National University of Singapore scientists have discovered a biodiverse bacteria thriving on microplastics across Singapore's beaches and coastal regions. This team of researchers determined that some bacteria are pathogenic that can cause damages to corals as well as infecting open wounds. The researchers also discovered some potentially useful bacteria alongside the harmful ones. Some of these can perform oil and plastic biodegradation.
Microplastics are small pieces of plastic that have a length of less than 5 mm occurring in the environment because of plastic pollution.
"Microplastics form a large proportion of plastic pollution in marine environments," said marine scientist Sandric Leong, a Senior Research Fellow at the NUS Tropical Marine Science Institute (TMSI), who was the senior author of the "Profiles of bacterial assemblages from microplastics of tropical coastal environments."
Microplastics are unique as a habitat as they are very common with 150 million tons of plastics in the ocean. Plastics, with a degradation rate of tens of thousands of years, make great habitat.
Researches about marine plastic pollution are at their early stage. It was only recently that scientists discovered that marine species are attracted to the food-smelling characteristic of marine plastics.
"Marine organisms may consume bits of microplastics unintentionally, and this could lead to the accumulation and subsequent transfer of marine pathogens in the food chain," Dr. Leong said.
Microbial elements that thrive on marine plastic pollutants
Dr. Leong and Emily Curren, an NUS Faculty of Science Ph.D. student, gathered microplastics from Singapore's beaches and coastal regions from April to July 2019. They obtained 275 microplastic particles from Sembawang Beach, Lazarus Island, and Changi Beach. These microplastics were subjected to throughout sequencing of 16S rRNAs and was able to determine the genus species of these 400 bacteria.
"Bad" bacteria identified
Photobacteriuam rosenbergii was identified and this species is related with coral bleaching and disease. The significance of this discovery is related with the restoration efforts of marine habitata and coral reef conservation along Singapore Strait.
Some marine Vibrio species known to cause wound infection in humans and Arcobacter species that cause gastroenteritis were identified along the beaches.
"Good" bacteria identified as well
Pesudomonas veronii and a variety of Erythrobacter species were also identified. The former helps clean up oil spills while the latter can help in plastic degradation.
"Given the predicted increase in plastic waste contamination in oceans, the discovery of such bacteria provides important nature-friendly alternatives for the mitigation of plastic pollution and toxic pollutants such as hydrocarbons," Ms. Curren pointed out.
