, WA and MC increased by 1.57%, 1.76%, and 10.80%, respectively at 40 wt.% DPF loading content when reinforced with RPVC. Moreover, the flexural strength, tensile strength and impact strength decreased as the loading content increased showing maximum reduction at 40 wt.% loading, varying depending on DPF geometry. Furthermore, micromechanics modelling scenarios to predict the fibre orientation was investigated. To determine the effectiveness of DPF orientations in the PLA and RPVC, the rule of mixtures (ROM), modified ROM, inverse rule of mixture (IROM), modified IROM and Halpin-Tsai were applied with three possible fibre orientations in the composites. The modified ROM and modified IROM closely matches the experimental results with the DPF oriented between 0° to 45° in the direction of compression force of the DPF/PLA and DPF/RPVC composites. Also, Composites where exposed to the brown-rot fungus Irpex lacteus and white rot fungus Tyromyces palustris to evaluate its resistance to biodegradation. To evaluate their feasibility to be utilized in the construction sector as a cladding and decking composite which can act as a substitute to wood in developing wood plastic composites (WPC). Composites developed using PLA had higher weight loss (%) when compared to the same samples but reinforced with RPVC. Composites with higher DPF content showed high rates of decay when used with different polymer matrix. Also, DPF length had a significant effect on the disintegration of the composites. DPF/PLA composites did not demonstrate significant weight loss under fungal decay in 8 weeks where the composites with 40 wt.% DPF showed the highest WL% reaching 5.61% and 5.46% when exposed to Tyromyces palustris and Irpex lacteus respectively. Furthermore, a novel investigation on the biodegradation of the samples showed that DPF reinforced PLA can be implemented and developed within a circular economy scheme in which the composite was fully decomposed by earth worm within 6 weeks, developing vermicompost as manure that may be utilized as a nutrient for plants. Furthermore, an investigation of the processing parameters effect (processing time, temperature, and pressure) on the physical and mechanical properties of DPF reinforced polyester (PES) composite is evaluated. For that, two different temperatures (90 and 110 oC) and three different pressures (1.0, 1.65, and 2.18) MPa which was achieved by varying the load applied (10, 15, and 20) ton and keeping the sample size constant are examined for three different processing durations (3, 6, and 9 min). Results showed that every processing parameter had different effects on the mechanical and physical properties of the composites developed. Moreover, investigations on the effect of varying DPF loading content (1, 2, and 3 wt.% of matrix), and length (10, 20, 30, and 40 mm) of untreated and alkali treated DPF on the mechanical properties of DPF reinforced Ordinary Portland cement (OPC) and DPF reinforced OPC/ground-granulated blast furnace slag (GGBS) were evaluated. Two different curing conditions, water and air, effect on the mechanical strength and physical properties of the composites developed were explored. Results showed that the inclusion of 20 mm treated DPF at a loading content of 1 wt.% with OPC/GGBS as a matrix showed the greatest enhancement in strength by 57.12% and 30.97% of flexural and compressive strength respectively at 28 days of ageing in a water bath. Alkali treatment of DPF demonstrated higher mechanical properties enhancing the optimal mix designs’ mechanical strength by 10% and at 28 days of water curing when compared to the untreated. Moreover, OPC as a pure matrix system had lower mechanical properties where the optimal mix design had an increase in 37.48% and 19.36% on flexural and compressive strength respectively at 28 days of curing in a water bath when compared to OPC/GGBS reinforced composites. Overall, this thesis paves the way for developing a comprehensive foundation for utilizing DPT by-products by optimizing the parameters of surface modification, fibre geometry, fibre loading, and processing parameters for developing sustainable composites that can be industrialised for various non-structural industrial applications (i.e., construction and automotive industries)

The Role of Mushrooms in Biodegradation and Decolorization of Dyes

Contamination of soil, water, and air by hazardous substances is the major environmental problem of today’s world. Mushroom consumption has become a tradition among many people due to its richness in flavors, proteins, and some medicinal importance. But its ability to degrade/decolorize hazardous substances and dyes by secreting various enzymes or by absorption and adsorption of colors from waste substances has made them of interest for use in the field of bioremediation. Mushroom acts as a good decomposer as it degrades cellulose and lignin of plants for their growth and development. It also maintains soil health by performing the role of hyperaccumulators. This chapter focused on the mushroom-based biodegradation/decolorization of dyes and effluents released from various industries or other sources. It also emphasizes the probable mechanisms involved in mushroom-based degradation and decolorization of dyes along with their recent achievements, advancements, and future prospective

