Plastisphere

Plastic marine debris, most notably microplastics, accumulates in aquatic environments and serves as a habitat for various types of microorganisms, including bacteria and fungi.

[11] The researchers used a combination of scanning electron microscopy and DNA sequencing to identify the distinct microbial community composition of the plastisphere.

[19] Plastic that does not reach a recycling facility or landfill, accumulates in marine environments due to accidental dumping of the waste, losses during transport, or direct disposal from ships.

[22] Scientists have found that microbial biofilms can form within 7–14 days on plastic film surfaces, and have the ability to alter the chemical properties of the soil and plants that we are ingesting.

[25][26][27][28] Polymer film fragments affect microbes in different ways, leading to mixed effects on microbial growth rates in the plastisphere.

[25] The bacterial and microbial communities in the plastisphere are significantly different from those found in surrounding soil samples, creating a new ecological niche within the ecosystem.

[25][28][33] In another study which looked at the factors influencing the diversity of the plastisphere, the researchers found that the highest degree of unique microorganisms tended to favor plastic pieces that were blue.

[34] A 2024 paper described an experiment carried out across the Atlantic Ocean and the Mediterranean Sea aimed at studying the colonisation and genetic variety of organisms in the marine plastisphere.

Phyla of bacteria that have increased presences in the plastisphere relative to soil samples without plastic micro-fragments include Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Planctomycetes, and Proteobacteria.

[25][44][45][46][47][48][49][50] Specific bacterial phyla present in the plastisphere due to their biodegradation abilities and their role in the carbon, nitrogen, and phosphorus cycles include Proteobacteria and Bacteroidetes.

[57] However, as plastic is broken down into smaller pieces and eventually microplastics, there is a higher likelihood that it will be consumed by plankton and enter into the food chain.

[19] and 90% bran in comparison to meal worms who were exclusively fed PS[63] Oftentimes the degradation process of plastic by microorganisms is quite slow.

[19] Recent work by Li et al. (2023)[69] has continued this effort via the novel approach by combining the PET-degradation capabilities of Ideonella sakaiensis with the saltwater affinity characteristics of Vibrio natriegens.

While this work was strictly laboratory based and at room temperatures, it signifies progress in the effort to develop microorganisms that can decompose micro- and nano-plastics that would otherwise accumulate in terrestrial and ocean environments.