北京大学：《微生物学》课程PPT教学课件（英文版）Biodegradation of xenobiotics

Biodegradation of xenobiotics DDT: dichloro phenyttrichioroethane P-SCHCOOCH Xenobiotics are chemically CH2?H synthesized compounds that Malathion, mercaptosuccinic adid diethyl ester have never been existed OCH COOH Cl naturally See of add tiona Cl.T 24-D, 2,4-dichlorophenaxy acetic acid Pesticides (he herbicides (a chlorophenoxy acetic acid derivative) insecticides, and fungicides) are xenobiotics that desired ChS CH to be degraded b Atrazine, 2-chloro-4-ethylamino-6-isopropylaminotriazine (a trazine derivative) microorganisms H N-C-N CHa Monuron: 3-(4-chlorophenyl)-1, 1-dimethylurea (a substituted urea)

Biodegradation of xenobiotics Xenobiotics are chemically synthesized compounds that have never been existed naturally. Pesticides (herbicides, insecticides, and fungicides) are xenobiotics that desired to be degraded by microorganisms

Biodegradation of 2x107 herbicide 2.4.5-T Growth by burkholderia Cells/ml 5x 106 Chlonide released (%) cepacia 2x10 Time(days) Cr CI OH OH 0 cetate C Dioxygenase H OH 24.5T 2, 4, 5-T: 2, 4,5-trichlorophenoxyacetic acid

Biodegradation of herbicide 2,4,5-T by Burkholderia cepacia 2,4,5-T: 2,4,5-trichlorophenoxyacetic acid

Polyethylene -CH2-CH PHB/HV Biodegradable -CH2-CH Polymers Polypropylene CH Most Polyvinyl chloride CHCI synthesized PVC polymers are not Polystyrene -CH2-CH(CgHs- SANARA biodegradable, only microbial Polyurethane R,-NH-Co-O-R2 fatit silte featur fit tichitt polymers PhA Institut are truly Teflon -CF2-CF2 biodegradable Cellulose C6H,O5(OC-CH3)3 tate fit tftt sellate frititatIt Silicones R

Biodegradable Polymers Most synthesized polymers are not biodegradable, only microbial polymers PHA are truly biodegradable PHB/HV

Plant-Microorganism Interactions Lichen consisting of two organisms: a fungus and an alga: Algae or cyanobacteria grow phototrophically and provide nutrient for the fungus, which offers a firm anchor and inorganic nutrient for the alga algae

Plant-Microorganism Interactions Lichen consisting of two organisms: a fungus and an alga: Algae or cyanobacteria grow phototrophically and provide nutrient for the fungus, which offers a firm anchor and inorganic nutrient for the algae

A cross section through a lichen Algal layer Fungal hyphae Rootlike connection to substrate

A cross section through a lichen

Mycorrhizae: the symbiotic association between plant roots and fungi US rhizomorphs Forked mycorrhiza

Mycorrhizae: the symbiotic association between plant roots and fungi

Effect of mycorrhiza on plant growth Left: nonmycorrhizal Right: mycorrhizal The plants are Six- month-old seedling of Monterey Pine growing in praire soil

Effect of mycorrhiza on plant growth Left: nonmycorrhizal Right: mycorrhizal The plants are six￾month-old seedling of Monterey Pine growing in praire soil

Agrobacterium and Plant Interactions Crown gall and Hairy root Crown gall: caused by Agrobacterium tumefaciens which carries a Ti(Tumor induction) plasmid that promotes the crown gall formation Hairy Root: caused by Agrobacterium rhizogenes which carries a Ri plasmid that leads to hairy roots formation

Agrobacterium and Plant Interactions: Crown gall and Hairy Root Crown gall: caused by Agrobacterium tumefaciens which carries a Ti (Tumor induction) plasmid that promotes the crown gall formation Hairy Root: caused by Agrobacterium rhizogenes which carries a Ri plasmid that leads to hairy roots formation

Tumongenesis on by T-DNA int plant genome Overview of events of crown gall disease Agrobacterium cell following infection of Ofnplasn A tumefaciens Transter of T-DNA to plant cell TDNA Processing of T-DNA from T plasmid

Overview of events of crown gall disease following infection of A. tumefaciens

Ti plasmid of Agrobacterium tumefaciens T-DNA onc Ops Tr stability genes pine catabolism genes genes

Ti plasmid of Agrobacterium tumefaciens