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Cellulose degrading oxidoreductases
Abstracts / New Biotechnology 33S (2016) S1–S213
about the molecular and gene regulatory mechanisms that control cellular phenotypes. They are known to be easily adapted to different culture conditions and to be highly variable. Beside genetic alterations, epigenetic regulation, such as histone modifications and DNA-methylation, can play a role in determining altered cells and production characteristics. We present a set of epigenome data from different CHO cell lines, both in response to different culture conditions, and during prolonged time in culture under identical conditions. In addition, short term response to environmental changes was analyzed during batch culture on the level of DNA methylation, histone modifications and gene expression, comparing temporal combinatorial patterns of chromatin states and gene expression defined by functionally related genes. While time in culture has the least effect on differential methylation, indicating that DNA methylation patterns are largely passed on to daughter cells, adaptation to different media/growth conditions or selection of high producing subclone causes significant differential methylation patterns. In the course of a batch culture, under decreased nutrient availability, analysis of histone modifications reveals that highly active, transcription related modifications undergo a continuous adaptation during batch culture, while repressed regions undergo few changes, indicating that short term regulation of transcription is primarily controlled by alteration in histone modifications. In addition, intersection between histone marks and DNA methylation reveals high methylation in areas of high transcriptional activity, while highly active promoters are fully de-methylated. http://dx.doi.org/10.1016/j.nbt.2016.06.743
BIOTOP-5 Cellulose degrading oxidoreductases Daniel Kracher University of Natural Resources and Life Sciences, Austria Lignocellulose will play a critical role as a renewable feedstock in the future energy supply. Controlled degradation into its sugar con-
S5
stituents can be achieved by highly specific enzymes produced by wood-decaying fungi. We studied the role of the copper-dependent lytic polysaccharide monooxygenase (LPMO) in this process, which oxidizes and untangles otherwise resistant crystalline parts of cellulose and enhances the activity of hydrolytic cellulases. Activation of LPMO can occur directly by the specific partner enzyme cellobiose dehydrogenase, which reduces LPMO via a flexible heme b-containing moiety [1]. Fungi lacking CDH activity may also rely on other oxidative enzymes, which are able to activate LPMO indirectly via wood-derived phenolic redox-mediators. Depending on the availability of such phenols, some fungi are able to secrete these compounds themselves in order to maintain LPMO activity. The utilization of several electron sources allows fungi to adapt to different growth conditions or habitats and therefore is an elementary aspect in fungal physiology [2]. A general understanding of the activity of these fascinating redox enzymes is crucial for their application in biorefineries to efficiently transform plant biomass into hydrocarbons or commodity chemicals. References [1] Tan T-C, Kracher D, et al. Nat Commun 2015;6:7542. [2] Kracher D, Scheiblbrandner S, et al. Science 2016, http://dx.doi.org/10.1126/science.aaf3165 [in press].
http://dx.doi.org/10.1016/j.nbt.2016.06.744
about the molecular and gene regulatory mechanisms that control cellular phenotypes. They are known to be easily adapted to different culture conditions and to be highly variable. Beside genetic alterations, epigenetic regulation, such as histone modifications and DNA-methylation, can play a role in determining altered cells and production characteristics. We present a set of epigenome data from different CHO cell lines, both in response to different culture conditions, and during prolonged time in culture under identical conditions. In addition, short term response to environmental changes was analyzed during batch culture on the level of DNA methylation, histone modifications and gene expression, comparing temporal combinatorial patterns of chromatin states and gene expression defined by functionally related genes. While time in culture has the least effect on differential methylation, indicating that DNA methylation patterns are largely passed on to daughter cells, adaptation to different media/growth conditions or selection of high producing subclone causes significant differential methylation patterns. In the course of a batch culture, under decreased nutrient availability, analysis of histone modifications reveals that highly active, transcription related modifications undergo a continuous adaptation during batch culture, while repressed regions undergo few changes, indicating that short term regulation of transcription is primarily controlled by alteration in histone modifications. In addition, intersection between histone marks and DNA methylation reveals high methylation in areas of high transcriptional activity, while highly active promoters are fully de-methylated. http://dx.doi.org/10.1016/j.nbt.2016.06.743
BIOTOP-5 Cellulose degrading oxidoreductases Daniel Kracher University of Natural Resources and Life Sciences, Austria Lignocellulose will play a critical role as a renewable feedstock in the future energy supply. Controlled degradation into its sugar con-
S5
stituents can be achieved by highly specific enzymes produced by wood-decaying fungi. We studied the role of the copper-dependent lytic polysaccharide monooxygenase (LPMO) in this process, which oxidizes and untangles otherwise resistant crystalline parts of cellulose and enhances the activity of hydrolytic cellulases. Activation of LPMO can occur directly by the specific partner enzyme cellobiose dehydrogenase, which reduces LPMO via a flexible heme b-containing moiety [1]. Fungi lacking CDH activity may also rely on other oxidative enzymes, which are able to activate LPMO indirectly via wood-derived phenolic redox-mediators. Depending on the availability of such phenols, some fungi are able to secrete these compounds themselves in order to maintain LPMO activity. The utilization of several electron sources allows fungi to adapt to different growth conditions or habitats and therefore is an elementary aspect in fungal physiology [2]. A general understanding of the activity of these fascinating redox enzymes is crucial for their application in biorefineries to efficiently transform plant biomass into hydrocarbons or commodity chemicals. References [1] Tan T-C, Kracher D, et al. Nat Commun 2015;6:7542. [2] Kracher D, Scheiblbrandner S, et al. Science 2016, http://dx.doi.org/10.1126/science.aaf3165 [in press].
http://dx.doi.org/10.1016/j.nbt.2016.06.744