The document discusses various types of microbiological interactions, emphasizing the importance of relationships between organisms within ecosystems. These interactions are categorized into positive, such as mutualism and commensalism, and negative, including parasitism and predation. The document provides detailed examples of each interaction type, illustrating their significance in ecological dynamics and community stability.

1. SUBMITTED BY- MANDEEP KAUR
CLASS – MSC BIOTECHNOLOGY –I
ROLL NO - 7464
MICROBIOLOGY

2. INTERACTIONS

3.  Interaction is relationship between two organisms.
 Also called as BIOLOGICAL OR ECOLOGICAL
INTERACTIONS.
 In a ecosystem, living (biotic) things have to interact with one
another as well as with non -living components of their
environment.
 All the vital process of living such as growth, nutrition &
reproduction requires such interactions between individuals in
same species or between species.
INTERACTIONS

4. INTERACTIONS
INTRASPECIFIC
INTERACTIONS
Interactions that occur between
individuals of same species
INTERSPECIFIC
INTERACTIONS
Interactions that occur between
individuals of different species

5. • These interactions deals with types of relationship that occur
between two organisms and their effects in organisms.
• Interacting with other organisms can have 3 results:
1.It can BENEFIT an organisms
2.It can HARM an organisms
3.It can NO EFFECT an organisms

6.  Such relationship between living organisms when they live in
close association of each other is called as SYMBIOTIC
RELATIONSHIP
SYMBIOTIC INTERACTIONS

7. SYMBIOTIC INTERACTIONS
MUTUALISM COMMENSALISM PREDATION PARASITISM COMPETITION

8.  The interaction between organisms may not be always beneficial to all the
interacting counter parts. Based on whether, the interaction is beneficial to
both interacting species or harmful to at least one interaction species, the
ecological of biological interactions are classified into two categories.
POSITIVE
INTERACTIONS
In this, interacted organisms help
one another or give benefits to each
other
The benefit may be in respect of
food , shelter or transportation
NEGATIVE
INTERACTIONS
In this interaction, one of interacted
organism is benefitted and other is
harmed
It occurs due to competing for
foods and excrete harmful wasters

9. • In positive interactions, the interacting populations help one another.
• The positive interaction may be in one way or reciprocal.
• The benefit may be in respect of food, shelter, substratum or
transportation.
• The positive association may be continuous, transitory, obligate or
facultative.
• The two interacting partners may be in close contact in such a way
that the tissues intermixed with each other; or they may live within a
specific area of the other; or attached to its surface.
POSITIVE INTERACTIONS

10. MUTUALISM
COMMENSALISM

11.  Mutualism, also called as symbiosis, is also a positive type of
ecological interaction.
 Mutualism is a symbiotic association between two organisms in
which both the interacting partners are mutually benefitted.
 Mutualism is different from proto-cooperation in the sense that
mutualism is obligatory and none of the partners of mutualism
can survive individually.
 In mutualism, the organisms enter into some sort of physical and
physiological exchange.
MUTUALISM

12. (A). LICHENS:
 Lichens are the symbiotic association between algae and fungi. The body of
lichen composed of fungal matrix in which the algal cells are embedded. The
fungi provide protection to algal components and also provide moisture and
nutrients to them. The algal components in turn will supply carbohydrates for
fungus.
(B). SYMBIOTIC NITROGEN FIXATION:
 Mutualistic interaction can be seen in the symbiotic nitrogen fixation of
Rhizobium associated with root nodules of leguminous plants is the best
example. Similarly other microorganisms associated with plants such as Alnus,
Casuarina, Cycas for nitrogen fixation are also belongs to mutualism.
EXAMPLES

13. LICHENS

14. (C). MYCORRHIZAE:
 They are the symbiotic association between fungi and the roots of some trees.
Fungal components help in the absorption of water and minerals by the plant.
The plant in turn supplies foot to fungal components.
(D). POLLINATION BY ANIMALS:
 Bees, moths, butterflies etc. derive food from the nectar of plants and in return
bring out pollination
(E). ASSOCIATION BETWEEN TERMITES AND TRICHONYMPHA:
 Termites feeds on wood, however they cannot digest the cellulose in the wood.
Trichonympha is a protozon which lives in the gut of termites. Trichonympha
can produce digestive enzymes and they digest cellulose of wood.
Trichonympha in turn obtain food and shelter from termite.

15. MYCORHIZZA

16. • Commensalism is a positive type of ecological interaction between
two species in an ecosystem.
• In commensalism, the association occurs between members of
two different species where one species is benefited the other is
neither benefited nor harmed.
• Here the two populations live together without entering into any
kind of physical exchange, and one is benefited without any effect
on the other.
COMMENSALISM

17. (A). CLIMBERS AND LIANAS
• Such as Bauhinia, Tinospora etc., which are rooted in the soil but climb over
large trees. These climbers use other trees as support to get enough sunlight,
more than that, the supporting plants do not have any positive or negative effect.
(B). EPIPHYTES:
• They are the plants which growing on the surface of other large plants. They use
other plants only as a support and not for water or food supply. They are
different from lianas in that they are not rooted in the soil.
• Example: Orchids, Mosses, Nephrolepis, Usnea, green algae growing on the
surface of snails, microbes such as bacteria and protozoans live within the body
cavity of other animals.
EXAMPLES

