Morphology, phylogeny, and polyurethane degrading ability of Lasiodiplodia iraniensis and Mortierella alpina

Abstract

ABSTRACT Millions of tons of plastic products are produced globally each year; however, the low degradation rate of plastics results in an accumulation of these products in almost every ecosystem on the planet, causing enormous environmental harm. In this study, we isolated three fungal strains found growing on a piece of foam and sought to determine if these fungi have the capacity to degrade plastic. According to multigene (ITS, LSU, TEF1-α and TUB2) phylogenetic analyses and morphological studies, the three fungal strains were identified as two distinct species: Lasiodiplodia iraniensis and Mortierella alpina. The strains were inoculated on potato dextrose agar (PDA), malt extract agar (MEA), and malt agar medium containing chloramphenicol (CMEA) and covered with polyurethane (PU) films and incubated for four months. It was found that Mortierella alpina (ZHKUCC 22–0283) contributed to the PU mass loss of 26.30% on CMEA at 32°C, while Lasiodiplodia iraniensis (ZHKUCC 22–0282) accounted for the PU mass loss of 13.55% on MEA at 32°C. The surface hyphae were washed off by the PU films, and scanning electron microscope (SEM) imaging was used to check the fungal degradation of the PU films. Full descriptions, illustrations, phylogenetic trees to show the position of the two fungal species and SEM images of PU films are provided.