Polyphasic characterization of the thermotolerant cyanobacterium Desertifilum sp. strain IPPAS B-1220

Abstract

A cyanobacterial strain from Lake Shar-Nuur, a freshwater lake in Mongolia, was isolated and characterized by a polyphasic approach. According to the 16S ribosomal RNA gene sequence, this strain (IPPAS B-1220) belongs to a newly described genus Desertifilum. In general, strains of Desertifilum maintain their genetic stability, as seen from the analysis of the 16S rRNA gene and 16S-23S rRNA internal transcribed spacer sequences from strains collected at distant locations. The newly discovered strain is characterized by an unusual fatty acid composition (16:1Δ7 and 16:2Δ7,10). Analysis of its draft genomic sequence reveals the presence of six genes for the acyl-lipid desaturases: two Δ9-desaturases, desC1 and desC2; two Δ12-desaturases, desA1 and desA2; one desaturase of unknown specificity, desX; and one gene for the bacillary-type desaturase, desG, which supposedly encodes an ω9-desaturase. A scheme for a fatty acid desaturation pathway that describes the biosynthesis of 16:1Δ7 and 16:2Δ7,10 fatty acids in Desertifilum is proposed.

A bridge too far in naming species: a total evidence approach does not support recognition of four species in Desertifilum (Cyanobacteria)

“…In the morphological comparison, our population (Figs. 5 and 6) and other Desertifilum tharense populations (Bravakos et al 2016, Cai et al 2017, Sinetova et al 2017) correspond with the description of D. tharense from the Thar desert of India (Table 4). The principal morphological traits such as thallus appearance, filament shape, sheath color, trichome and cell size, and apical cell morphology were very similar to those reported by Dadheech et al (2012).…”

“…, Sinetova et al. ) correspond with the description of D. tharense from the Thar desert of India (Table ). The principal morphological traits such as thallus appearance, filament shape, sheath color, trichome and cell size, and apical cell morphology were very similar to those reported by Dadheech et al.…”

“…Morphological characteristics for six sequenced strains of Desertifilum apart from the Mexican strain were compiled from the publications in which they were described or treated (Dadheech et al 2012, Bravakos et al 2016, Cai et al 2017, Sinetova et al 2017, Cellamare et al 2018. In some instances, the descriptions given were incomplete.…”

Cyano-assassins: Widespread cyanogenic production from cyanobacteria

“…Desertifilum tharense has been recorded in India, Kenya, Mexico, Greece, Mongolia, and China (González-Resendiz et al, 2019). The presence of Desertifilum tharense in Iceland, a different ecological niche, supports the theory that despite its wide ecological span, the genus Desertifilum remains genetically stable (Sinetova et al, 2017; González-Resendiz et al, 2019).…”

<p>Synthesis of Silver Nanoparticles Using a Novel Cyanobacteria <em>Desertifilum</em> sp. extract: Their Antibacterial and Cytotoxicity Effects</p>

“…The filaments had apical ends as well as these filaments were motile non-constructed or slightly constricted at cross-walls (Video 1), the trichomes appear narrow at the end and were enclosed by a hyaline sheath firm ( Figure 2B). 39 The resultant amplicon (1.5 kb) of the Desertifilum sp. is shown in Figure 3.…”