Production and Characterisation of Lignin Peroxidase from Newly Isolated Thermophilic Bacillus licheniformis from Empty Fruit Bunch

This research was initiated to screen for thermophilic ligninolytic bacteria native to Empty Fruit Bunch (EFB) compost with the aim of isolating and identifying bacteria with lignin degrading activity and carrying out a more in-depth study and evaluation on the production and characterisation of the key lignin degrading enzymes, namely lignin peroxidase, LiP from a newly isolated ligninolytic bacterium, Bacillus licheniformis

Soil-derived microbial consortia enriched with different plant biomass reveal distinct players acting in lignocellulose degradation

Here, we investigated how different plant biomass, and-for one substrate-pH, drive the composition of degrader microbial consortia. We bred such consortia from forest soil, incubated along nine aerobic sequential - batch enrichments with wheat straw (WS1, pH 7.2; WS2, pH 9.0), switchgrass (SG, pH 7.2), and corn stover (CS, pH 7.2) as carbon sources. Lignocellulosic compounds (lignin, cellulose and xylan) were best degraded in treatment SG, followed by CS, WS1 and WS2. In terms of composition, the consortia became relatively stable after transfers 4 to 6, as evidenced by PCR-DGGE profiles obtained from each consortium DNA. The final consortia differed by ~40 % (bacteria) and ~60 % (fungi) across treatments. A 'core' community represented by 5/16 (bacteria) and 3/14 (fungi) bands was discerned, next to a variable part. The composition of the final microbial consortia was strongly driven by the substrate, as taxonomically-diverse consortia appeared in the different substrate treatments, but not in the (WS) different pH one. Biodegradative strains affiliated to Sphingobacterium kitahiroshimense, Raoultella terrigena, Pseudomonas putida, Stenotrophomonas rhizophila (bacteria), Coniochaeta ligniaria and Acremonium sp. (fungi) were recovered in at least three treatments, whereas strains affiliated to Delftia tsuruhatensis, Paenibacillus xylanexedens, Sanguibacter inulus and Comamonas jiangduensis were treatment-specific

Obtaining Enzymatic Extract from Pleurotus spp. Associated with an Integrated Process for Conversion of Lignocellulosic Biomass to Bioproducts

The pretreatment of biomass has been integrated with enzyme production through the recycling of aqueous fractions. A process integrated with Pleurotus cystidiosus was grown, and enzymatic hydrolysis was realized. Samples of every liquid fraction from the fungal growing medium were analyzed to determine the chemical oxygen demand (OCD), glucose (Glu), xylose (Xyl), and total reducing sugars (RS). Separately, to obtain valuable polymers from this integration process, solid hemicellulose and lignin were isolated from the remaining liquid fractions through pH variation. The composition of the samples was determined using scanning electron microscopy (SEM), optical stereoscopic microscopy, and Fourier transform infrared (FTIR) spectroscopy and was compared with commercial homologs. The maximum conversion of cellulose to glucose by the obtained liquid fraction of the fungal medium was 61.3 ± 0.9% of the theoretical conversion yield of the commercial enzyme. Similarly, the conversion of hemicelluloses to xylose was 69.5 ± 1.5%. Finally, in this work, an integrated platform for cellulose, hemicellulose, lignin, enzymatic extract, and sugars production, which also significantly reduces water consumption, was proposed

Aggregated understanding of characteristics of wheat straw node and internode with their interfacial bonding mechanisms

