The structure and abundance of aquatic microbial communities, microalgae, protozoans and fungi contribute to characterize trophic webs and productivity. Nevertheless, in freshwater environments, the majority of the investigations were historically addressed towards the study of microalgae, either pelagic (“phytoplankton”) or periphytic. These two broad functional groups are composed of a wide variety of photosynthetic and mixotrophic organisms that show specific adaptations to different lake typologies and trophic status. Traditionally, in addition to the protist fraction, microalgae also include photosynthetic cyanobacteria. Based on high throughput sequencing approaches (HTS) (16S rDNA), previous studies carried out in Lake Garda and in the other large lakes south of the Alps allowed identifying a higher number of cyanobacterial taxa compared to those previously characterized by light microscopy. In this contribution, we will characterize and critically discuss the composition, alpha diversity, and seasonal dynamics of planktic photosynthetic and mixotrophic protists through a two-year study carried out in Lake Garda using HTS analyses (18S rDNA). The planktic community showed a higher diversity during late spring and summer, caused by a greater development of many algal groups (mostly Ochrophyta, Chlorophyceae, Dinophyceae). The main pattern of seasonal change was comparable to that obtained using the traditional microscopy methods. Compared to traditional approaches, for most of the algal groups (e.g. Zygnemophyceae, Dinophyceae) HTS allowed to discover a wider number of taxa never detected until then in the large lakes south of the Alps. Nevertheless, while HTS approaches enable increasing the knowledge of protists diversity, their use in the evaluation of target groups is not free of difficulties due, among the others, to the short length of 18S rDNA sequences obtained with present technologies. Further, the presence of varying copy number of 18S rDNA still represents a source of uncertainty in assessing community structure and seasonal dynamics in protists.

Salmaso, N.; Boscaini, A.; Pindo, M. (2019). Unveiling the hidden diversity ofphotosynthetic and mixotrophic protists in a large and deep subalpine lake using a high throughput sequencing approach. In: Seventh European Phycological Congress, Zagreb, Croatia, 25–30 August 2019: 75. doi: 10.1080/09670262.2019.1626610 url: http://epcseven.biol.pmf.hr/ handle: http://hdl.handle.net/10449/58804

Unveiling the hidden diversity ofphotosynthetic and mixotrophic protists in a large and deep subalpine lake using a high throughput sequencing approach

Salmaso, N.
Primo
;
Boscaini, A.;Pindo, M.
Ultimo
2019-01-01

Abstract

The structure and abundance of aquatic microbial communities, microalgae, protozoans and fungi contribute to characterize trophic webs and productivity. Nevertheless, in freshwater environments, the majority of the investigations were historically addressed towards the study of microalgae, either pelagic (“phytoplankton”) or periphytic. These two broad functional groups are composed of a wide variety of photosynthetic and mixotrophic organisms that show specific adaptations to different lake typologies and trophic status. Traditionally, in addition to the protist fraction, microalgae also include photosynthetic cyanobacteria. Based on high throughput sequencing approaches (HTS) (16S rDNA), previous studies carried out in Lake Garda and in the other large lakes south of the Alps allowed identifying a higher number of cyanobacterial taxa compared to those previously characterized by light microscopy. In this contribution, we will characterize and critically discuss the composition, alpha diversity, and seasonal dynamics of planktic photosynthetic and mixotrophic protists through a two-year study carried out in Lake Garda using HTS analyses (18S rDNA). The planktic community showed a higher diversity during late spring and summer, caused by a greater development of many algal groups (mostly Ochrophyta, Chlorophyceae, Dinophyceae). The main pattern of seasonal change was comparable to that obtained using the traditional microscopy methods. Compared to traditional approaches, for most of the algal groups (e.g. Zygnemophyceae, Dinophyceae) HTS allowed to discover a wider number of taxa never detected until then in the large lakes south of the Alps. Nevertheless, while HTS approaches enable increasing the knowledge of protists diversity, their use in the evaluation of target groups is not free of difficulties due, among the others, to the short length of 18S rDNA sequences obtained with present technologies. Further, the presence of varying copy number of 18S rDNA still represents a source of uncertainty in assessing community structure and seasonal dynamics in protists.
Metagenomics
Protists
2019
Salmaso, N.; Boscaini, A.; Pindo, M. (2019). Unveiling the hidden diversity ofphotosynthetic and mixotrophic protists in a large and deep subalpine lake using a high throughput sequencing approach. In: Seventh European Phycological Congress, Zagreb, Croatia, 25–30 August 2019: 75. doi: 10.1080/09670262.2019.1626610 url: http://epcseven.biol.pmf.hr/ handle: http://hdl.handle.net/10449/58804
File in questo prodotto:
File Dimensione Formato  
Salmaso_2019_7thEPC_Zagreb.pdf

solo utenti autorizzati

Tipologia: Abstract
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 175.01 kB
Formato Adobe PDF
175.01 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/58804
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 1
social impact