Establishment of an isolation method of Nostoc commune cells free from extracellular polysaccharides (EPS) using Percoll centrifugation

The terrestrial cyanobacterium Nostoc commune Vaucher ex Bornet et Flahault occurs worldwide, including in Japan and Antarctica. N. commune has a large amount of extracellular polysaccharides (EPS) that hold moisture and protect the cells and at the same time accumulate light-blocking substances whi...

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Bibliographic Details
Main Authors: Makiko Kosugi, Yasuhiro Kashino, Sakae Kudoh, Satoshi Imura
Format: Article in Journal/Newspaper
Language:English
Japanese
Published: National Institute of Polar Research 2012
Subjects:
Online Access:https://doi.org/10.15094/00009663
https://doaj.org/article/3daea65796cb4f28be781dab5787f454
Description
Summary:The terrestrial cyanobacterium Nostoc commune Vaucher ex Bornet et Flahault occurs worldwide, including in Japan and Antarctica. N. commune has a large amount of extracellular polysaccharides (EPS) that hold moisture and protect the cells and at the same time accumulate light-blocking substances which is believed to play an important part in adaptation to a severe environment. To evaluate the photoadaptation processes in N. commune and clarify the role(s) of EPS under ambient environmental condition at Antarctica, separation of cells from EPS is necessary. High yield is a prerequisite for the use of only small amount of natural N. commune from Antarctica. For this purpose, we developed a separation method by improving the Percoll density gradient centrifugation method using an EPS-coated field-grown Nostoc population. We established the most suitable condition to separate naked cells from EPS at high yield retaining high photosynthetic activity. The method is composed of centrifugation of cell homogenated N. commune in 10% (v/v) Percoll to separate cells efficiently from EPS followed by fractionating centrifugation to remove impurities using the gradient of Percoll (80% and 50%, v/v).