Download primary producers

Chapter 5
The Microbial
World
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Microorganisms are the most
important
primary producers in many
marine environment
2
Viruses
Viruses
Particle not make up of a cell
-- consist of small chain of nucleic acid (genetic
material)
-- protected by a outer coat (capsid(衣殼))
 Parasites and reproduce after infest a living cell
 Small: ~20 to 200 nm

4
Viruses type

Retroviruses(反轉病毒)

Lysogenic viruses(溶原病毒)
5
Retroviruses
Store genetic information in the RNA,
no DNA
 Responsible for deadly human disease
(e.g. AIDs and leukemia)
 Reproduction:
-- attach into a living cell, inject nucleic
acids into the cell
-- command the cell to deuplicate the virus
-- release as infected cell burst
-- infect other cell or infect new host

6
Lysogenic viruses
Reproduction:
-- inducing nucleic acid become part of the
genome of the host cell
-- directs the production of new viruses
-- viruses released as the infected cell
destroyed
 Bacteriophages

7
Role of viruses in marine ecosystem
Most abundant life-like particles in the ocean
-- abundance directly related to the abundance
of microbial life; bacteria
 Viruses infect bacteria and phytoplankton
 Important to “Microbial Loop”
-- causing release large quantity of DOM
-- release large quantity of essential nutrients
 Responsible for diseases of marine life:
shellfish, fishes, turtles, even human

8
Prokaryotes
9
Prokaryotes

The smallest, structurally simplest
and oldest form of life

Different from eukaryotes
10
Differences from viruses




Cell wall
Plasma membranes
Cellular machinery
Genetic information
12
Two domains

Bacteria
 Archaea
13
Bacteria
Branched out very early
on the tree of life
Have many shape
Decay bacteria
15
Cyanobacteria (blue-green algae)
-- Among the first photosynthetic organisms on earth
Photosynthetic bacteria

3 kinds of photopigments
-- phycocyanin (藻藍素)
-- phycoerythrin(藻紅素)
-- chlorophyll a
17
Fossil stromatolites(層疊石墊藻岩)
-- Almost everywhere in
marine environment
-- Epiphytes and endophytes
19
Archaea (archaebacteria)
20
Archaea (archaebacteria)

Among the simplist, most
primitive form of life
-- estimated at least 3.8 billion(38億) years old

Characters; (1) small, (2)
prokaryotic (3) extremophiles(極端生
物)
21
Prokaryote metabolism
metabolism
autotrophs;
photoautotrophs;
chemoautotrophs
22
Autotrophs
 Photoautotrophy
-- energy obtained from sun
-- e.g. photosynthesis
 Chemoautotrophy
-- energy obtained from other sources
-- e.g. hydrothermal vent; from earth
23
Hydrothermal vent
Heterotrophs
 Obtain energy by respiration
 bacteria
 Decomposer
 Aerobic and anaerobic bacteria
25
Nitrogen fixation
--
covert gases nitrogen to ammonium
Unicellular alga
Characters:
(1) aquatic, (2)
eukaryotes, (3) chloroplast
Belongs
to Protista (原生生物)
28
Unicellular alga

Color depends on the pigments
and their concentration

Lack true leaves, stems and roots
29
Diatom
Phylum (or Division) Bacillariophyta
Characters: (1) unicellular, (2) frustules
30
Life history characters
frustule(硅藻細胞)
 minute perforation
sinking is slow by oil droplet
in cells and spines

31
-- Photopigments; carotenoid;
chlorophyll a and c
-- Important primary producers in
temperature and polar regions
-- Half of estimated 12000 species
are marine
-- Both pelagic and benthic forms
32
Asexual reproduction; auxospore(增大細胞)
Bloom(藻華)
 Mechanims
 Cells
are smaller; asexual
reproduction, depletion of silicate
from the water column
34
Biogenous sediment
-- Diatomaceous (siliceous)
ooze
-- diatomaceous earth
Dianoflagellates
Phylum (or Division) Dinophyra
36
Characters
possession two flagella
cellulose plate
photosynthesis and
heterotrophs
37
-- About 1200 species; all marines
-- Reproduction almost exclusively
by simple cell division
-- Produce “red tides”, bioluminance
-- Especially bright when disturb
by boat or wave crash on shore
-- Zooxanthellae(蟲黃藻); and function
38
Other unicellular algaes
39
Silicoflatellates(硅鞭藻)
Phylum (or Division) Chryosphytes(金藻門)
40
-- common in marine sediment; used to date the sediment
Coccolithophorids, or coccoliths(球石藻)
Phylum Haptophyta:
41
Coccoliths
Made of calcium carbonate
Found in sediment as fossils
42
Cryptomonads(隱藻)
Phylum Cryptophyta
-- has two flagella
-- lack a skeleton
43
Protozoans: animal-like protists
 Structurally
simple and animal-
like
 Characters: (1) photosynthesis
and heterotrophs, (2) most singlecelled, (3) microscope
 About 50000 species
 everywhere and parasites
44
Forminiferans(有孔蟲)
Phylum Granuloreticulosa
45
Forminiferans
Forams
 Characters; (1) test (calcium
carbonate), (2) possess
pseudopodia , (3) benthos
 Spines to aid in floatation
 Shells of bottom-living foram
 Foraminiferan ooze

48
Applications
Geological temperature
variation
 Oil distribution
 Determine the age of
sediment

49
Radiolarians
Phylum Polycystina
50
Radiolarians
Planktonic marine protozoans
 Shell and pseudopodia
 Inhabit in open ocean
throughout the world
 Radiolarian ooze

51
Ciliates
Phylum Ciliophora
52
Ciliates
cilia for locomotion and feeding
creeping over seaweeds, in
bottom sediments, in the
intestine and skin of marine
animals
 Important in the microbial loop of
open-water; facilitate energy flow
53
Fungi
• Kingdom Fungi
• Eukaryotic and most multicellular
• Multicellular fungi form long filaments
called hyphae(菌絲)
• Heterotrophic life style
• Fungi have cell walls
54
Fungi
• At least 1500 species of marine fungi
• Characters: (1) mostly microscopic, (2)
decompose organic matter, some
parasite, some symbiotes
55
Marine Lichens(苔鮮)
Marine Lichens
• Cyanobacteria are nitrogen fixers
• Few types live on the shells of rocky shore
barnacles and limpets
57