Advanced Water Management Centre

AWMC Seminar Program: Frauke Kracke & Dr Guangming Jiang

Microbial Electrosynthesis - Electrical enhanced Systems for Bio Production (Frauke)

Abstract: Microbial electrosynthesis is an emerging technology that aims to improve bio production processes by optimizing the cellular redox balance. In so called bio-electrochemical systems electrons are exchanged between microbes and solid state electrodes. This technique becomes particularly exciting when using autotrophic organisms such as acetogens as the electron feed facilitates fixation of carbon dioxide from waste gases regardless of their hydrogen content.

While the concept is known for decades major knowledge gaps remain, which make it hard to evaluate its biotechnological potential. This project aims to provide insight into microbial physiology during electrically enhanced fermentations for production and therefore evaluate benefits and limitations of the technique. Stoichiometric network analysis is used to identify potential target processes for microbial electrosynthesis and study the involved metabolic processes. Since the fundamentals of microbe-electrode interactions have not been fully understood yet, different electron transfer options are proposed and in silico evaluated by their impact on growth and achievable product yields. Promising systems are tested in vivo in bio-electrochemical systems for optimization of production.

Title: Microbial Corrosion of Concrete Sewers with Wastewater Inoculation (Guangming)

Abstract: Frequent occurrences of wastewater inoculation is important for the development of microbial corrosion in concrete sewers. The wastewater can bring complicated effects of acid neutralization, wash-off of corrosion layer and biofilms scouring in addition to the microbial inoculation. This study comprehensively evaluated the impacts of different types of wastewater inoculation (flooding and spraying) on the corrosion development through a long-term (1.5 years) experiment using two types of concrete and two levels of hydrogen sulfide. It was found that wastewater inoculation increased the mass losses of concrete. However, the long-term effect could not be captured by measuring surface pH and sulfide uptake rate, which are instantaneous measurements. The microbial community, mainly composed of sulfide oxidizing bacteria, was found to change significantly due to the different inoculation approaches, and this is dependent on the types of concrete and the levels of hydrogen sulfide.

Event Details
Date & Time: 
Friday, 16 October 2015
9am - 10am
Venue: AIBN Building 75, Level 1 Seminar Room
  • Frauke Kracke
  • Dr Guangming Jiang

Event Contact: