Premium
Functional assessment of mycosporine‐like amino acids in M icrocystis aeruginosa strain PCC 7806
Author(s) -
Hu Chenlin,
Völler Ginka,
Süßmuth Roderich,
Dittmann Elke,
Kehr JanChristoph
Publication year - 2015
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12577
Subject(s) - biology , extracellular , mutant , microbiology and biotechnology , cyanobacteria , strain (injury) , amino acid , biosynthesis , extracellular matrix , reactive oxygen species , biochemistry , bacteria , gene , genetics , anatomy
Summary The biological role of the widespread mycosporine‐like amino acids ( MAA s) in cyanobacteria is under debate. Here, we have constructed and characterized two mutants impaired in MAA biosynthesis in the bloom‐forming cyanobacterium M icrocystis aeruginosa PCC 7806. We could identify shinorine as the sole MAA type of the strain, which is exclusively located in the extracellular matrix. Bioinformatic studies as wells as polymerase chain reaction screening revealed that the ability to produce MAA s is sporadically distributed within the genus. Growth experiments and reactive oxygen species quantification with wild‐type and mutant strains did not support a role of shinorine in protection against UV or other stress conditions in M . aeruginosa PCC 7806. The shinorine content per dry weight of cells as well as transcription of the mys gene cluster was not significantly elevated in response to UV ‐ A , UV ‐ B or any other stress condition tested. Remarkably, both mutants exhibited pronounced morphological changes compared with the wild type. We observed an increased accumulation and an enhanced hydrophobicity of the extracellular matrix. Our study suggests that MAA s in M icrocystis play a negligible role in protection against UV radiation but might be a strain‐specific trait involved in extracellular matrix formation and cell–cell interaction.