Cyanobacterial Blue Color Formation during Lysis under Natural Conditions

Abstract

dCyanobacteria produce numerous volatile organic compounds (VOCs), such as ␤-cyclocitral, geosmin, and 2-methylisoborneol, which show lytic activity against cyanobacteria. Among these compounds, only ␤-cyclocitral causes a characteristic color change from green to blue (blue color formation) in the culture broth during the lysis process. In August 2008 and September 2010, the lysis of cyanobacteria involving blue color formation was observed at Lake Tsukui in northern Kanagawa Prefecture, Japan. We collected lake water containing the cyanobacteria and investigated the VOCs, such as ␤-cyclocitral, ␤-ionone, 1-propanol, 3-methyl-1-butanol, and 2-phenylethanol, as well as the number of cyanobacterial cells and their damage and pH changes. As a result, the following results were confirmed: the detection of several VOCs, including ␤-cyclocitral and its oxidation product, 2,2,6-trimethylcyclohexene-1-carboxylic acid; the identification of phycocyanin based on its visible spectrum; the lower pH (6.7 and 5.4) of the lysed samples; and characteristic morphological change in the damaged cyanobacterial cells. We also encountered the same phenomenon on 6 September 2013 in Lake Sagami in northern Kanagawa Prefecture and obtained almost the same results, such as blue color formation, decreasing pH, damaged cells, and detection of VOCs, including the oxidation products of ␤-cyclocitral. ␤-Cyclocitral derived from Microcystis has lytic activity against Microcystis itself but has stronger inhibitory activity against other cyanobacteria and algae, suggesting that the VOCs play an important role in the ecology of aquatic environments.

Deodorization of Arthrospira platensis biomass for further scale‐up food applications

“…reported concentrations of α ‐ and β ‐ionone and 6,10,14‐ trimethyl‐decan‐2‐one derived from phytol, a derivative of chlorophyll. In A. platensis , β ‐carotene represented 67–79% of total carotenoids; therefore, the identification of β ‐cyclocitral as an AVOC was expected along with the identification of phytol and hydrocarbons as degraded compounds of chlorophyll and fatty acids . By contrast to previous publications, sulfur compounds were not detected …”

“…Different studies have reported algae and cyanobacteria volatile organic compounds (AVOCs) . Depending on the species and environmental conditions, the profile of these volatile organic compounds might change.…”

“…The detection of volatile compounds in cyanobacteria has been assayed by gas chromatography‐mass spectroscopy (GC‐MS), GC‐olfactory methods and headspace solid‐phase microextraction (HS‐SPME) . However, a limited amount of studies have described the presence of AVOCs from Arthrospira extracts.…”

In situ enclosure experiments on the occurrence, development and decline of black bloom and the dynamics of its associated taste and odor compounds

“…and by the disruption of their cellular integrity (Suurnakki et al, 2015). In addition, because ␤-cyclocitral has lytic activity against cyanobacteria ( Arii et al, 2015), a high concentration of ␤-cyclocitral would accelerate the decomposition of the cyanobacteria in the bloom, further increasing the release of ␤-cyclocitral and VOSCs.…”

A New Morphological Type of Volvox from Japanese Large Lakes and Recent Divergence of this Type and V. ferrisii in Two Different Freshwater Habitats

“…In rice paddies, the water is flooded during spring to summer and the water depth is less than 15 cm [21]. The water depth is more than 20 m in Lake Sagami and Lake Tsukui [22]. Therefore, these two Japanese lineages might have diverged rapidly in the two different habitats in Japan.…”