Haslea karadagensis(Bacillariophyta): a second blue diatom, recorded from the Black Sea and producing a novel blue pigment

Abstract

A new species of raphid pennate diatom producing a blue pigment, Haslea karadagensis Davidovich, Gastineau & Mouget, sp. nov., was recently isolated from the Crimean coast of the Black Sea (Ukraine). This organism is very similar to the well-known Haslea ostrearia, the first described 'blue' diatom, which produces marennine, the pigment involved in the greening of oysters. The Ukrainian diatom, H. karadagensis, differs slightly from H. ostrearia in the structure of its frustule, and the two organisms are unable to interbreed. Two molecular markers, rbcL and the ITS1-5.8S-ITS2 sequences, showed 2% and >50% differences, respectively, between the two species. UV-visible spectrophotometry and in vivo confocal micro-Raman spectroscopy were used to compare the pigment of H. karadagensis with marennine. Both pigments showed absorption bands in the UV and red regions, but the positions of the maxima differ between the pigments. Significant differences were observed by microRaman spectroscopy in the 1000-1700 cm À1 wavenumber range, revealing that the pigments are different molecules. Haslea karadagensis is the first example of a new 'blue' diatom and produces a novel blue pigment.

Marine Algal Antioxidants as Potential Vectors for Controlling Viral Diseases

“…Less investigated, but with a high antioxidant activity, and therefore as potential antiviral, are the polyphenolic compounds: antioxidants produced by marine algae, such as flavonoids, cinnamic acid, benzoic acid, gallic acid, quercetin [91] and phlorotannins, the latter being found in brown macroalgae [92], or diatoms [93]. Phlorotannins are tannin derivatives exhibiting numerous bioactivities, such as antioxidant, anti-inflammatory [94] antibacterial, and antimatrix metallopeptidases (MMP) activities [95]. Ahn et al [93] reported that phloroglucinol derivative 8,8 -bieckol inhibited the activity of recombinant RT and protease of HIV-1 in vitro.…”

“…Another peculiar polyphenol discovered in some diatoms, (Haslea sp.) marennine, presented relevant bioactivity and antiviral properties [95].…”

Photosynthetic Pigments in Diatoms

“…Another diatom, Haslea karadagensis , also has a blue pigment. Although it has quite different absorption maxima from those of marennine, its similar bioactivity has come to be called marennine-like [ 10 ]. While these unusual pigments occur only in selected species, there are some which are included in the more general group of photosynthetic pigments and are common among diatoms.…”

Prophylactic effect ofHaslea ostreariaculture supernatant containing the pigment marennine to stabilize bivalve hatchery production

“…29, 401 (2016) This microalga has long been considered the only one within the Bacillariophyceae able to produce such a pigment (Neuville and Daste 1978). Recently, two new species of blue Haslea have been described, one producing a pigment similar to marennine, H. provincialis (Gastineau et al 2016), the other, H. karadagensis, a different pigment but belonging to the same chemical family (Gastineau et al 2012b). Marennine accumulates in the apical regions of the cell before being released into the growth medium (Nassiri et al 1998), allowing the predominance of H. ostrearia due to marennine's allelopathic activity (Pouvreau et al 2007a;Prasetiya et al 2016).…”