Orientador: Marcelo Menossi Teixeira / Texto em português e inglês / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-24T15:47:59Z (GMT). No. of bitstreams: 1 Farani_TiagoLuz_D.pdf: 5590005 bytes, checksum: 5a826906d504777afc8a4763b6863d0c (MD5) Previous issue date: 2013 / Resumo: A cana-de-açúcar é uma das mais importantes culturas vegetais do mundo, sendo o Brasil o principal produtor. A relevância mundial desta planta tem aumentado e muito tem sido investido na obtenção de variedades de cana-de-açúcar com maiores teores de sacarose e mais resistentes a estresses bióticos e abióticos. O presente trabalho teve como objetivo caracterizar funcionalmente o gene ScCIPK8, relacionado ao acúmulo de sacarose em cana-de-açúcar. Com a finalidade de elucidar as redes de interação da proteína ScCIPK8, ensaios de duplo-híbrido em leveduras foram realizados. Foi identificado que a proteína ScCIPK8 interage com as proteínas ScCBL1, ScCBL3 e ScCBL6, mas não interage com as proteínas ScCBL2, ScCBL9 e ScCBL10. As interações identificadas em leveduras foram confirmadas in planta por ensaios de BiFC. No intuito de identificar alvos de interação diferentes das proteínas CBLs, foram realizados screenings de duas bibliotecas de cDNA transformadas em leveduras. Foram identificadas a interação da proteína ScCIPK8 com as porções C-terminal de uma provável proteína do tipo PP2C e de uma provável proteína MYC2. Avaliamos adicionalmente a resposta à seca do gene ScCIPK8 e dos seus alvos de interação através de ensaios de PCR em tempo real. O gene ScCIPK8 é induzido em uma variedade de cana-de-açúcar tolerante à seca após dois dias de estresse hídrico e é induzido após quatro dias de estresse hídrico, tanto na variedade sensível quanto na tolerante à seca. Por outro lado, o gene ScPP2C-1 é induzido apenas na variedade tolerante à seca após dois dias de estresse hídrico. As expressões dos genes ScCBL1 e ScCBL6 não foram alteradas de forma significativa nas condições testadas. Por outro lado, a expressão do gene ScCBL3 foi reprimida nas plantas da variedade tolerante sob quatro dias de seca e manteve-se inalterado em todas as outras condições testadas. Por fim, plantas transgênicas de Arabidopsis thaliana transformadas com o gene ScCIPK8 foram obtidas e avaliadas quanto à resistência a estresses hídrico e salino. Não foi verificada diferença significativa na tolerância das plantas transformadas com o gene ScCIPK8 em relação aos controles utilizados / Abstract: Sugarcane is one of the most important crop plants in the world and Brazil is the leading manufacturer. The world importance of sugarcane is increasing and much has been invested on obtaining better plants with increasing sucrose content and resistance to biotic and abiotic stresses. The present work aims to characterize the sugarcane ScCIPK8 gene involved in sucrose accumulation. To gain insights on the ScCIPK8 protein-protein interaction network, yeast two-hybrid assays were conducted. It was shown that ScCIPK8 protein interacted with ScCBL1, ScCBL3 and ScCBL6, but not with ScCBL2, ScCBL9 and ScCBL10. BiFC assays were conducted to confirm in planta the interactions observed in yeast cells. Yeast two-hybrid screenings using two different cDNA libraries were conducted to identify unknown targets of ScCIPK8 protein. It was shown that ScCIPK8 interacted with the C-terminal portions of a putative PP2C and a putative MYC2 protein. We also performed qPCR assays in order to evaluate the drought response of ScCIPK8 gene and its target genes. ScCIPK8 gene expression was induced in a tolerant sugarcane variety after two days of drought stress and was induced in both the sensitive and tolerant sugarcane varieties after four days of drought stress. On the other hand, ScPP2C-1 gene expression was induced in the tolerant variety after two days of drought stress. The expression of ScCBL1 and ScCBL6 was not significantly changed under the tested conditions, while ScCBL3 expression was repressed in the tolerant variety after four days of drought stress. Finally, Arabidopsis thaliana transgenic plants overexpressing ScCIPK8 were obtained and evaluated for their resistance to drought and salinity stresses. We could not observe any significant difference regarding drought tolerance between control and transgenic plants transformed with ScCIPK8 / Doutorado / Genetica Vegetal e Melhoramento / Doutor em Genetica e Biologia Molecular

