Tyrosinase and peroxidase production by Rhizopus oryzae strain ENHE obtained from pentachlorophenol‐contaminated soil

Abstract

BACKGROUND: The aim of this study was to investigate the ability of a zygomycete isolated from pentachlorophenol (PCP)-contaminated soil to produce peroxidase and phenoloxidase enzymes, and to determine the effect of tyrosine and PCP on the enzyme activities. The ability of the isolate to tolerate and remove PCP was also studied.

Pentachlorophenol sorption in nylon fiber and removal by immobilized Rhizopus oryzae ENHE

“…In this work, maximal PCP removal was 92% of the initial PCP achieved at 72 h in cultures with 25 mg PCP L −1 , twice the initial concentration reported by León-Santiesteban et al [17]. Similar results have been found by Lu et al [35], who reported that the removal rate of phenolic compounds by free fungi is lower than the removal rate observed by immobilized P. chrysosporium fungi.…”

“…oryze ENHE grew into nylon fiber impregnated with culture medium using the three conditions described in the methodology section: nylon at equilibrium sorption concentration impregnated with 3.0 mg PCP g −1 nylon; nylon at equilibrium sorption concentration impregnated with 3.0 mg PCP g −1 nylon plus 14 mg PCP L −1 , added to the culture medium used to impregnate the nylon fiber and as control nylon without PCP. Results showed that PCP inhibited growth of R. oryzae EHNE, as reported before by León-Santiesteban et al [17]. In the control culture, maximal biomass obtained was of 32 mg dry biomass g −1 nylon and, in cultures containing PCP, growth of R. oryzae ENHE was lower; maximal biomasss was of 18 and 15 mg biomass g −1 nylon in cultures with nylon cubes that contained PCP at equilibrium concentration and nylon at equilibrium concentration amended with 14 mg PCP g −1 nylon, respectively (Fig.…”

“…Microorganism and culture media R. oryzae ENHE isolated from a PCP-contaminated soil was used in this study [17]. The strain was kept in a 30% glycerol solution at −70 • C. Erlenmeyer flasks containing PDA (potato-dextrose agar) medium were inoculated with R. oryzae ENHE spores and incubated at 30 • C for 4-5 days to obtain asexual spores.…”

“…León-Santiesteban et al [17] showed that R. oryzae ENHE removed 90% of the initial PCP (12.5 mg L −1 ) at 48 h in submerged cultures. In this work, maximal PCP removal was 92% of the initial PCP achieved at 72 h in cultures with 25 mg PCP L −1 , twice the initial concentration reported by León-Santiesteban et al [17].…”

Bioremediation of PCP by Trichoderma and Cunninghamella Strains Isolated from Sawdust

“…Szewczyk et al (2003) have also previously reported the isolation of zygomycete, Mucor ramosissimus from contaminated site that was capabale of tolerating and transforming 10 mg/L of PCP to tetrachlorohydroquinone (TCHQ). Leon-Santiesteban et al (2008) reported the isolation of tyrosinase and peroxidase producing zygomycete, Rhizopus oryzae from PCP contaminated soil that tolerated and removed 90% of initial PCP concentration (12.5%). Carvalho et al (2009) also showed that besides basidiomycetes or white rot fungi, zygomycetes such as Cunninghamella sp.…”