LBEs research activities Christof Holliger September 2018 Two main - PowerPoint PPT Presentation

ENAC – ISTE Laboratory for Environmental Biotechnology LBE’s research activities Christof Holliger September 2018

Two main research topics  Aerobic granular sludge (AGS) for wastewater treatment  Organohalide respiration of chlorinated solvents

Granules are compact biofilm structures

Advantages of AGS • better settling characteristics  easier separation of sludge and water • C, N and P removal within after 1 min of settling one reactor • more compact systems • higher flexibility “Future of wastewater treatment” Source: Water21, April 2013

Understanding aerobic granular sludge systems at the community level granule bacterial community Nitrifiers Denitrifiers Process C-P-N Polyphosphate- parameters nutrient removal accumulating Micro- from wastewater environmental organisms (PAO) conditions Glycogen-accumulating organisms (GAO) Multivariate statistical methods Multilevel correlations

(enhanced) natural attenuation of chloroethenes contamination

The anaerobic respiration hypothesis -0,5 -0,5 0 0 0,5 0,5 (volts) (volts) O 2 to H 2 O O 2 to H 2 O Reduction Reduction CT to CF CT to CF PCE to TCE PCE to TCE DCB to MCB DCB to MCB NO 3 to NO 2 NO 3 to NO 2 DCE to VC DCE to VC SO 4 to H 2 S SO 4 to H 2 S CO 2 to CH 4 CO 2 to CH 4 Ferredoxin red. to ox Ferredoxin red. to ox Oxidation Oxidation NADH to NAD NADH to NAD 0 0 +50 +50 -50 -50 Free energy (kJ/mol of electrons transferred Free energy (kJ/mol of electrons transferred

Tentative model of the tetrachloroethene respiration chain of Dehalobacter restrictus H + /e - = 1.5 H + /e - = 1.5 (measured for Dehalobacter : 1.25±0.2) ( measuredfor Dehalobacter : 1.25 ± 0.2) 2H + 2H + H 2 ½DCE + Cl - ½DCE + Cl - ½PCE ½PCE H + H + Fe Fe 2e - 2e - HynL2 HynL2 Ni Ni Co Co 2e - 2e - Fe-S Fe-S 2H + 2H + HynS2 HynS2 PceA PceA Fe-S Fe-S Fe-S Fe-S Fe-S Fe-S Fe-S Fe-S Fe Fe MKH 2 MKH 2 FAD FAD ? ? ? Fe Fe Fe Fe MK MK ? cyt b cyt b HynC2 HynC2 « PceC » « PceC » PceB PceB 2H + 2H +

 approx. 600 members  Committee:  President (3-years term)  6 sections:  Past president (1y) or  clinical microbiology President elect (2y)  prokaryotic biology  Treasurer  environmental microbiology  Section leaders (6)  mycology  (General secretary)  virology  lay communication  events organized:  Major problem:  2-days Annual Meeting  Financial situation:  1-day Satellite Symposia or ► membership fee specific section events, e.g. payment Swiss Microbial Ecology, ► income < expenses Swiss Virology Meeting