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Separation of olive tree pruning oligomers from liquid hot water hydrolyzates using preparative gel filtration chromatography
New Biotechnology · Volume 25S · September 2009
hemicellulosic fraction obtained from the pretreatment of lignocellulosic materials for fuel ethanol production. The prebiotic effect is defined as the diet-induced increase of both the amount and activity of several microorganisms (e.g. Bifidobacterium) which can act at the large intestine by improving human health. Purified OS from olive tree pruning hydrolyzates were used as carbon and energy source in in vitro fermentations by Bifidobacterium adolescentis. Fermentations were performed in a modified basal medium at which a known amount of OS was added. Two OS fractions were selected as the most promising for inducing the growth of B. adolescentis. The first fraction corresponded to a pool of OS within an average degree of polymerization (DP) ranging from 5 to 19, with 85% OS and 0.9% monosaccharides. The other fraction corresponded to OS of an average DP of 5, with 75% OS and 3% monosaccharides. OS uptake was monitored throughout the experiments and related with microbial growth and the production of lactic acid and short-chain fatty acids. The highest specific growth rate of B. adolescentis was attained with the shorter chain OS (DP 5), whereas the pool of DP 5—19 gave rise to a slow and steady growth after the exponential growth phase until 48 hours of fermentation. This slower fermentability of longer chain OS might be interesting in terms of extending the bifidogenic activity more distally into the intestinal tract.
leading to the highest oligosaccharide yields. Preparative gel filtration chromatography (GFC) was used to separate oligosaccharides according to their apparent molecular mass, which also enable the separation of by-products (monosaccharides, acetic acid, furan derivatives and phenolic compounds). The different fractions were characterized by size exclusion chromatography (HPSEC) and HPLC following quantitative acid hydrolysis. Results in terms of profiles and yields showed an interesting range of fractions for several applications, namely for the growth of probiotic bacteria.
doi:10.1016/j.nbt.2009.06.553
Unlike lignocellulosic biomass, the major sugar in the red seaweed is galactose. Although Saccharomyces cerevisiae is capable of fermenting galactose into ethanol, ethanol yield and productivity from galactose are significantly lower than those from glucose. To improve ethanol yield and productivity from galactose in S. cerevisiae, we introduced a genome-wide perturbation library into S. cerevisiae, and then screened fast galactose-fermenting transformants. Characterization of genetic perturbations in the isolated transformants revealed novel targets which elicit enhanced galactose utilization in yeast. Interestingly, most of them are not directly related to galactose metabolism. Of the identified genetic perturbations, overexpression of a well-known transcriptional regulator in a truncated form drastically increased ethanol yield and productivity from galactose as well as from a mixture of glucose and galactose. These results suggest that global reconfiguration of sugar metabolism is more effective than overexpression of a single metabolic gene in the galactose assimilation pathway for efficient galactose fermentation in S. cerevisiae.
3.1.09 Separation of olive tree pruning oligomers from liquid hot water hydrolyzates using preparative gel filtration chromatography C. Cara 1,∗ , E. Ruiz 1 , E. Castro 1 , F. Carvalheiro 2 , P. Moura 2 , F. Gírio 2 1
2
Universidad de Jaén, Jaén, Spain INETI, Lisboa, Portugal
Biomass obtained by pruning of olive trees constitutes an abundant and renewable agricultural residue for which, in the lack of alternatives, conversion into fuel ethanol has been proposed. This conversion process requires a pretreatment step to make cellulose susceptible for enzymatic saccharification. In the case of a hydrothermal pretreatment, a liquid fraction (hydrolyzate) containing hemicellulose-derived sugars mainly in the oligomeric form is also obtained. Hemicellulosic oligosaccharides, such as xylooligosaccharides, have been refereed as emerging prebiotics with similar properties to other oligosaccharides already in the market. Commercial xylooligosaccharides are obtained by a two-stage process of an alkaline extraction of xylan followed by enzymatic hydrolysis. The selective fractionation of lignocellulosic residues by hydrothermal methods can be an economic interesting and environmental friendly alternative to obtain oligossacharides from xylan-rich materials. These oligosaccharides can be submitted to further purification and/or size fractionation steps to produce mixtures of known degree of polymerization range. This work addresses the purification and fractionation of oligosaccharides from olive tree biomass hydrolyzates when the raw material is pretreated by liquid hot water under conditions
doi:10.1016/j.nbt.2009.06.554
3.1.10 Improved galactose fermentation by Saccharomyces cerevisiae D.H. Kweon 1,∗ , K.S. Lee 1 , Y.J. Sung 1 , B.J. Yu 2 , S.M. Park 2 , Y.C. Park 3 , J.H. Seo 3 , Y.S. Jin 4 1
Sungkyunkwan University, Suwon, Republic of Korea Samsung Advanced Institute of Technology, Republic of Korea 3 Seoul National University, Republic of Korea 4 University of Illinois, Urbana-Champaign, United States 2
doi:10.1016/j.nbt.2009.06.555
3.1.11 Bioremediation potential of five distinctive microorganisms to effluent of municipality waste A. Kumar Beehive PG College Dehradun, Hardoi, India
Bioremediation uses microorganisms in the remediation of waste. Modern science has brought about hitherto unimagined progress and developments in human civilization. Although it is desirable, this progress is gradually making the world inhospitable due to adulteration and pollution of the environment by numerous prod-
www.elsevier.com/locate/nbt S249
hemicellulosic fraction obtained from the pretreatment of lignocellulosic materials for fuel ethanol production. The prebiotic effect is defined as the diet-induced increase of both the amount and activity of several microorganisms (e.g. Bifidobacterium) which can act at the large intestine by improving human health. Purified OS from olive tree pruning hydrolyzates were used as carbon and energy source in in vitro fermentations by Bifidobacterium adolescentis. Fermentations were performed in a modified basal medium at which a known amount of OS was added. Two OS fractions were selected as the most promising for inducing the growth of B. adolescentis. The first fraction corresponded to a pool of OS within an average degree of polymerization (DP) ranging from 5 to 19, with 85% OS and 0.9% monosaccharides. The other fraction corresponded to OS of an average DP of 5, with 75% OS and 3% monosaccharides. OS uptake was monitored throughout the experiments and related with microbial growth and the production of lactic acid and short-chain fatty acids. The highest specific growth rate of B. adolescentis was attained with the shorter chain OS (DP 5), whereas the pool of DP 5—19 gave rise to a slow and steady growth after the exponential growth phase until 48 hours of fermentation. This slower fermentability of longer chain OS might be interesting in terms of extending the bifidogenic activity more distally into the intestinal tract.