Orientador : Yong Kun Park / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos e Agricola / Made available in DSpace on 2018-07-15T03:27:46Z (GMT). No. of bitstreams: 1 CastroGomez_RaulJorgeHernan_D.pdf: 6640888 bytes, checksum: ab9364527326586d259e2a933e250d9a (MD5) Previous issue date: 1985 / Resumo: A informação apresentada neste trabalho mostra os resultados da pesquisa na produção de glicose e xilose do bagaço de cana de açúcar e sua subsequente fermentação a -etanol peIa levedura PaehysoZen tannophiZus NRRL y-2460. O bagaço de cana de açúcar foi submetido a processos de pré-tratamentos com alcali e de explosão -autohidrólise antes da sua sacarificação enzimática e ácida com celulases do Triehoderma reesei QM 94Z4 e com solução 5% de H2S04, respectivamente. Quando o bagaço de cana de açúcar foi tratada a 2000C durante 4,0 minutos com uma relação água: bagaço de 8:1, o rendimento de extração da hemicelulose pelo pré-tratamento, com alcali, forneceu uma fração fermentecível a etanol. Após a neutralização da solução até pH 5,0, a hemicelulose foi recuperada do filtrado obtido no pré-tratamento com alcali por uma precipitação com álcool etilico (95%), seguido de um processo de deslignificação com etanol à 700C por 4 horas. Ambas frações de hemicelulose, do processo de explosão - autohidrólise (fração IV) e do pré-tratamento com alcali (fração 11) foram submetidos a uma hidrólise ácida e enzimática. A sacarificação foi inibida por substâncias de baixo peso molecular não voláteis, introduzidas pelo processo de explosão-autohidrólise do bagaço de cana de açúcar. Estas substâncias inibidoras foram eliminadas por um processo de diálise. A eficiência da sacarificação foi de 36-94%, depedendo da concentração de sólidos presentes no líquido de autohidrólise. O maior grau de sacarificação correspondeu a fração de hemicelulose obtida pelo pré-tratamento alcalino (fração II) seguida da fração de hemicelulose dialisada, obtida pelo processo de explosão-autohidrólise (fração IV). A levedura pachysoLen tannophiLus NRRL y-2460 foi capaz de transformar a D-xilose, D-glicose e ambos hidrolisados do bagaço de cana de açúcar obtidos de acordo ao indicado acima, a etanol, sob as condições de fermentação de 32oC, 200 rpm., e pH 2,5-3,0. Meios de cultura contendo urna concentração inicial de 24,5 9 de D-xilose/L, rendeu 0,158 9 de etanol/g de D-xilose consumida. Durante a fermentação alcoólica da D-glicose à concentração inicial de 21,5 9 de D-glicose/L, a produção de etanol foi 0,384 g/g de D-glicose consurnida. A fermentação aIcoólica dos hidrolisados enzirnáticosdas frações IV e II do bagaço de cana de açúcar, produziram 0,098 e 0,10 9 de etanol/ 9 de açúcar redutor consumidos resp~ctivamente. Os hidrolisados ácidos destas frações produziram muito pouco ou nada de etanol. Os baixos rendimentosde etanol foram o resultado das condições sub-ótimas de fermentação, principalmente à condição de aeração que favoreceu a formação de biomassa / Abstract: The information presented in this work covers research findings on the pJ:ioduétii'on 'of glucose an xylose from sugar cane bagasse and the subsequentdirect fermentation of those sugars to obtain ethanol by the yeast PaahysoZentannophiZus NRRL y-2460. Sugar cane bagasse was subjected to heat explosion and alkali pre-treatments prior to enzymatic and acid saccharification with T~iahode~ma ~ee8ei QM 94Z4 cellulases and 5% H2S04 solution, respectively. When the sugar cane bagasse was. treated at 2009C for 4 minutes at a water-to-solids ratio of 8:1, the yield of hemicellulose extration was maximum. A sodium hydroxide extration yielded a hemicellulose fraction available for fermentation to ethanol. After the neutralization of the solution to pH 5.0, the hemicelulose was recovered from the liquid filtrates of the alkali pre-treatment, by ethylalcohol (95%) precipitation followed by deslignification with ethanol at 709C for 4 hours. Both hemicellulose fractions from the heat explosion (fraction IV) and alkali pre-treatments (fraction 11), were subjected to enzymatic and acid hydrolyses. The saccharification was inhibited by low molecular weight-non volatile substances, introduced by the heat explosion process of the sugar cane bagasse. Those inhibitory substances were eliminated by a dialyzed processo The saccharification efficie~cy was between 36 and 94%, depending of the solids concentration presen't in the auto-hydrolyzed liquido The highest degree of saccharification corresponded to the hemicellulose fraction obtained by the alkali pre-treatment (fraction lI), fo11owed by the dia1yzed hemice11u1ose rãction obtained from the heat exp1osion process (fraction IV) . The yeast PaahysoZen tannophiZus NRRL y-2460 was found to be capab1e of converting D-xilose, D-g1ucose and both enzymatic hydro1ysates from sugar cane bagasse, obtained by theOabove mentioned pre-treatments, to ethanol under the fermentation conditions of 32QC, 200 rpm and pH 2.5-3.0 Batch cu1ture initia11y containing 24.5 go of D-xylose/t, yie1ded 0.158 9 of ethanol/g of D-xylose consumed. During D-glucose fermentation at an initia1 concentration of. 21.5 9 of D-glucose/L the productti.on of ethanol of the enzymatic hydrolysates of the hemicel1ulose fraction of the sugar cane bagasse, gave 0.098 and 0.10 9 ethanol/g of reducing . sugars consumed for fractions IV and 11, respectively. Both acid hydrolysates of these fractions gave negligible quantities of ethanol. The low yield of ethanol obtained were the.result of the sub-optimal fermentation conditions, particularly the aeration condition through out the process which promote mainly biomass production / Doutorado / Doutor em Ciência de Alimentos

Internodes 5-8, 10, 13 and 15 of Saccharum sp. var. NCo376 were examined for evidence of symplasmic phloem unloading of sucrose from the phloem, via the bundle sheath to the storage parenchyma. The vascular bundle possesses wellisolated phloem comprised of large diameter sieve elements and small diameter companion cells. A layer of phloem parenchyma surrounds the phloem, except where the phloem abuts the crushed protophloem. Outside this is a sclerenchymatous sheath, directly endarch to a parenchymatous bundle sheath, which is surrounded by storage parenchyma. The bundle sheath is interrupted at the centrifugal pole of the vascular bundle by a phloem fibre cap. Scanning Electron Microscopy revealed plasmodesmal fields throughout the bundle sheath and pith tissue. Transmission Electron Microscopy studies provided evidence of plasmodesmal occlusion, but not in all tissues. Aniline blue reactions under UV light indicate the presence of occluded plasmodesmal fields at the phloem parenchyma / sclerenchymatous sheath interface, and in localised regions of cells which are smaller than the surrounding storage parenchyma cells. This suggests a symplasmic transport pathway at these locations, and, based on these positive aniline blue reactions, with regulation via callose-mediated transplasmodesmal transport. Osmotic stress experiments, which included the addition of Ca2+, did not reveal further callose occlusion in the parenchyma, suggesting that the plasmodesmata in these regions may be closed via a noncallosic mechanism. Dye-coupling studies, using Lucifer Yellow (LYCH), which was iontophoretically injected following turgor-pressure equalisation, showed only rare, limited symplastic transport, usually only between the injected cell and one adjacent cell. Most injections did not result in transport of LYCH, suggesting either a lack of plasmodesmal connectivity, occlusion, or gating of any plasmodesmata present. This limited symplasmic transport, combined with the presence of occluded plasmodesmata at the phloem parenchyma / sclerenchymatous sheath interface suggests the presence of a two-domain phloem-unloading pathway. While symplastic transport may occur from the phloem to the sclerenchymatous sheath, further sucrose transport to the storage parenchyma appears to proceed apoplasmically from the sclerenchymatous sheath / bundle sheath interface, and into storage parenchyma cells across the cell wall and cell membrane via specialised sucrose transporters.

