INTRODUCTION to SOIL MICROBIOLOGY Flashcards
It is the study of microorganisms that
live in the soil; their metabolic activity;
their roles in energy flow; and their roles
in nutrient cycling.
Soil Microbiology
“the branch of soil science concerned with soil-inhabiting microorganisms, their functions and activities”
Soil Microbiology
It is a dynamic natural body formed from weathering of rocks and minerals composed of mineral matter, organic matter, air and water, and possesses distinct characteristics and properties which in turn influence plant growth.
Soil
Importance of Soil Microbiology:
Soil as a living system
-Soil microbes and plant growth
-Soil microbes and soil structure
*soil aggregation or soil binding properties order:
fungi > actinomycetes > gum producing bacteria > yeasts
-Soil microbes and organic matter decomposition
*organic matter/substances include cellulose, lignins and
proteins (in cell wall of plants), glycogen (animal tissues),
proteins and fats (plants, animals).
- Soil microbes and humus formation
Importance of Soil Microbiology:
Soil microbes and cycling of elements
~ Soil Microbes and biological N, fixation
~* Soil microbes as bio-control agents
*eco-friendly bio formulations of microbial origin: Trichoderma
sp and Gleocladium sp for seed and soil-borne diseases,
fungal genera as insect pest or bacteria like Bacillus
thuringeinsis for leaf spot and worm diseases.
~Degradation of pesticides in soil by microorganisms
Biodegradation of hydrocarbons
Focus in the study of the biota
living in soil and concerned itself with the cycling of nutrients and their availability to agricultural
plants
Early years
More of an interdisciplinary study, involving agricultural production, aquatic and biogeochemical sciences, bioremediation, environmental quality, biodiversity, and global climate change
today
Approach 2
To study the chemical, geological and biological
processes and reactions that governs the
composition of the natural environment.
a. Biogeochemistry - how they affect our environment
chemically
b. Nutrient cycling - how they recycle compounds in soil
c. Global change - how they affect global properties
such as temperature and atmospheric chemistry
d. Ecology — how they interact with their environment
and with other microorganisms
To study the mechanical, physical, and biochemical
functions of living organisms.
a. Physiology - how they grow and metabolize
b. Taxonomy - what they look like and how they are
related to one another
c. Pathology - how they cause disease of plants,
animals and humans
d. Symbioses - how they interact with more complex
organisms
first written history of soil and soil biota originated
in the East where scholars were recognized in the
__________.
early Chinese royal courts
ancient Chinese regarded earthworms as
“angels of the earth.”
Romans, such as Aristotle, considered earth worms
as
“intestines of the earth’.
Inscriptions on ____________ show
that the production of beer and bread involved the
use of a starter (fungi) and required an incubation
time.
Egyptian walls from 2400 BCE
soil microbiology emerges as a distint branch of soil science during__________
first half of 19th century.
Recognized as being the first to see [giaealanae
bacteria in his self-designed microscopes.
Antonie van Leeuwenhoek
1632 — 1723
He observed minute, moving objects which he
called “animalcules’ (small animals) which are
now known as protozoa, fungi and bacteria.
Antonie van Leeuwenhoek
1632 — 1723
He for the first time made the authentic drawings of microorganisms (protozoa, bacteria, fungi).
Antonie van Leeuwenhoek
1632 — 1723
Robert Hooke (1635 — 1703)
Developed a compound microscope with
multiple lenses and described the fascinating
world of the microbes.
Robert Hooke (1635 — 1703)
Micrographia, was
published in 1665 and considered the first
microbiology textbook
Responsible for the process of heating liquids
to partially sterilize them (Pasteurization).
Louis Pasteur (1822 — 1895)
Can be said to have pioneered microbial
culture technique.
Robert Koch (1843 — 1910)
Investigated microbial activities directly
related to the soil and often called the “Father
of Soil Microbiology”.
- He studied nitrification, sulfur oxidation,
microbial oxidation of ferrous iron and
microbial growth on CO, and inorganic ions, a
process called chemoautotrophy. - Developed the Winogradsky column, a
self-contained ecosystem for studying the sulfur cycle.
Serge Winogradsky (1856-1953)
1. A specific microorganism can = always be found with a given disease. 2.The microorganism can be isolated and grown in a pure culture in the laboratory. 3.The pure culture will produce the disease when inoculated into a susceptible host. 4. The microorganism can be tecovered from the infected host and grown again in a pure culture.
Koch’s postulate:
cultured the first nitrogen-fixing bacteria
that grew symbiotically in association with
legumes and the first aerobic nitrogen-fixing
bacteria that grew asymbiotically as free-living
soil organisms. These were Rhizobium and
Azotobacter, respectively.
Martinus Beijerinck (1851-1931)
he is Considered the pioneer of antibiotics and
discovered evidence of the first antibiotic; penicillin
Sir Alexander Fleming (1881-1955)
he is Interested in the effects of soil organisms
on soil fertility and plant growth. Lipman’s
textbook “Bacteria in Relation to Country Life”
(Lipman 1908) was the first attempt to
popularize the science of soil microbiology.
Jacob Lipman (1874-1939)
who isolated a soil actinomycete called
Streptomyces. Streptomyces has _ antibiotic
properties much like those Fleming found with penecillum
Selman Waksman (1888-1973)
