陈超宇 严冬勤 王巧燕 鲍铮铮 钱薇 胡燕燕 王小燕 赵新景

Pollutants Chemic pollutants Physical pollutants Biologic pollutants Organic pollutantspollutants Inorganic pollutants

Pollutants Microorganisms artificial inartificial Organic pollutantspollutants Have the super power to destroy… Why???

Potential of the microorganisms Diversity in species Large number Diversity in metabolizing Distributing abroad The basic characteristics So they can deal with the great number of the various inartificial pollutants successfully

Potential of the microorganisms A big family

Potential of the microorganisms

To the artificial pollutants ? artificial pollutants ☆ in larger number ☆ more kinds ☆ increase at a great speed both in number and kind ☆ new to the world (microorganisms) … … Harder to degrade MicroorganismsMicroorganisms?

Potential of the microorganisms More characteristics ◎ resistance to environmental stresses ◎ small ◎ reproduce at a fast speed and in different ways ◎ simple structure ◎ easy to aberrance( 变异 ) Have the Potential to deal with the artificial pollutants

Potential of the microorganisms

Iron deposit in an unidentified bacterium stained with phenol cotton blue. Isolated from basin of a utility plant cooling tower

Potential of the microorganisms What will the microorganisms do ? mutation (form new kinds) inducement (form new enzyme system) Human need and could enhance their ability (u will c later…)

constitution of engineering bacteria Two methods : 1) Plasmid-assisted molecular breedingPlasmid-assisted molecular breeding 2) Genetic engineering breedingGenetic engineering breeding What ???

Plasmid Plasmids are small double-stranded DNA molecules. usually circular, that can exist independently of host chromosomes and are present in many bacteria. Plasmids can transfer copies of themselves to other bacteria during conjugation

Plasmid conjugative plasmid transfer integrative plasmid transfer recombinant plasmid transfer Two methods Plasmid-assisted molecular breeding Genetic engineering breeding transfer of plasmids artificial inartificial Hybridization of plasmid

Genetic engineering breeding Gene isolation DNA recombine Transfer by carrier Copy and expression Filtration and breeding

Genetic engineering breeding

Biodegradability of organic pollutants Biodegradation of the organic pollutants How to Assess that (biodegradability)? Easy? Hard?

Biodegradation Biodegradation is the breakdown of organic contaminants that occurs due to microbial activity. Biodegradation of any organic compound can be thought of as a series of biological degradation steps or a pathway that ultimately results in the oxidation of the parent compound.

Biodegradability Assessment Three methods: Assessed by the character of basic matter Assessed by breath rate Assessed by Bio-oxidation rate

Biodegradability Assessment Menstruate the character of organic pollutants, such as BOD 5,COD,VS,TS, the biodegradation can be assessed by the rate of BOD 5 /COD, and VS/TS Normally, the ratio BOD/COD is approximately 0.5. when this ratio falls below 0.3, it means that the sample contains large amounts of organic compounds that are not easily biodegraded. 1.Assessed by the character of basic matterbasic matter

the character of basic matter BOD (Biochemical Oxygen Demand) is the amount of dissolved oxygen consumed by microorganisms during the biochemical oxidation of organic and inorganic matter. BOD 5 (the 5-day BOD test) is a measure of the amount of oxygen consumed by a mixed population of heterotrophic bacteria in the dark at 20oC over a period of 5 days. COD (Chemical Oxygen Demand) is the amount of oxygen necessary to oxidize all of the organic carbon completely to CO 2 and H 2 O..

Biodegradability Assessment 1.Assessed by the character of basic matter The relationship between BOD 5 /COD and Bio-oxidation rate BOD 5 /COD >0.40.4~0.30.3~0.2<0.2 Bio-oxidation rate fastnormalslowVery slow

Biodegradability Assessment Bio-oxidation rate=————————————*100% 2. Assessed by Bio-oxidation rate oxygen needed when the stroma be decomposed by microorganism oxygen needed to totally decompose the stroma

Biodegradability Assessment The date should be compared in the same condition,for example, the same environment and activated sludge toluene53 vinly acetate( 醋酸 乙烯酯 ) 34 benzene24 ethylenediamine ( 乙二胺 ) 24 mineral acid5 Bio-oxidation rate(%) 2. Assessed by Bio-oxidation rate

Biodegradability Assessment 2. Assessed by Bio-oxidation rate 华氏呼吸仪

Biodegradability Assessment 3. Assessed by the graph of the breath rate Red : Exogenous respiration line Blue : Endogenous respiration line (1)Indicate that the polluted water is not poisonous to the microorganisms, and the organic pollutants isn’t biodegradable (2)Indicate that the polluted water has the disadaptive toxicity to the microorganisms, and the larger the interval between the two lines, the more poisonous of the water.

Biodegradability Assessment 3. Assessed by the graph of the breath rate (3)Indicate that the polluted water is biodegradable. And the larger the interval between the two lines, the better of the biodegradability of the organics. (4)Indicate that the polluted water is poisonous to the microorganisms at certain degree, with culturing time going, the microorganisms can adjust to the environment quickly, and destroy the pollutants.

Connection between biodegradability and chemical structure The complexity of chemical structure, the character and position influence the biodegradability.

An example of degradation by microorganisms Aromatics compounds Aromatics compounds contain at least one unsaturated ring system with the general structure C 6 H 6, where R is any functional group. Under aerobic conditions, the most common initial transformation is a hydroxylation that involves the incorporation of molecular oxygen. the enzymes :monooxygenases or dioxygenases.

Transferring way In general, prokaryotic microorganisms transform aromatics by an initial dioxygenase attack to cis-dihydrodiols. The cis-dihydrodiols is rearomatized to form a dihydroxylated intermediate, catechol. The catechol ring is cleaved by a second either between the two hydroxyl groups (ortho pathway) or next to one of the hydroxyl groups (meta pathway) and further degraded to completion.

Transferring way Under aerobic conditions ( take benzene for example )

Transferring way

Other Compounds degradation Paths Define: Compounds containing two or more fused benzene rings are called poly-aromatic hydrocarbons. Containing ： naphthalin 、 anthracene 、 phenanthrene 、 indene…those can lead to cancer 、 abnormality and mutation.

Metabolizing way of PATHS is similar with that of aromatics compounds