Fungal biodegradation of phthalate plasticizer in situ

Abstract

This unique study describes how Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n-hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5% w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15-0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

Biodegradation of di-n-butyl phthalate in sequencing batch reactor bioaugmented with Micrococcus sp. and the bacterial community analysis

“…Luo et al (2009) studied the degradability of the three dimethyl phthalate isomer esters (DMPEs) by a Fusarium species isolated from mangrove sediment. Pradeep et al (2013) reported the complete degradation of the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, isolated from heavily plastics-contaminated soil.…”

Achromobacter denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

“…HQ645935; MTCC No. 5710, a patent deposit from our laboratory), isolated from heavily plastics polluted sewage sludge collected from the Canoly Canal; flowing through Kozhikode City, Kerala, India (11.2500 N;75.7667 E) was cultured in a simple BSM containing (g/L) K 2 HPO 4 , 1.0; NaCl, 1.0; NH 4 Cl, 0.5 and MgSO 4 , 0.4 (initial pH, 7.2; and supplemented with DEHP blended) (in situ cultivation) BB Pradeep et al, 2013). Commercially available HL haemopack BB (Batch No.…”

“…We for the first time demonstrated that the mycelial fungi can efficiently degrade DEHP blended in a commercial PVC plastics in situ, i.e., blood bag (BB) Pradeep et al, 2013). Many bacteria are also known to degrade various phthalates (Liang et al, 2008).…”

A monograph on the remediation of hazardous phthalates

“…Phthalates or esters of phthalic acid are a class of xenobiotic organic compounds widely employed to make plastic goods more flexible. Some of the commonly used phthalates are described in Table 1 [2,3], which are not chemically bound to the polymer mesh, and hence, they would easily migrate from plastic products into the surrounding environments [4][5][6]. Many experimental studies (in silico, in vitro mechanistic, pre-clinical and clinical) have shown that phthalates act as endocrine disruptors in vivo, apart from causing various health problems including hepatomegaly, osteoporosis, peroxisome proliferation, feminization of boys, reduction in body weight, skin and breast cancers, etc.…”