Sugarcane bagasse

Potential resources of xylans are by-products produced in forestry and the pulp and paper industries (forest chips, wood meal and shavings), where GX and AGX comprise 25-35% of the biomass as well as annual crops (straw, stalks, husk, hulls, bran, etc.), which consist of 25-50% AX, AGX, GAX, and CHX [4]. New results were reported for xylans isolated from flax fiber [16,68], abaca fiber [69], wheat straw [70,71], sugar beet pulp [21,72], sugarcane bagasse [73], rice straw [74], wheat bran [35,75], and jute bast fiber [18]. Recently, about 39% hemicelluloses were extracted from vetiver grasses [76]. 

Santos, J.C., Silva, S.S., Mussatto, S.I., Carvalho, W. and Cunha, M.A.A., Immobilized cells cultivated in semi-continuous mode in a fluidized bed reactor for xylitol production from sugarcane bagasse, World. Microbiol. Biotech., 21 (2005) 531-535. 

The approach "select favorable raw material has a major impact on the selection of pretreatment processes. For example, the poplar responds splendidly to many pretreatments that fail with Douglas fir or pine-based materials (I). Specific tissues and cells of a given biomass raw material will respond quite differently. For example, the rind fiber of sugarcane bagasse behaves quite differently from the pith fiber (11)- In woody species, the selection of tissues low in bark and extractives is an important factor in the ease or resistance to cellulose hydrolysis. Before embarking on development of processes for hydrolysis of a biomass resource, it is highly desirable to exercise discretion with respect to the choice of raw materials at both the species and tissue levels. This idea is all the more important in an initial choice of species and pretreatment process. 

The Purdue concepts have been applied to several different agricultural products, such as corn stalks, alfalfa, orchard grass, tall fescue, and sugarcane bagasse. No experiments have been reported on either hardwoods or softwoods. The processes have been explored in two major modes. In the first, the entire agricultural residue is treated with solvent in the second, a dilute acid pretreatment to remove hemicellulose precedes solvent treatment. The first process is especially desirable for making furfural or fermentation products from hemicellulose as a separate activity. Then, the hemicellulose-free raw material can be converted to substantially pure glucose. 

Recent studies have proven ethanol to be an ideal liquid fuel for transportation and renewable lignocellulosic biomass to be an attractive feedstock for ethanol fuel production by fermentation (1,2). The major fermentable sugars from hydrolysis of lignocellulosic biomass, such as rice and wheat straw, sugarcane bagasse, corn stover, corn fiber, softwood, hardwood, and grasses, are D-glucose and D-xylose except that softwood... 

Application of Xylanase from Thermomyces lanuginosus IOC-4145 for Enzymatic Hydrolysis of Corncob and Sugarcane Bagasse... 

Index Entries Xylanase Thermomyces lanuginosus agricultural residues enzymatic hydrolysis corncob sugarcane bagasse. 

In this article, we describe the production of xylanase by T. lanuginosus IOC-4145 in semisolid cultivation using corncob as raw material in optimized conditions. Furthermore, we describe the pretreatment effect on corncob and sugarcane bagasse and the enzymatic hydrolysis of these lignocellulosic materials using the produced thermophilic xylanase. 

The end products of acid and enzymatic hydrolysis of corncob and sugarcane bagasse were analyzed by using a high-performance liquid chromatograph (Waters, Milford, MA) equipped with a Rheodyne automatic injector with a 20- iL injection capacity loop, a Shodex Sugar SC 1011 column, and an integrator model 747 with a model 410 RI detector. The mobile phase was deionized water, and the flow rate was adjusted to 0.8 mL/min. 

Xylose Yield of Corncob and Sugarcane Bagasse With and Without Pretreatment... 

Determination of Xylose in Sugarcane Bagasse and Corncob by Acid Hydrolysis... 

Table 1 shows the percentage of xylose present in corncob and sugarcane bagasse with and without pretreatments. The values are in accordance with those reported in the literature (18). The results also revealed that xylose content decreased when pretreatments were applied (alkali and thermal), particularly when both of them were used. 

Enzymatic Hydrolysis of Xylan, Sugarcane Bagasse, and Corncob With and Without Pretreatments... 

Enzymatic hydrolysis of sugarcane bagasse and corncob was carried out with a concentration of solids of 36 g of biomass TL using different amounts of xylanase as well as different incubation times and conditions of the reaction. 

The second set of experiments was carried out using sugarcane bagasse and corncob both pretreated either thermally or with alkali and thermally, using a fixed amount of enzyme (3000 U/g of dried material). 

Degree of Hydrolysis of Thermally Pretreated Sugarcane Bagasse After Incubation with Xylanase from T. lanuginosus IOC-4145... 

The total monosaccharide composition of OCL acid posthydrolysate is approx 26 g/L of monosaccharides, with a ratio of 2 5 3 for glucose xylose arabinose. Compared to other hydrolysates, it has higher arabinose but lower xylose contents than rice straw (37), sugarcane bagasse (38), Eucalyptus wood (16), and corncobs (36), where the latter two hydrolysates were also obtained in a similar two-step procedure. Nevertheless, the total monosaccharide content is in the same range, e.g., as rice straw, Eucalyptus wood, or corncobs. 

Pentoses contained in hemicellulose are used to produce furfural, a useful industrial chemical, used as a solvent for resins and waxes and in petrochemical refining. It is also used as a feedstock for a range of aromatic substances (it has an almond odour) including preservatives, disinfectants and herbicides. Furfural can be converted to furfuryl alcohol and used to make resins for composite applications with fibreglass and other fibres. These are of interest in the aircraft component and automotive brake sectors. Furfural is commercially derived from acid hydrolysis of waste agricultural by-products, such as sugarcane bagasse, com cobs and cereal brans. Around 450 000 tonnes is produced by this method per year. 

Dekker, R. F. H., and Wallis, A. F. A. 1983. Enzymic saccharification of sugarcane bagasse pretreated by autohydrolysis-steam explosion. Biotech. Bioeng., 25, 3027-3048. 

Figure 1. Products from industrial soda sugarcane bagasse spent pulping liquors.

Figure 2. Molecular mass distribution of soda sugarcane bagasse hemicellulose as determined on a G-50 sephadex column.

Van der Klashorst, G. H Venter, J.S.M. Utilization of Sugarcane Bagasse Hemicellulose-Part I Surface Sizing Agent of Linerboard and Corrugating Medium. Appita. 1987, 40, 279-282. 

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