Biotechnology advances have allowed bacteria, yeasts, plants, mammalian and insect cells to function as heterologous protein expression systems. Recently, microalgae have gained attention as an innovative platform for recombinant protein production, due to low culture media cost, compared to traditional systems, as well as the fact that microalgae such as Chlamydomonas reinhardtii are considered safe (GRAS) by the Food and Drug Administration (FDA). Previous studies showed that recombinant protein production in traditional platforms by semicontinuous process increased biomass and bio product productivity, when compared to batch process. As there is a lack of studies on semicontinuous process for recombinant protein production in microalgae, the production of recombinant mCherry fluorescent protein was evaluated by semicontinuous cultivation of Chlamydomonas reinhardtii in bubble column photobioreactor. This semicontinuous cultivation process was evaluated in the following conditions: 20%, 40%, and 60% culture portion withdrawal. The highest culture withdrawal percentage (60%) provided the best results, as an up to 161% increase in mCherry productivity (454.5 RFU h⁻¹ – Relative Fluorescence Unit h⁻¹), in comparison to batch cultivation (174.0 RFU h⁻¹) of the same strain. All cultivations were carried out for 13 days, at pH 7, temperature 25°C and, by semicontinuous process, two culture withdrawals were taken during the cultivations. Throughout the production cycles, it was possible to obtain biomass concentration up to 1.36 g L⁻¹.

中文翻译：

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用于在莱茵衣藻中生产重组 mCherry 蛋白的半连续系统


生物技术的进步使得细菌、酵母、植物、哺乳动物和昆虫细胞能够作为异源蛋白质表达系统。最近，微藻作为重组蛋白生产的创新平台而受到关注，因为与传统系统相比，其培养基成本较低，而且莱茵衣藻等微藻被美国食品和药物管理局认为是安全的 (GRAS) （FDA）。先前的研究表明，与间歇工艺相比，通过半连续工艺在传统平台中生产重组蛋白可提高生物量和生物产品生产率。由于缺乏对微藻重组蛋白半连续生产工艺的研究，通过在泡罩柱光生物反应器中半连续培养莱茵衣藻来评估重组mCherry荧光蛋白的生产。在以下条件下评估该半连续培养过程：20%、40%和60%培养部分取出。最高的培养物退出百分比 (60%) 提供了最好的结果，与分批培养 (174.0 RFU h ^-1 ) 相比， mCherry生产力 (454.5 RFU h ^-1 – 相对荧光单位 h ^-1 ) 提高了 161% ）同一菌株。所有培养均在pH 7、温度25℃下进行13天，并且通过半连续过程，在培养期间取出两次培养物。在整个生产周期中，可以获得高达1.36 g L ^-1的生物质浓度。