This document discusses the genus Arthrospira, which includes the cyanobacteria used to make the dietary supplement spirulina. It provides details on the taxonomy, morphology, occurrence, uses, and cultivation methods of Arthrospira species. Key points include that Arthrospira forms helical trichomes, is found in alkaline waters worldwide, its uses as a food supplement and in biotechnology/medicine, and that it can be cultivated in wastewater to remove pollutants and produce biomass.

1. Arthrospira

2. Introduction
• Arthrospira is a genus of free-floating
filamentous cyanobacteria characterized by cylindrical,
multicellular trichomes in an open left-hand helix.
• A dietary supplement is made from A. platensis and A. maxima, known
as spirulina. The A. maxima and A. platensis species were once classified
in the genus Spirulina.
• Although the introduction of the two separate
genera Arthrospira and Spirulina is now generally accepted, there has
been much dispute in the past and the resulting taxonomical confusion is
tremendous.

3. Taxonomy
• The common name, spirulina, refers to the dried biomass of Arthrospira platensis, which
belongs to the oxygenic photosynthetic bacteria that cover the
groups' Cyanobacteria and Prochlorales.
• These photosynthetic organisms were first considered to be algae, a very large and
diverse group of eukaryotic organisms, until 1962 when they were reclassified
as prokaryotes and named Cyanobacteria.
• This designation was accepted and published in 1974 by Bergey's Manual of
Determinative Bacteriology.
• Scientifically, quite a distinction exists between
the Spirulina and Arthrospira genera. Stizenberger, in 1852, gave the
name Arthrospira based on the presence of septa, its helical form, and its multicellular
structure, and Gomont, in 1892, confirmed the aseptate form of the genus Spirulina.

4. • Geitler in 1932 reunified both members designating them
as Spirulina without considering the septum. Research on microalgae was
carried out in the name of Spirulina, but the original species used to
produce the dietary supplement spirulina belongs to the
genus Arthrospira.
• This misnomer has been difficult to correct. At present, taxonomy states
that the name spirulina for strains that are used as food supplements is
inappropriate, and agreement exists that Arthrospira is a distinct genus,
consisting of over 30 different species, including A.
platensis and A. Maxima.

5. Occurrenc
e
• Species of the genus Arthrospira have been
isolated from alkaline brackish and saline
waters in tropical and subtropical regions.
Among the various species included in the
genus, A. platensis is the most widely
distributed and is mainly found in Africa, but
also in Asia. A. maxima are believed to be
found in California and Mexico.
• Most cultivated spirulina is produced in
open channel raceway ponds, with paddle-
wheels used to agitate the water.[14] The
largest commercial producers of spirulina
are located in the United States, Thailand,
India, Taiwan, China, Pakistan, Myanmar,
Greece and Chile.

6. Morphology
• The genus Arthrospira comprises helical trichomes of
varying size and with various degrees of coiling,
including tightly-coiled morphology to a straight form.
• The helical parameters of the shape
of Arthrospira are used to differentiate between and
even within the same species. These differences may
be induced by changing environmental conditions,
such as temperature.
• The helical shape of the trichomes is
only maintained in a liquid environment. The filaments
are solitary and reproduce by binary fission, and the
cells of the trichomes vary in length from 2 to
12 μm and can sometimes reach 16 μm.

7. Uses
• Spirulina is widely known as a food supplement, but there are other possible uses
for this cyanobacterium. As an example, it is suggested to be used medically for
patients for whom it is difficult to chew or swallow food, or as a natural and cheap
drug delivery system.
• Further, promising results in the treatment of certain cancers, allergies, and anemia,
as well as hepatotoxicity and vascular diseases were found.Spirulina may also be
used as a healthy addition to animal feed if the price of its production can be further
reduced.
• Spirulina can be used in technical applications, such as the biosynthesis of silver
nanoparticles, which allows the formation of metallic silver in an environmentally
friendly way.

8. uses
• The creation of textiles harbors some advantages
since they can be used for the production of antimicrobial
textiles and paper or polymer materials.
• They also may have an antioxidant effect and may maintain
the ecological balance in aquatic bodies and reduces
various stresses in the aquatic environment.

9. Cultivation method
• The microalgae biomass production from swine wastewater is a possible solution for
the environmental impact generated by wastewater discharge into water sources.
• The biomass can be added to fish feed, which can be used in the formulation of
meat products.
• This work addresses the adaptation of the microalgae Spirulina platensis
(Arthrospira platensis) in swine wastewater and the study of the best dilution of the
wastewater for maximum biomass production and for removal of Chemical Oxygen
Demand (COD), ammonia and phosphorous to the microalgae.
• The cultivation of Spirulina platensis, strain Paracas presented maximum cellular
concentrations and maximum specific growth rates in the wastewater concentration
of 5.0 and 8.5%.

10. Cultivation method
• The highest COD removals occurred with 26.5 and 30.0% of wastewater in the
medium. The maximum removal of total phosphorous (41.6%), was with 8.5% of
wastewater, which is related to the microalgae growth.
• The results of Spirulina culture in the swine wastewater demonstrated the possibility
of using these microalgae for the COD and phosphorous removal and for biomass
production.
• The swine culture is an important economical activity in rural methods. Brazil
possesses the fourth largest worldwide swine flock, with the production of 2.87
million tons of meat.
• Swine dejects constitute one of the most important pollution sources when they are
discharged into nature without previous treatment .

11. Cultivation method
• The residues are not adequately treated and their release into the environment
cause serious pollution problems. The swine wastewater is rich in inorganic
phosphorous and nitrogen, which usually accumulate in the water generating
eutrophic systems .
• The characteristics of treated swine wastewater are high values of Biochemistry
Oxygen Demand (BOD), nitrogen and phosphorous concentrations.
• The aerobic processes of wastewater treatment are the most appropriate ones for
removing these compounds. Some examples are the stabilization ponds, which are
favorable for cyanobacterium development, among them the Spirulina platensis.

12. Cultivation method
• According to Cañizares-Villanueva et al. (1995), the swine wastewater can
be used as a medium for microalgae and cyanobacterium growth after
stabilization through aeration or anaerobic digestion.
• Moreover, the nutrients found in the wastewater can be converted into
biomass, removing the compounds that cause pollution, enabling the reuse
of the water after the treatment
• The Spirulina platensis culture in swine wastewater can be beneficial
because the microalgae can use the nitrate as a source of nitrogen.
• Additionally, the oxygenation caused by photosynthesis reduces the total
coliform count.

13. Cultivaton method
• The produced biomass can be used as animal feed, energy
production, and fertilizers or to produce fine chemistry products such
as pigments, polysaccharides, carotenes, sterols, vitamins, polly-
unsaturated fatty acids and lipids.
• This work addresses the adaptation of the microalgae Spirulina
platensis in swine wastewater and studies the ideal wastewater
dilution for maximum biomass production, in addition to Chemical
Oxygen Demand (COD), and the microalgae capability to remove
ammonia and phosphorous.