Alkalinema pantanalense Vaz et al. 2015

Lee, Ok-Min, 2022, Newly recorded genera and species, Pantanalinema rosaneae and Alkalinema pantanalense (Leptolyngbyaceae, Cyanobacteria) isolated in Korea, Journal of Species Research 11 (1), pp. 10-21 : 13-16

Alkalinema pantanalense Vaz et al. 2015 ( Fig. 3 )

Morphology and description

The trichomes do not have sheaths but do have a diffluent mucilage. Colonies are grown on interwoven mats. Cells are longer than they are wide, 2.2-3.1 μm long by 2.8-3.2 μm wide, with a narrowed apical cell. As above, morphological features of this strain were identical to the original description of the type species ( Vaz et al., 2015).

Ecology: The species was first collected in the saline-alkaline lake of wetland in Pantanal, Brazil and named as Alkalinema pantanalense . Alkalinema pantanalense (CENA 528) was reported to survive in the range of pH 8.4 to 9.9 for growth experiment but brought about a change to 8.4 to 9.9 pH in the cultured medium ( Vaz et al., 2015). In this study, it turned out to be an epilithic species growing on gravels in the freshwater, implying that they can be distributed in an extensive water environment.

Site of collection: Anseongcheon, Anseong-si , Gyeonggi Province (37°00 ʹ 04.2 ʺ N / 127°16 ʹ 13.5 ʺ E) .

Date of collection: September 20, 2020.

Specimen Locality: FBCC-A1468, FBCC-A 1469 in the Nakdonggang National Institute of Biological Resources (NNIBR).

Gene sequences: The 16S rRNA to 23S rRNA gene sequences: GenBank accession Nos. MZ567048 , MZ56 7049.

16S rRNA gene and phylogenetic affiliation of Alkalinema pantanalense

The region from 16S rDNA to 23S rDNA were sequenced for two strains ( MZ567048 , MZ567049 ) of Alkalinema pantanalense . DNA analysis showed that the two strains had completely identical 16S rRNA gene sequences (DNA similarity 99.7%). The phylogenetic relationships of the genus Alkalinema and other relatives were investigated by using a ML tree constructed from their partial 16S rRNA gene sequences. The additional Bayesian tree turned out to be quite close to the ML tree ( Fig. 4 ). The strains of A. pantanalense (FBCC-A1468, FBCC-A1469) clustered with the type species A. pantanalense (CENA 528) and another strains of A. pantanalense (CENA 529, 530, 531), and are clearly identified to be the same species in the ML tree.

The strain of A. pantanalense FBCC-A1468 showed a 100% DNA similarity to FBCC-A1469 and 0.00% p -distance between them. On the other hand, the strains of A. pantanalense (FBCC-A1468, FBCC-A1469) showed a 99.5 to 99.9% DNA similarity to type species A. pantanalense ( CENA 528 ) and 0.00% p -distance between them ( Table 1 ) .

Figures

Fig. 3. Microphotographs of Alkalinema pantanalense from the strain FBCC-A1469. (A-C) Colonies (mats) formed in culture, (D-F) Hormogonia, (G-I) Morphologies of apical cells, (J-L) Firm sheathes of trichomes in culture. Scale bars=(A) 100 μm, (B-L) 10 μm.

Fig. 4. Phylogenetic position of Pantanalinema and Alkalinema within the family Leptolyngbyaceae inferred from 16S rRNA sequences with the maximum-likelihood (ML) algorithm. 16S rRNA sequences of genera (Gloeobacter violaceus, Accession No. NR074282/ Gloeobacter kilaueenis, Accession No. NR121745) were included as the outgroup. Additionally, the probability of Bayesian analysis was incor- porated into the ML tree to support the strength of each branch. The first and second numbers at the nodes display the bootstrap proportions (BP) (>50%) in ML and posterior probabilities (PP;>0.50) in Bayesian analysis, respectively. The branch lengths are proportional to the scale given.