Ye Zhuoliang, Song Jingyi, Zhu Enhao, Song Xin, Chen Xiaohui, Hong Xiaoting
School of Chemical Engineering, Fuzhou University, Fuzhou, China.
National Engineering Research Center for Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, China.
Front Microbiol. 2018 May 25;9:1071. doi: 10.3389/fmicb.2018.01071. eCollection 2018.
In Acetone-Butanol-Ethanol fermentation, bacteria should tolerate high concentrations of solvent products, which inhibit bacteria growth and limit further increase of solvents to more than 20 g/L. Moreover, this limited solvent concentration significantly increases the cost of solvent separation through traditional approaches. In this study, alginate adsorbent immobilization technique was successfully developed to assist extraction using octanol which is effective in extracting butanol but presents strong toxic effect to bacteria. The adsorbent improved solvent tolerance of under extreme condition of high concentration of organic solvent. Using the developed technique, more than 42% of added bacteria can be adsorbed to the adsorbent. Surface area of the adsorbent was more than 10 times greater than sodium alginate. Scanning electron microscope image shows that an abundant amount of pore structure was successfully developed on adsorbents, promoting bacteria adsorption. In adsorbent assisted ABE fermentation, there was 21.64 g/L butanol in extracting layer compared to negligible butanol produced with only the extractant but without the adsorbent, for the reason that adsorbent can reduce damaging exposure of to octanol. The strategy can improve total butanol production with respect to traditional culture approach by more than 2.5 fold and save energy for subsequent butanol recovery, which effects can potentially make the biobutanol production more economically practical.
在丙酮-丁醇-乙醇发酵过程中，细菌需要耐受高浓度的溶剂产物，这些产物会抑制细菌生长，并限制溶剂进一步增加至超过20 g/L。此外，这种有限的溶剂浓度通过传统方法显著增加了溶剂分离成本。在本研究中，成功开发了海藻酸盐吸附剂固定化技术，以辅助使用对丁醇提取有效但对细菌具有强毒性作用的辛醇进行提取。该吸附剂在高浓度有机溶剂的极端条件下提高了溶剂耐受性。使用所开发的技术，超过42%的添加细菌可被吸附到吸附剂上。吸附剂的表面积比海藻酸钠大10倍以上。扫描电子显微镜图像显示，吸附剂上成功形成了大量的孔结构，促进了细菌吸附。在吸附剂辅助的丙酮-丁醇-乙醇发酵中，提取层中有21.64 g/L的丁醇，而仅使用萃取剂而不使用吸附剂时产生的丁醇可忽略不计，原因是吸附剂可减少细菌与辛醇的有害接触。该策略相对于传统培养方法可使丁醇总产量提高超过2.5倍，并为后续丁醇回收节省能源，这些效果可能使生物丁醇生产在经济上更具实用性。
