![High organic matter (OM)
in soil (plant litter &
animal bodies)
Mucor
Increase zymogenous population (Mucor, Rhizopus)
Among bacteria (Bacillus &
Pseudomonas)
Population slowly
changes to
ascomycetes,
actinomycetes &
protozoans.
Organisms degrade fungal hyphae. Fungus is part of
initial invasion (attack) of substrate
OM stimulate 자극하다
microbial spores [break the
dormancy (sleeping or quiescent)
of spores]
High competitive saprophytic
ability (live on dead or
decomposing matter)
Consumed easily
utilizable
substrates
pH drops due to
immobilisation of
cations](https://image.slidesharecdn.com/16159550-221005161201-883d7302/85/16159550-ppt-51-320.jpg)
16159550.ppt
- 1. Concept of Microbial Ecology Fundamentals of Microbial Ecology Development of Microbial Communities Succession & Colonisation
- 2. Concept of Microbial Ecology Fundamentals of Microbial Ecology Development of Microbial Communities Succession & Colonisation Microbial Ecology Relationship between microorganisms & their environments Biotic Abiotic
- 3. Organisms occupying place – Sediment, humus rich soil, nasal cavity, Intestinal tract Common Terms in Microbial Ecology Ecosystem Basic Unit of Ecology comprising of biotic & abiotic components Biotic element Community of living organisms dealing with populations of MO’s Population Consisting of clones of one or several species Abiotic Chemical & physical conditions for microbial life Habitat
- 4. Common Terms in Microbial Ecology Microhabitat Specialized species (Leaf miners) Live only in the upper Photosynthetic layer of the leaves. Leaf contributes a microhabitat for leaf miners. Leaf miners
- 5. Common Terms in Microbial Ecology Niche 생태적 지위 In general terms - organism lives Functional role Survival Reproduction No two population can occupy the same niche at the same time Cellulose- 셀룰로오스 Eg. Cellulolytic bacteria degrade cellulose anaerobically Gain energy by fermentation 발효 Maintain themselves & flourish in the rumen
- 6. Classification of microorganisms in ecosystem Numbers constant in ecosystem Autochthonous Indigenous 토착 Present in given ecosystem Soil Intestine Presence more or less number based on nutrient supply Zymogenous Allochthonous
- 7. Found in ecosystem at very low number Occasional increase Increase based on specific nutrient supply Eg. Cellulolytic microbes High number when soil cellulose is high Classification of microorganisms in ecosystem Autochthonous Zymogenous Allochthonous Cellulose- 셀룰로오스
- 8. Strangers in ecosystem / not permanent residents Eg. Soil spores of soil dwellers Present in air for short time period for dispersal Classification of microorganisms in ecosystem Autochthonous Zymogenous Allochthonous
- 9. Concept of Microbial Ecology: Energy Flow Use chemicals instead of light Ecosystems are in a dynamic steady state 역학 확고한 Controlling the activity of individual Maintaining equilibrium 평형 Energy Chemosynthetic bacteria Primary producer (use light in photosynthesis to reduce CO2)
- 10. Radiant Energy Chemical Energy Sun Producers Consumers Decomposers (Metabolism) (Metabolism) (Metabolism) Heat Energy Heat Energy Heat Energy “Primary Productivity” (Kcal/m2/day) Stored energy in primary producers In the form of C or OM
- 11. Mechanical Energy - two forms Kinetic or free energy Potential energy Moving Energy Measured by the amount of work done in bringing the body to rest Stored Energy Useful after conversion into kinetic energy Organisms potential energy is chemical energy of food
- 12. Grazing Food web Herbivores Carnivores Omnivores Detrivores Detritus Food Web Eat dead bodies or decaying materials Food oxidation Release energy Used to do work Chemical Energy Mechanical Energy Food Chain Transfer of energy stored in organic compounds from one organism to other Energy transfer in different steps Trophic level Food web Interrelationship of food chain
- 13. Bio-geochemical Cycle (BGC) Movement of material by biochemical activities Atmosphere (air) Hydrosphere (water) Lithosphere (soil) BGC cycle Physical (Precipitation, Fixation) & Chemical transformation (Biosynthesis, biodegradation) & Combination of both Microbes vital role Energy absorbed, converted, temporarily stored & Flow C, H, O, N, P & S
- 14. Bubble surface Attachment properties of Microbes Adhesion 부착 All nontoxic, animate & inanimate surfaces Solid surface Air-water interface
- 15. Longer in natural environment if they are absorbed than when they are free. Extracellular polymeric substance Consequence 결과적 of phenomenon 현상 of adhesion 부착 Organic & inorganic nutrients Adsorbed surface of object Extracellular enzymes Absorbed microbial surface Microbes attachment Prevent form predators or from desiccation Survival of viruses & bacteriophages
