Dahlin Lukas R, Van Wychen Stefanie, Gerken Henri G, McGowen John, Pienkos Philip T, Posewitz Matthew C, Guarnieri Michael T
Department of Chemistry, Colorado School of Mines, Golden, CO, United States.
National Renewable Energy Laboratory, National Bioenergy Center, Golden, CO, United States.
Front Plant Sci. 2018 Oct 29;9:1513. doi: 10.3389/fpls.2018.01513. eCollection 2018.
Algae offer promising feedstocks for the production of renewable fuel and chemical intermediates. However, poor outdoor winter cultivation capacity currently limits deployment potential. In this study, 300 distinct algal strains were screened in saline medium to determine their cultivation suitability during winter conditions in Mesa, Arizona. Three strains, from the genera , and , were chosen following laboratory evaluations and grown outdoors in 1000 L raceway ponds during the winter. Strains were down-selected based on doubling time, lipid and carbohydrate amount, final biomass accumulation capacity, cell size and phylogenetic diversity. Algal biomass productivity and compositional analysis for lipids and carbohydrates show successful outdoor deployment and cultivation under winter conditions for these strains. Outdoor harvest-yield biomass productivities ranged from 2.9 to 4.0 g/m/day over an 18 days winter cultivation trial, with maximum productivities ranging from 4.0 to 6.5 g/m/day, the highest productivities reported to date for algal winter strains grown in saline media in open raceway ponds. Peak fatty acid levels ranged from 9 to 26% percent of biomass, and peak carbohydrate levels ranged from 13 to 34% depending on the strain. Changes in the lipid and carbohydrate profile throughout outdoor growth are reported. This study demonstrates that algal strain screening under simulated outdoor environmental conditions in the laboratory enables identification of strains with robust biomass productivity and biofuel precursor composition. The strains isolated here represent promising winter deployment candidates for seasonal algal biomass production when using crop rotation strategies.
藻类为可再生燃料和化学中间体的生产提供了有前景的原料。然而，目前较差的户外冬季培养能力限制了其部署潜力。在本研究中，在盐培养基中筛选了300种不同的藻类菌株，以确定它们在亚利桑那州梅萨冬季条件下的培养适宜性。经过实验室评估后，从、和属中选择了三种菌株，并在冬季于1000升跑道池中进行户外培养。根据倍增时间、脂质和碳水化合物含量、最终生物量积累能力、细胞大小和系统发育多样性对菌株进行了筛选。这些菌株的藻类生物量生产力以及脂质和碳水化合物的成分分析表明，它们在冬季条件下能够成功地进行户外部署和培养。在为期18天的冬季培养试验中，户外收获产量生物量生产力范围为2.9至4.0克/平方米/天，最大生产力范围为4.0至6.5克/平方米/天，这是迄今为止在开放式跑道池中盐培养基中生长的藻类冬季菌株所报道的最高生产力。脂肪酸峰值水平占生物量的9%至26%，碳水化合物峰值水平根据菌株不同在13%至34%之间。报告了整个户外生长过程中脂质和碳水化合物谱的变化。本研究表明，在实验室模拟户外环境条件下进行藻类菌株筛选能够识别出具有强大生物量生产力和生物燃料前体成分的菌株。这里分离出的菌株代表了在采用作物轮作策略时，用于季节性藻类生物量生产的有前景的冬季部署候选菌株。
