Metabolic engineering of Saccharomyces cerevisiae for bioconversion of d-xylose to d-xylonate

详细信息	查看全文 | 推荐本文 |

• 作者：Mervi Toivari^a ; ^{mervi.toivari@vtt.fi} ; Yvonne Nygå ; rd^a ; Esa-Pekka Kumpula^a ; Maija-Leena Vehkom&auml ; ki^a ; Mojca Ben膷ina^b ; ^c ; Mari Valkonen^a ; Hannu Maaheimo^a ; Martina Andberg^a ; Anu Koivula^a ; Laura Ruohonen^a ; Merja Penttil&auml ; ^a ; Marilyn G. Wiebe^a
• 关键词：d-xylose dehydrogenase ; d-xylonic acid ; d-xylose ; Saccharomyces cerevisiae ; Bioconversion
• 刊名：Metabolic Engineering
• 出版年：2012
• 期刊代码：98_10967176
• 类别：ce
• 出版时间：July, 2012
• 卷：14
• 期：4
• 页码：427-436
• 文件大小：900 K

摘要

An NAD⁺-dependent d-xylose dehydrogenase, XylB, from Caulobacter crescentus was expressed in Saccharomyces cerevisiae, resulting in production of 17卤2 g d-xylonate l^鈭? at 0.23 g l^鈭? h^鈭? from 23 g d-xylose l^鈭? (with glucose and ethanol as co-substrates). d-Xylonate titre and production rate were increased and xylitol production decreased, compared to strains expressing genes encoding T. reesei or pig liver NADP⁺-dependent d-xylose dehydrogenases. d-Xylonate accumulated intracellularly to 鈭?0 mg g^鈭?; xylitol to 鈭?8 mg g^鈭?. The aldose reductase encoding gene GRE3 was deleted to reduce xylitol production. Cells expressing d-xylonolactone lactonase xylC from C. crescentus with xylB initially produced more extracellular d-xylonate than cells lacking xylC at both pH 5.5 and pH 3, and sustained higher production at pH 3. Cell vitality and viability decreased during d-xylonate production at pH 3.0. An industrial S. cerevisiae strain expressing xylB efficiently produced 43 g d-xylonate l^鈭? from 49 g d-xylose l^鈭?.