Liquid culture of N ostoc flagelliforme

• Published in: Microbial biotechnology 2015-11, Vol.8 (6), p.1006-1012
• Main Authors: Gao, Xiang, Yi‐Wen Yang, Li‐Juan Cui, De‐Bao Zhou, Bao‐Sheng Qiu
• Format: Article
• Language: English
• Subjects: Algae; Aridity; Biomass; Coatings; Colonies; Culture; Desiccation; Drying; Exploitation; Grasslands; Light; Liquid culture; Morphology; Nitrogen; Nostoc; Photosynthesis; Physiology; Polyvinyl alcohol; Polyvinylpyrrolidone; Protective coatings; Restoration; Seeds; Steppes; Terrestrial environments; Ultraviolet radiation
• ISSN: 1751-7915
• DOI: 10.1111/1751-7915.12279

Nostoc flagelliforme is a terrestrial edible cyanobacterium that grows in arid and semi‐arid steppes. The continued over‐exploitation in the last century has led to a sharp decline of this resource and a severe deterioration of the steppe ecology. Liquid‐cultured N. flagelliforme serves as promising algal ‘seeds’ for resource restoration. In this study, macroscopic (or visible) aquatic‐living colonies (MaACs) of N. flagelliforme were developed under weak light and high nitrogen conditions. In a 24 day shake‐flask culture, MaACs were propagated by about 4.5‐fold in biomass without loss of their macro‐morphology; at the same time, the addition of weak UV‐B treatment resulted in slightly bigger MaACs. Polyvinylpyrrolidone (PVP) k30, a water‐soluble polymer, was used to generate the coating around MaACs, and after full desiccation, the coated MaACs could recover their photosynthetic physiological activity when rehydrated, with 4% PVP k30 for coating being most effective. In contrast, PVP k30‐coated microscopic aquatic‐living colonies of N. flagelliforme and non‐coated MaACs showed no resistance to full desiccation. The macroscopic morphology or structure of MaACs should be crucial for the formation of protection by PVP k30 coating. PVP k30‐coated MaACs were more approaching to actual application for resource restoration.