leading to the highest oligosaccharide yields. Preparative gel filtration chromatography (GFC) was used to separate oligosaccharides according to their apparent molecular mass, which also enable the separation of by-products (monosaccharides, acetic acid, furan derivatives and phenolic compounds). The different fractions were characterized by size exclusion chromatography (HPSEC) and HPLC following quantitative acid hydrolysis. Results in terms of profiles and yields showed an interesting range of fractions for several applications, namely for the growth of probiotic bacteria.
doi:10.1016/j.nbt.2009.06.553
Unlike lignocellulosic biomass, the major sugar in the red seaweed is galactose. Although Saccharomyces cerevisiae is capable of fermenting galactose into ethanol, ethanol yield and productivity from galactose are significantly lower than those from glucose. To improve ethanol yield and productivity from galactose in S. cerevisiae, we introduced a genome-wide perturbation library into S. cerevisiae, and then screened fast galactose-fermenting transformants. Characterization of genetic perturbations in the isolated transformants revealed novel targets which elicit enhanced galactose utilization in yeast. Interestingly, most of them are not directly related to galactose metabolism. Of the identified genetic perturbations, overexpression of a well-known transcriptional regulator in a truncated form drastically increased ethanol yield and productivity from galactose as well as from a mixture of glucose and galactose. These results suggest that global reconfiguration of sugar metabolism is more effective than overexpression of a single metabolic gene in the galactose assimilation pathway for efficient galactose fermentation in S. cerevisiae.
3.1.09 Separation of olive tree pruning oligomers from liquid hot water hydrolyzates using preparative gel filtration chromatography C. Cara 1,∗ , E. Ruiz 1 , E. Castro 1 , F. Carvalheiro 2 , P. Moura 2 , F. Gírio 2 1
2
Universidad de Jaén, Jaén, Spain INETI, Lisboa, Portugal
Biomass obtained by pruning of olive trees constitutes an abundant and renewable agricultural residue for which, in the lack of alternatives, conversion into fuel ethanol has been proposed. This conversion process requires a pretreatment step to make cellulose susceptible for enzymatic saccharification. In the case of a hydrothermal pretreatment, a liquid fraction (hydrolyzate) containing hemicellulose-derived sugars mainly in the oligomeric form is also obtained. Hemicellulosic oligosaccharides, such as xylooligosaccharides, have been refereed as emerging prebiotics with similar properties to other oligosaccharides already in the market. Commercial xylooligosaccharides are obtained by a two-stage process of an alkaline extraction of xylan followed by enzymatic hydrolysis. The selective fractionation of lignocellulosic residues by hydrothermal methods can be an economic interesting and environmental friendly alternative to obtain oligossacharides from xylan-rich materials. These oligosaccharides can be submitted to further purification and/or size fractionation steps to produce mixtures of known degree of polymerization range. This work addresses the purification and fractionation of oligosaccharides from olive tree biomass hydrolyzates when the raw material is pretreated by liquid hot water under conditions
doi:10.1016/j.nbt.2009.06.554
3.1.10 Improved galactose fermentation by Saccharomyces cerevisiae D.H. Kweon 1,∗ , K.S. Lee 1 , Y.J. Sung 1 , B.J. Yu 2 , S.M. Park 2 , Y.C. Park 3 , J.H. Seo 3 , Y.S. Jin 4 1
Sungkyunkwan University, Suwon, Republic of Korea Samsung Advanced Institute of Technology, Republic of Korea 3 Seoul National University, Republic of Korea 4 University of Illinois, Urbana-Champaign, United States 2
doi:10.1016/j.nbt.2009.06.555
3.1.11 Bioremediation potential of five distinctive microorganisms to effluent of municipality waste A. Kumar Beehive PG College Dehradun, Hardoi, India
Bioremediation uses microorganisms in the remediation of waste. Modern science has brought about hitherto unimagined progress and developments in human civilization. Although it is desirable, this progress is gradually making the world inhospitable due to adulteration and pollution of the environment by numerous prod-
www.elsevier.com/locate/nbt S249