Micro 221: History of Phycology

• Phycology is being introduced.
• The course is Micro 221-Phycology for 2024.
• Learning outcomes include tracing the history of phycology and identifying major algal groups.
• Another outcome is explaining the importance of algae in human lives.

History of Phycology

• Carolus Linnaeus contributed in 1754.
• Antoine Laurent de Jussieu contributed in 1789.
• Romans referred to algae as Fucus.
• Chinese referred to algae as Tsao.
• Hawaiians referred to algae as Limu.
• Detailed knowledge became available after the 17th century with the invention of the microscope.
• Heophrastus, a Greek philosopher and botanist, along with Dioscorides, a prominent physician and pharmacologist of the ancient world, made significant contributions to the study of algae during their respective research periods, which culminated towards the end of the 18th century. Their work focused on classifying and understanding various algae species, which had implications for medicine, nutrition, and ecological studies. Heophrastus is often regarded as the "father of botany," while Dioscorides' writings paved the way for future botanical studies. Their findings laid the foundation for the scientific exploration of marine biology and the role that algae play within various ecosystems, highlighting the importance of algae in both human health and environmental science.
• Heophrastus and Dioscorides drew from a wealth of observational knowledge, cataloging various forms of algae and their properties, which encouraged advancements in both scientific inquiry and practical applications. Their studies underscore the significance of understanding algae not only for their medicinal uses but also for ecological balance, suggesting that these organisms are essential for sustaining marine environments and supporting biodiversity, which researchers continue to explore today.
• The second phase of phycology began around 1800 and lasted until about 1880.
• The third phase of phycology lasted from about 1880 to the early 1950s.
• The current, or modern, phase began in the early 1950s and continues to the present day.

1st Phase

• Von Zalusian (1592) grouped algae with fungi, lichens, and seaweeds under the category Musci.
• Bauhin (1620) listed Muscus, Fucus, Conferva, and Equisetum (=Chara) under algae.
• Fucus, Conferva, Ulva, and Corallina are examples of algae that were studied.

2nd Phase

• J. Stackhouse was the first to study zygote germination in Fucus and describe the fertilization process (1801).
• Dawson and Turner contributed in 1802.
• Vaucher contributed in 1803.
• Lamouroux contributed in 1813.
• Lyngbye contributed in 1819.
• Greville contributed in 1830.
• William Henry Harvey contributed in 1846-51, 1852-1858.
• CA Agardh and J.G Agardh both contributed.
• F.T. Kutzing contributed in 1843 and 1849.
• Roth contributed from 1797-1805, studying Hydrodictyon, Batrachospermum, and Rivularia.
• H.E. Link of Germany contributed from 1820-1833, studying Tetraspora, Oedogonium, and Spirogyra.
• Jean Vincent Félix Lamouroux contributed in 1805-1816
• C.A. Agardh studied Diotomaceae, Nostochineae, Confervoideae, Ulvaceae, Florideae, and Fucoideae.
• Thurret published the first monograph on Fucus in 1854-55.
• Areschoug, from 1866-84, studied zoospore in Urospora and Cladophora.
• Areschoug is credited with the morphological account of Laminaria and Macrocystis.

3rd phase

• De Toni (1889) summarized the taxonomy and nomenclature of algae in Sylloge Algarum.
• Schmitz studied Rhodophyta in 1883 and 1889.
• Kuckuck and Kjellman studied Phaeophycota in 1912 and 1897.
• Wille studied Chlorophycota from 1897-1911.
• Oltmanns contributed in 1904 and 1922.
• Fritsch contributed in 1935 and 1945.
• O. Borge (1894-1936) researched freshwater algae in Sweden.
• Classical research on freshwater algae of Britain was carried out by West and West.
• G. S. West authored 'Algae', a book on algal structure and reproduction.
• Felix Eugen Fritsch and Rich (1907-37) researched freshwater algae in South Africa.
• Felix Eugen Fritsch published the classification of algae.
• Pia (1910) and Wolcott (1914) made significant contributions to some fossil algae.
• Harvey produced a series of flora of marine algae, viz., Phycologia Australica, Phycologia Brittanica etc.

