Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine

BMC Biotechnology

Monica Normark¹  Sandra Winestrand¹  Torbjörn A Lestander²  Leif J Jönsson¹ 

[1] Department of Chemistry, Umeå University, Umeå SE-901 87, Sweden

[2] Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, Umeå SE-901 83, Sweden

关键词: Enzymatic saccharification;    Dilute-acid pretreatment;    Chemical composition;    Scots pine;   

Others  :  834890
DOI  :  10.1186/1472-6750-14-20

 received in 2013-12-27, accepted in 2014-03-12,  发布年份 2014

【 摘 要 】

Background

Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification.

Results

All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification.

Conclusions

Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass.

【 授权许可】

   
2014 Normark et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 4.

【 参考文献 】

• [1]Sims REH, Mabee W, Saddler JN, Taylor M: An overview of second generation biofuel technologies. Bioresour Technol 2010, 101:1570-1580.
• [2]Pu Y, Kosa M, Kalluri UC, Tuskan GA, Ragauskas AJ: Challenges of the utilization of wood polymers: how can they be overcome? Appl Microbiol Biotechnol 2011, 91:1525-1536.
• [3]Skogsstyrelsen: Skogsstatistisk Årsbok. Jönköping; 2012.
• [4]Mabee WE, Gregg DJ, Arato C, Berlin A, Bura R, Gilkes N, Mirochnik O, Pan X, Pye EK, Saddler JN: Updates on softwood-to-ethanol process development. Appl Biochem Biotechnol 2006, 129–132:55-70.
• [5]Galbe M, Zacchi G: Pretreatment of lignocellulosic materials for efficient bioethanol production. Adv Biochem Eng Biotechnol 2007, 108:41-65.
• [6]Saddler JN: Bioconverison of Forest and Agricultural Plant Residues. Wallingford: CAB International; 1993.
• [7]Sjöström E: Wood Chemistry: Fundamentals and Applications. 2nd edition. San Diego: Academic Press; 1993.
• [8]Lestander TA, Geladi P, Larsson SH, Thyrel M: Near infrared image analysis for online identification and separation of wood chips with elevated levels of extractives. J Near Infrared Spec 2012, 20:591-599.
• [9]Bertaud F, Holmbom B: Chemical composition of earlywood and latewood in Norway spruce heartwood, sapwood and transition zone wood. Wood Sci Technol 2004, 38:245-256.
• [10]Burkhardt S, Kumar L, Chandra R, Saddler J: How effective are traditional methods of compositional analysis in providing an accurate material balance for a range of softwood derived residues? Biotechnol Biofuels 2013, 6:90. BioMed Central Full Text
• [11]Willför SM, Ahotupa MO, Hemming JE, Reunanen MH, Eklund PC, Sjöholm RE, Eckerman CS, Pohjamo SP, Holmbom BR: Antioxidant activity of knotwood extractives and phenolic compounds of selected tree species. Agric Food Chem 2003, 51:7600-7606.
• [12]Lestander TA, Lundström A, Finell M: Assessment of biomass functions for calculating bark proportions and ash contents of refined biomass fuels derived from major boreal tree species. Can J For Res 2012, 42:59-66.
• [13]Tao G, Lestander TA, Geladi P, Xiong S: Biomass properties in association with plant species and assortments I: A synthesis based on literature data of energy properties. Renew Sust Energ Rev 2012, 16:3481-3506.
• [14]Kenney KL, Smith WA, Gresham GL, Westover TL: Understanding biomass feedstock variability. Biofuels 2013, 4:111-127.
• [15]Fengel D, Wegener G: Wood: Chemistry, Ultrastucture, Reactions. Berlin: Walter de Gruyter; 1983.
• [16]Glasser WG, Glasser HR: The evaluation of lignin’s chemical structure by experimental and computer simulation techniques. Pap Puu 1981, 63:71-74.
