Bacterial Diversity: Lecture 3 Dr.Amarakoon

• Lecture 1 covers Prokaryotic Diversity, specifically focusing on Bacteria
• Icolyn AMARAKOON is the lecturer, and can be reached via [email protected]

Learning Outcomes

• Aims to describe the biochemical and metabolic diversity within the microbial world
• Aims to help you understand the major bacterial lineages
• Aims to describe the facultative nature of microorganisms and their energy metabolism
• Aims to help you to understand Human pathogens
• Aims to describe that the bacterial significance is Agriculture, Food/Medicine and Industry

Phylogenetic Tree

• At least 80 bacterial lineages (phyla or divisions) are discovered
• Numerous Bacteria phyla are only known from environmental sequences
• Proteobacteria are the largest group within Bacteria

Phylum Cyanobacteria

• Key cyanobacteria Genera: Proclorococcus, Crocosphaera, Synechococcus, Trichodesmium, Oscillatoria, Anabaena
• Large morphologically heterogeneous group of Bacteria is phototrophic
• Distinct from purple and green bacteria
• Obligate oxygenic phototrophs
• Derives name from the blue-green color of phycocyanin and chlorophyll pigments
• It was first called blue green algae
• Cyanobacteria have a long evolutionary history and are around 3.5 billion years old
• They are found in -stromatholiths
• Earth’s atmosphere has Oxygen which is thought to have originated from cyanobacterial photosynthesis.
• Cyanobacteria were the first oxygen-evolving phototrophic organisms
• They are gram -ve and show a relationship to gram positive bacteria

Morphology

• Shark Bay, Western Australia contains microbial structures formed by cyanobacteria
• Three main forms exist: unicellular, colonial, and filamentous
• They are classified by morphology and cell division type into five groups
• Wide variations in cell size exist, ranging from 0.5 to 220 μm in diameter
• Colors also vary widely

Genera and Morphological Grouping of Cyanobacteria

• Group I (Chroococcales): Unicellular, divides by binary fission like a single cell
  • Genera: Gloeothece, Gloeobacter, Synechococcus, Cyanothece, Gloeocapsa, Synechocystis, Chamaesiphon, Merismopedia, Prochlorococcus, Prochloron
• Group II (Pleurocapsales): Pleurocapsalean reproduces through formation of small spherical cells called baeocytes which are produced by multiple fission like a colony
  • Genera: Dermocarpa, Xenococcus, Dermocarpella, Pleurocapsa, Myxosarcina, Chroococcidiopsis
• Group III (Oscillatoriales): Oscillatorian are Filamentous cells. Divides by binary fission on a single plane, and they are non-heterocystous
  • Genera: Oscillatoria, Spirulina, Arthrospira, Lyngbya, Microcoleus, Pseudanabaena
• Group IV (Nostocales): Nostocalean, filamentous and produces heterocysts
  • Genera: Anabaena, Nostoc, Calothrix, Nodularia, Cylindrospermum, Scytonema
• Group V (Stigonematales): Branching: cells divide to form branches
  • Genera: Fischerella, Stigonema, Chlorogloeopsis, Hapalosiphon
• Morphological Diversity: Impressive morphological diversity which can be unicellular, Filamentous or Branching

Examples of Cyanobacteria Groups

• Group 1: Cyano Bacteria like Gloeothece divide by binary fission
• Group 1: Includes unicellular Cyano Bacteria like Synochocysis
• Group II: Pleurocapsales such as Dermocarpa divide by multiple fission
• Group III: Oscillatoriales are filamentous, divide by binary fission and is a non-heterocytous example- Oscillatoria
• Group IV: Cyanobacteria are filamentous heterocystous like Anabaena
• Anabaena Circinalis is the largest cyanobacteria in length having 220um in length which aggregates into microscopic colonies which produces neurotoxins
• Gloeotrichia radiate colonies of heteropolar tapering filaments, which each has a heterocyst and akinetes which is at the base and has terminal cells at the opposite end. Each filament has a sheath, and their whole colony envelops mucilage
• Group V: Stigonematales have filamentous branching and a bright field (Fischerella)

In Mat Community

• Microbial Mat: a multi layered sheet of microorganisms
• Cyanobacteria have large mat like colonies that are toxic to other organisms

Harmful Blooms

• Harmful blooms begin with loss of water clarity
• Suppresses aquatic macrophytes
• Negatively affecting invertebrate and fish habitats

Cyanobacterial Physiology

• Oxygenic phototrophs host photosystems Type I and Type II
• All species can fix CO2 and some are capable of fixing N2
• Certain filamentous species can survive in darkness with glucose as a source
• Certain species can switch from oxygenic photosynthesis to anoxygenic, employing H₂S in place of H₂O as the electron source
• Cell walls contain peptidoglycan
• Thylakoids: specialized membrane systems can increase the ability of light harvesting
• Chlorophyll a production
• Characteristic phycobilin pigments are present for photosynthesis.
  • Phycocyanin: class of soluble phycobiliproteins are blue and together with the Chlorophyll a gives a blue green color

