TY  - JOUR
A1  - Hu, Chenlin
A1  - Ludsin, Stuart A.
A1  - Martin, Jay F.
A1  - Dittmann, Elke
A1  - Lee, Jiyoung
T1  - Mycosporine-like amino acids (MAAs)-producing Microcystis in Lake Erie
BT  - Development of a qPCR assay and insight into its ecology
JF  - Harmful algae
N2  - Mycosporine-like amino acids (MAAs) are UV-absorbing metabolites found in cyanobacteria. While their protective role from UV in Microcystis has been studied in a laboratory setting, a full understanding of the ecology of MAA-producing versus non-MAA-producing Microcystis in natural environments is lacking. This study presents a new tool for quantifying MAA-producing Microcystis and applies it to obtain insight into the dynamics of MAA-producing and non-MAA-producing Microcystis in Lake Erie. This study first developed a sensitive, specific TaqMan real-time PCR assay that targets MAA synthetase gene C (mysC) of Microcystis (quantitative range: 1.7 × 101 to 1.7 × 107 copies/assay). Using this assay, Microcystis was quantified with a MAA-producing genotype (mysC+) in water samples (n = 96) collected during March-November 2013 from 21 Lake Erie sites (undetectable − 8.4 × 106 copies/ml). The mysC+ genotype comprised 0.3–37.8% of the Microcystis population in Lake Erie during the study period. The proportion of the mysC+ genotype during high solar UV irradiation periods (mean = 18.8%) was significantly higher than that during lower UV periods (mean = 9.7%). Among the MAAs, shinorine (major) and porphyra (minor) were detected with HPLC-PDA-MS/MS from the Microcystis isolates and water samples. However, no significant difference in the MAA concentrations existed between higher and lower solar UV periods when the MAA concentrations were normalized with Microcystis mysC abundance. Collectively, this study’s findings suggest that the MAA-producing Microcystis are present in Lake Erie, and they may be ecologically advantageous under high UV conditions, but not to the point that they exclusively predominate over the non-MAA-producers.
KW  - Shinorine
KW  - Porphyra
KW  - UV irradiation
KW  - Sunscreen
KW  - Eutrophication
KW  - Harmful algal bloom
Y1  - 2018
U6  - https://doi.org/10.1016/j.hal.2018.05.010
SN  - 1568-9883
SN  - 1878-1470
VL  - 77
SP  - 1
EP  - 10
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Huwe, Björn
A1  - Fiedler, Annelie
A1  - Moritz, Sophie
A1  - Rabbow, Elke
A1  - de Vera, Jean-Pierre Paul
A1  - Joshi, Jasmin Radha
T1  - Mosses in Low Earth Orbit
BT  - Implications for the Limits of Life and the Habitability of Mars
JF  - Astrobiology
N2  - As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of abiotic space- and Mars-like conditions were performed to analyze the resistance of a range of model organisms. The simulated abiotic space- and Mars-stressors were extreme temperatures, vacuum, and Mars-like surface ultraviolet (UV) irradiation in different atmospheres. We present for the first time simulated space exposure data of mosses using plantlets of the bryophyte genus Grimmia, which is adapted to high altitudinal extreme abiotic conditions at the Swiss Alps. Our preflight tests showed that severe UVR200-400nm irradiation with the maximal dose of 5 and 6.8 x 10(5) kJ center dot m(-2), respectively, was the only stressor with a negative impact on the vitality with a 37% (terrestrial atmosphere) or 36% reduction (space- and Mars-like atmospheres) in photosynthetic activity. With every exposure to UVR200-400nm 10(5) kJ center dot m(-2), the vitality of the bryophytes dropped by 6%. No effect was found, however, by any other stressor. As the mosses were still vital after doses of ultraviolet radiation (UVR) expected during the EXPOSE-R2 mission on ISS, we show that this earliest extant lineage of land plants is highly resistant to extreme abiotic conditions.
KW  - Extremotolerant
KW  - Bryophyte
KW  - Plant performance
KW  - Grimmia sp
KW  - Irradiation
KW  - UV irradiation
Y1  - 2019
U6  - https://doi.org/10.1089/ast.2018.1889
SN  - 1531-1074
SN  - 1557-8070
VL  - 19
IS  - 2
SP  - 221
EP  - 232
PB  - Liebert
CY  - New Rochelle
ER  -