Fig 1.
Map of the study sampling locations.
(TA: Taean, SH: Sihwa, EW: Eulwang-ri).
Table 1.
Strains of the benthic diatoms isolated in this study, information on their collection, and accession numbers of 18S rRNA and rbcL gene sequences.
Species names were determined by morphological analyses.
Fig 2.
Pie chart showing morphological affiliations of the strains isolated in this study.
Fig 3.
Light micrograph of diatoms isolated in this study belonging to Cylindrotheca, Nitzschia, and Tryblionella.
(a) Nitzschia paleacea TA406. (b) N. paleaeformis TA394. (c) N. dubiiformis SH366. (d) N. dissipata TA44. (e) N. dubia TA37. (f) N. pellucida EW229. (g) Bacillaria sp.1 SH349. (h) N. sigmaformis TA311. (i) Nitzschia sigma TA341 (400x). (j) Nitzschia sp.1 Dillu16. (k) Nitzschia sp.2 TA61. (l) N. liebetruthii TA353. (m) Nitzschia sp.4 TA409. (n) Tryblionella apiculate TA-85. (o) Cylindrotheca closterium TA256. (p) C. gracilis TA46 (400x). (q) Cylindrotheca sp.1 TA198. (r) Bacillaria paxillifer EW234. (s) Nitzschia bergii TA139. (t) N. ligowskii TA426. (u) N. pusilla TA420. (v) N. aequorea Dillu38. Scale bar = 10 μm. Note that scale bars of 9 and 16 are inside of the picture.
Fig 4.
Light micrograph of diatoms isolated in this study belonging to Berkeleya, Gyrosigma, Haslea, Parlibellus, and Pleurosigma.
(a) Gyrosigma limosum TA152. (b) Pleurosigma sp.1 TA34. (c) Haslea pseudostrearia TA280. (d) H. nipkowii SH381. (e) Parlibellus delognei TA387. (f) Berkeleya rutilans TA440. (g) B. fennica TA424. Scale bar = 10 μm.
Fig 5.
Light micrograph of diatoms isolated in this study belonging to Navicula and Seminavis.
(a) Navicula gregaria TA289. (b) N. agatkae TA291. (c) Navicula incertata TA414. (d) Navicula sp.1 TA298. (e) Navicula sp.5 TU3. (f) Navicula sp.3 EW220. (g) N. ramosissima TA316. (h) N. flagellifera TA105. (i) Navicula sp.2 TA64. (j) N. salinicola TA204. (k) N. perminuta TA441. (l) N. trivialis TA83. (m) N. salinarum TA402. (n) N. cf. salinarum TA407. (o) N. salinarum var. minima TA416. (p) Navicula sp.4 TA323. (q) Navicula sp.6 TA446. (r) Seminavis sp.1 TA305. Scale bar = 10 μm.
Fig 6.
Light micrograph of diatoms isolated in this study belonging to Entomoneis and Petodictyon.
(a, b) Entomoneis paludosa TA208. (c) Entomoneis sp.2 SH373. (d, e) Entomoneis sp.3 EW239. (f, g) Entomoneis sp.1 TA410. (h) Petrodictyon gemma TA201. Scale bar = 10 μm.
Table 2.
Morphometric data and classification based on the morphology of diatom strains isolated in this study.
Species name and sequence identity of the closest relative found in GenBank using BLASTn.
Fig 7.
Phylogenetic trees obtained using 18S rRNA (a) and rbcL (b) gene sequences of 61 culture strains. Bootstrap values obtained by neighbor–joining, maximum–likelihood, and maximum–parsimony methods are shown on the nodes. Expanded tree of Navicula sensu stricto and Nitzschia sensu stricto are shown in Figs 8 and 9, respectively.
Fig 8.
Phylogenetic tree of Navicula sensu stricto obtained using 18S rRNA (a) and rbcL (b) gene sequences. Bootstrap value obtained by neighbor–joining, maximum–likelihood, and maximum–parsimony methods are shown on the nodes.
Fig 9.
Phylogenetic tree of Nitzschia sensu stricto obtained using 18S rRNA (a) and rbcL (b) gene sequences. Bootstrap value obtained by neighbor–joining, maximum–likelihood, and maximum–parsimony methods are shown on the nodes.
Table 3.
Nucleotide sequence distances of the 18s rRNA and rbcL genes within a genus according to Jukes and Cantor [47] model.