Improving Pbat/Pla Mulching Film Biodegradation Through a Trichoderma Harzianum and Bacillus Amyloliquefaciens Consortium and its Effects on Soil Microbial Taxonomic and Functional Communities

Abstract

Inoculation with Trichoderma harzianum and Bacillus amyloliquefaciens, applied individually and as a consortium, significantly accelerates PBAT/PLA film biodegradation, observed as increased levels of degradation by-products measured with Dispersive Liquid Liquid Microextraction Gas Chromatography Mass Spectrometry (DLLME-GC-MS). The microbial consortium Trichoderma harzianum/Bacillus amyloliquefaciens (A+B) showed the greatest biodegradation efficacy, followed by Trichoderma harziamun (A), due to the direct synergistic interactions between them or indirectly through increases in some bacterial and fungal communities, favouring the degrading species of Bacillus, Streptomyces, and Fusarium without apparent detrimental impacts on overall soil functionality. Potential functional genes related to C degradation and N fixation also increased.From an environmental and agronomic perspective, leveraging microbial consortia to biodegrade biobased plastics such as PBAT/PLA offers substantial promise. This process not only reduces plastic accumulation in agricultural soils but also potentially enhances soil fertility and health, as demonstrated in agroecosystems. Future research should include validation under field conditions.

Keywords: biodegradable, soil, films, agriculture, microorganisms