Ms. Penelope Galbraith

Ms. Penelope Galbraith

Postgraduate Student
Department of Civil Engineering
Room 222, Building 69, Monash University, Clayton, VIC, 3800, Australia

Penelope completed her Bachelor of Arts/Science (Hons) at Monash University, 2015. After working as a research assistant at Monash University in the Environmental and Public Health Microbiology (EPHM) laboratory, Civil Engineering (2015-2016), she commenced her PhD under the supervision of Assoc. Prof. David McCarthy and Dr. Rebekah Henry (2016).


  • Honours Degree of Bachelor of Science, Monash University, 2014
  • Bachelor of Science (Microbiology and Biochemistry), Monash University, 2014
  • Bachelor of Arts (Geography & Environmental Science), Monash University, 2015

Research Interests

Biofilters and WSUD, water decontamination, plant sciences, microbiology, molecular biology, interdisciplinary environmental sciences, microbial source tracking, public health

Research Projects

Current projects

The Antimicrobial Influence of Plants and Autochthonous Microorganisms on Pathogen Die-Off in Stormwater Biofilters

Stormwater represents a valuable alternative fresh water resource. Prior to reuse, stormwater must undergo treatment for the removal of pollutants of concern to human health, the most significant of which are disease-causing faecal microorganisms (faecal pathogens). Biofilters are low-cost, low-energy soil-plant based water treatment systems that have demonstrated promising results in reducing faecal pathogen concentrations in stormwater. However, removal rates are unreliable under certain operational conditions, representing a key impediment to their uptake by urban water managers.

Biofilter vegetation is an under-researched yet significant design component that influences pathogen removal from stormwater. Preliminary research has demonstrated that certain plant species (Melaleuca, Leptospermum spp.) can improve reductions in faecal microorganism loads relative to the vegetation gold standard Carex appressa. Nevertheless, the exact mechanisms by which plants enhance pathogen removal are unknown. It is hypothesised that biotic processes moderated by plants, particularly the biogenesis of antimicrobial compounds, may account for the observed differences in removal between species.

Thus, the overall aim of this project is to investigate the influence of vegetation on the survival/die-off of faecal microorganisms in stormwater biofilters. Specific reference will be made to the importance of the key mechanisms by which plants mediate antibiosis, namely: (a) deposition of plant debris/litter; (b) subsurface root exudation; and (c) fostering antimicrobial-producing soil microorganisms. The antimicrobial impacts of these vegetation-modulated biotic factors will be addressed by conducting both in vitro and lab-scale biofilter column experiments. Emphasis will be placed on (a) antimicrobial testing of biofilter vegetation (leaves and root exudates); (b) metabolomic profiling of biofilter vegetation root exudates; and (c) metagenomic profiling of microorganisms in planted systems. Addressing these knowledge gaps will help inform vegetation guidelines to optimise biofilter design for pathogen removal in existing and emerging passive vegetated stormwater treatment systems.

Henry R, Galbraith P, Coutts S, Prosser T, Boyce J, McCarthy DT (2018). What’s the risk? Identifying potential human pathogens within grey-headed flying foxes faeces. PLoS ONE, 13(1).

Galbraith P, Henry R, McCarthy DT (2019). Rise of the killer plants: investigating the antimicrobial activity of Australian plants to enhance biofilter-mediated pathogen removal. Journal of Biological Engineering, 13(52).



Kathleen Strumila
How do root exudates influence faecal microorganism die-off in stormwater biofilters?
2018 to 2018

Jiayi Zheng
Optimisation and validation of stormwater biofilter vegetation for the removal of faecal microorganisms
2018 to 2018

Raghav Rana
The effect of plant type, temperature and drying period on microbial removal in stormwater biofilters
2019 to 2019

Teaching Commitments

  • CIV4268 - Water Resources Management
Last modified: June 7, 2019