Dynamics and polyphasic characterization of odor-producing cyanobacterium Tychonema bourrellyi from Lake Erhai, China

Abstract

The previous studies indicated that Tychonema-like strains from Lake Erhai could release geosmin so that the species was listed as the potential harmful cyanobacteria influencing the drinking water safety around Lake Erhai. But, the dynamics and biological information of this species were too limited. In this study, the polyphasic approach was used to reveal its biological characterization and the dynamics in Lake Erhai. The characters of trichomes, including filaments with solitary or bundle state, reddish-brown or bluegreen color, planktonic habitat, and presence of keritomized content, were examined by the microscopic method. The 16S rDNA sequences of these strains were used for phylogenetic analysis and molecular identification. The strains were morphologically classified as Tychonema bourrellyi, and geosmin and β-ionone were identified as the major volatile substances using gas chromatography-mass spectrometry (GC-MS) analysis. No strains of T. bourrellyi were found to produce microcystin by the HPLC and mcy gene approaches. Cell numbers at 12 sampling sites in Lake Erhai were shown as an average of 3×10 4 cells L −1 in 2009 and 2010. The obvious peaks occurred in July and August each year. This was the first report on occurrence of T. bourrellyi from outside of Europe, and T. bourrellyi was also a newly recorded species in China. Such a result demonstrated that T. bourrellyi could distribute extending from cold waters in North Europe to the warm waters in subtropical regions. It was interesting to observe the coincidence of the occurrence of T. bourrellyi with slightly eutrophicated waters since Lake Erhai had been regarded as an early phase of eutrophicated lake.

Fatal Neurotoxicosis in Dogs Associated with Tychoplanktic, Anatoxin-a Producing Tychonema sp. in Mesotrophic Lake Tegel, Berlin

“…As trichome width ranged from 6.8–8.9 µm in Tychonema from Lake Tegel, unequivocal species identification was not possible based on morphological characteristics alone. Genetic characterization of isolated strains may support species identification [ 30 , 31 ], but attempts to establish cultures were futile.…”

Algal Blooms in Lakes in China Over the Past Two Decades: Patterns, Trends, and Drivers

“…Cyanobacterial bloom problems in several lakes in China, including Lake Taihu, Chaohu, Erhai, and Dianchi, have attracted widespread concern from both the general public and the scientific community (Guo et al., 2022; W. Lu et al., 2017; H. Zhang et al., 2016). Our study not only confirmed the severe problems in these lakes but also further found that 103 of the 171 examined lakes have been affected by algal blooms in the past two decades, and many of these lakes suffer from comparable or even more severe blooms than those reported in other lakes.…”

Degradation and remediation of environmental pollutants by algae

“…Some microalgae species, such as Chlorella and Spirulina, have been used in commercial production and utilization [18]. A large number of studies have shown the prospect of microalgae as a bioremediation technology [19], they can use wastewater organic matter as a carbon source and nutrient source, so that they can treat wastewater, and finally make algae culture cost-effective [20].…”