Cyanobacterial Cellular Structure

• Cellular structures store energy, reproduce, and survive
• They produce mucilaginous envelopes or sheaths which bind cell groups

Structures

• Akinetes are cells with thickened outer walls
• Akinetes protects the organism in cold, darkness or desiccation and during favourable conditions, it will germinate by breaking the outer wall
• Hormogonium: Short, motile filaments break away from longer filaments for dispersal when an Oscillatora is under stress

Other Cellular and Motility Structures

• Storage granules: cyanophycin, polyglucan and lipid vacuoles provide nitrogen storage
• Motility Structure: such as gas vesicles provides Buoyancy and keeps cell in light
• Many cyano bacteria display gliding motility

Heterocysts

• Nostocales and Stigonematales: facilitate fixation of dinitrogen using special cells
  • They are specialized cells called heterocysts which are at the end point of the filaments or along the filaments
  • heterocyst are a response to nitrogen starvation
  • Fix dinitrogen from atmosphere with enzyme nitrogenase to form ammonia
  • Heterocysts lack a photosystem II that are plugged at both ends to slow cell - cell diffusion
  • Vegetative cells: Carbohydrates and products of photosynthesis
  • Intercellular channels: are a source of intercellular channels for exchange of fixed nitrogen

Strategies for Dinitrogen Fixation

• Some cyanobacteria: fix nitrogen in unspecialized cells like Filamentous cyanobacteria
• Photosynthesis and dinitrogen fixation: are separated when Nitrogen fixes at night and photo during night
• Filamentous cyanobacteria are not heterocyst forming, they form bundles with Nitrogen fixing filaments shielding them from oxygen

Symbiotic Interactions

• Cyanobacteria form symbiotic interactions in plants. They fix Nitrogen and provides in exchange for carbohydrates
• Different signals with mucilage attract cyano bacteria which are not their own cells

Photosynthesis

• Oxygen in our earth’s atmosphere: began with Cyanobacterial photosynthesis
• Cyanobacteria: are photoautotrops and are aerobic bacteria
• Photoheterotrophy: displayed by Organic organisms containing sugars and acetate
• Marine cyanobacteria: make 25% of oxygen in atmosphere

Oxygenic and Anoxygenic photosynthesis Equations

• Oxygenic photosynthesis: 6CO2 + 12H2O + light energy = C6H12O6 + 602 + 6H2O
• Anoxygenic photosynthesis: CO2 + 2H2A + light energy = [CH2O] + 2A + H2O

Related Bacteria

• Oxygenic prototrophic prokaryotes exhibit photosynthesis similar to eukaryotes
• Chlorophyll a is a photosynthetic pigment in carotenoids like the phycobilins found in phycobilisomes
• Water is utilised to fix carbon dioxide and Calvin cycle used
• Photosynthetic apparatus has Chlorophyll A reacting
  • centers which reacts: photosystem I (PS1), photosystem II (PS2) and cytochrome b6f complex are joined in Electron carrier
  • Phycobilisomes: are soluble, have 50% cellular protein and has light harvesting

Phycobilisome Structure

• Phycobilisome has the structure for absorbance of light ranging orange, red, blue and green pigments

Cyanobacteria’s Ecological Importance

• They are an important group for Ecology and have many habitats to occupy which are pioneering phototrophic for the extremophiles
• They inhabit rivers, lakes, deserts, marine environments, interiors, rocks, and hot springs
• Cyanobacteria are suggested for Mars having oil formation
• They are important for the cycles of: carbon, nitrogen and oxygen to ecology

Toxic Cyano Bacteria

• They produce bloom which make cyanotoxin
• Toxin Production: unknown and has excess nutrient run off waters that cause excessive forming species
• Some: have toxic effect that risks human marine life
• Three groups: hepatotoxins, neurotoxins, and dermatotoxins are produced by cyanobacteria
• Microcystins: Anabaena, Nostoc, and Oscillatoria possess the most common hepatotoxin which is
• Anabaena: and Oscillatoria possess the most potent neurotoxins like
• Lyngbia Martensiana: creates dermatitis

Developments

• Researchers have sequenced genomes of cyanobacteria because of their potential use for bio fuel
• Biofuel: and is tested from cyanobacterial lipids

Spirulina

• Is consumed as wonder food -Arthrospira platensis
• It is rich in B, Mg, Iron, beta carotene, linolei trace and calcium providing 60% of the protein source supported by NASA and WHO
• Strengthens the function of all T-lymphocyte disease's fighting cells
• Sulpholipids: help in fighting for medically important ingredients and components the the AIDS virus.
• A water based extract of Spirulina: has inhibitory components on a virus virus
• Has been medically successful in stopping cancers
• It has been also helpful for Radiation Ilinesses

Joule's Helioculture

• Process by which Joule had modified Bacteria(cyano) that has plants ingredients which involves Carbon dioxide, potassium, light which secretes fuel by harvesting
• Other products which involves tumor selectivity is the Epoxy ketone

