scholarly journals Biodegradation of nitroaromatic compounds in Red Water by white rot fungi Pleurotus ostreatus and floridae

Author(s):  
Cristiane Patrícia Kist ◽  
Claudio Eduardo Scherer ◽  
Marlene Soares ◽  
Marcio Barreto Rodrigues

Pleurotus fungi are basidiomycetes that stand out in the degradation of recalcitrant organic compounds such as lignin derivatives and phenolic compounds. The aim of this study was to make a comparative evaluation of the capacity of the Pleurotus ostreatus POS 560 and Pleurotus floridae PSP1 fungi in the degradation of 2,4 and 2,6-dinitrotoluene (DNTs) in effluent from an explosive factory. The characterization of the effluent indicated 318 mg L-1 of DNTs, 246 mg L-1 of COD and toxicity factor for Daphnia magna corresponding to 8. The conduct of a multivariate study estimated the influence of the variables pH (5.0 and 6.0), co-substrate concentration (10 and 20 g L-1 of glucose) and species of the fungus Pleurotus (ostreatus and floridae) on the degradation of DNTs, indicating that the variables Fungus and [Glucose] were significant (p <0.05) presenting effects in the order of + 4.45 ± 0.26 and -1.14 ± 0.26, respectively. The reproduction of the best efficiency conditions (P. floridae; pH 6.0 and 10 g L-1 of glucose) in agitated flasks (100 rpm, 26oC) was able to carry out, within 14 days of treatment, the removal of organic matter and toxicity factor in levels on the order of 55 and 50%, respectively, in addition to the complete degradation of DNTs which occurred in the first 120 hours of treatment. In this period, the maximum activity of the peroxidase and Mn-peroxidase enzymes was also characterized, suggesting high potential of the bioprocess under study for remediation of effluents contaminated with nitroaromatic compounds.

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3797-3807
Author(s):  
Magdah Ganash ◽  
Tarek M. Abdel Ghany ◽  
Mohamed A. Al Abboud ◽  
Mohamed M. Alawlaqi ◽  
Husam Qanash ◽  
...  

Lignocellulolytic white-rot fungi allow the bioconversion of agricultural wastes into value-added products that are used in a myriad of applications. The aim of this work was to use corn residues (Zea mays L.) to produce valuable products under solid-state fermentation (SSF) with Pleurotus ostreatus. White-rot fungus P. ostreatus was isolated from maize silage (MS) and thereafter it was inoculated on MS as substrate and compared with maize stover (MSt) and maize cobs (MC) to determine the best lignocellulosic substrate for the production of lignocellulolytic enzymes and extracellular protein. The MS gave the highest productivity of CMCase (368.2 U/mL), FPase (170.5 U/mL), laccase (11.4 U/mL), and MnPase (6.6 U/mL). This is compared to productivity on MSt of 222 U/mL, 50.2 U/mL, 4.55 U/mL, and 2.57 U/mL, respectively; and productivity on MC at the same incubation period as 150.5 U/mL, 48.2 U/mL, 3.58 U/mL, and 2.5 U/mL, respectively. The levels of enzyme production declined with increasing incubation period after 15 and 20 days using MS and MC, respectively, as substrates. Maximum liberated extracellular protein content (754 to 878 µg/mL) was recorded using MS, while a low amount (343 to 408 µg/mL) was liberated with using MSt and MC.


2013 ◽  
Vol 6 (4) ◽  
pp. 1154-1164 ◽  
Author(s):  
Ling-Ping Xiao ◽  
Zheng-Jun Shi ◽  
Yuan-Yuan Bai ◽  
Wei Wang ◽  
Xue-Ming Zhang ◽  
...  

1999 ◽  
Vol 65 (9) ◽  
pp. 3805-3809 ◽  
Author(s):  
Michael A. Pickard ◽  
Rosa Roman ◽  
Raunel Tinoco ◽  
Rafael Vazquez-Duhalt

ABSTRACT We studied the metabolism of polycyclic aromatic hydrocarbons (PAHs) by using white rot fungi previously identified as organisms that metabolize polychlorinated biphenyls. Bran flakes medium, which has been shown to support production of high levels of laccase and manganese peroxidase, was used as the growth medium. Ten fungi grown for 5 days in this medium in the presence of anthracene, pyrene, or phenanthrene, each at a concentration of 5 μg/ml could metabolize these PAHs. We studied the oxidation of 10 PAHs by using laccase purified from Coriolopsis gallica. The reaction mixtures contained 20 μM PAH, 15% acetonitrile in 60 mM phosphate buffer (pH 6), 1 mM 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS), and 5 U of laccase. Laccase exhibited 91% of its maximum activity in the absence of acetonitrile. The following seven PAHs were oxidized by laccase: benzo[a]pyrene, 9-methylanthracene, 2-methylanthracene, anthracene, biphenylene, acenaphthene, and phenanthrene. There was no clear relationship between the ionization potential of the substrate and the first-order rate constant (k) for substrate loss in vitro in the presence of ABTS. The effects of mediating substrates were examined further by using anthracene as the substrate. Hydroxybenzotriazole (HBT) (1 mM) supported approximately one-half the anthracene oxidation rate (k = 2.4 h−1) that ABTS (1 mM) supported (k = 5.2 h−1), but 1 mM HBT plus 1 mM ABTS increased the oxidation rate ninefold compared with the oxidation rate in the presence of ABTS, to 45 h−1. Laccase purified from Pleurotus ostreatus had an activity similar to that ofC. gallica laccase with HBT alone, with ABTS alone, and with 1 mM HBT plus 1 mM ABTS. Mass spectra of products obtained from oxidation of anthracene and acenaphthene revealed that the dione derivatives of these compounds were present.


2008 ◽  
Vol 38 (2) ◽  
pp. 268-277 ◽  
Author(s):  
Simone Tagger ◽  
Claude Périssol ◽  
Stéven Criquet ◽  
Guy Aubert ◽  
Pierre Neville ◽  
...  

The relationships between microorganisms and microfauna were studied in an evergreen oak ( Quercus ilex L.) forest floor located in a French Mediterranean region characterized by hot and dry summers. The soil was a brown fersialitic soil with an amphimull, i.e., a mull with a thick litter. A micromorphological study of both litter and organomineral layers was used to observe relationships between white-rot fungi and fauna, such as oribatids, millipedes, enchytraeids, and earthworms. Microbiological properties of the litter and physicochemical properties of the soil were analysed. Enchytraeids comminute the faeces of other animals, whereas earthworms form aggregates. These two opposite actions probably modify aeration and water movements in deeper layers. Brown leaves and animal faeces constitute a nutritional substrate for white-rot fungi and other animals. Inside degraded cells of rootlets and bleached leaves, fungi form calcium oxalate crystals because the absorbent complex is saturated by an excess of calcium. Enzymes such as laccases, manganese peroxidases, cellulases, or xylanases were detected in the litter at significant levels. The high activity values of phosphatases in the litter could reflect a deficiency in available phosphorus. This deficiency could partly explain a low rate of litter degradation and the presence of an OH sublayer.


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