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.The demand for the efficient utilisation of straw biomass requires detailed analyses of its fundamental chemical structures, morphological complexity, individual cell wall components and the correlation of physicochemical to mechanical properties. The study involved two main areas: understanding the details of microstructure and characterisation/differentiation of properties of various profiled wheat straw. Comprehensive and systematic experimental programmes were therefore designed in order to thoroughly investigate the node and internode of wheat straw with quantitative appraisals and qualitative interpretations. This could contribute towards its valorisation in bio-refinery pathways. The sophisticated morphology of node and internode, inner and outer surface was investigated. It was found that the morphology across node area has a great variety when the longitudinal profile is investigated in the upwards direction to grain head. A 3D image of nodes illustrated the dense core with elliptical shaped rings organised in order to provide the echanical strength to the overall stem. The variation of cell wall composition across wheat straw node and internode showed that node yielded slightly higher Klason lignin, extractives and ash content than internode, which could be related to their morphology, precisely the higher ash and extractives content in the node are explained by thicker epidermis tissue. The physicochemical and mechanical properties of node and internode were differentiated and the effects of a combination of mild physical pre-treatment were monitored. The results indicated: i) the reduction of waxes from the outer surface, ii) significantly lower (P < 0.05) extractives and iii) the dissolution of silicon (Si weight %) on the outer surface of node and internode. The tensile strength of nodes and internodes after pre-treatments also resulted in a significant increase (P < 0.05). The accumulated characteristic data enabled the investigation of interfacial properties and bonding mechanisms of the inner and outer surface of wheat straw with thermosetting resins. Different surface functionalities and anatomical sections, altered the bonding performance, i.e. waxes and silica concentrated on the outer surface inhibited the quality of the interface. Nevertheless, the treatment improved interface (P < 0.05) between resins and the micro-porous surface of wheat straw by causing the microcellular structure of straw to expand and hence inspire the mechanical entanglement on a micro level upon resin solidification.Engineering and Physical Sciences Research (EPSRC

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

Lignocellulosic biomass (LCB) is the most abundantly available bioresource amounting to about a global yield of up to 1. 3 billion tons per year. The hydrolysis of LCB results in the release of various reducing sugars which are highly valued in the production of biofuels such as bioethanol and biogas, various organic acids, phenols, and aldehydes. The majority of LCB is composed of biological polymers such as cellulose, hemicellulose, and lignin, which are strongly associated with each other by covalent and hydrogen bonds thus forming a highly recalcitrant structure. The presence of lignin renders the bio-polymeric structure highly resistant to solubilization thereby inhibiting the hydrolysis of cellulose and hemicellulose which presents a significant challenge for the isolation of the respective bio-polymeric components. This has led to extensive research in the development of various pretreatment techniques utilizing various physical, chemical, physicochemical, and biological approaches which are specifically tailored toward the source biomaterial and its application. The objective of this review is to discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components. The article further discusses the advantages and disadvantages of the various pretreatment methodologies as well as addresses the role of various key factors that are likely to have a significant impact on the pretreatment and digestibility of LCB

White Rot Fungi Pleurotus Ostreatus Pretreatment on Switchgrass to Enhance Enzymatic Hydrolysis and Ethanol Production

Biofuels and high value chemicals derived from cellulosic biomass are good substitutes for petroleum energy and are more environmentally beneficial than corn or soybean based biofuels. The high cost of biomass conversion to biofuels is the main impediment for large scale biofuel production, in which pretreatment is one of the most expensive processing steps. White rot fungal pretreatment shows good potential to efficiently degrade lignin and enhance enzymatic hydrolysis and fermentation under mild environmental conditions. In this thesis biological pretreatment was applied to switchgrass with an emphasis on white rot fungi-associated pretreatment. Two specific studies were conducted: Pleurotus ostreatus pretreatment on large switchgrass bales (either square or round bales) in a natural environment and lab scale P. ostreatus pretreatment in a controlled environment. For the study in a natural environment, P. ostreatus was applied to large switchgrass bales and stored for 9 months. Sampling was done at three months, five months, seven months and nine months after fungus applied. Fungal treated samples were subjected to composition analysis, hydrothermolysis pretreatment and enzymatic hydrolysis. Fungal treated square bales had a lignin fraction ranging from 1.8% to 3.2% higher than untreated bales. There were no clear trends for composition of hydrothermolysis pretreated samples or glucose yield from enzymatic hydrolysis. Fungus did not grow in round bales and bale moisture contents varied between 6% and 11%, which was too low for fungal growth. Glucan and lignin contents of stored samples increased and xylan contents decreased from March to May and were constant from May to September. For enzymatic hydrolysis of hydrothermolysis (200 �C/10 min or 180 �C/20 min) treated samples, there were no significant differences among samples of unwashed and washed samples, which indicates washing is not necessary. For the lab study in a controlled environment, switchgrass was treated with varied initial inoculum loading and substrate moisture content. Results showed that no ethanol was produced during SSF of untreated switchgrass. For fungal treated samples, after 80 days fungal pretreatment, samples with 75% substrate moisture content and 5 ml initial inoculum loading had the highest lignin degradation, 52%, and the highest ethanol yield, 45%.Biosystems & Agricultural Engineerin