Joe Min-Ho, Kim Ji-Youn, Lim Sangyong, Kim Dong-Ho, Bai Suk, Park Hyun, Lee Sung Gu, Han Se Jong, Choi Jong-Il
Department of Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 Republic of Korea ; School of Biological Sciences and Biotechnology, Chonnam National University, Gwangju, 500-757 Republic of Korea.
Department of Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 Republic of Korea.
Biotechnol Biofuels. 2015 Aug 27;8:125. doi: 10.1186/s13068-015-0308-x. eCollection 2015.
Lignocellulosic biomass has long been recognized as a potential sustainable source of sugars for biofuels. However, many physicochemical structural and compositional factors inhibit the enzymatic digestibility of the lignocellulosic biomass. In this study, efficient pretreatment method of rice straw (RS) was developed and the RS hydrolysate was applied in the cultivation of microalgae for lipid production.
Gamma ray irradiation (GRI) and alkali solution were used for the pretreatment, and saccharification was carried out with lignocellulolytic enzymes. When RS was pretreated by combined GRI and alkali method, the glucose and xylose saccharification yield after enzymatic hydrolysis increased up to 91.65 and 98.84 %, respectively. The enzymatic hydrolysate from the RS pretreated with the combined method was used to cultivate Chlorella protothecoides for lipid production. The maximum concentrations of biomass and fatty acid methyl ester of cells were 6.51 and 2.95 g/L, respectively. The lipid content of C. protothecoides from RS hydrolysate was comparable to that from glucose, and the lipid composition was similar between different carbon sources.
These results demonstrate that the combined pretreatment with gamma irradiation was highly effective in preparing hydrolysate, and the rice straw hydrolysate could be used as an alternative carbon source for microalgal lipid production for biofuel.
木质纤维素生物质长期以来一直被认为是生物燃料潜在的可持续糖源。然而，许多物理化学结构和组成因素会抑制木质纤维素生物质的酶解消化率。在本研究中，开发了稻草（RS）的高效预处理方法，并将RS水解产物应用于微藻培养以生产脂质。
采用γ射线辐照（GRI）和碱溶液进行预处理，并用木质纤维素分解酶进行糖化。当采用GRI和碱联合法对RS进行预处理时，酶解后葡萄糖和木糖的糖化产率分别提高到91.65%和98.84%。用联合法预处理的RS酶解产物用于培养原球藻以生产脂质。细胞的最大生物量浓度和脂肪酸甲酯浓度分别为6.51 g/L和2.95 g/L。RS水解产物中原球藻的脂质含量与葡萄糖相当，不同碳源之间的脂质组成相似。
这些结果表明，γ辐照联合预处理在制备水解产物方面非常有效，稻草水解产物可作为微藻脂质生产生物燃料的替代碳源。
