Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate
Abstract Background Efficient and economically viable production of biofuels from lignocellulosic biomass is dependent on mechanical and chemical pretreatment and enzymatic hydrolysis of plant material. These processing steps yield simple sugars as well as plant-derived and process-added organic aci...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-06-01
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| Series: | Biotechnology for Biofuels |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13068-019-1510-z |
| _version_ | 1811255850435608576 |
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| author | Kyle R. Pomraning James R. Collett Joonhoon Kim Ellen A. Panisko David E. Culley Ziyu Dai Shuang Deng Beth A. Hofstad Mark G. Butcher Jon K. Magnuson |
| author_facet | Kyle R. Pomraning James R. Collett Joonhoon Kim Ellen A. Panisko David E. Culley Ziyu Dai Shuang Deng Beth A. Hofstad Mark G. Butcher Jon K. Magnuson |
| author_sort | Kyle R. Pomraning |
| collection | DOAJ |
| description | Abstract Background Efficient and economically viable production of biofuels from lignocellulosic biomass is dependent on mechanical and chemical pretreatment and enzymatic hydrolysis of plant material. These processing steps yield simple sugars as well as plant-derived and process-added organic acids, sugar-derived dehydration products, aldehydes, phenolics and other compounds that inhibit the growth of many microorganisms. Lipomyces starkeyi is an oleaginous yeast capable of robust growth on a variety of sugars and lipid accumulation on pretreated lignocellulosic substrates making it attractive as an industrial producer of biofuels. Here, we examined gene expression during batch growth and lipid accumulation in a 20-L bioreactor with either a blend of pure glucose and xylose or pretreated corn stover (PCS) that had been enzymatically hydrolyzed as the carbon sources. Results We monitored sugar and ammonium utilization as well as biomass accumulation and found that growth of L. starkeyi is inhibited with PCS hydrolysate as the carbon source. Both acetic acid and furfural are present at concentrations toxic to L. starkeyi in PCS hydrolysate. We quantified gene expression at seven time-points for each carbon source during batch growth and found that gene expression is similar at physiologically equivalent points. Analysis of promoter regions revealed that gene expression during the transition to lipid accumulation is regulated by carbon and nitrogen catabolite repression, regardless of carbon source and is associated with decreased expression of the translation machinery and suppression of the cell cycle. We identified 73 differentially expressed genes during growth phase in the bioreactor that may be involved in detoxification of corn stover hydrolysate. Conclusions Growth of L. starkeyi is inhibited by compounds present in PCS hydrolysate. Here, we monitored key metabolites to establish physiologically equivalent comparisons during a batch bioreactor run comparing PCS hydrolysate and purified sugars. L. starkeyi’s response to PCS hydrolysate is primarily at the beginning of the run during growth phase when inhibitory compounds are presumably at their highest concentration and inducing the general detoxification response by L. starkeyi. Differentially expressed genes identified herein during growth phase will aid in the improvement of industrial strains capable of robust growth on substrates containing various growth inhibitory compounds. |
| first_indexed | 2024-04-12T17:31:02Z |
| format | Article |
| id | doaj.art-6a7288294f754d37b91bad653e2f07fd |
| institution | Directory Open Access Journal |
| issn | 1754-6834 |
| language | English |
| last_indexed | 2024-04-12T17:31:02Z |
| publishDate | 2019-06-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels |
| spelling | doaj.art-6a7288294f754d37b91bad653e2f07fd2022-12-22T03:23:08ZengBMCBiotechnology for Biofuels1754-68342019-06-0112111510.1186/s13068-019-1510-zTranscriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysateKyle R. Pomraning0James R. Collett1Joonhoon Kim2Ellen A. Panisko3David E. Culley4Ziyu Dai5Shuang Deng6Beth A. Hofstad7Mark G. Butcher8Jon K. Magnuson9Pacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryPacific Northwest National LaboratoryAbstract Background Efficient and economically viable production of biofuels from lignocellulosic biomass is dependent on mechanical and chemical pretreatment and enzymatic hydrolysis of plant material. These processing steps yield simple sugars as well as plant-derived and process-added organic acids, sugar-derived dehydration products, aldehydes, phenolics and other compounds that inhibit the growth of many microorganisms. Lipomyces starkeyi is an oleaginous yeast capable of robust growth on a variety of sugars and lipid accumulation on pretreated lignocellulosic substrates making it attractive as an industrial producer of biofuels. Here, we examined gene expression during batch growth and lipid accumulation in a 20-L bioreactor with either a blend of pure glucose and xylose or pretreated corn stover (PCS) that had been enzymatically hydrolyzed as the carbon sources. Results We monitored sugar and ammonium utilization as well as biomass accumulation and found that growth of L. starkeyi is inhibited with PCS hydrolysate as the carbon source. Both acetic acid and furfural are present at concentrations toxic to L. starkeyi in PCS hydrolysate. We quantified gene expression at seven time-points for each carbon source during batch growth and found that gene expression is similar at physiologically equivalent points. Analysis of promoter regions revealed that gene expression during the transition to lipid accumulation is regulated by carbon and nitrogen catabolite repression, regardless of carbon source and is associated with decreased expression of the translation machinery and suppression of the cell cycle. We identified 73 differentially expressed genes during growth phase in the bioreactor that may be involved in detoxification of corn stover hydrolysate. Conclusions Growth of L. starkeyi is inhibited by compounds present in PCS hydrolysate. Here, we monitored key metabolites to establish physiologically equivalent comparisons during a batch bioreactor run comparing PCS hydrolysate and purified sugars. L. starkeyi’s response to PCS hydrolysate is primarily at the beginning of the run during growth phase when inhibitory compounds are presumably at their highest concentration and inducing the general detoxification response by L. starkeyi. Differentially expressed genes identified herein during growth phase will aid in the improvement of industrial strains capable of robust growth on substrates containing various growth inhibitory compounds.http://link.springer.com/article/10.1186/s13068-019-1510-zLipomyces starkeyiOleaginousYeastBioreactorBiofuelCorn stover |
| spellingShingle | Kyle R. Pomraning James R. Collett Joonhoon Kim Ellen A. Panisko David E. Culley Ziyu Dai Shuang Deng Beth A. Hofstad Mark G. Butcher Jon K. Magnuson Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate Biotechnology for Biofuels Lipomyces starkeyi Oleaginous Yeast Bioreactor Biofuel Corn stover |
| title | Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| title_full | Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| title_fullStr | Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| title_full_unstemmed | Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| title_short | Transcriptomic analysis of the oleaginous yeast Lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| title_sort | transcriptomic analysis of the oleaginous yeast lipomyces starkeyi during lipid accumulation on enzymatically treated corn stover hydrolysate |
| topic | Lipomyces starkeyi Oleaginous Yeast Bioreactor Biofuel Corn stover |
| url | http://link.springer.com/article/10.1186/s13068-019-1510-z |
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