Characterizing the impact of invasive species on microbial biofilms

• Main Author: Toh, Jerlin Sher Ying
• Other Authors: Scott Rice
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Science::Biological sciences
• Online Access: https://hdl.handle.net/10356/143303
• Institution: Nanyang Technological University

In recent years, the study of emergent properties of mixed-species biofilms and how they may be superior to mono-species biofilms have garnered great interest amongst researchers. One emergent property that has been highlighted in extant literature is the stability of these mixed-species biofilms, given its critical role in maintaining the normal functioning of the ecosystem. In the face of disturbance, multi-species biofilms provide stability in terms of proportion of resident species and biomass production. This study aims to focus on the stability of single- vs dual-species biofilms of Pseudomonas aeruginosa alone or in combination with Pseudomonas protegens following pulse and press disturbance by an environmental and a pathogenic K. pneumoniae strain. Our results indicated that a more diverse biofilm conferred enhanced resistance to invasion by the environmental strain, but not to the pathogenic strain. This highlights the difference in biofilm community invasiveness between the both strains. However, the prolonged disturbance of the community by the environmental K. pneumoniae strain enabled it to overcome the complexity of the resident biofilm to cause disturbance. These results suggest that the invader could utilize available nutrients better than the resident species, or invader-secreted anti-microbial compounds were able to inhibit growth of the resident species.