Sugarcane is a major crop in many countries. It is the most abundant lignocellulosic material in tropical countries such as South Africa. It is one of the plants with the highest bioconversion efficiency. The sugarcane crop is able to efficiently fix solar energy, yielding some 55 tons of dry matter per hectare of land annually. After harvest, the crop produces sugar juice and bagasse. Sugarcane bagasse is a residue that results from the crushing of sugarcane in the sugar industry. It is a renewable feedstock that can be used for power generation and manufacturing cellulosic ethanol. As biomass, sugarcane bagasse holds promise as a fuel source since it can produce more than enough electricity and heat energy to supply the needs of a common sugar factory. However, in the sugarcane industry the bagasse is currently burnt inefficiently in boilers that provide the heating for the industry. This project seeks to investigate the possibility of gasifying sugarcane bagasse as an efficient conversion technology. The investigation is necessary because fuel properties govern the gasifier design and ultimately, the gasification efficiency. Proximate and ultimate analysis of sugarcane bagasse was conducted after which the results were used to conduct a computer simulation of the mass and energy balance during gasification. The kinetic investigation undertaken through the TGA and DTG analyses revealed the activation energy and pre – exponential factor which were obtained by the model – free Kissinger method of kinetic analysis and were found to be 181.51 kJ/mol and 3.1 × 103/min respectively. The heating value of sugarcane bagasse was also measured and found to be 17.8 MJ/kg, which was used in the calculation of the conversion efficiency of the gasification process. Fuel properties, including moisture content and gasifier operating parameters were varied in order to determine optimum gasifier operating conditions that results in maximum conversion efficiency. The highest conversion efficiency was achieved at low moisture content after computer simulation of the gasification process. Moisture content also affected the volume of CO and H2 as the former decreases with increasing moisture content while the latter increases with increasing moisture content, accelerating the water – gas reaction. Scanning electron microscope fitted to an Energy dispersive X – ray spectroscopy was also used in order to view the shape and size distribution as well as determine the elemental composition of sugarcane bagasse. The results obtained established that the fuel properties and gasification conditions affect the conversion efficiency. During computer simulation, it was established that smaller particle size resulted in higher conversion efficiency. The smaller throat diameter also resulted in higher conversion efficiency. The throat angle of 25° also resulted in higher conversion efficiency. The temperature of input air was also found to be one of the major determining factors in terms of conversion efficiency. The dissertation presents the proximate and ultimate analysis results as well as the kinetic analysis results. The SEM/EDX analysis as well as the computer simulation results of the gasification process is also presented. The major contribution of this project was on the investigation of the gasification characteristics of sugarcane bagasse and the utilization of these in the design of a laboratory scale sugarcane bagasse gasifier with enhanced conversion efficiency through computer simulation.

Please read the abstract in the section, 00front of this document / Thesis (PhD (Agricultural Economics))--University of Pretoria, 2008. / Agricultural Economics, Extension and Rural Development / PhD / unrestricted

An estimate of potential evapotranspiration is acquired to implement an irrigation scheduling program. Four equations, which estimate potential evapotranspiration (evaporation) were evaluated for prediction of Class "A" Pan evaporation. The equations used were Penman's combination equation, the Jensen-Haise temperature and radiation equation, and two of the Christiansen-Hargreaves polynomial regression type equations. Measured and calculated radiation was used together with two values of albedo. Four years of daily climate data from Rhodesia was evaluated by general linear regression methods. Despite the significant variations between the four annual regression lines of each equation, the use of confidence intervals indicate that the Penman and Christiansen-Hargreaves equation adequately predict Class "A" pan evaporation for irrigation control purposes. Using class "A" pan evaporation as the measure of potential evapotranspiration for sugarcane, a computerized irrigation scheduling model was developed. Controlled plant moisture stress was incorporated in the program with an irrigation coefficient related to the limiting effects of low soil moisture on plant transpiration. Five soil moisture regimes and two levels of irrigation were studied. Within the limits of the defined soil moisture assumptions, the program exhibited considerable flexibility in computation and the control of desired plant moisture stress.

