Bioaugmentation Dhanya.O.G2020-10-114

Bioaugmentation

practice of adding actively growing, specialized microbial

strains into a microbial community (indegenious)in an effort to enhance the ability of the microbial community to respond to process fluctuations or to degrade certain compounds, resulting in improved treatment.

Bio augmentation is defined as the addition of bacteria, nutrients, and other growth factors to enhance the bioremediation process

steps

studying the indigenous varieties present in the location to determine if biostimulation is possible.

If the indigenous variety do not have the metabolic capability to perform the remediation process, 

exogenous varieties with such sophisticated pathways are introduced.

• Abiotic stress factors influencing the growth of the species in consideration.

• Properties of microbes - microbial interaction - microbial diversity - metabolic activity - survival and tolerance to high conc. of contaminants

Factors influencing……

bio augmentation requires total system management by controlling the key system parameters such as pH, temperature and oxygen levels. Addition of nutrients to ensure good growth and a healthy population

Applications…

Bioaugmentation – waste water treatment

• Bioaugmentation is commonly used in municipal wastewater treatment to restart activated sludge bioreactors.

eg.Penicilliumsp.,Aspergillussp., Flavobacterium, Arthrobacter, Pseudomonas

• advantages over traditional technology•no need of - chemicals, equipments, or other consumables, and has been used in secondary wastewater treatment systems for decades.(cost effective).•Bioaugmentation is easy-to-use, no operational difficulties•Bioaugmentation improves plant efficiency

Bioaugmentation of chlorinated solvents- soil treatment

Bioaugmentation –tetrachloroethylene and trichloroethylene in soil

ethylene and chloride (non toxic)• Other than chlorinated ethane, it is potential to biodegrade other

compounds including BTEX,chloroethanes, chloromethane, and MTBE.

• Bioaugmentation is typically performed in conjunction with the addition of electron donor (biostimulation) to achieve geochemical conditions in groundwater that favor the growth of the dechlorinating microorganisms in the bioaugmentation culture.

Others…

probioticsanimal feed -Direct fed microbials enhance the natural microbial community in the gut of animals, improving digestionAgriculture -Improved Nitrification , adding nitrifying bacteria eg.Nitrosomonasodour suction production of valued resourcesBy-products of this natural process include water, carbon dioxide and bacterial biomass which is rich in protein,-organic waste in to valued resources.

Different Approaches for Use of Bioaug-mentation as a Remediation Technology

Bioaugmentation approach Organism(s) used Contaminant(s)

 

Cell culture

Comamonas Ralstonia eutropha

3-Chlorobenzoate Cadmium

Phytoaugmentation  Arabidopsis thaliana 

 

methylmercury

Immobilized Alcaligenes faecalis .

phenol

Problems ..Number of exogenous microorganisms decreases shortly after addition to the site due to• competition from indigenous organisms for limited nutrients,• antagonistic interactions - antibi-otic production by competing organisms, • predation by protozoa and bacteriophages.• biotic as well as abiotic stress

Difficult to deliver the inoculant to the desired location

Bioaugmentation future concern• Novelmethods to increase survival of microorganisms inoculat

ed into contaminated sites• The development of genetically engineered microorganisms

with increased remediation capabilities;

• use of reporter genes to monitor the activity and/or presence of introduced microorganisms;

• use of suicid egenes to control the spread of genetically engineered microorganisms

• plant-based technologies for delivering remediation genes to a contaminated sites