Research on the consumption and degradation of plastics by Zophobas atratus larvae
Author of the article:LI Chen-Jing;WANG Zhe;ZHANG Ya-Lin
Author's Workplace:Key Laboratory of Plant Protection of Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China;Key Laboratory of Plant Protection of Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China;Key Laboratory of Plant Protection of Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China
Key Words:polystyrene; polyethylene; growth and development; plastic degradation; gut microbiota
Abstract:
[Objectives] The consumption and breakdown of plastic waste by insects has been a
popular research topic in recent years. We investigated the growth and
development of Zophobas atratus larvae, changes in its gut microbiota
and the molecular weight of plastics consumed by these larvae, in order to provide
a foundation for further research on plastic degradation by this species. [Methods] Larvae were fed either polystyrene or
polyethylene foam, and their survival rate, weight and pupation rate were
measured and compared. The molecular weight of plastics after passing through
the guts of larvae was analyzed with gel permeation chromatography and the gut
microbiota of larvae fed on plastics, and their relationship to pail-based
plastics, were analyzed using Beta diversity, community composition and PICRUSt
function prediction. [Results] The survival rates of larvae fed on
polystyrene or polyethylene foam were (58.67 ± 4.04)% and (62.50 ± 5.27)%, respectively, after 25 days, compared to
(84.50 ± 0.87)% for the bran-fed control group. No
significant increase in larval weight occurred in larvae that fed on plastics,
nor did these larvae pupate. The molecular weight of polystyrene decreased
after being digested by the larval gut, whereas that of polyethylene increased.
The relative abundance of bacteria associated with plastic degradation
increased in the guts of the larvae that fed of plastics. Larvae that fed on
polystyrene had higher numbers of bacteria carrying aromatic hydrocarbon and
alkane degradation genes in their gut whereas those that were fed on polyethylene
did not. [Conclusion] Polystyrene
is more easily degraded than polyethylene by Z. atratus larvae. However,
neither polystyrene nor polyethylene provide sufficient nutrition and energy
for the normal growth and development of Z. atratus larvae.