Polyphasic characterization of Westiellopsis prolifica (Hapalosiphonaceae, Cyanobacteria) from the El-Farafra Oasis (Western Desert, Egypt)

Abstract:

Westiellopsis prolifica, a true-branching cyanobacterium isolated from the hyperarid desert soil habitats of El-Farafra Oasis (Western Desert of Egypt), was investigated with a polyphasic approach. The main morphological characteristics of our material, together with its habitat properties, corresponded (with minor discrepancies in the dimensions) to descriptions in the literature. On the basis of molecular data of the 16S ribosomal RNA gene, the strain of W. prolifica isolated from the El-Farafra Oasis clustered with available isolates of Westiellopsis and other genera of Hapalosiphonaceae. Bio-organic screening showed the presence of thylakoid lipids characterized by low unsaturation index and short fatty acyl chains, features presumably ensuring membrane functionality at high temperatures. Carotenoid and xanthophyll composition were typical of cyanobacteria (α/β carotene 38.1%, echinenone 14.3%, zeaxanthin 13.4%, and myxoxanthophyll 8.8%). This study improved the knowledge on the distribution, autecology, phylogenetic position, and bio-organic characteristics of W. prolifica. Moreover, it confirmed that polyphasic studies of cyanobacteria are not only an important prerequisite for species delineation, but are also useful in characterizing ecophysiological adaptive mechanisms to special habitats.

Key Words::

• 16S rRNA
• Autecology
• Bio-organic screening
• Egypt
• El-Farafra Oasis
• Polyphasic study
• Westiellopsis prolifica

ACKNOWLEDGEMENTS

AAS is deeply thankful to Prof. Abd El-Salam M. Shaaban, Professor of Phycology at the Botany Department, Faculty of Science, Ain Shams University (Egypt), for his kind support with specimen identification and cultivation. MC was partially funded by the Autonomous Province of Trento and the Museo delle Scienze – MUSE, Limnology and Phycology Section, Trento, Italy. JM was funded by the Czech Science Foundation grant no. 15-11912S and the long-term research development project no. RVO 67985939. The authors are grateful to Laura Aycock, Phycology Section, Academy of Natural Sciences of Drexel University (Philadelphia, Pennsylvania, USA), for editing the English. The topic of the present paper was presented at the 20th Cyanophyte/Cyanobacteria Research Symposium at the Institute of Botany, University of Innsbruck, Austria, 28 August–2 September 2016.

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/16-107.1.s1