Annamia toxica gen. et sp. nov. (Cyanobacteria), a freshwater cyanobacterium from Vietnam that produces microcystins: ultrastructure, toxicity and molecular phylogenetics

TY - JOUR

T1 - Annamia toxica gen. et sp. nov. (Cyanobacteria), a freshwater cyanobacterium from Vietnam that produces microcystins: ultrastructure, toxicity and molecular phylogenetics

AU - Nguyen, Lien Thi Thu

AU - Cronberg, Gertrud

AU - Moestrup, Øjvind

AU - Daugbjerg, Niels

PY - 2013/1

Y1 - 2013/1

N2 - A freshwater cyanobacterium from Hoamy Reservoir, Hue, Vietnam was isolated into clonal culture (April 2004). Based on general morphology (including size and shape) from light microscopy it was identified as Pseudanabaena cf. moniliformis. However, transmission electron microscopy revealed the thylakoids to be radially arranged, in contrast to the Pseudanabaena group sensu Komárek & Čáslavská (1991), which was characterized by a more or less concentric arrangement of the thylakoids. Furthermore, the phylogenetic relationship of the Vietnamese culture was investigated by sequencing the phycocyanin gene and the gene encoding 16S rRNA. Using morphology, toxicity and gene sequences, we showed that the Vietnamese culture and a culture of Pseudanabaena galeata from the UTEX collection were not related at the generic level. To examine this in greater detail, a search was made for a culture of P. catenata, the type species of Pseudanabaena. Two cultures with that name were available from the SAG culture collection in Göttingen, Germany. Thin sections revealed that both strains were characterized by concentric thylakoids. Based on our polyphasic approach, the Vietnamese material was therefore described as Annamia toxica gen. et sp. nov.

AB - A freshwater cyanobacterium from Hoamy Reservoir, Hue, Vietnam was isolated into clonal culture (April 2004). Based on general morphology (including size and shape) from light microscopy it was identified as Pseudanabaena cf. moniliformis. However, transmission electron microscopy revealed the thylakoids to be radially arranged, in contrast to the Pseudanabaena group sensu Komárek & Čáslavská (1991), which was characterized by a more or less concentric arrangement of the thylakoids. Furthermore, the phylogenetic relationship of the Vietnamese culture was investigated by sequencing the phycocyanin gene and the gene encoding 16S rRNA. Using morphology, toxicity and gene sequences, we showed that the Vietnamese culture and a culture of Pseudanabaena galeata from the UTEX collection were not related at the generic level. To examine this in greater detail, a search was made for a culture of P. catenata, the type species of Pseudanabaena. Two cultures with that name were available from the SAG culture collection in Göttingen, Germany. Thin sections revealed that both strains were characterized by concentric thylakoids. Based on our polyphasic approach, the Vietnamese material was therefore described as Annamia toxica gen. et sp. nov.

U2 - 10.2216/10-097.1

DO - 10.2216/10-097.1

M3 - Journal article

SN - 0031-8884

VL - 52

SP - 25

EP - 36

JO - Phycologia

JF - Phycologia

IS - 1

ER -