- 16. Two stage process of attachment Physical or chemical adsorption Not controlled by the organism Organisms secrete Protein or Glycoprotein 당 단백질glue 아교 Adsorption 흡착 Adhesion 부착 To attracts similar species to forming a colony
- 17. Van der Waal’s attraction Electrostatic repulsion Adsorption 흡착 Adsorption is governed by two kinds of forces Van der Waals forces Attraction & repulsions between atoms, molecules, & surfaces, as well as other intermolecular forces
- 18. Negatively charged surfaces at neutral pH owing anionic groups (COO-) within their wall polymers Also negative charge due to isomorphic (iso-equal, morphe- shape) replacement. Bacteria & fungi Soil Clay These negative charged surfaces attract ions of opposite charge in two layers 1) First layer is firmly (Tightly 단단히) attached 2) Second layer is diffuse layer attachment (100 nm distance from surface) Distance reduced to 0.5 nm in concentrated solutions of polyvalent ions (Na+ is univalent and Ca2+, Al3+ is polyvalent)
- 20. Attachment – either “adsorbed” or “produced by microbes” The attachment charge is “directly proportional to distance between them” Effect surface chemistry Surface coating of material Surface Chemistry study of substances surfaces - adsorption, the formation of colloids 콜로이드, heterogeneous catalysis, corrosion 부식, dissolution, crystallization, etc. At a given ionic strength Repulsion between bacterium & surface
- 22. The balance between the van der Waal’s forces of attraction and the electro static repulsion determines 결정 whether the bacterium is attracted to the surface or repelled from it.
- 23. Development of Microbial Communities
- 24. What is Community? Highest biological Unit Made up of Individuals & Populations What is Microbial Community? Assemblage of microbial populations Interacting between them at given location Habitat Study of community - Synecology Study of individual & population - Autecology
- 25. Heterogenicity of ecosystem is diversity Various organisms occurring together Important role in food web Food energy move by multitude pathway if community is diverse Loss of one species cause changes or collapse community Increase of one species – rise of predator population What is Diversity 종 다양성?
- 26. Dominant species determine the less & abundant species 1 or more population attain high number - Diversity decrease What is Diversity 종 다양성? Biological communities Few species with many individuals Many species with few individual Dominant species take most of energy
- 27. What Determines Diversity 종 다양성? - Community has complex structure More number of species Require low energy Maintain ecosystem structure Stable diversity Dominant by single species Require more energy To maintain stable condition
- 28. Diversity related to abundance of ecological niches. Complex community offers a variety of ecological niches than simple community. Diversity inversely related to isolation. Example: Islands 섬 less diverse than ecologically similar continents 대륙 because difficult many species reaching islands. Diversity inversely 반대로 related to stress & extreme environments
- 29. ‘Edge effect’ – Where two ecosystems overlap, the overlapping area supports species from both, plus another species that is only found in the overlapping area. Diversity reduced when anyone species becomes dominant within a community So it is able to remove a disproportionate share of available resources Thus preventing the growth of many other species.
- 30. Species Diversity Indices (SDI) Several mathematical methods describe the species richness are called Species Diversity Indices (SDI) which are used to describe the assemblage of species diversity within a community. But SDI cannot be applied to the microbial community due to technical difficulties (quantitatively the data is insufficient).
- 31. Succession & Colonization Succession Colonisation Pre-emptive Colonisation Outcome of Succession Types of Succession Autogenic succession Substrate succession Trends in Succession
- 32. Colonisation First colonisers of a virgin environment Microbial growth & reproduction on a material, animal or person without damage Primary succession (first appearance of MO’s) Habitat not previously colonised (eg. Gastro-intestinal tract of new born) Secondary succession Succession occurs in a habitat with a previous colonisation (volcanic eruption, barren land 황무지, etc.) Pioneer organisms
- 33. Pre-emptive Colonisation Pioneer 개척자 organisms alter the condition in the habitat New Organisms Populations better adapted to the newly colonised habitat Replace the pioneers Gradually secondary invaders are also replaced. Succession ends when a relatively stable community called a climax community is achieved.
