1、welcome,陈超宇 严冬勤 王巧燕 鲍铮铮 钱薇 胡燕燕 王小燕 赵新景,Microorganisms,&,Organic Pollutants,Pollutants,Pollutants,Organic pollutants,Inorganic pollutants,Pollutants,Microorganisms,Organic pollutants,Have the super power to destroy,Why?,Potential of the microorganisms,Diversity in species Large number Diversity in me
2、tabolizing 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,Potential of the microorganisms,To the artificial pollutants ?,artificial p
3、ollutantsin larger numbermore kindsincrease at a great speed both in number and kindnew to the world (microorganisms),Harder to degrade,Microorganisms?,Potential of the microorganisms,More characteristics resistance to environmental stresses small reproduce at a fast speed and in different ways simp
4、le structure easy to aberrance(变异) Have the Potential to deal with the artificial pollutants,Potential of the microorganisms,Potential of the microorganisms,Potential of the microorganisms,Iron deposit in an unidentified bacterium stained with phenol cotton blue. Isolated from basin of a utility pla
5、nt 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 breeding2) Genetic
6、 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 tran
7、sfer,integrative plasmid transfer,recombinant plasmid transfer,Two methods,Plasmid-assisted molecular breeding,Genetic engineeringbreeding,transfer of plasmids,Genetic engineering breeding,Gene isolation DNA recombine Transfer by carrier Copy and expression Filtration and breeding,Genetic engineerin
8、g 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 th
9、ought 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,M
10、enstruate the character of organic pollutants, such as BOD5,COD,VS,TS, the biodegradation can be assessed by the rate of BOD5/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 ar
11、e not easily biodegraded.,Assessed by the character of basic 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. BOD5 (the 5-day BOD test)is a measure of th
12、e 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 CO2 and H2O. .,Biodegradability Assessment,Assessed by the charact
13、er of basic matter,The relationship between BOD5/COD and Bio-oxidation rate,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,Th
14、e date should be compared in the same condition ,for example, the same environment and activated sludge,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,
15、Red : Exogenous respiration line Blue : Endogenous respiration line,(1)Indicate that the polluted water is not poisonous to the microorganisms, and the organic pollutants isnt biodegradable(2)Indicate that the polluted water has the disadaptive toxicity to the microorganisms, and the larger the inte
16、rval 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
17、 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 characte
18、r 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 C6H6 , where R is any functional group. Under aerobic conditions,the most common initial transfor
19、mation 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
20、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),Trans
21、ferring way,Other Compounds degradation Paths,Define: Compounds containing two or more fused benzene rings are called poly-aromatic hydrocarbons. Containing :naphthalin、anthracene、phenanthrene、indenethose can lead to cancer 、abnormality and mutation.,Metabolizing way of PATHS is similar with that of aromatics compounds,谢谢观赏,