We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Mineralization and microbial utilization of poly(lactic acid) microplastic in soil
AI summary Read the abstract
Researchers tracked how polylactic acid (PLA) microplastics, a common biodegradable plastic, actually break down in different agricultural soils. They found that standard testing methods significantly overestimate how quickly PLA degrades because they fail to account for interactions with soil organic matter. The study reveals that PLA microplastics may persist longer in some soils than previously thought, raising questions about how truly biodegradable these materials are in real-world conditions.
The current carbon dioxide (CO) evolution-based standard method for determining biodegradable microplastics (MPs) degradation neglects its priming effect on soil organic matter decomposition, which misestimates their biodegradability. Here, a C natural abundance method was used to estimate the mineralization of poly(lactic acid) (PLA) MP in various agricultural soils, and to trace its utilization in different microbial groups. In alkaline soils, the PLA-derived CO emissions increased with increasing soil carbon/nitrogen (C/N) ratios, and the mineralization of PLA MP concentrations ranged from 3-33 %, whereas the CO evolution method probably over- or under-estimated the mineralization of PLA in alkaline soils with different soil C/N ratios. Low PLA mineralization (1-5 %) were found in the acidic soil, and the standard method largely overestimated the mineralization of PLA MP by 1.3- to 3.3-fold. Moreover, the hydrolysate of PLA MP was preferentially assimilated by Gram-negative bacteria, but Gram-positive bacterial decomposition mainly contributed to the release of PLA-derived CO at low MP concentrations (≤ 1 %). Overall, the C natural abundance method appears to be suitable for tracking the mineralization and microbial utilization of biodegradable PLA in soils, and the PLA-derived C is mainly assimilated and decomposed by bacterial groups.
More Papers Like This
Transformation of Polylactic Acid (PLA) Microparticles in Soil and their Effects on Soil Properties: A Review
AI summary Read the abstract
This review examined how polylactic acid (PLA) microplastics transform in soil over time and affect soil physical, chemical, and biological properties including pH, organic matter, nutrient cycling, and microbial communities, highlighting the complexities of PLA as a supposedly biodegradable agricultural plastic.
Determining the impact of common microplastic extraction methods from soil matrices on the biodegradable polymers polylactic acid and polyhydroxybutyrate
AI summary Read the abstract
Researchers tested whether standard lab methods used to extract microplastics from soil samples inadvertently degrade biodegradable plastics like polylactic acid (PLA) and polyhydroxybutyrate (PHB) before they can be measured. They found significant degradation, particularly of PLA when exposed to the enzyme protease, meaning common soil extraction protocols may undercount biodegradable plastic fragments and give a false impression of how completely these materials break down in nature.
Bioplastics in agricultural soils: Biodegradability, analytical techniques, and soil microbial impact
AI summary Read the abstract
Researchers reviewed the evidence on how bioplastics degrade in agricultural soils, finding that commonly used analytical techniques overestimate biodegradation rates because they measure surface changes rather than full carbon mineralization, meaning biodegradable microplastic residues may persist across seasons under realistic conditions.
Hydrolyzable microplastics in soil—low biodegradation but formation of a specific microbial habitat?
AI summary Read the abstract
Hydrolyzable microplastics such as polylactic acid showed low biodegradation in soil despite their marketed degradability, while their surfaces hosted distinct microbial communities forming a specialized plastisphere. The study questions the environmental safety of biodegradable plastics in agricultural soil contexts.
Impact of moisture on the degradation and priming effects of poly(lactic acid) microplastic
AI summary Read the abstract
Researchers examined how soil moisture levels affect the degradation of biodegradable poly(lactic acid) microplastics and their influence on soil organic carbon decomposition. The study found that moisture significantly increased PLA degradation in acidic soils, and PLA induced both positive and negative priming effects on native soil carbon depending on moisture levels and soil type.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.