Presented By: Soumya Sephalika Swain
Microbial Perspectives of Biowaste Degradation and
Management

• Waste can be simply defined as a material that is no longer useful and is
unwanted by its producer. As an example, a newspaper that has been read, a
package that has been emptied, or an apple that has been eaten, have all lost their
original value.
• So, waste generation not only negatively impacts human health but also the
environment as well and which leads to climatic catastrophe, harms wildlife, and
impacts our own health.
• According to the World Bank’s 2018 report, rise in
population growth and urbanization, annual waste
generation in the world is expected to increase by 73%
from 2020 levels to 3.88 billion tonnes in 2050, resulting
in a daily footprint of 0.79 kilograms per person.
What is Waste?

Mining Waste Bio Waste Industrial Waste
Household & Commercial Waste Construction Demolition Waste Waste Wate Bodies
Types of Wastes

Untreated waste is defined as waste that has not been
immobilized, disinfected, or sterilized and contains high levels
of phosphorus and nitrogen, hydrocarbons, pathogenic
microbes, heavy metals, endocrine disruptors, and organic
matter in the natural ecosystem.
The disposal of waste without treatment creates landfills,
pollutes the soil causes soil infertility, and threatens the green
life in that area, as well as its impact on all life on earth.
What is Untreated Waste?
Why do we need to treat waste?

Composition of Biowaste
• Biowaste or biodegradable waste is a type of feedstock defined as waste
from organic origin. It includes any organic matter in waste which can be
broken down into carbon dioxide, water, methane, or simple organic
molecules by microorganisms and other living things by composting,
aerobic digestion, and anaerobic digestion or similar processes.
• As discussed above, the major portion of biowaste
is organic in nature, the main proportion is plant
materials, and agricultural wastes which contain a
high proportion of cellulosic, hemicellulosic, and
lignin, collectively known as lignocellulosic matter
(Sachez, 2009)

What is Microbial Degradation?
• Microorganisms are ubiquitous in the environment, where they play a
variety of critical roles in the natural recycling of organic materials. In fact,
it is the process by which active microflora break down organic materials
into smaller molecules.
• So, the basic procedures for the microbiological conversion of organic
wastes are included, along with a characterization of an enzyme that
metabolizes biological materials.
• It is based on two processes: growth and cometabolism. In growth, an
organic pollutant is used as the sole source of carbon and energy, which
leads to the complete degradation of the pollutants. In cometabolism, the
contaminant is luckily degraded by an enzyme or cofactor produced during
microbial metabolism of another compound.

Steps of Microbial Degradation:
There are many steps in the microbial degradation of pollutants and have certain terminologies
by which they can be identified.
a) Bio-deterioration- It defines the action of certain organisms that are responsible for the
physical as well chemical decomposition of the waste. This results in surface degradation
that alters the properties of the material including mechanical, physical, and chemical
properties.
b) Bio-fragmentation- It refers to the certain catalytic actions that break down the polymeric
chains and converts them into respective oligomers, dimers, or monomers by x free radicals
or ectoenzymes that the microorganisms release.
c) Assimilation- It is the getting together or union of the constituent molecules transported in
the cytoplasm in the metabolic pathways or strategies of microbes.
d) Mineralisation- In this process, the molecules degenerate in a way that results in their total
deterioration and excretion of fully oxidized metabolites like CO2, N2, CH4 and H2O.

Biowaste
Plant
Waste
Food
Waste
Animal
Waste
Produces
Enzymes
Enzymes liquify
Organic waste
Degradation of complex
compounds through
hydrolases, dioxygenase,
peroxidase, etc.
Microbes
digest the
liquid waste
Multiply &
Cell division
Nutrient
acquisition by
active and passive
transport
Secreting carrier
proteins to the
environment
Bring the
need nutrient
back into the
cell
By-products
Inoculation of
Microorganism
CO2
Ethanol Methanol
Process of Microbial Degradation:

Role of Microbes in Biodegradation
• 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). So, the microorganisms involved in this process produce different lytic
enzymes which break down organic matter to form humus along with the production
of CO2, water, and heat.
• They recycle nutrients in the environment, by decomposing organic materials, such as
animal carcasses, leafy litter, and tree trunks.
• 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.
• Although many microbes are able to metabolize organic pollutants, a single microbe
does not possess the enzymatic capability to degrade all or even most of the organic
compounds in polluted soil. As a result, mixed microbial communities can degrade a
complex mixture of organic compounds more rapidly than single-microbial
communities.

Biofuel
Biopoly
-mers
Bioferti
-lizers
Enzym
es
Organi
c acids
Single
cell
protein
Animal
feed
Bioelec
t-ricity
Biogas
BIOWASTE
Management of waste in various Bio-based products:

Name of the Microorganisms Reported Waste
Digestion
By-products from the
digested waste
Authors
Bacillus amyloliquefaciens (GenBank
accession number: KX 583567.1)
Potato peel waste Bioethanol Production Chauhan et al., 2022
Streptomyces rochei Domestic Agro waste Composting and Treatment of
Pulp-Paper Mill Effluent
Limaye et al., 2017
Eisenia fetida and Pseudomonas sp. Agricultural waste Biofertilizer Rajkhowa et al., 2019
Brevibacillus borstelensis, Bacillus
licheniformis, Bacillus thuringiensis and
Food Waste Bioenzymes (ɑ-amylase &
cellulase)
Awasthi et al., 2017
Bacillus subtilis B1U/1, B. subtilis
D3L/1 and Pseudomonas sp
Common organic
wastes
Compost Pan et al., 2011
Pleurotus sajorcaju, Trichoderma viridae,
Aspergillus niger and Pseudomonas
striatum
Sugarcane waste Compost Kumar et al., 2010
Saccharomyces cerevisiae Starch based waste Bioethanol Production Kumar et al., 2016
Some reported studies related to Biowaste digestion:

Thank You