18. EPIPHYTES

19. CLIMBER AND LIANAS

20. (C ). SPECIES OF BARNACLES WITH WHALE :
• Various species of barnacles attach themselves to the skin of skin
of whales . Whales transports the barnacles to planktons-rich
waters, where both species feed on microorganisms

21. BARNACLES BARNACLES WITH WHALE

22.  In negative interactions, one of the interacting populations
is benefited and the other is harmed.
 In negative interaction one population may eat members of
the other population, compete for foods or excrete harmful
wasters.
NEGATIVE INTERACTIONS

23. AMMENSALISM
PARASITISM
COMPETITION
PREDATION

24. • Ammensalism is a negative type of population interaction.
• In ammensalism one species is harmed or inhibited other is neither benefitted
nor harmed.
• Some authors prefer to use the term antibiosis for commensalism.
• Antibiosis is the partial or complete inhibition or death of one organism by
another through the production of some substances or environmental
conditions as a result of its metabolic pathway.
• In antibiosis none of them derives any benefit.
• The process of antibiosis is common in microbial populations and the chemical
substances produced by microbes for antibiosis are generally called as
antibiotics.
AMMENSALISM

25. (a). Chlorella vulgaris produces a toxin (chlorellin, an antibiotic)
which is harmful to other algae.
(b). Larger and more powerful organism excludes another
organism from its source of shelter or food is also a type of
ammensalism
(c). Algal blooms such as red tide or green blooms are also example
of ammensalism
EXAMPLES

26. ALGAL BLOOMS
GREEN BLOOMS RED TIDE

27. • Parasitism is a negative type of population interaction.
• Parasitism belongs to the exploitation' category of negative population
interactions.
• In exploitation, one species harms the other by making its direct or indirect use
for shelter or food.
• A parasite is the organism living on or in the body of another organisms and
deriving food form its tissues.
• The harmed one is called host, the benefitted one is called parasite.
• A parasite usually takes a host which is usually larger than its body size
• Usually a specialized parasite does not kill the host at least until it has completed
its reproductive cycle.
• Those organisms which derive their nourishment only partly and remain in
contact with their host only for a short period of their life cycle are not true
parasites (examples: mosquitos).
• Some parasites requires more than one host to complete its life cycle and such
parasites are called heteraceous parasites (example Puccinia, Malarial parasite).
PARASITISM

28. (a). Cuscuta is a total stem parasite which lives on the surface of other large plants.
They are devoid of chloroplasts and hence they cannot prepare their own food. Thy
have specialized absorptive structures called haustoria. In the case of complete
parasite, the haustoria will be inserted into the phloem tissue of host plants and
they absorb the prepared food materials from the host phloem.
(b). Rafflesia, Orabanche and Conopholis are complete root parasites
(c). Loranthus and Viscum (Loranthaceae) are partial stem parasites.
They bear leaves with chlorophylls and hence they can prepare their own food. The
haustoria of partial parasite are attached to the xylem of host plants. Form the
xylem of host plants, partial parasite absorbs water and minerals and they prepare
their own food by photosynthesis.
EXAMPLES

29. (d). Santalum album and Thesium are partial root parasites. Their
roots are attached to the host plants.
(e). Microorganisms such as bacteria, virus, fungi, mycoplasma,
protozoans etc. which cause many diseases in human and other
animals and plants are parasites.
(f). Hyperparasites: Parasitic microbes growing in or on other
parasites are called hyper parasites.

30. Rafflesia
Orabanche
Conopholis
COMPLETE ROOT PARASITE

31. COMPLETE ROOT PARASITES
Cuscuta
PARTIAL STEM PARASITES
Viscum Loranthus

32. • Predation is a negative type of population interaction and it
belongs to the 'exploitation' category of negative population
interactions.
• In predation, one species kill and feeds on another species.
• The killer species is called predator and the one who dead are
called prey.
• The predators are usually larger and power-full than prey.
• Predation is very important in community dynamics and it helps to
maintain the constancy of number of different trophic levels in the
ecosystem and thereby maintain the stability of ecosystem.
PREDATION

33.  Lion, tiger and Beer are predators of forest ecosystem. They
predate herbivores
EXAMPLES

34. • Competition is the association of two or more species; each species is adversely
affected by the presence of other species in respect of food, shelter, space, light etc.
• Competition occurs when individuals attempt to obtain a resource that is
inadequate to support all the individuals seeking it or even if the resources are
adequate individuals harm one another in trying to obtain it.
• The resources in the environment for which the individuals compete include raw
materials for life such as water, light and nutrients, space for occupying and
selection of mates for sexual reproduction.
• The competition in the ecosystem may be of two types:
• (A). INTRA-SPECIFIC COMPETITION
• (B). INTER-SPECIFIC COMPETITION
COMPETITION

35. (A). INTRA-SPECIFIC COMPETITION:
• It is the competition occurring between the individuals of the same
population (competition within population).
• It is also called as scramble competition. Intra-specific competition is an
important density dependent factor regulating population size.
• Intra-specific competition is also responsible for the even distribution of
individuals of the species in an ecosystem.
(B). INTER-SPECIFIC COMPETITION:
• It is the competition occurring between populations of different species
whose requirements are common and inadequate in the ecosystem
(competition between population).
• It is also called as contest or interference competition.

36. INTRASPECIFIC COMPETITION INTERSPECIFIC COMPETITION