Laboratory of Biochemical Engineering and Environmental Technologies (LBEET), Department of Chemical Engineering, University of Patras, 26504 Patras, Greece; Institute of Circular Economy and Environment (ICEE), University of Patras' Research and Development Center, 26504 Patras, Greece.
Botany Department, Faculty of Science, Tanta University, Tanta 31527, Egypt; Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
Bioresour Technol. 2023 Nov;387:129621. doi: 10.1016/j.biortech.2023.129621. Epub 2023 Aug 5.
Recently, the rising demand of the industry for natural phenolic antioxidant compounds has turned to the study of microalgae as potential sources. Yet, more economic substrates for microalgal cultivation are sought to lower production costs. To this end, the present work deals with the utilization of rice hull hydrolysate (RHH) as substrate for microalgae Botryococcus braunii through a novel two-stage cultivation system. Initially, RHH was optimized to maximize the contained nutrients while minimizing its inhibitors content. The optimum point was reached under 121 °C, 60 min, 2% (v/v) HSO, 30% (w/v) loading. Next, B. braunii was successfully grown first heterotrophically in RHH (25%, v/v), obtaining high biomass production (6.67 g L) and then autotrophically to enhance phenolics accumulation. At the end, a high phenolic content of 7.44 ± 0.60 mg Gallic Acid Equivalents g DW was achieved from the produced biomass, thus highlighting the potential of this novel biotechnological method.
最近，工业界对天然酚类抗氧化剂化合物的需求不断增加，促使人们转向研究微藻作为潜在的来源。然而，为了降低生产成本，人们仍在寻找更经济的微藻培养底物。为此，本工作通过一种新型的两段式培养系统，利用稻壳水解物（RHH）作为小球藻（Botryococcus braunii）的培养基。首先，对 RHH 进行优化，以最大限度地提高其中的营养物质含量，同时最大限度地降低其抑制剂的含量。在 121°C、60 分钟、2%（v/v）硫酸、30%（w/v）装载条件下，达到了最佳点。然后，小球藻首先在 RHH（25%，v/v）中异养生长，获得了较高的生物量生产（6.67g L），然后进行自养培养以提高酚类物质的积累。最后，从生产的生物质中获得了 7.44±0.60mg 没食子酸当量 g DW 的高酚含量，从而突出了这种新型生物技术方法的潜力。
