Polythene and plastic waste are found to accumulate in the environment, posing a major ecological threat. They are found to be considered non-degradable, once it enters the environment it has been found to remain there indefinitely. However, significant attention has been placed on biodegradable polymer, identification of microbes with degradative potential on plastic material. The aim of the present investigation was to biodegrade low-density polyethylene (LDPE) using potential fungi isolated from landfill soil. Based on 18S rRNA analyses the isolated strain was identified as Aspergillus clavatus. LDPE degradation by A. clavatus was monitored for 90 days of incubation in aqueous medium. The degradation was confirmed by changes in polyethylene weight, CO2 evolution by Strum test, infrared spectra and morphological changes by SEM and AFM analysis.

Low‐density polyethylene (LDPE) is potential source of environmental pollution. In this study, biodegradation of LDPE was achieved by employing fungus and actinobacteria isolated from waste dumping site. Among all the isolates, two potential strains were obtained through enrichment technique. Based on 18S rRNA and 16S rRNA analyses the isolated strains were identified as Aspergillus nomius and Streptomyces sp., respectively. The biodegradation of LDPE was determined by evaluating weight loss and morphological changes of the LDPE samples. The isolated strains; Aspergillus nomius had the capacity to degrade 4.9% and Streptomyces sp. showed 5.2% of weight loss of LDPE films respectively. Weight loss of LDPE film after inoculation of isolates in degradation medium indicated that it was capable of using polyethylene as carbon and energy source. CO2 evolution was checked after degradation of polyethylene pieces, the level of CO2 reached 2.85 g L−1 in the presence of Aspergillus nomius and Streptomyces sp. produced 4.27 g L−1. Sophisticated instrumentation was used like atomic force microscopy, Fourier transform infra‐red spectroscopy (FTIR). The breakdown products of the LDPE film after exposure to the isolates was recorded employing GCMS. FTIR spectrum of LDPE film confirmed changes in the presence of chemical groups like amine, alkanes, phenols, and alcohol after degradation of LDPE films by Aspergillus nomius and Streptomyces sp. and the most prominent structural changes of the spectrum were observed in the LDPE sample after 90 days of degradation. The results affirmed the isolates were capable of degrading LPDE films efficiently. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 147–154, 2017

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Fipronil is a phenylpryazole insecticide which is extensively used for the protection of agricultural yields. However, this insecticide poses various threats to  the environment. Therefore it is essential to develop an effective method to degrade or eliminate this pollutant from the  environment. In this present study, a fungal strain AJAG1 capable of degrading fipronil and its metabolite, fipronil sulfone, was isolated through enrichment technique. Isolated fungal strain was identified as Aspergillus glaucus based upon its morphological, and 18S rRNA sequence analysis. Strain AJAG1 could degrade 900 mg L of fipronil efficiently in both aqueous medium and soil. In addition, fipronil degradation was tested with various kinetic models and the results revealed that biodegradation in aqueous medium and soil was ascertained by pseudo-first order and zero order rate kinetics, respectively. The infrared spectrum of fipronil degraded sample confirmed the formation of esters, nitro, and alkanes groups. A tentative degradation pathway of fipronil by strain AJAG1 has been proposed on the basis of gas chromatography-mass spectrometry (GC-MS) analysis. The lignolytic enzymes activities were studied during fipronil degradation by strain AJAG1. Further, scanning electron microscopy (SEM) was used to examine the surface morphology of strain AJAG1 after fipronil degradation. In the present investigation, bioformulation of strain AJAG1 was developed using low cost materials such as groundnut shell powder, molasses, and fly ash to remediate the fipronil from agricultural field. These results highlight A. glaucus strain AJAG1 may have potential for use in bioremediation of fipronil-contaminated environment.

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