Various steps involved in the production of an antibiotic are
as follows:
(i) A large number of aerobic heterotrophic microbes grow
in the aeration tank. They include bacteria, some filamentous
fungi, yeast and protozoans. These aerobes grow in “flocs”
and consume a major part of organic matter so that the BOD
of sewage is reduced. Now the effluent is passed through a
sedimentation tank where microbial flocs are allowed to settle
down. The settled materials is called ‘activated sludge’.
(ii) A small part of the activated sludge is pumped back into
the aeration tank to serve as the inoculum. The remaining
major part of the activated sludge is pumped into large tanks
called anaerobic sludge digesters. The aerobic microbes in the
sludge get killed. The anaerobic bacteria digest the organic
mass including dead bacteria and fungi in the sludge and
produce mixture of gases like methane, hydrogen sulphide
and CO 2 which constitute biogas. The left out sludge is used
as manure.- The natural method of pest and pathogen control involving
use of viruses, bacteria and other insects (which are their
natural predators and pests) is called biocontrol or biological
control. For example, Lady bird beetle (beetle with red and
black markings) feeds on aphids while dragonflies prey upon
mosquitoes. Free living fungus Trichoderma exerts biocontrol
over several plant pathogens. An example of microbial
biocontrol agents that can be introduced in order to control
butterfly caterpillars is the bacteria Bacillus thuringiensis.
Biofertilisers are the microorganisms such as bacteria,
cyanobacteria, fungi etc., which bring about soil nutrient
enrichment, maximise the ecological benefits and minimise
the environmental hazards. - Azolla pinnata is a free floating fresh water fern which
multiplies rapidly, doubling every 5–7 days. The fern can
coexist with rice plants because it does not interfere with
their growth. A symbiotic blue green algae, Anabaena azollae
resides in the leaf cavities of the fern. It fixes nitrogen. A part
of the fixed nitrogen is excreted in the cavities and becomes
available to the fern. The decaying fern plants release the
same for utilisation of the rice plants. When field is dried at
the time of harvesting, the fern functions as the green manure,
decomposing and enriching the field for the next crop.
Unscramble the given words using the references given below.
Scrambled letters Clues Words- POIETEP Antigenic determinant. ...........................................
- VSAINONI A stage of ecological succession. ...........................................
- IRPOAMRACOPIOGTN Helps in rapid multiplication of plants. ...........................................
- GNYOLSYECO An ecological study at community level. ...........................................
- BVNILFIORA Also called yellow enzyme and its deficiency
causes cheilosis. ........................................... - TCIFOIRNBITOIAFO Plant breeding for improved food quality. ...........................................
- YHRONTAKORE Male birth. ...........................................
- PECLTSOUAL Plant cell organelle which stores substances
like starch, fat and proteins. ........................................... - INCTNLAOIC Peptide hormone that acts opposite to
parathyroid hormone in Ca2+ metabolism. ........................................... - ESRKAPTSIOTEN Helps in clearing blood clots inside the
blood vessels. ...........................................
U N S C R A M B L E M E
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