Simulated microgravity alters growth and microcystin production in Microcystis aeruginosa (cyanophyta)

Yuan, Xiao; Liu, Yongding; Wang, Gaohong; Hao, Zhixin; An, Yanjun

doi:10.1016/j.toxicon.2010.01.026

Cited by 30 publications

(22 citation statements)

References 25 publications

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“…The stronger decrease in MDA content and CAT activity in our 1 g controls is due to the fact that it often takes some time for cyanobacteria to accommodate to a new culture environment after inoculation. Xiao et al (2010) reported that cyanobacteria showed a significant decrease in growth and metabolism until the 4th day after inoculation. Due to the relative shorter sampling period in this study, this effect can be observed in the 1 g reference samples.…”

Section: Resultsmentioning

confidence: 99%

Physiological Responses of Synechocystis sp. PCC 6803 under Clinorotation

Wang

et al. 2012

Microgravity Sci. Technol.

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Photosystem efficiency and the characteristic on oxidative stress were examined to elucidate the metabolic responses of Synechocystis sp. PCC 6803 to short-term clinorotation. Results compiled when using clinostat to simulate microgravity for 60 h, showed that clinorotation clearly prohibited the photochemical quantum yield, but promoted the synthesis of chlorophyll and total protein. This may be a compensatory mechanism for the algal cell to maintain its normal metabolism. An increased malondialdehyde (MDA) content of algal cell upon clinorotation, together with an enhanced catalase (CAT) activity was observed during the whole period of clinorotation. One conclusion is that short-term clinorotation acts as a kind of stress, and that these physiological responses may be a special way for an algal cell to adapt itself to a different environment other than earth gravity.

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Section: Resultsmentioning

confidence: 99%

Physiological Responses of Synechocystis sp. PCC 6803 under Clinorotation

Wang

et al. 2012

Microgravity Sci. Technol.

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“…Kaebernick et al (2000) reported that the damage of the photosynthetic system of Microcystis might negatively impact intracellular MC production. Factors including light, simulated microgravity, and organic pollutants can also significantly affect MC production and release (Wang et al 2007;Wiedner et al 2003;Xiao et al 2010). In our study, the detection of extracellular MC in the control group can be attributed to the high culture density (Wiedner et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Effects of laser irradiation on a bloom forming cyanobacterium Microcystis aeruginosa

Liu

et al. 2016

Environ Sci Pollut Res

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Effects of laser irradiation on photosystem II (PS II) photochemical efficiencies, growth, and other physiological responses of Microcystis aeruginosa were investigated in this study. Results indicate that laser irradiation (wavelengths 405, 450, 532, and 650 nm) could effectively inhibit maximal PS II quantum yield (Fv/Fm) and maximal electron transport rates (ETR max ) of M. aeruginosa, while saturating light levels (E k ) of M. aeruginosa did not change significantly. Among the four tested wavelengths, 650 nm laser (red light) showed the highest inhibitory efficiency. Following 650 nm laser irradiation, the growth of M. aeruginosa was significantly suppressed, and contents of cellular photosynthetic pigments (chlorophyll a, carotenoid, phycocyanin, and allophycocyanin) decreased as irradiation dose increased. Meanwhile, laser irradiation enhanced the enzyme activities of superoxide dismutase (SOD) and peroxidase (POD) in M. aeruginosa cells. Lower irradiation doses did not change the intracellular microcystin contents, but higher dose irradiation (>1284 J cm −2 ) caused the release of microcystin into the culture medium. Transmission electron microscope examination showed that the ultrastructure of M. aeruginosa cells was destructed progressively following laser irradiation. Effects of laser irradiation on M. aeruginosa may be a combination of photochemical, electromagnetic, and thermal effects.

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“…As running lab experiments in space is a complex process and very expensive, much of the research is done on Earth with space simulations. Clinostats can simulate microgravity conditions and have promoted the development of space biology (Liu et al, 1993;Wang et al, 2006;Olsson-Francis & Cockell, 2010;Xiao et al, 2010). Although clinostats have been widely used to simulate microgravity conditions, most of the studies have concentrated on the effect of microgravity on tissues and cells of higher plants and mammals.…”

Section: Introductionmentioning

confidence: 99%

Cadmium uptake capacity of an indigenous cyanobacterial strain, Nostoc entophytum ISC32: new insight into metal uptake in microgravity-simulating conditions

et al. 2016

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Among nine cyanobacterial strains isolated from oil-contaminated regions in southern Iran, an isolate with maximum cadmium uptake capacity was selected and identified on the basis of analysis of morphological criteria and 16S rRNA gene sequence similarity as Nostoc entophytum (with 99 % similarity). The isolate was tentatively designated N. entophytum ISC32. The phylogenetic affiliation of the isolates was determined on the basis of their 16S rRNA gene sequence. The maximum amount of Cd(II) adsorbed by strain ISC32 was 302.91 mg g 21 from an initial exposure to a solution with a Cd(II) concentration of 150 mg l 21 . The cadmium uptake by metabolically active cells of cyanobacterial strain N. entophytum ISC32, retained in a clinostat for 6 days to simulate microgravity conditions, was examined and compared with that of ground control samples. N. entophytum ISC32 under the influence of microgravity was able to take up cadmium at amounts up to 29 % higher than those of controls. The activity of antioxidant enzymes including catalase and peroxidase was increased in strain ISC32 exposed to microgravity conditions in a clinostat for 6 days, as catalase activity of the cells was more than three times higher than that of controls. The activity of the peroxidase enzyme increased by 36 % compared with that of the controls. Membrane lipid peroxidation was also increased in the cells retained under microgravity conditions, up to 2.89-fold higher than in non-treated cells. Images obtained using scanning electron microscopy showed that cyanobacterial cells form continuous filaments which are drawn at certain levels, while the cells placed in a clinostat appeared as round-shaped, accumulated together and distorted to some extent.

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Simulated microgravity alters growth and microcystin production in Microcystis aeruginosa (cyanophyta)

Cited by 30 publications

References 25 publications

Physiological Responses of Synechocystis sp. PCC 6803 under Clinorotation

Physiological Responses of Synechocystis sp. PCC 6803 under Clinorotation

Effects of laser irradiation on a bloom forming cyanobacterium Microcystis aeruginosa

Cadmium uptake capacity of an indigenous cyanobacterial strain, Nostoc entophytum ISC32: new insight into metal uptake in microgravity-simulating conditions

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