Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

Abstract

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Abiotic and Biotic Degradation of Oxo-Biodegradable Plastic Bags by Pleurotus ostreatus

“…Co-metabolic processes are commonly used in the treatment of recalcitrant compounds, where a carbon source is added to induce the synthesis of certain enzymes that degrade not only natural substrates but also undesired pollutants or residues [29],[30]. As in our previous work, paper towel provided the carbon source that initiated fungal growth and synthesis of lignocellulolytic enzymes [9]. Chemical and physical alterations to the plastic after sunlight exposure (Table 1, Figure 1) may have intensified enzymatic activity (Figure 7).…”

Mushroom as a product and their role in mycoremediation

“…Recently, it is reported that mushroom species are able to degrade polymers such as plastics (da Luz et al [2013]).…”

Jatropha seed cake supplementation for improved fungal growth and later use as animal feed

“…This difference is important for animal feed, because a negative relationship between digestibility and lignocellulosic compounds content has been observed for more than 70 years (Woodman and Stewart, 1932). Recently, P. ostreatus growth in Jc was observed to increase its in vitro digestibility and the amount of nonfiber carbohydrates and crude protein (da Luz et al, 2014), which are all desirable features for animal feed (Montagne et al, 2003). Moreover, Kasuya et al (2012) showed that Jc after P. ostreatus growth was well-accepted by goats, leading to an increase in dry mass intake.…”

“…However, these compounds can be degraded by bacteria (Joshi et al, 2011) or white rot fungi, such as Pleurotus ostreatus (da Luz et al, 2014;Kasuya et al, 2012). Similarly, fungi have been efficiently used to increase the digestibility and nutritional value of agroindustrial residue, such as cocoa husk (Alemawor et al, 2009), Brachiaria sp.…”

“…Jc has been used as a substrate for white-rot fungal growth (de Barros et al, 2011;Kasuya et al, 2012;da Luz et al, 2013;Da Luz et al, 2014). However, previous studies focused on the degradation of phorbol ester to improve the usefulness of this material.…”