Flow-through and cyclic fed-batch cultivation of the green microalga Haematococcus pluvialis in recirculating aquaculture effluent: Strategies for sustained biomass production and astaxanthin biosynthesis

IF 4.3 2区农林科学 Q2 AGRICULTURAL ENGINEERING

Aquacultural Engineering Pub Date : 2025-05-24 DOI:10.1016/j.aquaeng.2025.102573

Hemanta Timilsina , Minna Hiltunen , Marco L. Calderini , Pauliina Salmi , Juhani Pirhonen , Katja Pulkkinen

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引用次数: 0

Abstract

Integrating microalgal cultivation with recirculating aquaculture systems (RAS) offers a sustainable solution for nutrient recovery and the production of high-value bioproducts. The conventional batch cultivation technique for microalgae is constrained by limited biomass yields and short cultivation cycles. This study investigated the potential of cultivating Haematococcus pluvialis in RAS effluent and assessed flow-through and cyclic fed-batch cultivation strategies to enhance biomass and astaxanthin production. Both cultivation modes were investigated in two separate laboratory-scale experiments. Experiment I used (i) synthetic medium (modified BG-11) and (ii) untreated RAS effluent, while Experiment II used (i) autoclaved and (ii) filtered-autoclaved RAS effluent. Light stress was applied to the outflow from flow-through and the withdrawn culture from cyclic fed-batch cultivation to stimulate astaxanthin biosynthesis. In both experiments, the flow-through mode consistently outperformed the cyclic fed-batch mode in growth rate, cell density, biomass concentration, and nutrient uptake. In Experiment I, untreated RAS effluent supported H. pluvialis growth; however, microbial interference during the post-growth phase affected astaxanthin synthesis. In Experiment II, using pretreated RAS effluent, the flow-through mode achieved a maximum growth rate of 0.39 ± 0.01 day⁻¹ , nitrate removal of 64.28 ± 1.84 % and ∼100 % phosphate removal. The cyclic fed-batch mode achieved a maximum growth rate of 0.34 ± 0.01 day⁻¹ , nitrate removal of 55.05 ± 6.25 % and ∼100 % phosphate removal. Although, astaxanthin content was similar between modes (6.30 ± 0.48 mgg⁻¹ DW), the higher biomass concentration in flow-through mode resulted in a higher astaxanthin concentration (2.96 ± 0.78 mgL⁻¹) compared to cyclic fed-batch mode (1.6 ± 0.31 mgL⁻¹).

查看原文本刊更多论文

绿色微藻雨红球菌在循环水养殖废水中的流动和循环补料分批培养：持续生物质生产和虾青素生物合成的策略

将微藻养殖与循环水养殖系统（RAS）相结合，为营养物的回收和高价值生物产品的生产提供了可持续的解决方案。传统的微藻分批培养技术受到生物量产量有限和培养周期短的限制。本研究探讨了在RAS废水中培养雨红球菌的潜力，并评估了流式和循环补料分批培养策略，以提高生物量和虾青素产量。在两个独立的实验室规模试验中对两种培养模式进行了研究。实验1使用(I)合成介质（改性BG-11）和（ii）未经处理的RAS废水，而实验2使用(I)高压灭菌和（ii）过滤高压灭菌的RAS废水。在循环分批补料培养的流出液和回采液中施加光胁迫，刺激虾青素的生物合成。在这两个实验中，流式模式在生长速度、细胞密度、生物量浓度和养分吸收方面始终优于循环分批投料模式。在实验1中，未经处理的RAS废水支持雨芽孢杆菌的生长；然而，在生长后期，微生物的干扰影响了虾青素的合成。在实验二中，使用预处理的RAS出水，流式模式的最大生长速率为0.39 ± 0.01天（⁻¹ ），硝酸盐去除率为64.28 ± 1.84 %，磷酸盐去除率为~ 100 %。循环进料批模式的最大生长速率为0.34 ± 0.01天（⁻¹ ），硝酸盐去除率为55.05 ± 6.25 %，磷酸盐去除率为~ 100 %。虽然两种模式之间虾青素的含量是相似的（6.30 ± 0.48 mg -⁻¹DW），但与循环喂料模式（1.6 ± 0.31 mg -⁻¹）相比，流动模式下较高的生物量浓度导致虾青素的浓度更高（2.96 ± 0.78 mg -⁻¹）。

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来源期刊

Aquacultural Engineering 农林科学-农业工程

CiteScore

8.60

自引率

10.00%

发文量

审稿时长

>24 weeks

期刊介绍： Aquacultural Engineering is concerned with the design and development of effective aquacultural systems for marine and freshwater facilities. The journal aims to apply the knowledge gained from basic research which potentially can be translated into commercial operations. Problems of scale-up and application of research data involve many parameters, both physical and biological, making it difficult to anticipate the interaction between the unit processes and the cultured animals. Aquacultural Engineering aims to develop this bioengineering interface for aquaculture and welcomes contributions in the following areas: – Engineering and design of aquaculture facilities – Engineering-based research studies – Construction experience and techniques – In-service experience, commissioning, operation – Materials selection and their uses – Quantification of biological data and constraints