Influence of environmental changes on growth and biofilm formation of potentially pathogenic bacteria isolated from plastic debris

Mariana Arango Saavedra

Studenteropgave: Speciale


Infectious diseases are estimated to be the cause of approximately 25% of deaths reported annually worldwide. The re-emergence and outbreaks of waterborne diseases in tropical countries have been correlated to an increase in temperature and severity in rainfalls, which tend to follow seasonal periods. These climatic phenomena are expected to rise as a consequence of climate change. It has also been suggested that the incidence of this type of infections is influenced by the lack of proper waste management and poor sanitation conditions. Taking into account the increase of plastic waste production that leads to the accumulation of plastic litter among diverse ecosystems and the ability of potentially pathogenic bacteria to form strong binding in the surface of plastic particles, it is of particular interest to gain understanding on the relations between plastic debris and bacteria. In order to evaluate the risk that contact with plastic litter pose to human health, potentially pathogenic bacteria were isolated from plastic waste samples collected in Zanzibar. Vibrio cholerae was successfully isolated and identified in one of the plastic samples, and its growth rate and biofilm development was investigated under different salinity concentrations and temperatures to estimate the impact of climate change on the survival of this bacteria. Growth rate increased at warmer temperatures and decrease at lower temperatures and lower salinities. On the other hand, biofilm formation was more influenced by temperature than by salinity and higher biofilm densities were found at high temperatures and high salinity concentrations. These results suggest the potential of plastic to enhance the survival of pathogenic bacteria and underline the urgency of implementing effective waste managements controls to reduce human contact with plastic litter.

UddannelserMiljøbiologi, (Bachelor/kandidatuddannelse) Kandidat
Udgivelsesdato3 jun. 2019
Antal sider55
VejledereKristian Syberg & Lotte Jelsbak