Dunaliella salina

from Wikipedia, the free encyclopedia
Dunaliella salina
Dunaliella salina: A: vegetative cell, B: zoospores during cell division, C: gametes, D: mature zygospore, E: germination of the zygospore

Dunaliella salina : A: vegetative cell, B: zoospores during cell division, C: gametes, D: mature zygospore, E: germination of the zygospore

Systematics
without rank: Chlorophyta
without rank: Chlorophyceae
Order : Volvocales
Family : Dunaliellaceae
Genre : Dunaliella
Type : Dunaliella salina
Scientific name
Dunaliella salina
( Dunal ) Teodoresco , 1905

Dunaliella salina is a species of the genus Dunaliella from the class Chlorophyceae , one of the two large groups of green algae . The unicellular alga lives in hypersaline waters, which are reddish in color when they occur in large numbers.

features

Dunaliella salina is very diverse and can be distinguished from other species of the genus in that, under high light and salt concentrations, it can accumulate very large amounts of β-carotene , namely over 5% (up to 14%) of the dry weight. Dunaliella salina generally consists of green to dark red individual cells that can be oval, spherical, egg or pear-shaped, ellipsoidal or cylindrical in shape. They are usually shaped radially symmetrically , but under extreme conditions the shape can also be bilateral , dorsiventral or asymmetrical . They get their red color from the strong accumulation of β-carotene , which makes up more than 5% of their dry weight and which is stored as droplets inside the chloroplast . The cells become 5-29 μm (average 10.9-16.9 μm) long and 3.8-20.3 μm (average 7.9-13.2 μm) wide. The two flagella are about as long as their cell length. The chloroplast is cup-shaped with well-developed side lobes that sometimes reach the base of the flagellum. The pyrenoid is large and interspersed with many starch grains both axially and basally (the so-called amylosphere). The anterior eye spot is just blurry and indistinct, especially in red cells. The propagation is carried heterothallic , smooth zygospores (flagellated spores) are spherical and measure 17-19 microns in diameter. Their red to green content depends on the copulating gametes . The aplanospores (non-chiseled permanent spores) are also spherical and 12-20 μm in size with a thick, wrinkled, often two-layered cell wall, and a green, brownish or red, often grainy-looking content. It may Palm harboring (ie unbegeißelte cells gelatinous aggregates form) occur.

Algal bloom in Lake Sasyk ( Crimean peninsula )

Ecology and diffusion

Dunaliella salina lives in a hypersaline environment in natural and artificial waters such as ponds and dams worldwide from Antarctica to desert regions near the equator . The salinity may be from 5% up to the saturation of 20 to 25% NaCl -rich. The alga can also withstand extreme basic conditions up to a pH value of 11.

meaning

Due to its ability to produce carotenes, Dunaliella salina is also used industrially. There are plants in Australia, the USA and Israel. There are smaller plants in China, Chile, Australia, USA, Spain and Kuwait. In addition, the species is also used to produce glycerol , since glycerol Dunaliella salina is used to regulate osmosis . It is also believed that glycerol protects enzyme activities in these conditions.

Systematics

Michel Félix Dunal observed the species for the first time and described it as Haematococcus salinus in 1837 . In 1905 Teodoresco created the genus Dunaliella in Dunal's honor with Dunaliella salina as the type species . Clara Hamburger recognized the genre's independence in the same year.

Currently (as of 2007) is the way in which section Dunaliella provided with four described subspecies or forms whose status is not yet fully understood:

  • Dunaliella salina ssp. salina f. salina : typical accumulation of β-carotene
  • Dunaliella salina ssp. salina f. magna : larger than the type form: 7.5–29 μm long and 4–19 μm wide
  • Dunaliella salina ssp. salina f. oblonga : the cell shape is more elongated to ellipsoid
  • Dunaliella salina ssp. sibirica : The cells are inverted ovate and wider in the middle or the front end and a narrower and rounded, slightly pointed rounded rear end. The vegetative cells produce α-carotene. The classification as a subspecies is controversial.

Individual evidence

  1. ↑ a b c d e f Michael A. Borowitzka & Christopher J. Siva: The taxonomy of the genus Dunaliella (Chlorophyta, Dunaliellales) with emphasis on the marine and halophilic species . In: J Appl Phycol . tape 19 , 2007, pp. 567-590 , doi : 10.1007 / s10811-007-9171-x .
  2. ^ A b Michael A. Borowitzka: The Mass Culture of Dunaliella salina . In: Technical Resource Papers: REGIONAL WORKSHOP ON THE CULTURE AND UTILIZATION OF SEAWEEDS; VOLUME II . Cebu City, Philippines 1990 ( available online ).
  3. ↑ Dorinde MM Klei Negri, Marcel Janssen, Willem A. Brandenburg, René H. Wijffels: Continuous production of carotenoids from Dunaliella salina . In: Enzyme and Microbial Technology . tape 48 , no. 3 , 2011, p. 253-259 , doi : 10.1016 / j.enzmictec.2010.11.005 .
  4. ^ A b Aharon Oren: A hundred years of Dunaliella research: 1905–2005 . In: Saline Systems . tape 1 , no. 2 , 2005, doi : 10.1186 / 1746-1448-1-2 .
  5. ↑ MR Hadi, M. Shariati, S. Afsharzadeh: Microalgal biotechnology: Carotenoid and glycerol production by the green algae Dunaliella isolated from the Gave-Khooni salt marsh, Iran . In: Biotechnology and Bioprocess Engineering, . tape 13 , no. 5 , 2008, p. 540 , doi : 10.1186 / 1746-1448-1-2 .
  6. ↑ Algaebase , accessed on December 28, 2015

Web links

Commons : Dunaliella salina  - Collection of images, videos and audio files