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Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The development of ―energycane‖ varieties of sugarcane for ethanol production is underway, targeting the use of both sugar juice (first generation ethanol) and bagasse (second generation ethanol). Nevertheless, identification of the preferred varieties represents the biggest challenge to the development of energycane due to large number of samples produced during breeding. In the present study, dilute acid pretreatment, enzymatic hydrolysis and fermentation processes were used to evaluate the processability of bagasse (fibrous residue generated after juice sugar extraction) from different varieties of sugarcane to select preferred varieties with the properties of improving combined ethanol yield (ethanol from juice and bagasse) per hectare. The impact of variety selection on combined ethanol yield (ethanol from juice and bagasse) per hectare was also assessed. In the first part of this study, 115 varieties of sugarcane originated from classical breeding and precision breeding (genetic engineering) were screened based on agronomic data and experimental data from biochemical processes (dilute acid pretreatment and enzymatic hydrolysis) applied to the bagasse fraction of each variety. The results showed wide variations in the chemical composition of bagasse between the varieties. Structural carbohydrates and lignin content ranged from 66.6 to 77.6% dry matter (DM) and 14.4 to 23.1% DM, respectively. The majority of precision breeding varieties showed higher arabinoxylan, lower lignin and lower ash content than most of classical breeding varieties. Combined sugar yield from the bagasse after pretreatment and enzymatic hydrolysis also varied significantly among the varieties. Up to 27.9 g/100g (dry bagasse) difference in combined sugar yield was observed. Combined sugar yield was inversely correlated with lignin as well as ash content, but it correlated positively with structural carbohydrates content. Total potential ethanol yields per hectare, calculated based on cane yield, soluble and non-soluble sugar content also differed significantly among the varieties (8,602−18,244 L/ha). Potential ethanol from bagasse contributed approximately one third of the total potential ethanol yield. Interestingly, some of the varieties had combined properties of high potential ethanol yield per hectare and improved bagasse convertibility. Thus, six varieties (3 from each breeding technology) were selected as preferred varieties for further investigation. To enhance sugar yield from bagasse, optimisation of pretreatment was conducted on the selected varieties. Industrial bagasse was included for comparison purposes. The pretreatment optimisation was based on maximising combined sugar yield from the combined pretreatment-hydrolysis process. A central composite design (CCD) was applied to investigate the effects of temperature, acid concentration and residence time on the responses and was later used to determine the maximum combined sugar yield. Pretreatment optimisation was conducted at gram scale (22.9 ml reactor) and at bench scale (1000 ml reactor). Significant differences in sugar yields (xylose, glucose, and combined sugar) between the varieties were observed. The combined sugar yields from the best performing varieties and industrial bagasse at optimal pretreatment-hydrolysis conditions differed by up to 34.1% and 33% at gram and bench scale, respectively. A high ratio of carbohydrates to lignin and low ash contents increased the release of sugar from the substrates. At mild pretreatment conditions, the differences in bioconversion efficiency between varieties were greater than at severe conditions. This observation suggests that under less severe conditions the conversion efficiency was largely determined by the properties of the biomass. Furthermore, it was demonstrated that the pretreatment conditions with temperature ranged from 184 to 200 °C and varying residence time to provide a severity factor between 3.51 and 3.96 was observed to be the area in common where 95% of maximum combined sugar yield could be obtained. Simultaneous Saccharification and Fermentation (SSF) was performed on the unwashed pressed-slurry from bagasse pretreatment at conditions for maximum combined sugar yield at bench scale. Batch and fed-batch SSF feeding strategy at different solid loadings and enzyme dosages were used aiming to reach an ethanol concentration of at least 40 