4th or modern Phase

• Smith published Manual of Phycology in 1951.
• Widespread availability of the Electron Microscope helped, as well as the invention of scuba gear helped.
• New societies were founded: Phycological Society of America, La Societe Phycologique de France, the Japanese Phycological Society and the International Phycological Society
• Journals exclusive to algae include: Phycologia, Phykos etc.

Algae Characteristics

• Algae is pond scum or Thallophyta.
• The plant body of algae is always a thallus.
• Algae are a green group of autotrophic, non-vascular thalloid plants.
• Algae have unicellular or multicellular, non-jacketed sex organs with no embryo formation.
• Phycology is the study of algae (Phycos- "sea weeds" and logos “study").
• Algae are chlorophyll bearing thalloid plants with no differentiation into tissue or tissue system.
• Only a few algae are not aquatic.
• Sex organs are unicellular generally, while multicellular sex organs can each reproduce.
• Sex organs are never surrounded by a sterile jacket layer.
• No embryo is formed after gametic fusion.
• Sporophytic and gametophytic generations are independent when represented in the life cycle.
• Reproduction in algae can occur in vegetative, asexual, and sexual modes.
• Algae are chlorophyll-bearing organisms.

Major Groups of Algae

• Criteria in classifying algae include:
• Nuclear organization
• Cell wall components
• Pigments
• Flagellation
• Chemical nature of reserve material
• Type of life cycle and reproduction

Nuclear Organization

• Algae can be either prokaryotic or eukaryotic.
• Cyanophyceae or cyanobacteria (blue green) are prokaryotic in nature.
• In Cyanophyceae, the nuclear membrane is absent and genetic material (chromatin threads) is present.

Cell Wall Composition

• Cellulose is found in walls.
• The inner wall is an insoluble cellulosic layer, and the outer wall is made of pectic substances.
• Phaeophyceae cell walls contain alginic and fucinic acid.
• Bacillariophyceae walls contain silica.
• Rhodophyceae walls contain Xylan and Galactan.
• Cyanophyceae walls contain mucopeptide.

Pigments

• Pigments are an important criteria for classification.
• There are 5 types of chlorophyll: chlorophyll a, b, c, d, and e.
• Carotenoids are yellow or orange-colored pigments responsible for various colors in algae.
• There are 3 types of carotenoids: carotene, xanthophylls, and carotenoid acids.
• Phycobilins or biliproteins, a special type of pigment, include phycocyanin, phycoerythrin and allophycocyanin.

Nature of Reserve Food Material

• Starch is a reserve food material.
• Chlorophyceae stores starch.
• Cyanophyceae stores myxophycean starch.
• Rhodophyceae stores Floridean starch.

Flagellation

• appear in different forms in algae.

Type of Life Cycle and Reproduction

• Presence or absence of sexual reproduction is a key factor.
• Complexity of reproductive organs is important.
• The method of reproduction is considered.

Characteristics of Algae Groups

• Division Euglenophyta includes euglenoids.
• Division Pyrrhophyta includes dinoflagellates.
• Division Chrysophyta includes diatoms, golden-brown algae, and yellow-green algae.
• Division Chlorophyta includes green algae.
• Division Phaeophyta includes brown algae.
• Division Rhodophyta includes red algae.

Division Euglenophyta

• Euglenoids include many non-pigmented organisms.
• Zoologists classify euglenoids as members of the phylum Protozoa.
• Photosynthetic species have pigments similar to those of green algae.
• Euglenoids have a cell organization similar to that which evolved hundreds of millions or years ago.

Division Pyrrhophyta

• Dinoflagellates lack histones.
• Dinoflagellates have intranuclear mitosis with chromosomes that never decondense during interphase.
• Botanists consider dinoflagellates to be an isolated line that originated in the very first stages of the evolution of eukaryotic cells.

Division Chrysophyta

• This diverse group is sometimes divided into several separate divisions or included with the brown algae.
• Chrysophyta and brown algae have similar biochemistry and photosynthetic pigments (chlorophylls a and c).

