As part of a preliminary investigation of yeast diversity associated with grey mangrove trees ( Avicennia marina ) in Kuwait, a total of 17 yeast isolates were recovered from leaves and soil of trees in Shuwaikh. Among them, one strain (Shy33) exhibited distinct morphological and molecular characteristics that could not be assigned to any known species and was therefore described as a novel taxon, Nigromyces azzae gen. nov., sp. nov. Phylogenetic analyses based on the internal transcribed spacer (ITS1–5.8S–ITS2), SSU rDNA and LSU rDNA regions and partial β -tubulin gene ( TUB2 ) revealed that the strain is closely related to members of the genus Zalaria but forms a distinct lineage within the family Zalariaceae (order Dothideales ). The strain exhibited typical black yeast-like features, including melanized cell walls, meristematic growth and budding yeast cells. Physiological testing showed that the strain lacked fermentative capacity but could assimilate a variety of carbon sources such as d -glucose, sucrose, cellobiose, salicin and d -mannitol. The strain demonstrated growth at temperatures between 21°C and 42°C but not at 18°C or 45°C. Based on these findings, we propose a new genus and species, N. azzae gen. nov., sp. nov., with Shy33 as the type strain (CBS 148914 T = MUCL 58501 T ).
Al-Sammar et al. (Fri,) studied this question.