g/L. The results revealed significant improvement in overall ethanol yield after SSF for the selected varieties (84.5–85.6%) compared to industrial bagasse (74.8%). The maximum ethanol concentration from the best performing varieties was 48.6−51.3 g/l and for poor performing varieties was 37.1−38.3 g/l. Ethanol concentration in the fermentation broth was inversely correlated with lignin content and the ratio of xylose to arabinose, but it showed positive correlation with glucose yield from pretreatment-enzymatic hydrolysis. The overall assessment of the varieties showed greater improvement in combined ethanol yields per hectare (71.1–90.7%) for the best performing varieties with respect to industrial sugarcane. The performance in terms of ethanol yields of selected varieties from a number harvest years was evaluated. The results showed considerable variations in ethanol yields across harvests. The results showed that the best variety in terms combined ethanol yield was not maintained across harvests. The differences in ethanol yields were greater among the varieties than across the harvests. Prolonged severe drought significantly affected the ethnol yields of all varieties represented by lower and intermediate lignin content for cane yield compared to that which had highest lignin content. However, carbohydrates content in the bagasse and sugar yield/recovery between the harvest years did not change for the most of the varieties. In summary, the present study provides evidence of the impact of cultivar selection and pretreatment optimisation in increasing conversion efficiency of bagasse. The results demonstrate that varieties with lower lignin and ash content, as well as highly substituted xylan resulted in higher sugar and ethanol yields. These results suggest that lower process requirements can be achieved without adversely affecting juice ethanol and cane yield per hectare. Nonetheless, an attempt to reduce lignin content in the bagasse, to reduce processing requirements for ethanol production, can also target the improvement of crop tolerance toward severe drought conditions. / AFRIKAANSE OPSOMMING: Die ontwikkeling van ―energie-riet‖ rasse vir etanol produksie is goed op dreef, waar beide die sap (eerste generasie etanol) en die bagasse (tweede generasie etanol) geteiken word. Die groot aantal monsters wat tydens teling geproduseer word, bied egter die grootste uitdaging vir die identifisering van nuwe rasse ten einde energie-riet te ontwikkel. In die huidige studie is verdunde suurvoorbehandeling, ensiematiese hidrolise en fermentasie-prosesse gebruik om die verwerkbaarheid van bagasse (veselagtige residu gegenereer na sap suiker ekstraksie) van verskillende suikerrietrasse te evalueer om nuwe variëteite te selekteer wat eienskappe van verbeterde gekombineerde etanolopbrengs (etanol van sap en bagasse) per hektaar toon. Die impak van variëteit-seleksie op gekombineerde etanol opbrengs (etanol van sap en bagasse) per hektaar is ook beoordeel. In die eerste deel van hierdie studie het uit ‗n siftingsproses van 115 suikerriet rasse bestaan wat deur klassieke en presisie (geneties gemodifiseerde) teling gegenereer is. Die sifting was op agronomiese data gebaseer, asook op data van verdunde suur voorafbehandeling en ensimatiese hidrolise eksperimente wat op die bagasse fraksie van elke ras uitgevoer is. Die resultate het op groot variasie in die chemiese samestelling van die bagasse van verskillende rasse gedui. Die strukturele koolhidrate het tussen 66.6 en 77.6% droë massa (DM) gewissel, terwyl die lignien inhoud ‗n variasie van 14.4 en 23.1% DM getoon het. Verder het meeste van die presisie-teling variëteite ‗n hoër arabinoxilaan, maar ‗n laer lignien en as-inhoud as meeste van die klassieke teling rasse gehad. Die gekombineerde suikeropbrengs (GSO) van die bagasse na voorafbehandeling en ensimatiese hidrolise het ook beduidend tussen rasse gewissel, waar ‗n verskil van tot 27.9 g/100g (droë bagasse) waargeneem is. Daar was ‗n omgekeerde korrelasie tussen die gekombineerde suikeropbrengs en die lignien en as-inhoud gewees, maar die opbrengs het ‗n sterk positiewe korrelasie met die strukturele koolhidrate getoon. Die totale potensiële etanol opbrengs per hektaar wat vanaf die suikerriet se oplosbare en nie-oplosbare suikerinhoud bereken is, het ook beduidend tussen rasse verskil (8,602−18,244 L/ha), waar die potensiële etanol opbrengs van die bagasse gedeelte ongeveer een derde van die totale potensiële etanol opbrengs beslaan het. Interessante