Micro 221: Phycology Introduction

Introduction to Phycology

• Micro 221-Phycology is being taught by Mangaoang in 2024.
• The topic outline includes the history of phycology, major groups of algae, and the importance of algae.
• The intended learning outcomes are to trace the history and developments in phycology, identify major groups of algae, and explain the significance of algae in human lives.

History of Phycology

• Carolus Linnaeus contributed to the field in 1754.
• Antoine Laurent de Jussieu contributed to the field in 1789.
• Romans referred to algae as Fucus.
• Chinese referred to algae as Tsao.
• Hawaiians referred to algae as Limu.
• Detailed knowledge of algae increased after the invention of the microscope in the 17th century.
• Theophrastus and Dioscorides contributed and concluded their research by the end of the 18th century.
• The second phase of phycology occurred approximately from 1800 to 1880.
• The third phase spans from about 1880 to the early 1950s.
• The fourth or modern phase began in the early 1950s and continues to the present.

1st Phase

• Von Zalusian (1592) included algae with fungi, lichens, and seaweeds under the term Musci.
• Bauhin (1620) listed algae under Muscus, Fucus, Conferva, and Equisetum (=Chara).
• Algae were classified as Fucus, Conferva, Ulva, and Corallina.

2nd Phase

• J. Stackhouse was the first to study zygote germination in Fucus, describing the process of fertilization in 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 from 1846-51 and 1852-1858.
• C.A. Agardh and his son J.G. Agardh also contributed.
• F.T. Kutzing contributed in 1843 and 1849.
• Roth contributed between 1797-1805 with Hydrodictyon, Batrachospermum, and Rivularia.
• H.E. Link of Germany contributed between 1820-33 with Tetraspora, Oedogonium, and Spirogyra.
• Jean Vincent Félix Lamouroux contributed from 1805-1816 with Laminaria.
• C.A. Agardh contributed with Diotomaceae, Nostochineae, Confervoideae, Ulvaceae, Florideae, and Fucoideae.
• Thurret contributed from 1854-55, publishing the first monograph on Fucus.
• Areschoug contributed from 1866-84, studying zoospore in Urospora and Cladophora.
• Areschoug contributed to the morphological account of Laminaria and Macrocystis.

3rd phase

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

4th Phase

• Smith's Manual of Phycology came out in 1951.
• Electron Microscopy and scuba became widely available.
• New societies such as the Phycological Society of America, La Societe Phycologique de France, the Japanese Phycological Society, and the International Phycological Society were founded.
• Dedicated journals for algae studies, such as Phycologia and Phykos, started being published.

Algae Characteristics

• Algae can be found as pond scum.
• Plant body of algae is always a thallus.
• Algae are Thallophyta.
• Algae is a green group of autotrophic, non-vascular thalloid plants that are unicellular or multicellular, having non-jacketed sex organs and no embryo formation.
• Phycology is the study of algae, referencing "phycos" as sea weeds and "logos" as study.

Distinctive Characters of Algae

• Algae are chlorophyll-bearing thalloid plants without differentiation into tissue or tissue systems.
• Almost all algae are aquatic.
• Sex organs are generally unicellular; when multicellular, each cell can 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.
• Algae reproduce in vegetative, asexual, and sexual modes.
• Algae are chlorophyll-bearing.

Major Groups of Algae and Classifying Criteria

• 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 prokaryotic or eukaryotic.
• Cyanophyceae, also known as cyanobacteria (blue-green algae), are prokaryotic.
• Cyanophyceae lack a nuclear membrane, and their genetic material is in the form of chromatin threads.

Chemical Composition of Cell Wall

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

Pigments

• Pigments are a crucial criteria for classification.
• There are five types of chlorophyll:
  • chlorophyll a
  • chlorophyll b
  • chlorophyll c
  • chlorophyll d
  • chlorophyll e
• Carotenoids are yellow or orange pigments responsible for various colors in algae, and are classified into carotene, xanthophylls, and carotenoid acids.
• Phycobilins or biliproteins are special pigment types including phycocyanin, phycoerythrin, and allophycocyanin.

Nature of Reserve Food Material

• Starch is the main reserve food, but the food material differs among algae types.
  • Chlorophyceae store starch.
  • Cyanophyceae store myxophycean starch.
  • Rhodophyceae store floridean starch.

Flagellation

• Flagellation is a key characteristic to classify algae.

Type of Life Cycle and Reproduction

• The presence or absence of sexual reproduction, complexity of reproductive organs, and method of reproduction are all important.

Characteristics of Various Groups of Algae

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

Division Euglenophyta

• Euglenoids have many non-pigmented species.
• Classified by zoologists in the Protozoa phylum.
• Photosynthetic species contain pigments similar to those in green algae.
• Euglenoids appear very ancient, with a cell organization similar to that which evolved hundreds of millions of years ago.

