Research | gamzegulez

Research Vision

My vision is to develop solutions, inspired by and in harmony with nature, for establishing a truly ecological, self-sustaining, self-organized society. That is why as an environmental engineer and microbial ecologist I have been interested in understanding complex adaptive microbial systems and how they could shape our future. I am especially interested in biofilms, which are surface attached microorganisms embedded in extracellular matrix. Due to their unique features, such as closely living cells giving rise to many interactions, biofilms are suitable models to study the complexity of microbial life. Moreover, their existence on almost any surface or interface increases their importance not only in environmental science and engineering practices but also in medical science, public health, material science, art, and even future fashion design.

Research Projects

Bacterial Dispersal via Fungal Hyphae (mycelium) on Food Surfaces

Bacteria can rapidly colonize a surface by exhibiting flagellar motility, which is hindered under water-limited conditions. However, bacteria in nature and other settings, like the cheese surface, interact with other microorganisms, which can also facilitate bacterial dispersal. Indeed, in water-limited soil, bacteria use thin water films on the fungal hyphae (filaments making up the mycelium) for dispersal through the water deprived pores. Hence, this project aims to quantify flagellar motility mediated dispersal of bacteria via fungal hyphae on surfaces as a function of water potential (solute and matric potential components) and to determine its effect on bacterial-fungal (metabolic) interactions, adaptive stress responses and underlying mechanisms on food surfaces.

(2021-present. Wageningen University Research)

Dry Biofilms on Food and Food Processing Surfaces

Dry biofilms, like wet biofilms, can act as the reservoir of pathogens and other undesirable microorganisms. Compared to wet biofilms, they are more resistant to antimicrobials and disinfectants. Dry biofilms may also play a role in the spread of antibiotic resistance genes.This projects aims to investigate formation of dry and/or partially hydrated bacterial biofilms on food processing surfaces. Emphasis will be on how mechanical and material properties of biofilms change upon drying and how that affects ecological, physiological, molecular levels responses and resistance to cleaning agents/disinfectants.

(2021-present. Wageningen University Research)

The Ecology of Stream Biofilm Morphogenesis

The project is about understanding pattern formation in stream biofilms as certain patterns may affect biogeochemical functions and resilience of microorganisms in those habitats. Within that context, I am investigating how microbial cells self-organize into specific patterns under nutrient limitation and different flow velocities using microfluidic devices. With microfluidic devices I am able to create laminar flow conditions similar to microenvironments of stream biofilm and also make real-time microscopic observation of biofilm formation at a single cell resolution.

(Postdoctoral Scientist, 2015-2017. Swiss National Science Foundation, PI: T. Battin,École Polytechnique Fédérale de Lausanne, Switzerland, 2015-2017)

Biofilm Formation on Bio-inspired Self-Cleaning Surfaces

Developing anti-fouling materials is important to prevent bacterial growth on food packaging, medical implants, or drinking water filtering systems. Inspired by nature's own anti-fouling features offers a possibility to produce "self-cleaning" surfaces. In this collaborative project, I designed experiments for the MS student N.Constantin to test bacterial biofilm formation on the surfaces which are produced by mimicking the surface structures of lotus leaves and other plant species.

(2016-2017. collaboration with Y. Leterrier, Material Science & Engineering, N.Constantin, School of Life Sciences, and T. Battin, Insitute of Environmental Engineering, École Polytechnique Fédérale de Lausanne, Switzerland)

The Drinking Water Microbiome and Human Health: Polymicrobial Units of Respiratory Significance in Drinking Water Systems

The project was about establishing the link between drinking water microbiome and airway microbiome of Cystic Fibrosis patients, as it was suspected CF patients get infected by bacteria distributed by the water supply systems. Under this context, I prepared the initial sampling and experimental plan for premise plumbing and the questionnaire for Cystic Fibrosis patients about their health, life habits and the conditions of their premise plumbing

(Postdoctoral Researcher, Summer 2013. MCubed-University of Michigan Internal Funding, PI: L.Raskin, University of Michigan, Ann Arbor, USA)

Role of Water Connectivity On Bacterial Growth & Pollutant Removal In Unsaturated Conditions

This project focused on understanding physical limitations to pollutant biodegradation in soil. Using an experimental platform named porous surface model (PSM), which simulates water limited conditions as experienced in soil habitats I tested how water limitation affected bacterial swimming motility. By redesigning the PSM to be operated under more environmentally relevant conditions I determined the changes in the bacterial gene expression profile to find about their adaptive responses . I also studied the role of extracellular polymeric substance (EPS) in bacterial survival, adaptation strategies and surface colonization under water limitation. More specifically, I investigated changes in bacterial colony morphologies and gene expression profiles in the presence and absence of EPS under water limited conditions.

(Research Assistant, 2007-2008; PhD Researcher, 2008-2011; Postdoctoral Researcher, 2011-2012. DTU, RECETO and Villum Kann Rasmussen Foundation, PI: B.Smets, Technical University of Denmark, Denmark )

Application of Municipal Solid Waste Decision Support Tool to Wake County, North Carolina

Within this project, I evaluated different waste management scenarios using a life cycle analysis based multi-criteria optimization decision support model.

(Graduate Researcher, 2005-2006. US Environmental Protection Agency, PI: R.Ranijthan, M. Barlaz, North Carolina State University, USA 2005-2009)

Molecular and Engineering Approaches for Analyzing Microbial Selection in Activated Sludge: Competition between Filaments and Floc-formers

Filamentous bacteria are associated with operational problems in activated sludge, a biological wastewater treatment process. Within that respect, I tested different carbon and inoculum sources to select filamentous bacteria in lab scale reactors and compared the effectiveness of molecular biology vs traditional microbiology methods in the identification of these bacteria

(Graduate Researcher,2003-2005. National Science Foundation, PI: F. L. de los Reyes III, North Carolina State University, USA, 2001-2007)

Removal of Halogenated Compounds with Sequential (Anaerobic/Aerobic) Biological Systems

I performed 'Anaerobic Toxicity Assay' to assess the anaerobic biodegradation of pentachlorophenol, which is a commonly used toxic pesticide.

(Undergraduate Researcher, Summer 2000. The Scientific and Technical Research Council of Turkey, PI: G. Demirer, Middle East Technical University, Turkey, 1998-2001)