Volume 5 Issue 1
- Editorialpp 1-2Hubbe, M. A., and Buehlmann, U. (2010). "A continuing reverence for wood," BioRes. 5(1), 1-2.AbstractPDFOur ancestors knew a great deal about wood. They had to in order to do well in life. Wood has played a dominant role in human infrastructure for many generations, and for most of that time woodcraft has depended on the decentralized knowledge passed down among families and guilds. This editorial, while celebrating the knowledge, skills, and insights of the woodworkers of past generations, also calls for a renewed attention to wood’s unique character, including characteristics that today are too often classified as “defects.” We may need to take lessons from generations past to truly derive the best value from wood resources.
- Editorialpp 3-4Wang, Q., and Zhu, S. (2010). "Genetically modified lignocellulosic biomass for improvement of ethanol production," BioRes. 5(1), 3-4.AbstractPDFProduction of ethanol from lignocellulosic feed-stocks is of growing interest worldwide in recent years. However, we are currently still facing significant technical challenges to make it economically feasible on an industrial scale. Genetically modified lignocellulosic biomass has provided a potential alternative to address such challenges. Some studies have shown that genetically modified lignocellulosic biomass can increase its yield, decreasing its enzymatic hydrolysis cost and altering its composition and structure for ethanol production. Moreover, the modified lignocellulosic biomass also makes it possible to simplify the ethanol production procedures from lignocellulosic feed-stocks.
- Editorialpp 5-7Shen, J., Song, Z., and Qian, X. (2010)."Possible trends of renewable organic fillers and pigments derived from natural resources for sustainable development of paper industry," BioRes. 5(1), 5-7.AbstractPDFThe use of traditional inorganic fillers and pigments for both filling and coating applications in papermaking may have certain limitations in such aspects as recyclability and combustibility. Novel renewable organic fillers and pigments derived from natural resources can possibly be completely recyclable, combustible, biodegradable, and environmentally friendly, and they can potentially be used as substitutes for inorganic fillers and pigments to improve the recyclability and other properties of the paper products. Although there are still challenges lying ahead, the strategic significance of the use of renewable organic fillers and pigments for the sustainable development of papermaking industry is an indisputable and demonstrable fact.
- Researchpp 8-22Saritha, V., Maruthi, A., and Mukkanti, K. (2010). "Potential fungi for bioremediation of industrial effluents," BioRes. 5(1), 8-22.AbstractPDFTwo fungi (unidentified) were isolated from soil and marine environ-ments. These isolates were used for bioremediation of pulp and paper mill effluent at the laboratory scale. The treatment resulted in the reduction of color, lignin, and COD of the effluent in the order of 78.6%, 79.0%, and 89.4% in 21 days. A major part of reductions in these parameters occurred within 5 days of the treatment, which was also characterized by a steep decline in the pH of the effluent. The enzyme activity of these fungi was also tested, and the clearance zone was obtained in the plate assay.
- Researchpp 23-42Zhang, X., Tu, M., Paice, M., Sacciadis, G., Jiang, Z., Jemaa, N., and Thibault, A. (2010). "Bioconversion of knot rejects from a sulphite pulp mill to ethanol," BioRes. 5(1), 23-42.AbstractPDFKnot rejects obtained from pulp screening after sulphite pulping are difficult to dewater, which makes landfilling expensive and burning inefficient. The rejects were found to contain up to 50% cellulose, which is very susceptible to enzymatic hydrolysis to glucose. Knot rejects were hydrolyzed at 20% consistency in a laboratory peg mixer with cellulase enzyme. The thick slurry was liquefied within the first hour of mixing and resulted in a glucose concentration of over 100 g/L after 24 hours of reaction. This solution was fermented by yeast to give an ethanol concentration of over 5%. The laboratory results were confirmed at pilot scale with a mortar mixer (high consistency) or stirred tank reactor (medium consistency) at the 400 L and 6000 L scales, respectively. It was found that washing the knots with ammonia resulted in increased glucose conversion. Enzyme costs could be lowered by separating the enzyme from the hydrolyzed sugars by membrane ultrafiltration and recycling the enzyme to the subsequent batch of substrate. The combination of high-consistency hydrolysis and enzyme recycling minimizes capital investment, energy requirements, and enzyme costs, which are significant factors in the overall economic viability of cellulose conversion to ethanol.
- Researchpp 43-54Abdel-Kader, A. H., and Darweesh, H. H. (2010). "Setting and hardening of agro/cement composites," BioRes. 5(1), 43-54.AbstractPDFIn this study, the use of bagasse fiber (BF) and unbleached bagasse pulp (BP) in a cement matrix, as a raw material, to produce lightweight construction materials is reported. The bagasse was used as partial replacement of cement at different levels: 0% (control cement), 1%, 2% 3%, and 4% by weight. The average size of bagasse fibers was less than 2 mm. Although a reduction in the physical and mechanical strength was observed, the incorporation of either fiber or pulp increased the water of consistency and setting time. A composite containing 4% of bagasse fibers can be used for lightweight concrete. FT-IR spectra showed that the BF or BP adversely affect the rate of calcium silicate hydrate (CSH) formation by decreasing its promotion.
