A novel one-stage cultivation/fermentation strategy for improved biogas production with microalgal biomass.
A novel one-stage cultivation/fermentation strategy for improved biogas production with microalgal biomass.
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DOI：
10.1016/j.jbiotec.2015.05.008
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发表时间：
2015-12
影响因子：
4.1
通讯作者：
V. Klassen;Olga Blifernez-Klassen;Yoep Hoekzema;J. Mussgnug;O. Kruse
中科院分区：
文献类型：
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作者：
V. Klassen;Olga Blifernez-Klassen;Yoep Hoekzema;J. Mussgnug;O. Kruse
利用藻类生物质生产沼气已经研究了五十多年，但直到今天，几个明显的特征，如低效的降解和低C/N比，限制了藻类生物质在更大规模生产沼气中的适用性。在这项工作中，我们研究了一种新的，一个阶段的联合培养/发酵策略，包括固有的进步氮饥饿条件，以产生改善微藻生物质底物。对于这种策略，在栽培过程中施用相当低量的氮肥，并且不需要进行额外的酶、化学或物理预处理。本研究的结果表明，进行氮限制导致连续增加的生物量的C/N比高达24-26的水平为所有三个测试的衣藻菌株（莱茵衣藻，Parachlorella kessleriandScenedesmus）。重要的是，随着饥饿的进行，藻细胞的降解效率增加，导致在发酵过程中菌株特异性细胞崩解效率为35%-100%。限氮处理使C. reinhardtiibomass（max. 698 ± 23 mL沼气g−1VS）。对于P。kessleriandS.产量分别提高了94%和106%（最大值）。706 ± 39 mL和586 ± 36 mL生物气g-1VS）。从这些结果中，我们得出结论，这种具有固有氮限制的新型一阶段培养策略可用作微藻生物量产生的预处理，以产生具有优化C/N比的可获得底物用于随后的厌氧发酵过程，从而增加甲烷产量并避免发酵罐内氨抑制效应的风险。
The use of alga biomass for biogas generation has been studied for over fifty years but until today, several distinct features, like inefficient degradation and low C/N ratios, limit the applicability of algal biomass for biogas production in larger scale. In this work we investigated a novel, one-stage combined cultivation/fermentation strategy including inherently progressing nitrogen starvation conditions to generate improved microalgal biomass substrates. For this strategy, comparable low amounts of nitrogen fertilizers were applied during cultivation and no additional enzymatic, chemical or physical pretreatments had to be performed. The results of this study demonstrate that progressing nitrogen limitation leads to continuously increasing C/N ratios of the biomass up to levels of 24–26 for all three tested alga strains (Chlamydomonas reinhardtii,Parachlorella kessleriandScenedesmus obliquus). Importantly, the degradation efficiency of the algal cells increased with progressing starvation, leading to strain-specific cell disintegration efficiencies of 35%–100% during the fermentation process. Nitrogen limitation treatment resulted in a 65% increase of biogas yields forC. reinhardtiibiomass (max. 698 ± 23 mL biogas g−1VS) when compared to replete conditions. ForP. kessleriandS. obliquus, yields increased by 94% and 106% (max. 706 ± 39 mL and 586 ± 36 mL biogas g−1VS, respectively).From these results we conclude that this novel one-stage cultivation strategy with inherent nitrogen limitation can be used as a pretreatment for microalgal biomass generation, in order to produce accessible substrates with optimized C/N ratios for the subsequent anaerobic fermentation process, thus increasing methane production and avoiding the risk of ammonia inhibition effects within the fermenter.