Division Chlorophyta

• Green algae are extremely diverse structurally.
• Green algae are very homogenous and well defined biochemically.
• Green algae are almost identical to true plants in terms of basic metabolism.
• Green algae are universally considered to be the ancestors of true plants.

Division Phaeophyta

• Brown algae are a large group of species that often have large, complex bodies.
• They are common along rocky coasts.
• Some kelps have well-defined tissues, one of which strongly resembles phloem that transports organic molecules.

Division Rhodophyta

• Red algae, many species have simple filamentous bodies.
• Filaments may be aggregated and resemble parenchyma.
• Red algae never have a flagella.
• Red algae have a strongly prokaryotic organization to their chloroplasts.
• Red algae have phycobilisomes, like cyanobacteria.
• Nuclear structure and mitosis do not appear to be unusual in red algae.

Importance of Algae

• Algae constitute the link of the food chain.
• Algae is useful in fish culture.
• Algae is often used as food.
• Algae like chlorella and spirulina are blue-green seaweeds.
• Arame, wakame, kelp, and kombu are brown seaweeds.
• Sea grapes and sea lettuce are green seaweeds.
• Nori, dulse and irish moss are red seaweeds.
• Algae can be used as fodder.
• Algae can be used as fertilizer.
• Chlorella promotes lant growth and increases the contents of metals in corn plants.
• Nannochloropsis oculata increases the content of sugars and carotenoids in tomato fruits.
• Chlorella sp. increases the germination rate of corn seeds and shortens the germination period, while promoting root and leave growth.
• Chlorella vulgaris enhances soil nutrients for wheat plants.
• C. Vulgaris & Spirulina platensis enhance soil fertility and yield for rice plants.
• Blue-green algae like Nostoc, Scytonema, Anabaena and Aulosira are helpful in the reclamation of alkaline land.
• Algae can assist in the binding of soil particles.
• Algae has uses in space research.
• Red algae such as Gelidium, Gracilaria, and Gigartina are sources of agar agar.
• Carrageenin comes from Chondrus crispus, Gigartina stellata and Iridaea laminaroides.
• Species of Laminaria, Fucus, Ascophyllum, Macrocystis, Nereocystis, Ecklonia, and Sargassum are the chief sources of commercial algin.
• Diatomite can be derived.
• Algae can have medicinal uses.
• Alaria kelp strengthens the stomach/restores appetite after sickness.
• Alginates are used for their haemostatic nature.
• Fucoidin and sodium laminarin sulphate are blood coagulants.
• Digenia simplex is an Antihelmintic drug.
• Agar-agar has an absorptive and lubricating action.
• Chlorellin is an antibiotic against coliform and related intestinal bacteria.
• Extracts of Cladophora, Lyngbya kills strains of Psuedomonans and Mycobacterium and exhibit antiviral activity.
• Algae can be used in sewage disposal.
• Chlamydomonas, Scenedesmus, Chlorella, Euglena, Eudorina and Pandorina have sewage disposal usage.
• Phaeophyceae is a source of mannitol and fucoidin.
• Laminariales is a source of Iodine and Bromine.

Toxicity and Parasitism

• Negative Importance:
• Gymnodinium veneficum, Prymnesium parvum and Species of Microcystis causes mortality in fish and in domestic animals that drink infested water.
• Gonyaaulax produce endotoxins
• Microcystis auruginosa and Anabaena flos-aquae cause animal poisoning in temperate countries
• Anabaena and Microcystis causes gastric trouble
• Gymnodinium brevis causes respiratory disorders
• Lyngbya and Chlorella causes skin Infections
• Cephleuros causes "red rust of tea"
• Algae causes fouling of marine vessels.
• Loss of recreational and fishing values of pools, ponds, and lakes.
• Algae can impart abnormal tastes and odors through decomposition.
• Clogging of water filters.
• Coloration of raw and finished waters.
• Production of toxic substances.
• Corrosion of concrete and metallic walls of pipes and boilers can occur.
• Changes in Ph, CO2, bicarbonate, and oxygen content of water.