Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform.
Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform.
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DOI：
10.1186/s13068-017-0736-x
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发表时间：
2017
影响因子：
6.3
通讯作者：
Betenbaugh MJ
中科院分区：
文献类型：
--
作者：
Li T;Li CT;Butler K;Hays SG;Guarnieri MT;Oyler GA;Betenbaugh MJ
异养光合共生的可行性进行了测试，通过配对的酵母菌株隐球菌弯曲，红酵母，或酿酒酵母与分泌蔗糖的蓝藻细长聚球藻。光合细菌S.细长体在含有酵母提取物的标准BG-11培养基中不显示生长，但在单独的BG-11培养基或补充有不含氨基酸的酵母氮碱（YNB w/o aa）的BG-11培养基中生长良好。在三种酵母中，C. curvatus和R.在BG-11培养基中添加YNB w/o aa、蔗糖和维持S. elongatus，而S.酿酒酵母高度依赖于蔗糖水平。R. tagiis和C. curvatus高效生长并利用共培养中伴侣产生的蔗糖。S. elongatus和R.在分批培养和半连续培养中，芽孢杆菌都能维持1个月以上，与芽孢杆菌的分批单培养物相比，分批共培养中的最终生物量和总脂质产率高40 - 60%。细长的共培养物显示棕榈油酸和亚油酸的水平提高。此外，蓝细菌在与R.无菌生长显著上级无菌生长，S.当在液体培养基中以较低密度培养时，细长体在没有酵母伴侣的情况下不能生长。积累的活性氧严重抑制蓝藻的无菌生长，这是有效地缓解通过过氧化氢酶供应，甚至更有效地与R。是的。本研究的人工地衣中蓝细菌和真核异养生物的配对证明了光养生物和异养生物之间相互作用的重要性，例如，光养生物为异养生物提供碳源，而异养生物通过去除/消除氧化应激来帮助光养生长和存活。我们的研究结果建立了一个潜在的稳定生产平台，该平台结合了光合自养生物捕获无机碳的代谢能力，并将所得有机碳直接引导到一个强大的异养生物伙伴，用于生产生物燃料和其他化学前体。本文的在线版本（doi：10.1186/s13068-017-0736-x）包含补充材料，可供授权用户使用。
The feasibility of heterotrophic–phototrophic symbioses was tested via pairing of yeast strains Cryptococcus curvatus, Rhodotorula glutinis, or Saccharomyces cerevisiae with a sucrose-secreting cyanobacterium Synechococcus elongatus. The phototroph S. elongatus showed no growth in standard BG-11 medium with yeast extract, but grew well in BG-11 medium alone or supplemented with yeast nitrogen base without amino acids (YNB w/o aa). Among three yeast species, C. curvatus and R. glutinis adapted well to the BG-11 medium supplemented with YNB w/o aa, sucrose, and various concentrations of NaCl needed to maintain sucrose secretion from S. elongatus, while growth of S. cerevisiae was highly dependent on sucrose levels. R. glutinis and C. curvatus grew efficiently and utilized sucrose produced by the partner in co-culture. Co-cultures of S. elongatus and R. glutinis were sustained over 1 month in both batch and in semi-continuous culture, with the final biomass and overall lipid yields in the batch co-culture 40 to 60% higher compared to batch mono-cultures of S. elongatus. The co-cultures showed enhanced levels of palmitoleic and linoleic acids. Furthermore, cyanobacterial growth in co-culture with R. glutinis was significantly superior to axenic growth, as S. elongatus was unable to grow in the absence of the yeast partner when cultivated at lower densities in liquid medium. Accumulated reactive oxygen species was observed to severely inhibit axenic growth of cyanobacteria, which was efficiently alleviated through catalase supply and even more effectively with co-cultures of R. glutinis. The pairing of a cyanobacterium and eukaryotic heterotroph in the artificial lichen of this study demonstrates the importance of mutual interactions between phototrophs and heterotrophs, e.g., phototrophs provide a carbon source to heterotrophs, and heterotrophs assist phototrophic growth and survival by removing/eliminating oxidative stress. Our results establish a potential stable production platform that combines the metabolic capability of photoautotrophs to capture inorganic carbon with the channeling of the resulting organic carbon directly to a robust heterotroph partner for producing biofuel and other chemical precursors. The online version of this article (doi:10.1186/s13068-017-0736-x) contains supplementary material, which is available to authorized users.