''Dictyochloropsis'' is a genus of unicellular

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

of the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Chlorophyta. This genus consists of

free-living Free-living may refer to: * a non-parasitism, parasitic organism * a non-Sessility (zoology), sessile (or free-swimming) organism {{dab ...

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

which have a reticulate (net-like)

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

that varies slightly in morphology between species, and that when mature always lacks a pyrenoid. ''Dictyochloropsis'' is asexual and reproduces using autospores. Previously, many species of the morphologically similar genus '' Symbiochloris'' were incorrectly classified to this taxon. These species were recently reclassified on the basis of molecular DNA analyses. ''Dictyochloropsis'' is found in terrestrial environments all over the world, but can live and grow in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

environments as well. Recently, there has been promising research towards growing ''Dictyocloropsis'' in culture for the production of

biofuel Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...

Etymology

The name of ''Dictyochloropsis'' comes from the Greek language. The prefix “dictyo” is derived from the Greek word “δίκτυο” or “díktyo” meaning “network”, which is in reference to the net-like

present in this genus. The medial “-chloro-” is from “χλωρός” or “chloros” meaning “the colour green” because of the green pigment,

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

, which colours the algae. The suffix “-opsis” comes from “ὄψις” or “opsis”, roughly translating to “appearance,” “sight” or “view”. Thus, “''Dictyochloropsis''” when translated from its Greek roots means “network of green appearance,” an accurate description of the green algae characterized by its reticulate green chloroplast.

History of knowledge

''Dictyochloropsis'' was first identified as a genus in 1966 by Lothar Geitler, who defined it as a unicellular

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

with a complex

that reproduces using autospores. Geitler’s observations were not complete, he was unsure if he had correctly defined the new genus, and he requested supplementary observations from other scientists to attempt at further defining the taxon. In the early 1980s, Elisabeth Tschermak-Woess used Geitler’s definition to classify several species of

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.taxon. However, some of these algae reproduce with zoospores or aplanospores, which does not agree with Geitler’s observations. In 2014, Francesco Dal Grande used microsatellite markers to discover that ''Dictyochloropsis'' as previously defined was polyphyletic, forming two distinct

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

s. The first clade is composed exclusively of

free-living Free-living may refer to: * a non-parasitism, parasitic organism * a non-Sessility (zoology), sessile (or free-swimming) organism {{dab ...

algae which reproduce using autospores. The second clade included

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.zoospores or aplanospores. Organisms in both clades have similar morphologies and life cycles, and this is why they were initially classified in this polyphyletic genus. In 2016, Pavel Skaloud et al. moved the ''Dictyochloropsis''

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Symbiochloris'' based on data from phylogenetic analysis of the 18S rRNA gene. As a result ''Dictyochloropsis'' was redefined to its current

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

meaning.

Habitat and ecology

''Dictyochloropsis'' is an ecologically important algae most commonly found living as an

epiphyte An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

or in soil. Although species in the

Chlorophyta mainly live in

habitats, ''Dictyochloropsis'' is usually found in terrestrial environments. This algae does not feed, it uses photosynthesis to create its energy, and thus it only lives in habitats with access to light. Species have been found and

cultured Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tylor ...

from places all over the world, including the Czech Republic, Malaysia, Austria, Germany,

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, Pakistan, Ukraine and Indonesia. Habitats which ''Dictyochloropsis'' has been cultured from include soil, tree bark, and hard surfaces such as rocks and concrete. ''Dictyochloropsis'' is also able to survive and grow in freshwater environments. When isolated, ''Dictyochloropsis'' cultures are typically grown in nutrient-rich freshwater environments.

Description

Morphology

Members of ''Dictyochloropsis'' are

free-living Free-living may refer to: * a non-parasitism, parasitic organism * a non-Sessility (zoology), sessile (or free-swimming) organism {{dab ...

, unicellular

. Their

cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

lack

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

and are globular at all life cycle stages. In this genus, young cells from autospores can be as small as 6 μm in diameter, and the largest species grow up to 50 μm in diameter before reproducing. The cell is often surrounded by a thick envelope of mucilage when mature. Their

gives ''Dictyochloropsis'' cells their characteristic green colour. Their large, reticulate

is a key character used to identify this genus. At some ontogenetic stages, the

forms lobes in a parallel arrangement. When mature, the chloroplast lacks a pyrenoid. Chloroplast morphology can vary between members of ''Dictyochloropsis'' at the same life cycle stage, and is often used to identify specific species within this genus. For example, young ''D. splendida'' cells have parietal chloroplasts, while young ''D. asterochlorodies'' cells have asteroid chloroplasts. ''Dictyochloropsis'' cells are

uninucleate {{Short pages monitor