Division Pyrrhophyta

• Dinoflagellates lack histones and have intranuclear mitosis with chromosomes remaining uncondensed during interphase.
• Many botanists now consider them to be an isolated line that originated in the early stages of eukaryotic cell evolution.

Division Chrysophyta

• Includes diatoms, golden-brown algae, and yellow-green algae.
• Diverse group sometimes divided into several separate divisions or included with brown algae.
• They and brown algae have similar photosynthetic pigments (chlorophylls a and c) and unusual storage products.

Division Chlorophyta

• Green algae is extremely diverse structurally but very homogenous and well-defined biochemically.
• Almost identical to true plants regarding basic metabolism.
• Universally considered ancestors of true plants.

Division Phaeophyta

• Brown algae is a large group of species with often large, complex bodies that are common along rocky coasts.
• Some kelps have well-defined tissues, one of which resembles phloem and is involved in the long-distance transport of organic molecules.

Division Rhodophyta

• Red algae includes many species with simple filamentous bodies.
• Filaments may be aggregated and resemble parenchyma.
• They never have a flagella at any time.
• Unique in having a strongly prokaryotic organization to their chloroplasts.
• There are phycobilisomes as in cyanobacteria.
• Nuclear structure and mitosis are not unusual.

Importance of Algae

• Algae are a crucial link in the food chain.
• Algae are useful in fish culture.
• Some types of algae can be used as food.
  • Blue-green algae (chlorella and spirulina)
  • Brown algae (arame, wakame, kelp, and kombu)
  • Green algae (sea grapes and sea lettuce)
  • Red algae (nori, dulse and irish moss)
• Algae also acts as a food source for animals.
• Algae can be used as fertilizer.
  • Chlorella sp: Promotes corn plant growth and increases metal content.
  • Nannochloropsis oculata: increases sugar and carotenoid content in tomato fruits.
  • Chlorella sp. increases germination rate of corn, and seed, shortens germination, and promote roots and leaves.
  • Chlorella vulgaris enhances soil nutrients in wheat plants.
  • C. Vulgaris & Spirulina platensis enhance soil fertility and yield in rice plants.
• Algae can be useful in the reclamation of alkaline land using blue-green algae (Nostoc, Scytonema, Anabaena and Aulosira).
• Algae can be used for binding soil particles.
• Algae can be useful for space research.
• Algae has commercial products such as:
  • Agar-agar which are obtained from red algae like Gelidium, Gracilaria Gigartina etc.
  • Carrageenin which are obtained from Chondrus crispus, Gigartina stellata and Iridaea laminaroides.
  • Algin and Alginates, where the species of Laminaria, Fucus, Ascophyllum, Macrocystis, Nereocystis, Ecklonia, and Sargassum are the chief sources of commercial algin.
• Diatomite can be obtained from harvesting algae.
• Medicinal uses for algae:
  • Alaria (kelp): strengthen the stomach and restore appetite after sickness.
  • Alginates: has hemostatic nature.
  • Fucoidin and sodium laminarin sulphate: used for blood coagulation.
  • Digenia simplex (Rhodophyaceaea): used as antihelmintic drug.
  • Agar-agar has absorptive and lubricating action to prevent constipation.
  • Chlorellin (Chorella) is an antibiotic against coliform and related intestinal bacteria.
  • Extracts of Cladophora and Lyngbya kill strain of Psuedomonans and Mycobacterium and exhibit antiviral activity
• Chlamydomonas, Scenedesmus, Chlorella, Euglena, Eudorina and Pandorina are used in sewage disposal. -Mannitol and fucoidin are other products of Phaeophyceae
• Laminariales can be used for iodine and Bromine.
• Negative aspects of algae and toxicity.
  • Gymnodinium veneficum, Prymnesium parvum and species of Microcystis can cause fish mortality 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 cause Gastric trouble.
• Gymnodinium brevis cause Respiratory disorders.
• Lyngbya and Chlorella lead to Skin Infections.
• Cephleuros causes “red rust of tea”.
• Fouling of marine vessels.
• Algae is important in municipal water supplies.
• Algae causes loss of recreational and fishing values of pools, ponds, and lakes.
• Algae imparts abnormal tastes and odors by the metabolic or decomposition products of organisms.
• Algae clogs water filters.
• Algae leads to coloration of raw and finished waters.
• Algae leads to production of toxic substances.
• Algae can caused corrosion of concrete and metallic walls of pipes and boilers.
• Aalgae changes in pH, CO2, bicarbonate, and oxygen content of water