Cyanobacteria are prokaryotic oxygenic phototrophs receiving attention in a wide variety of technological applications such as food and feed supplements and production of valuable polymers. Among these, carbohydrates (e.g. glycogen) and polyhydroxyalkanoates (PHAs) are of increasing interest due to their potential as a biofuel substrate and bioplastics, respectively. However, biofuels and bioplastics from cyanobacteria have seen many years of effort towards commercialization with only limited success. Their main limitation for polymer production is the high cost of the nutrient source; wastewater, as an inexpensive and widely available alternative, may overcome this bottleneck. Though cyanobacteria have demonstrated a capacity to treat wastewater effluents, their cultivation in such a variable environment involves certain challenges of which the chief one is linked to contamination by other species, especially green algae. This would represent a serious drawback during cyanobacterial biomass production and affect further PHA and carbohydrate production. The present study reviews the potential of cyanobacteria to grow in wastewater effluents from different sources. Conditions favoring them in mixed-culture reactors are described, focusing on nutritional and operational aspects. Current advances and future prospects in PHA and carbohydrate production are explored and discussed.

中文翻译：

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废水中生长的蓝藻生产聚合物：现状、挑战和未来前景

蓝藻是原核含氧光合生物，在各种技术应用中受到关注，例如食品和饲料补充剂以及有价值聚合物的生产。其中，碳水化合物（例如糖原）和聚羟基链烷酸酯（PHA）由于它们分别作为生物燃料底物和生物塑料的潜力而受到越来越多的关注。然而，来自蓝藻的生物燃料和生物塑料已经经历了多年的商业化努力，但收效甚微。它们对聚合物生产的主要限制是营养源的高成本；废水作为一种廉价且广泛可用的替代品，可以克服这一瓶颈。尽管蓝藻已证明有处理废水的能力，它们在如此多变的环境中的培养涉及某些挑战，其中主要挑战与其他物种，尤其是绿藻的污染有关。这将代表蓝藻生物质生产过程中的严重缺陷，并影响进一步的 PHA 和碳水化合物生产。本研究回顾了蓝藻在不同来源的废水中生长的潜力。描述了有利于它们在混合培养反应器中的条件，重点是营养和操作方面。探索和讨论了 PHA 和碳水化合物生产的当前进展和未来前景。本研究回顾了蓝藻在不同来源的废水中生长的潜力。描述了有利于它们在混合培养反应器中的条件，重点是营养和操作方面。探索和讨论了 PHA 和碳水化合物生产的当前进展和未来前景。本研究回顾了蓝藻在不同来源的废水中生长的潜力。描述了有利于它们在混合培养反应器中的条件，重点是营养和操作方面。探索和讨论了 PHA 和碳水化合物生产的当前进展和未来前景。