Distribution and Abundance of MAAs in 33 Species of Microalgae across 13 Classes

We provide a direct comparison of the distribution and abundance of mycosporine-like amino acids (MAAs) in a diverse range of microalgal cultures (33 species across 13 classes) grown without supplementary ultraviolet radiation (UV). We compare the MAAs in cultures with those present in characterised natural phytoplankton populations from the English Channel. We detected 25 UV absorbing compounds including at least two with multiple absorption maxima. We used LC-MS to provide chemical characterisation of the six most commonly occurring MAAs, namely, palythene, palythine, mycosporine-glycine, palythenic acid, porphyra-334 and shinorine. MAAs were abundant (up to 7 pg MAA cell−1) in 10 species, with more minor and often unknown MAAs in a further 11 cultures. Shinorine was the most frequently occurring and abundant MAA (up to 6.5 pg cell−1) and was present in all but two of the MAA-containing species. The study provides further insight into the diversity and abundance of MAAs important from an ecological perspective and as potential source of natural alternatives to synthetic sunscreens

Sources of mycosporine-like amino acids in planktonic Chlorella-bearing ciliates (Ciliophora)

Mycosporine-like amino acids (MAAs) are a family of secondary metabolites known to protect organisms exposed to solar UV radiation. We tested their distribution among several planktonic ciliates bearing Chlorella isolated from an oligo-mesotrophic lake in Tyrol, Austria. In order to test the origin of these compounds, the MAAs were assessed by high performance liquid chromatography in both the ciliates and their symbiotic algae.Considering all Chlorella-bearing ciliates, we found: (i) seven different MAAs (mycosporine-glycine, palythine, asterina-330, shinorine, porphyra-334, usujirene, palythene); (ii) one to several MAAs per species and (iii) qualitative and quantitative seasonal changes in the MAAs (e.g. in Pelagodileptus trachelioides). In all species tested, concentrations of MAAs were always <1% of ciliate dry weight.Several MAAs were also identified in the Chlorella isolated from the ciliates, thus providing initial evidence for their symbiotic origin. In Uroleptus sp., however, we found evidence for a dietary source of MAAs.Our results suggest that accumulation of MAAs in Chlorella-bearing ciliates represents an additional benefit of this symbiosis and an adaptation for survival in sunlit, UV-exposed waters

Ultraviolet and osmotic stresses induce and regulate the synthesis of mycosporines in the cyanobacterium Chlorogloeopsis PCC 6912

The cyanobacterium Chlorogloeopsis PCC 6912 was found to synthesize and accumulate two putative UV sunscreen compounds of the mycosporine (mycosporine-like amino acid; MAA) type: mycosporine-glycine and shinorine. These MAAs were not constitutively present in the cells; their synthesis could be induced specifically either by exposure to UVB radiation (280-320 nm) or by osmotic stress, but not by other stress factors such as heat or cold shock, nutrient limitation or photooxidative stress. A significant synergistic enhancement of MAA synthesis was observed when both stress factors were applied in combination. Although osmotic stress could induce MAA syn thesis, comparison of the intracellular contents of MAAs with those of sugar osmolytes (glucose and trehalose) indicated that MAAs play no significant role in attaining osmotic homeostasis. UVB strongly enhanced the accumulation of shinorine, whereas osmotic stress had a more pronounced effect on mycosporine-glycine. This differential effect on the steady-state contents of each MAA could be explained either by differential regulation of biosynthesis or by differential loss rates of MAAs (leakage) under each condition. A preferential leakage of mycosporine-glycine from the cells after a hypoosmotic shock was detected. The results are interpreted in terms of an adaptive necessity for a combined regulatory control responding to both UV and external osmotic conditions in organisms that accumulate water-soluble sunscreens intracellularly

A novel prokaryotic UVB photoreceptor in the cyanobacterium Chlorogloeopsis PCC 6912

We present evidence for the presence and nature of a UVB‐specific photoreceptor in the cyanobacterium Chlorogloeopsis PCC 6912. The photoreceptor mediates at least the photosensory induction of mycosporine‐like amino acid (MAA) synthesis. Because MAA synthesis in this organism can also be induced under salt stress, we could distinguish between the photosensory and the purely biochemical requirements of MAA synthesis. Neither visible light nor UV radiation was necessary for the biosynthetic process, thus indicating that the UVB (280–320 nm) dependence of biosynthesis is based on a UV photosensory capacity of the organism. An action spectrum of the MAA synthesis showed a distinct peak at 310 nm tailing down into the UVA (320–400 nm) region with no detected activity above 340 nm. We found that radiation below 300 nm caused significant inhibition of synthesis of MAAs indicating that the action spectrum at these wavelengths may not have been satisfactorily resolved. We propose that a pterin is a good candidate for a photoreceptor chromophore as (1) reduced pterins present absorption spectra congruent with the action spectrum obtained; and (2) an inhibitor of the biosynthetic pathway of pterins and an antagonist of excited states of pterins, both depressed the photosensory efficiency of induction but not its chemosensory efficiency

SARA - Subjective and objective data acquisition for physiotherapy treatment support

The work of physiotherapists is very important for the cure of patients. Physiotherapy has a long historical background. Physiotherapists are working almost manually, treat pain and movement restrictions, support rehabilitation and support the recovering of strength and wellbeing. The healing of the patients is a slow process and subjective impressions about pain or discomfort are important for the quality and adjustment of the treatment. The quality of treatment is dependent by the skills and knowledge of the therapist. Unfortunately, objective indicators of a good or successful treatment in the area of physiotherapy are rare; a comprehensive documentation after the therapy is often missing. With SARA, a platform for physiotherapy treatment support, the physiotherapist have received a new tool that allows an objective assessment of the treatment progress, the condition of their patients, and a documentation about the physical performance and further needs. This paper describes the concept and the measurement methods for the unobtrusive monitoring of the treatment quality and the results of the therapy