bevindinge het op sommige rasse met gekombineerde eienskappe van hoë potensiële opbrengs per hektaar asook ‗n hoë omskakelingsvermoë gedui. Derhalwe is ses variëteite (drie van elke telingstegnologie) as voorkeurvariëteite vir verdere studie gekies. Om die etanol opbrengs vanaf die bagasse te verbeter was voorafbehandeling van die voorkeurvariëteite geoptimeer, en waar industriële bagasse vir vergelykingsdoeleindes ingesluit was. Vir die optimering was dit ten doel gestel om die gekombineerde suikeropbrengs van die gekombineerde voorafbehandeling-hidrolise proses te maksimeer. ‗n Sentrale saamgestelde ontwerp (SSO) is gebruik om die effek van temperatuur, suurkonsentrasie en residensietyd op die responsveranderlikes vas te stel wat uiteindelik gebruik is om die maksimum gekombineerde suikeropbrengs te bepaal. Die optimering van die voorafbehandeling is op gram-skaal in ‗n 22.9 ml reaktor, asook op bank-skaal in ‗n 1000 ml reaktor uitgevoer. Beduidende verskille in die suikeropbrengs (xilose, glukose en gekombineerde suiker) is tussen die voorkeurrasse waargeneem. Tussen die rasse wat die beste gevaar het, asook die industriële bagasse, het die gekombineerde suikeropbrengs by optimale voorafbehandeling-hidrolise toestande onderskeidelik met tot 34.1% en 33% op gram-skaal en bank-skaal gevarieer. ‗n Hoë verhouding van koolhidrate tot lignien, asook ‗n lae as-inhoud het tot ‗n toename in die vrystelling van suiker uit die substraat gelei. By matige voorafbehandelingstoestande was die verskille in omskakelingseffektiwiteit tussen rasse groter as onder hewige toestande, wat daarop gedui het dat omskakelingseffektiwiteit grotendeels deur die eienskappe van die biomassa bepaal is. Verder is daar ook gedemonstreer dat die voorbehandelingsomstandighede met temperatuur tussen 184 en 200ºC en verandering van die residensietyd om 'n hewigheidsfaktor van tussen 3.51 en 3.96 te verskaf, 'n gemeenskaplike area gelewer het waar 95% van maksimum gekombineer suiker opbrengs (GSO) verkry kon word. Gelyktydige versuikering en fermentasie (GVF) is na voorafbehandeling op ongewaste, gepersde bagasse substraat by toestande vir die maksimum gekombineerde suikeropbrengs op bank-skaal uitgevoer. Bondel en voerbondel SSF voerstrategie by verskillende vaste ladings en ensiemdoserings is gebruik om 'n etanol konsentrasie van ten minste 40 g/L te bereik. Ná GVF was die algehele etanol opbrengs vir die voorkeurvariëteite (84.5–85.6%) beduidend beter relatief tot die industriële bagasse (74.8%). Die maksimum etanol opbrengs na SSF van die rasse met die beste prestasie was 48.6-51.3 g/L en 37.1-38.3 g/L vir rasse wat swak presteer het. Die etanol konsentrasie in die fermentasiesop was omgekeerd met lignien en die verhouding van xilose tot arabinose gekorreleer, maar was duidelik positief met die glukose opbrengs vanaf voorafbehandeling-hidrolise gekorreleer. ‗n Algemene assessering het op ‗n duidelike verbetering van die voorkeurvariëteite in terme van gekombineerde etanol opbrengs per hektaar gedui (71.1–90.7%), relatief tot die industriële suikerriet. Die prestasie in terme van etanol opbrengs van geselekteerde variëteite is oor 'n reeks oesjare ge-evalueer. Die resultate het aansienlike variasies in etanol opbrengs oor oesjare getoon. Die resultate het gewys dat die beste variëteite in terme van gekombineerde etanol opbrengs nie volhou is oor oeste nie. Die verskille in etanol opbrengste tussen variëteite was groter as die verskille oor oesjare. Verlengde ernstige droogte het die etanol opbrengs van alle variëteite met laer en intermediere lignien inhoud vir rietopbrengs aansienlik beinvloed, in vergelyking met dié wat die hoogste lignien inhoud gehad het. Die koolhidraatinhoud in die bagasse en suiker opbrengs/lewering tussen die oesjare het vir die meeste variëteite egter nie gewissel nie. Ter opsomming, die huidige studie verskaf bewyse van die impak van kultivarseleksie en voorbehandelings optimisering op die verhoging van die omskakelings-doeltreffendheid van bagasse. Die resultate wys dat variëteite met laer lignien- en asinhoud, en hoogs-gesubstitueerde xilaan hoër suiker- en etanol opbrengs gelewer het. Hierdie resultate stel voor dat verminderde voorbehandelingsvereistes bereik kan word sonder om die sap etanol en rietopbrengs per hektar te benadeel. Nieteenstaande, 'n poging om die lignien inhoud van die bagasse te verminder om die verwerkingsvereistes vir etanolproduksie te verminder, kan ook die verbetering van gewas-toleransie tov ernstige droogte-toestande teiken.