Prochlorophytes

• Prochlorophytes- domain Bacteria, phylum cyanobacteria and order Prochlorales

Prochlorophytes Classification

• Oxygenic phototrophic prokaryotes are closely related to cyano bacteria
• It has chlorophyll A and B but is lacking phycobilins
• It it similar to plant having chlorophyll b

Known Genera

• All diversity depends on ecological niches: Prochlorokokkon, trochothrix, and Chloron

Unique Traits

• Prochloron
  • Has symbiotic connections
• Prochlorococcus
  • Occupies ocean
• Prochlorothrix
  • Fresh water type

Structure

• Photosynthesis is connected with membranes with Chloroplast thylakoid showing symbiotic like structures
• Prochloron: It has symbiotic associations that has spherical cells having B and A with phycobilins
• Prochlorothrix: rare and has Chlorophyll and is only founded by Europe
• Prochlorokokk: It is free, shape is Cocci and its is 0.8 in diameter

Properties

• Bacteria, is different that it contains chlorophyll B, which is needed by light. They don’t live in soil or the inland type ecosystems

• Chloroplast: membrane enclosed bag which is need for A and B for sunlight

• Chloroplast Lineages: the early cyano started with bacteria due to endosymbiotic activity

Green Sulfur Bacteria

• Key Genera: Chlorobium, Chlorobaculum, “Chlorochromatium”
• Phylogenic: all distinct from bacteria
• An oxygenic has aerobic types of conditions in the water which helps in sulfur
• The aerobic contains short or tall rods and has some green to brown

Chlorobiium, Clathraiforme

• Clathraiforme is used in sunlight conditions to use but does use without oxygen is where they live that is why some account % 80 of the sulfur type bacteria live in that part of the lakes only using 15 0 the total type’s

Similarities

• The purple bacteria are sulfur but these Sulfur from purple type is used out

• Bacterio: it has C, E and D helps give cells the properties of helping the

• Is needed for Chlorosomes to use and absorb the light where photosynthesis

• Green sulfur bacteria also helps the to get the bacteria a lot of ATP and helps in synthases

• Green sulfurs help get more ATP and light it

• The green sulfr bacteria is used to test the soil sample water because it is aerobic

Species and Consortium

• Anaerobes help bacteria out
• Epibionant: which means phototonic cells
• The epibionant is useful in attaching to all others

Green Sulfur Bacteria Consortium

• Central Cells support the Phototros on photosynthesis
• Photo CO2 fixation happens after the cell benefits which changes the morphology and it allows aggregatum
• The chlorosomes also work as well as chains, the ebonants
• These types work in the cell or the direct way of the Epibonts

GNS

• Chloro uses what it’s called different: the thermo is interesting because there is so many lipids it makes
• These acids then make ester on a type of glycerol, only cells that have a small peptide which makes a polymer to attach

Chloroflexus

• In most regions is is neutral
• It’s with cyanobacteia when it comes to being thick
• Photo anoxygenic helps help also auto helps and aerobic

Chloroflexus And relatives Properties

• They’re very yellow and their color comes in with what’s called in its carotenoid
• Green no sulfur has some of the important cells they make like what we all ready went over

Unique Feature

• D shape
• Most times you see that there all negative the gono is the one we want

Mophology and Motitlty for Spirootes:

• Most of the bacteria will come all over
• The cells are what get all the cylinder
• The cells will move it’s all

Anaerobic Type

• Pallidum, comes with infection like waves
• It’s hard to maintain it’s properties or all
• It’ has come cells that all say they don’t like certain things

All Types

• Pallidum, is connected to types and all of has bacteria and
• It moves the body through the skins outer
• It moves through the body And to test for is a antibiotics

Boella :

• It’s an animal and human cell of light
• It goes in human and effects all others

Unique type of bacteria

• Heat, is resistant and is in almost all types of area

Species: is is resistant to radiation has a ton of heat

• Genome of all can cause mutation that do not help it

Species of cell

• Cell is best best way of DNA support is to get more support
• If you have heat and cell it repairs the DNA and the chomor are all better because they will move all through

Chlamdiya:

• It will spread to an animal
• Spreads from sex and will move on and also through the hosts

A type of bacterial cell

• Pneumonia may come on because of type of way the bacteria will spread to get all the

Class Properties

• Have all the special types and special cells to grow and spread is all the different types in cell form
• The Eb- cell wall and the RB wall is all and then from the host it will come on

Summary Time

• Chlorflex:

  • Bacteria contains Bactero chlorin a and is rod shaft it has the special properties that help to change its stain and all

• Also has what is high and can take can all and can auto and use no heat

• The all heat bacteria: it has micro properties that will not have and cannot grow and other canot

• The Spiro bacteria: also have different strains that it is made of and will transfer in many ways

• Procologytes, you will has all different cells that will move and not mix if bacteria

I hope that helps! I am still learning, please let me know if i can do anything else to improve!