MECHANISM OF AEROBIC ANAEROBIC BIODEGRADATION 1162020 1 Role

MECHANISM OF AEROBIC & ANAEROBIC BIODEGRADATION 11/6/2020 1

Role of Microorganisms in the Decomposition of Organic Matter Decomposition refers to the breakdown of the body which occurs following a death

Process of Decomposition by Microorganisms �Within a very short time period microorganisms can breakdown and digest a large amount of soft tissue, resulting in a large production of gas and ‘decomposition fluid’

Microorganisms are Collectively known as Decomposers �Decomposers obtain a great source of energy from the body such as proteins, fats, organic carbohydrates and nucleic acids which are used as a food source. �This energy is then released through aerobic/anaerobic respiration. �This energy allows rapid multiplication which leads to more decomposition.

CONTENT Ø Biodegradation Ø Types Ø Aerobic degradation Ø Mechanism of aerobic degradation Ø Anaerobic degradation Ø Mechanism of anaerobic degradation Ø Difference between aerobic and anaerobic 11/6/2020 5

BIODEGRADATION Ø Biodegradation is a natural and complex process of decomposition facilitated by biochemical reactions Ø It is biological transformation of an complex organic material to simpler by micro organisms Ø Biodegradable matter is generally organic material such as plant & animal matter Ø The time of biodegradation is different according to the complexity of material. 11/6/2020 6

DEGRADATION TIME PRODUCT TIME TO DEGRADE APPLE CORE 1 -2 months GENERAL PAPER 1 -3 months CARDBOARD BOX 2 months COTTON CLOTH 5 months TIN CANS 50 -100 months ALUMINIUM CANS 150 -200 months 11/6/2020 7

BIODEGRADEBILITY Ø Very easily degradable Ø Easily degradable Ø Potentially Ø Very degradable slowly degradable 11/6/2020 8

Types of Biodegradation : Ø aerobic biodegradation Ø an-aerobic biodegradation 11/6/2020 9

Aerobic Biodegradation �It is the breakdown of organic contaminants by micro organism when oxygen is present �Organic contaminants are rapidly degraded under aerobic conditions by aerobic bacteria called aerobes 11/6/2020 10

AEROBIC DEGRADATION OF BIOPOLYMERS It mainly includes two steps: 1. Complex organic compounds Exoenzyme action Simple adsorbable polymers 2. Simple polymers respiration Basic elements + energy 11

MECHANISM OF AEROBIC DEGRADATION 11/6/2020 12

Tricarboxylic acid (TCA) cycle or the Krebs cycle 11/6/2020 13

Example of the bacteria , which participated in this type of degradation : GRAM NEGATIVE STRAINS GRAM POSITIVE STRAINS Pseudomonas spp. Nocardia spp. Flavobacterium spp. Mycobacterium spp. Xanthomonas spp. Arthrobacter spp. Acinetobacter spp. Bacillus spp. 11/6/2020 14

AEROBIC BIODEGRADATION OF CARBOHYDRATES Lignin, cellulose, hemicellulose, starch, glycogen Hydrolysis (by respective enzymes) Glucose glycolysis Pyruvate Fructose, cellobiose, pentoses fructokinase glycolysis Fructose 1 phosphate TCA cycle CO₂+ water+ energy +growth 11/6/2020 15

Glycolysis 11/6/2020 16

AEROBIC DEGRADATION OF LIPIDS Neutral fats, Phospholipids, Wax Hydrolysis Lipases, phospholipa ses Fatty acids Activation Fatty Acyl Co. A β - oxidation Acetyl co. A CO₂+ water+ energy +growth TCA CYCLE 11/6/2020 17

AEROBIC DEGRADATION OF PROTEINS Proteins Hydrolysis (by Proteases) Aminoacid peptidases Carboxylic acids of Arg, His, Glu, Pro Ala, Thr, Gly, Ser Phe, Tyr, Leu, Trp Phe, Tyr 2 -Oxo glutarate Pyruvate Acetoacetyl. Co A Fumarate Acetyl. Co. A TCA cycle 11/6/2020 CO₂+ water+ energy +growth 18

AN-AEROBIC BIODEGRADATION Ø Anaerobic digestion occurs when the anaerobic microbes are dominant over the aerobic microbes widely used to treat wastewater and biodegradable waste because it provides volume and mass reduction Ø e. g Clostridia, Eubacterium spp. 11/6/2020 19

PROCESS There are four key biological and chemical stages of anaerobic degradation Ø Hydrolysis Ø Acidogenesis Ø Acetogenesis Ø Methanogenesis 11/6/2020 20

STAGES 11/6/2020 21

ORGANISMS INVOLVED Ø Acedogenesis- Clostridium, Eubacterium, Ruminococcu Ø Acetogenesis. Syntrophobacter wolanii Syntrophomonas wolfii Ø Methanogenesis- Methanothrix � Methanosacenia 11/6/2020 22

ANAEROBIC BIODEGRADATION OF CARBOHYDRATES Lignin, cellulose, hemicellulose, starch, glycogen Hydrolysis (by respective enzymes) Monomers (Glucose, Pentoses, Cellobiose) Fermentation Formate, Butyrate, Lactate, etc Acetogenesis Acetate Methanogenesis Methane 11/6/2020 + CO 2 23

ANAEROBIC DEGRADATION OF PROTEIN Proteins Hydrolysis (by Proteases) Aminoacid Deamination NH 3 Organic acids Fermentation Formate, Butyrate, etc Acetogenesis Acetate Methanogenesi s 11/6/2020 Methane + CO 2 24

ANAEROBIC DEGRADATION OF LIPIDS Neutral fats, Phospholipids Inositol, Glycerol, Glucose Fermentation Fatty Acids Glycolipids β- Oxidation Acetyl co. A Acetate Methanogenesis Methane + CO 2 11/6/2020 25

Difference between aerobic and anaerobic biodegradation AEROBIC ANAEROBIC Ø Most rapid and fast Ø Time consuming and degradation. slow Ø No pungent gas Ø Pungent gas produced. Ø More expensive Ø Less expensive Ø Large disposable Ø Less waste is waste generated Ø Microbes are Xanthomonas, Coma Ø Clostridia , Eubacteria monas etc. 11/6/2020 26

Role of Microorganisms in the Recycling of Carbon Bacteria and fungi contribute to the decay of the body.

Microorganisms Found on Corpses Early Stages of decomposition: �Bacillus �Staphylococcus �Candida �Streptococcus Followed by: �Salmonella �Cytophaga �Agrobacterium Bacillus Salmonella