Nephroselmis
From Wikipedia, the free encyclopedia
| Nephroselmis | |
|---|---|
,_plate_19_cropped.jpg) | |
| Nephroselmis olivacea | |
Scientific classification  | |
| Kingdom: | Plantae |
| Division: | Chlorophyta |
| Class: | Nephrophyceae |
| Order: | Nephroselmidales |
| Family: | Nephroselmidaceae |
| Genus: | Nephroselmis Stein |
| Species | |
Nephroselmis is a genus of green algae. It has been placed in the family Nephroselmidaceae,[1] although a 2009 study suggests that it should be separated into its own class, Nephroselmidophyceae.[2] One species can be an endosymbiont of Hatena arenicola.
The cell body is right-left flattened. On the ventral side are two heterodynamic unequal flagella; the shorter beats towards the anterior direction while the long trails behind. Nephroselmis have a single cup-shaped chloroplast that contains an eyespot in its anterior-ventral edge below the short flagellum and a pyrenoid with starch plates. A vacuole is located in the left-anterior side, and the nucleus is located in the right-posterior side. The flagellar root system consists of a rhizoplast and three microtubular roots, one of which is multilayered.[3]
The cell's surface area is covered with layers of unminerallized scales,[4] while the surface of the flagella has hairs as well.[5] The cell body surface is covered by two to four layers of body scales. Flagella are covered with at least two scale layers, the second is characteristically rod-shaped. On top of that Nephroselmis has either a third layer of flagellar scales or flagellar pit scales.[3]
The morphology of the scales are an important taxonomic characteristic for differentiating between the species. In the case of Nephroselmis spinosa, that exhibits some distinctive morphological characteristics, one of them is a unique outer scale type that has a spine that is extended for about 1 μm, is slightly curved and has a hook shape at the end.[3]
Symbiosis with Hatena arenicola
A unique symbiosis occurs between the katablepharid Hatena arenicola and Nephroselmis rotunda. One of the interpretations to the observations of their interaction is that this symbiosis stage is leading to a secondary endosymbiosis, which will produce a completely new life form.[6]
This symbiosis is distinct from other reported cases of ongoing symbiosis in that the symbiont plastid is selectively enlarged up to ten times than the normal size.[6]
There is a possibility that retention of Nephroselmis-derived compartments is a precondition of the cell division process of H. arenicola, due to the fact that cell division was only observed in H. arenicola individuals after they have incorporated the N. rotunda parts into their cell body.[6]
Ecology
The genus Nephroselmis according to reports and documentations done until 2009 appears to have global worldwide distribution. All species of Nephroselmis are marine inhabitants except for Nephroselmis olivacea which is found strictly in freshwater environments.[7]
The biofuel production potential of strains of Nephroselmis under certain treatments was examined in a research published in April 2022 concluding with - "isolated Nephroselmis sp. KGE2 is a candidate microalgal for biodiesel production using AMD as an iron source. The proposed process can be useful in overcoming the bottlenecks of microalgae cultivation. This can make the commercialization of biofuels economically feasible, and the products can be an alternative to fossil-derived commodities with zero carbon emissions."[8]
Nephroselmis is known to be mixotrophic: in addition to photosynthesis, it consumes bacteria by phagocytosis.[9]