Biological Processing, Idaho National Laboratory, Idaho Falls 83415, USA.
Arizona Center for Algae Technology and Innovation, Arizona State University, Mesa 85212, USA.
J Ind Microbiol Biotechnol. 2023 Feb 17;50(1). doi: 10.1093/jimb/kuad004.
Long-term storage is necessary to mitigate for seasonal variation in algae productivity, to preserve biomass quality and to guarantee a constant biomass supply to a conversion facility. While ensiling has shown promise as a solution, biomass attributes for successful storage are poorly understood. Storage studies of Monoraphidium sp. biomass indicate a strong correlation between nitrogen management in algae cultivation and stability of post-harvest algae biomass. Algae cultivated with periodic nitrogen addition were stored poorly (>20% loss, dry basis) compared to biomass from nitrogen depleted cultivation (8% loss, dry basis). A follow-up study compared the post-harvest stability of Monoraphidium biomass cultivated in nitrogen-deplete or nitrogen-replete conditions. Replete biomass experienced the largest degradation (24%, dry basis), while deplete biomass experienced the least (10%, dry basis). Dry matter loss experienced among blends of each correlated positively with nitrogen-replete biomass content. The composition of the post-storage algae microbial community was also affected by cultivation conditions, with Clostridia species being more prevalent in stored biomass obtained from nitrogen-replete cultivations. Nitrogen management has long been known to influence algae biomass productivity and biochemical composition; here, we demonstrate that it also strongly influences the stability of post-harvest algae biomass in anaerobic storage.
长期储存对于缓解藻类生产力的季节性变化、保持生物质质量以及保证转化设施的生物质供应的稳定性是必要的。虽然青贮已被证明是一种可行的解决方案，但成功储存的生物质特性仍未被充分理解。对 Monoraphidium sp.生物质的储存研究表明，藻类培养过程中的氮管理与收获后藻类生物质的稳定性之间存在很强的相关性。与氮耗尽培养的生物质（干基损失 8%）相比，周期性添加氮的藻类培养物的储存效果较差（干基损失超过 20%）。后续研究比较了在氮耗尽或氮充足条件下培养的 Monoraphidium 生物质的收获后稳定性。氮充足的生物质经历了最大的降解（干基损失 24%），而氮耗尽的生物质经历了最小的降解（干基损失 10%）。每种混合体的干物质损失与氮充足生物质含量呈正相关。储存后藻类微生物群落的组成也受到培养条件的影响，在氮充足培养中获得的储存生物质中更常见到梭菌属物种。氮管理长期以来一直被认为会影响藻类生物质的生产力和生物化学组成；在这里，我们证明它还强烈影响收获后藻类生物质在厌氧储存中的稳定性。
