Singh Saumya, Arya Shailendra Kumar, Krishania Meena
Department of Biotechnology, University Institute of Engineering and Technology, Panjab University, Chandigarh, India.
Center of Innovative and Applied Bioprocessing (DBT-CIAB), Sector-81 (Knowledge City), Mohali, 140306, India.
Biotechnol Biofuels Bioprod. 2024 Feb 24;17(1):31. doi: 10.1186/s13068-024-02475-8.
The present work models the fermentation process parameters of the newly isolated, Meyerozyma caribbica CP02 for enhanced xylitol production and its fermentability study on rice straw hydrolysate. The study examined the impact of each of the process variables by one variable at a time optimization followed by statistical validation. Temperature of 32 °C, pH of 3.5, agitation of 200 rpm, 1.5% (v/v) inoculum, 80 gL initial xylose was optimized. Subsequently, a sequential two-stage agitation approach was adopted for fermentation. At these optimized conditions, xylitol yield of 0.77 gg and 0.64 gg was achieved using media containing commercial and rice straw derived xylose, respectively. For scale up, in 3L batch bioreactor, the highest xylitol yield (0.63 gg) was attained at 72 h with rice straw hydrolysate media containing initial xylose (59.48 ± 0.82 gL) along with inhibitors (1.55 ± 0.10 gL aliphatic acids, 0.0.048 ± 0.11 gL furans, 0.64 ± 0.23 gL total phenols). The results imply that even under circumstances characterized by an acidic pH and elevated initial xylose level, M. caribbica CP02, as an isolate, displays robustness and shows favorable fermentability of rice straw hydrolysate. Therefore, isolate CP02 has potential to be used in bio-refineries for high yield xylitol production with minimal hydrolysate processing requirements.
本研究对新分离的加勒比梅奇酵母CP02的发酵工艺参数进行了建模,以提高木糖醇产量,并对其在稻草水解物上的发酵能力进行了研究。该研究通过一次只改变一个变量的优化方法,随后进行统计验证,来考察每个工艺变量的影响。优化得到的条件为:温度32℃、pH值3.5、搅拌速度200 rpm、接种量1.5%(v/v)、初始木糖80 g/L。随后,采用了连续两阶段搅拌方法进行发酵。在这些优化条件下,分别使用含有商业木糖和稻草衍生木糖的培养基,木糖醇产量达到了0.77 g/g和0.64 g/g。为了扩大规模,在3L分批生物反应器中,使用含有初始木糖(59.48±0.82 g/L)以及抑制剂(1.55±0.10 g/L脂肪酸、0.048±0.11 g/L呋喃、0.64±0.23 g/L总酚)的稻草水解物培养基,在72小时时获得了最高木糖醇产量(0.63 g/g)。结果表明,即使在酸性pH值和较高初始木糖水平的情况下,作为分离菌株的加勒比梅奇酵母CP02仍表现出稳健性,并显示出对稻草水解物良好的发酵能力。因此,分离菌株CP02有潜力用于生物精炼厂,以在对水解物处理要求最低的情况下高产木糖醇。