Role of Micro-organisms in Biodegradation of Organic Waste

1. SHRI SHIVAJI EDUCATION SOCIETY AMRAVATI
SHRI SHIVAJI COLLEGE OF ARTS COMMERCE
AND SCIENCE AKOLA(MS)
NAAC REACCREDITED WITH A GRADE(CGPA OF( 3.24)COLLEGE WITH POTENTIAL FOR EXCELLENCE(STATUS BY
UGC)LEAD COLLEGE (STATUS BY SGBAU, AMRAVATI) DST-FIST SUPPORT
DEPARTMENT OF BOTANY
ROLE OF MICROORGANISMS IN BIODEGRADATION OF
ORGANIC WASTES
BY
DR. RASIKA N. PATIL
ASSISTANT PROFESSOR
SHRI SHIVAJI COLLEGE OF ARTS COMMERCE AND SCIENCE AKOLA

2. INTRODUCTION
 Microbes able to degrade the contaminant and increase in numbers when
the contaminant is present. When the contaminant is degraded, the
biodegradative population become declines. The residues for the treatment
are usually harmless product including water carbon dioxide and cell
biomass.
 The most significant effect of the microbes on earth is their ability to recycle
the primary elements that make up all living systems, especially carbon,
oxygen, and nitrogen (N). Primary production involves photosynthetic
organisms which take up CO2 from the atmosphere and convert it to organic
(cellular) material.

3.  Microorganisms are ubiquitous in the environment, where they have
a variety of essential functions.
 Microbes play an essential role in the natural recycling of living
material. All naturally produced substances are biodegradable, which
means that living organisms, such as bacteria or fungi, can break them
down.
 Many of the microorganisms capable of the degradation and
bioconversion of organic compounds.
 Basic processes of the microbiological conversion of xenobiotics are
considered along with a characterization of the enzymes that bring
about these bioconversions.
 Special attention is paid to the processes of microbiological
transformation of xenobiotics which lead to more recalcitrant and
toxic intermediates compared to their parent compounds.

4. The basic biochemical reaction in aerobic
biological waste disposal systems is the
same for all microorganisms.
Food + Microorganisms + Oxygen –
* Increased Microorganisms + Carbon dioxide + Water + Waste
products (+ Energy)

5.  Industrial wastes often contain unusual organic compounds not readily
found in large concentrations in nature.
 Many of these compounds are toxic to microorganisms in very low
concentrations. It is possible to treat wastes containing toxic organic
compounds by slowly adapting the bacteria to the toxic compound.
 This is usually done by growing a large quantity of microorganisms on
nontoxic organic compounds and then slowly removing the nontoxic
compound and substituting the toxic compound.
 One of the major problems in the aerobic stabilization for the stabilization
of organic matter is through the acid form. Unless the system has sufficient
buffer to neutralize the acid that is formed, the pH will quickly drop below
the level for optimum efficiency.
 Bacterial systems prefer a pH between 6.5 and 9.5. The buffer problem is
most critical with metabolism of neutral compounds such as sugars,
alcohols, aldehydes, and ketones.

6. PROCESS OF BIODEGRADATION
 Degradation of pollutants by
microbes by using the materials as
energy sources.
 Biodegradable simply means to be
consumed by microorganisms and
return to compounds found in nature.

7.  Biodegradation is a very important property for toxic chemicals, because if
the biodegradation rate is high, the concentration and thereby the toxic effect
will be reduced rapidly, while very persistent chemicals will maintain their
toxic effect for a very long time.
 The range of biodegradation rates is very wide – from readily biodegraded
compounds as for instance monomer carbohydrates, low molecular alcohols,
and acids to very refractory compounds that have a biological life cycle of
several years.
 In principle, biodegradation is carried out by many organisms, but in most
cases we consider microbiological biodegradation for the most important
from an environmental point of view.
 The biodegradation rates in water and in soil by microorganisms are of
particularly interest. It is, however, not a characteristic value that can be used
as a constant for a compound, because the biodegradation is strongly
dependent on the conditions for the microorganisms in the water and in the
soil. The biodegradation is furthermore dependent on the presence or
absence of oxygen; it means aerobic or anaerobic conditions.

10.  Microorganisms have several vital roles in
ecosystems: decomposition, oxygen production,
evolution, and symbiotic relationships.
Decomposition is where dead animal or plant
matter is broken down into more basic
molecules. This process only happens because of
the microorganisms that find their way into the
dead matter.
 Micro-organisms (or microbes for short) play
a very important role in our lives. These
microscopic organisms play a key role in
maintaining life on earth, fixing gases and
breaking down dead plant and animal matter
into simpler substances that are used at the
beginning of the food chain.
ROLE OF MICROORGANISMS IN
BIODEGRADATION

11. The basic considerations for the most efficient economical biological
treatment system for industrial wastes are as follows:
1. Uniform waste feeding.
2. Proper pH adjustment.
3. Proper nutrient adjustment.
4. Uniform air utilization.
5. Instantaneous waste mixing.
6. Uniform organic level in the aeration system.
7. A minimum of mechanic equipment.
8. Simplicity of operation.
9. Ability to absorb shock organic and hydraulic loads. Needless to say, it is
impossible to design a system that completely solves all these problems.
One effort to eliminate these problems and to design a new type of
biological treatment system is given here.
BIOLOGICAL TREATMENT PROCESS
FOR INDUSTRIAL WASTE

12. MICROBES ARE USED IN THE
FOLLOWING PROCESSES
 Aerobic biodegradation of
pollutants
 Anaerobic biodegradation of
pollutants
 Bioavailability, chemotaxis and
transport of pollutants
 Oil biodegradation
 Cholesterol biodegradation
 Analysis of waste biotreatment
 Metabolic engineering and
biocatalytic applications
 Fungal biodegradation

13.  The most significant effect of the microbes on earth is their ability to recycle
the primary elements that make up all living systems, especially carbon,
oxygen, and nitrogen (N).Thus along with all these benefits, microbes greatly
contribute in maintaining sustainability of environment.
 Microorganisms recycle nutrients in the environment, by decomposing
organic materials. Organic materials, such as animal carcasses and tree
trunks, decay by the action of decomposing microbes, which are also
responsible for getting rid of industrial and household waste.
 When waste is created, it gives priority to preparing it for re-use, then
recycling, then recovery, and last of all disposal (e.g. landfill).
IMPORTANCE OF MICROBES