- 34. New Environment Alter the condition Pioneer organisms Develop the Environment Not allowed further succession Pre-emptive colonisation Altered habitat Gradually secondary invaders Succession ends Stable community Climax community
- 35. Climax community No further changes Difficult to apply the concept of climax community to microbial community Because disturbance affect successional processes So not reaching full equilibrium
- 36. Succession Later, some populations are replaced by other populations that are better adapted to fill the ecological niches. Ecological niche Community Individual populations Ecological niche Ecological niche Then Later Ecological niche replaced by other populations Communities of organisms not exist suddenly but develop gradually by series of stages until they reach maturity state. Individual populations of a community occupy the niches in the ecosystem.
- 37. Succession is replacement of one community by another as the condition within the habitat changes How its replaced? Changes by the organism (by reduction in nutrient & oxygen level or changes in the pH) or changes from outside New Environment Pioneer organisms Develop the Environment
- 38. Some interrelationships loose associations where one microbial population can replace the other (rhizosphere) Some interrelationships tight associations where one microbial population cannot replace another (symbiotic association of Rhizobium). When it reach the Ecological stability of the community? Interrelationship among populations in a community & adaptations within a population contribute to the ecological stability of the community. New Environment Pioneer organisms Develop the Environment If microbes not have stability Community continues..
- 39. Outcome of Succession Each stage in a succession is called sere Seral take long-term New Environment Pioneer organisms Develop the Environment sere sere sere
- 40. Eg. Bare rocks Starting with algae or lichens Converted to stable soils At the start of the sere There is stress in the environment (very low nutrient) and the species diversity is low. Bare rocks
- 41. Habitat is colonised Number of species grow increases Reach climax (final stage) Dynamic equilibrium between organism and environment Stable
- 43. Stable communities Example, communities in hot thermal springs have a low species diversity but are very stable because of the environment. Individuals species come & go Finally the balance between the species vary slight The overall list of organisms remain stable. Thus stability is not related to diversity but it is imposed from outside
- 44. Hot summer Favourable climate No organisms disappear Low species diversity, but stable Succession occurs due to influence of physical & chemical changes from outside the community. Community succession begins with colonisation or invasion침입 of a habitat by microbial population.
- 45. Types of Succession Autogenic succession Example: Creation of anaerobic conditions by facultative anaerobes allows the growth of obligate anaerobes. Microorganisms modify the habitat Permits a new population to develop Facultative anaerobes: grow with or without oxygen because they metabolise energy aerobically or anaerobically. Obligate anaerobes: poisoned by oxygen, so they grow low Oxygen Allogenic succession Allogenic succession
- 46. Habitat is altered by environmental factors Eg. salt marsh 바닷물이 드나 드는 늪 (zone between land & open salt water) Then coastal marshes converted completely into terrestrial communities Pioneer organisms dominated by salt-loving organisms (eg. Algae) Grow & add organic nutrients to the marsh Followed by nitrogen fixing algae Types of Succession Autogenic succession Allogenic succession Substrate succession
- 47. (eg. Porphyrosiphon notarisu, Gloeocapsa spp., Gloecocystis spp., Nostoc muscorum) Microbes involved in the development of structured soils (eg. bare rock surfaces) Low soluble minerals, no organic matter & so high temperature & moisture on the rocks Uninhabited or virgin environment Pioneer organisms Only tolerant algae & cyanobacteria with mucilaginous walls (갑옷) or slime capsule grow Fix nitrogen Types of Succession Autogenic succession Substracte succession Allogenic succession
- 48. Organic matter accumulates from wind-blown dust & oxygen Nutrients set back to zero (or) diversity of microbes & nutrients support growth of higher plants Algae & lichens then fungi & bacteria & then protozoa These processes build up of primitive thin soil which has more nutrients (organic).
- 49. Which reflect the colonisation of newly arrived species of organic matter Sere shortened if organic matter is added from outside Long-term sere (from primitive to mature soil) Many short-term changes in the microbial populations Types of Succession Autogenic succession Substracte succession Allogenic succession
- 51. High organic matter (OM) in soil (plant litter & animal bodies) Mucor Increase zymogenous population (Mucor, Rhizopus) Among bacteria (Bacillus & Pseudomonas) Population slowly changes to ascomycetes, actinomycetes & protozoans. Organisms degrade fungal hyphae. Fungus is part of initial invasion (attack) of substrate OM stimulate 자극하다 microbial spores [break the dormancy (sleeping or quiescent) of spores] High competitive saprophytic ability (live on dead or decomposing matter) Consumed easily utilizable substrates pH drops due to immobilisation of cations
- 52. Species diversity decreased Succession of Final stage Invasion (attack) by autochthonous organisms especially those degrading lignin (supporting material for algae tissues or plants) During a substrate succession Activity of microorganisms increases High environmental diversity Utilisable nutrients used up & reduced