• [17]Davison BH, Sadie RD, Tuskan GA, Davis DF, Nghiem NP: Variation of S/G ratio and lignin content in a Populus family influences the release of xylose by dilute acid hydrolysis. Appl Biochem Biotechnol 2006, 129–132:427-435.
• [18]Studer MH, DeMartini JD, Davis MF, Sykes RW, Davison B, Keller M, Tuskan GA, Wyman CE: Lignin content in natural Populus variants affects sugar release. Proc Natl Acad Sci USA 2011, 108:6300-6305.
• [19]Jönsson LJ, Alriksson B, Nilvebrant N-O: Bioconversion of lignocellulose: inhibitors and detoxification. Biotechnol Biofuels 2013, 6:16. BioMed Central Full Text
• [20]Larsson S, Palmqvist E, Hahn-Hägerdal B, Tengborg C, Stenberg K, Zacchi G, Nilvebrant N-O: The generation of fermentation inhibitors during dilute acid hydrolysis of softwood. Enzyme Microb Tech 1999, 24:151-159.
• [21]Kim KH, Tucker M, Nguyen Q: Conversion of bark-rich biomass mixture into fermentable sugar by two-stage dilute acid-catalyzed hydrolysis. Bioresour Technol 2005, 96:1249-1255.
• [22]Boussaid A-L, Esteghlalian AR, Gregg DJ, Lee KH, Saddler JN: Steam pretreatment of douglas-fir wood chips: Can conditions for optimum hemicellulose recovery still provide adequate access for efficient enzymatic hydrolysis? Appl Biochem Biotechnol 2000, 84–86:693-705.
• [23]Brownell HH, Saddler JN: Steam-explosion pretreatment for enzymatic hydrolysis. Biotechnol. Bioenerg. Symp. 1984, 14:55-68.
• [24]Schwald W, Brownell HH, Saddler JN: Enzymatic hydrolysis of steam-treated aspen wood: influence of partial hemicellulosc and lignin removal prior to treatment. J Wood Chem Technol 1988, 8:543-560.
• [25]Jakobsons J, Hortung B, Erins P, Sundquist J: Characterization of alkali soluble fraction of steam exploded birch wood. Holzforschung 1995, 49:51-59.
• [26]Sannigrahi P, Dong KH, Seokwon J, Ragauskas A: Pseudo-lignin and pretreatment chemistry. Energy Environ Sci 2011, 4:1306-1310.
• [27]Kumar R, Hu F, Sannigrahi P, Jung S, Ragauskas AJ, Wyman CE: Carbohydrate derived-pseudo-lignin can retard cellulose biological conversion. Biotechnol Bioeng 2013, 110:737-753.
• [28]Ucar G, Fengel D: Characterization of the acid pretreatment for the enzymatic-hydrolysis of wood. Holzforschung 1988, 42:141-148.
• [29]Ramos LP, Nazhad MM, Saddler JN: Effect of enzymatic hydrolysis on the morphology and fine structure of pretreated cellulosic residues. Enzyme Microb Technol 1993, 15:821-831.
• [30]Arantes V, Saddler JN: Cellulose accessibility limits the effectiveness of minimum cellulase loading on the efficient hydrolysis of pretreated lignocellulosic substrates. Biotechnol Biofuels 2011, 4:3. BioMed Central Full Text
• [31]Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D, Crocker D: Determination of structural carbohydrates and lignin in biomass. Golden, Colorado: National Renewable Energy Laboratory; 2008. NREL/TP-510-42-618
• [32]Gerber L, Eliasson M, Trygg J, Moritz T, Sundberg B: Multivariate curve resolution provides a high-throughput data processing pipeline for pyrolysis-gas chromatography/mass spectrometry. J Anal Appl Pyrol 2012, 95:95-100.
• [33]Overend RP, Chornet E: Fractionation of lignocellulosics by steam-aqueous pretreatments. Phil Trans R Soc London, Series A 1987, 321:523-536.
• [34]Chum HL, Johnson DK, Black SK, Overend RP: Pretreatment-catalyst effects and the combined severity parameter. Appl Biochem Biotechnol 1990, 24/25:1-4.