- Researchpp 55-69Afzal, M. T., Bedane, A. H., Sokhansanj, S., and Mahmood, W. (2010). "Storage of comminuted and uncomminuted forest biomass and its effect on fuel quality," BioRes. 5(1), 55-69.AbstractPDFWhite birch was stored in the form of bundles, wood chips, and loose slash for a period of one year to examine the changes in biomass fuel properties. The samples were collected at regular quarterly intervals to measure moisture content, CNS content, ash content, and calorific value. Data loggers were also placed into the stored woody biomass to measure the temperature change inside the piles. After the first quarter of the storage period and continuing into the next three months of storage, the moisture content showed the most significant change. The moisture content of the biomass bundles increased from 29 % to above 80 % (db). The moisture content of the pile of wood chips covered with a tarp decreased from 51% to 26% and showed a continuous decline in moisture content to the end of storage period to an average range of 16.5% (db). However, the moisture content of uncovered wood chip pile was observed to continuously increase throughout the storage period, resulting in more than double in magnitude from 59% to 160% (db). The dry matter loss was higher in wood chip piles (8~27%) than in bundles (~3%). Among the other properties, there was slightly higher loss of calorific value in wood chips (~1.6%) as compared to bundles (~0.7%) at the end of one year.
- Researchpp 70-80Sahin Kol, H., Ozbay, G., Köse, L., and Kurt, S. (2010). "Effects of some impregnation chemicals on combustion characteristics of laminated veneer lumber (LVL) produced with oak and poplar veneers," BioRes. 5(1), 70-80.AbstractPDFThe objective of this research was to investigate the effects of impregnation chemicals on the combustion properties of 3-ply laminated veneer lumber (LVL) made of Oak (Quercus petraea subsp. İberica) and Poplar (Populus tremula L.). For this purpose, oak wood was used as the outer ply and poplar used for the core ply in LVL. Borax (BX), boric acid (BA), borax+boric acid (BX+BA), and di-ammonium phosphate (DAP) were used as impregnation chemicals, and urea formaldehyde (UF), phenol formaldehyde (PF), and melamine-urea-formaldehyde (MUF) adhesives as bonding agent were used to produce LVLs. The vacuum – pressure method was used for the impregnation process. The combustion test was performed according to the procedure defined in the ASTM–E 69 standards, and during the test the mass reduction, temperature, and released gas (CO, O2) were determined for each 30 seconds. As a result, di-ammonium phosphate was found to be the most successful fire retardant chemical in LVL with MUF adhesive. LVL produced from a combination of oak and poplar veneers with MUF adhesive and impregnated with DAP can be recommended to be used as a fire resistant building material where required.
- Researchpp 81-98Soni, S. K., and Soni, R. (2010). "Regulation of cellulase synthesis in Chaetomium erraticum," BioRes. 5(1), 81-98.AbstractPDFChaetomium erraticum was capable of producing all the three components of a cellulase enzyme system including exoglucanase, endoglucanases, and b-glucosidase extracellularly. However, the cultivation conditions and the medium composition markedly affected the ability of microorganism to synthesize various enzymes. Exoglucanase was highest under static conditions, while endoglucanase and b-glucosidase were maximized under shake conditions. Among the various defined substrates, CMC proved to be the best inducer for exoglucanase under static conditions and b-glucosidase under shake conditions. MCC induced maximum endoglucanase under shake conditions. The biosynthesis of all three components of cellulases was repressed with different concentrations of glucose, puromycin, actinomycin, and actidione, while the supplementation of exogenous cyclic-AMP was fully capable of releasing the catabolite repression for production of all three components.
- Researchpp 99-107Xie, J., Luo, S., Feng, L., Xu, N., Wang, Y., Xu, W., and Fu, S. (2010). "Production of Trametes gallica lignocellulases for wheat straw degradation," BioRes. 5(1), 99-107.AbstractPDF
Trametes gallica (T. gallica) is a high producer of lignin-degrading enzymes including laccases, lignin peroxidases (LiPs), manganese-dependent peroxidases (MnPs), and hemicellulases (Hcels). The enzyme activities could peak at an early stage of fermentation. The activities of laccases and LiPs were high in high-nitrogen, low–carbon, and high inorganic salt media, while the activities of MnPs, and Hcels were the high in low-nitrogen, high–carbon, and high inorganic salt medium. It was found that T. gallica caused 34.4% mass losses after 20 days, 46.7% after 30 days, and 70.1% after 60 days, and at the same time T. gallica was able to degrade lignin at an early stage of solid fermentation. Based on these results, T. gallica may be a strain candidate for biopulping in the paper industry.