Characterization of extracellular matrix components from the desiccation-tolerant cyanobacterium <i>Nostoc commune</i>

Abstract

The terrestrial cyanobacterium Nostoc commune forms macroscopic colonies in its natural habitats, and these colonies consist of both cellular filaments and massive extracellular matrixes. In this study, the biochemical features of the extracellular matrix components were investigated. Naturally growing N. commune was tolerant to desiccation, and produced massive extracellular polysaccharides that contained both neutral sugars and glucuronic acid as constituent monosaccharides. The extracellular polysaccharide contents and desiccation tolerance were compared in laboratory culture strains of Nostoc species. The laboratory culture of N. commune strain KU002 was sensitive to desiccation and produced smaller amounts of extracellular polysaccharides, unlike the field-isolated naturally growing colonies. Nostoc punctiforme strain M-15, which is genetically closed to N. commune, was able to tolerate desiccation, although the other Nostoc strains were desiccation-sensitive. A laboratory culture strain of the aquatic cyanobacterium Nostoc sphaericum produced massive extracellular polysaccharides but was sensitive to desiccation, suggesting that extracellular matrix production is not enough to make this strain tolerant to desiccation. WspA (water stress protein) and SodF (superoxide dismutase) were found to be characteristic protein components of the extracellular matrix of N. commune. Because the WspA proteins were heterogeneous, the wspA genes were highly diverse among the different genotypes of N. commune, although the sodF gene was rather conservative. The heterogeneity of the WspA proteins suggests their complex roles in the environmental adaptation mechanism in N. commune.

Four chemotypes of the terrestrial cyanobacterium Nostoc commune characterized by differences in the mycosporine‐like amino acids

“…), are held at the Kakuma Campus of Kanazawa University (Inoue‐Sakamoto et al . ). To confirm the presence of all four chemotypes at Kanazawa University, the MAA compositions were characterized using 47 samples of N. commune colonies (Table S3 in the Supporting Information).…”

“…; Inoue‐Sakamoto et al . ). These N. commune laboratory culture strains were deposited in the Microbial Culture Collection at the National Institute for Environmental Studies (NIES‐Collection) with the following collection numbers: NIES‐2538 ( N. commune strain KU002), NIES‐3989 ( N. commune strain KU006), NIES‐3990 ( N. commune strain KU007) and NIES‐3991 ( N. commune strain KU008).…”

“…; Inoue‐Sakamoto et al . ), trehalose accumulation (Sakamoto et al . , ; Yoshida & Sakamoto ), antioxidative molecules (Matsui et al .…”

Characterization of mycosporine-like amino acids in the cyanobacterium <i>Nostoc verrucosum</i>

“…The molecular mechanism underlying the extreme desiccation tolerance of this species is thought to involve multiple processes that include extracellular polysaccharide (EPS) production, compatible solute accumulation, and antioxidants. We have studied physiologically and biochemically the desiccation tolerance in N. commune (Inoue-Sakamoto et al, 2018;Matsui et al, 2011Matsui et al, , 2012Morsy et al, 2008;Nazifi et al, 2013Nazifi et al, , 2015Sakamoto et al, 2009Sakamoto et al, , 2011Tamaru et al, 2005;Yoshida and Sakamoto 2009).…”

“…The presence of WspA is a remarkable common feature in these Nostoc species (Arima et al 2012;Sakamoto et al, 2011), which suggests the same, or a very similar, architecture of their extracellular matrix. Interacting with EPS and UV-absorbing pigments, namely mycosporine-like amino acids (MAAs) and scytonemin, WspA is thought to play a role in modulating the structure and function of the three-dimensional extracellular matrix in N. commune (Helm and Potts, 2012;Hill et al, 1994;Inoue-Sakamoto et al, 2018;Wright et al, 2005).…”