Effect of growth conditions on the production of manganese peroxidase by three strains of Bjerkandera adusta

2001 ◽  
Vol 47 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Yuxin Wang ◽  
Rafael Vazquez-Duhalt ◽  
Michael A. Pickard
2001 ◽  
Vol 47 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Yuxin Wang ◽  
Rafael Vazquez-Duhalt ◽  
Michael A Pickard

We were looking for a strain of Bjerkandera adusta that produces high titres of manganese peroxidase under optimal conditions for large-scale enzyme purification. We have chosen two strains from the University of Alberta Microfungus Collection and Herbarium, UAMH 7308 and 8258, and compared the effects of growth conditions and medium composition on enzyme production with the well-characterized strain BOS55 (ATCC 90940). Of four types of cereal bran examined, rice bran at 3% (w/v) in 60 mM phosphate buffer pH 6 supported the highest levels of enzyme production. Using 100 mL medium in 500-mL Erlenmeyer flasks, maximum enzyme levels in the culture supernatant occurred after about 10 days of growth; 5.5 U·mL–1 for UAMH 7308, 4.4 U·mL–1 for UAMH 8258, and 1.7 U·mL–1 for BOS55, where units are expressed as micromoles of Mn-malonate formed per minute. Growth as submerged cultures in 10-L stirred tank reactors produced 3.5 U·mL–1 of manganese peroxidase (MnP) by UAMH 8258 and 2.5 U·mL–1 of MnP by 7308, while enzyme production by BOS55 was not successful in stirred tank reactors but could be scaled up in 2-L shake flasks containing 400 mL rice bran or glucose – malt – yeast extract (GMY) – Mn-glycolate medium to produce MnP levels of 1.7 U·mL–1. These results show that the two strains of B. adusta, UAMH 7308 and 8258, can produce between two and three times the manganese peroxidase level of B. adusta BOS55, that they are good candidates for scale up of enzyme production, and that the rice bran medium supports higher levels of enzyme production than most previously described media.Key words: growth conditions, cereal bran, manganese peroxidase, Bjerkandera adusta, white rot fungi.


Fuel ◽  
2013 ◽  
Vol 112 ◽  
pp. 295-301 ◽  
Author(s):  
Zaixing Huang ◽  
Christiane Liers ◽  
René Ullrich ◽  
Martin Hofrichter ◽  
Michael A. Urynowicz

1997 ◽  
Vol 75 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Tamara Vares ◽  
Annele Hatakka

Ten species of white-rot fungi, mainly belonging to the family Polyporaceae (Basidiomycotina), were studied in terms of their ability to degrade14C-ring labelled synthetic lignin and secrete ligninolytic enzymes in liquid cultures under varying growth conditions. Lignin mineralization by the fungi in an air atmosphere did not exceed 14% within 29 days. Different responses to the elevated Mn2+concentration and the addition of a manganese chelator (sodium malonate) were observed among various fungal species. This could be related with the utilization of either lignin peroxidase (LiP) or manganese peroxidase (MnP) for lignin depolymerization, i.e., some fungi apparently had an LiP-dominating ligninolytic system and others an MnP-dominating ligninolytic system. The LiP isoforms were purified from Trametes gibbosa and Trametes trogii. Isoelectric focusing of purified ligninolytic enzymes revealed the expression of numerous MnP isoforms in Trametes gibbosa, Trametes hirsuta, Trametes trogii, and Abortiporus biennis grown under a high (50-fold) Mn2+level (120 μM) with the addition of the chelator. In addition, two to three laccase isoforms were detected. Key words: white-rot fungi, lignin degradation, lignin peroxidase, manganese peroxidase, manganese, malonate.


2016 ◽  
Vol 74 (8) ◽  
pp. 1809-1820 ◽  
Author(s):  
Muhammad Bilal ◽  
Muhammad Asgher ◽  
Hongbo Hu ◽  
Xuehong Zhang

An indigenous and industrially important manganese peroxidase (MnP) was isolated from solid-state bio-processing of wheat bran by white-rot fungal strain Ganoderma lucidum IBL-05 under pre-optimized growth conditions. Crude MnP extract was partially purified (2.34-fold) to apparent homogeneity by ammonium sulphate precipitation and dialysis. The homogeneous enzyme preparation was encapsulated on gelatin matrix using glutaraldehyde as a cross-linking agent. Optimal conditions for highest immobilization (82.5%) were: gelatin 20% (w/v), glutaraldehyde 0.25% (v/v) and 2 h activation time using 0.6 mg/mL of protein concentration. Gelatin-encapsulated MnP presented its maximum activity at pH 6.0 and 60 °C. Thermo-stability was considerably improved after immobilization. The optimally active MnP fraction was tested against MnSO4 as a substrate to calculate kinetic parameters. More than 90% decolorization of Sandal-fix Red C4BLN (Reactive Red 195A) dye was achieved with immobilized MnP in 5 h. It also preserved more than 50% of its original activity after the sixth reusability cycle. The water quality parameters (pH, chemical oxygen demand, total organic carbon) and cytotoxicity (brine shrimp and Daphnia magna) studies revealed the non-toxic nature of the bio-treated dye sample. A lower Km, higher Vmax, greater acidic and thermal-resistant up to 60 °C were the improved catalytic features of immobilized MnP suggesting its suitability for a variety of biotechnological applications.


2019 ◽  
Vol 23 (2) ◽  
pp. 287-301
Author(s):  
Teresa Korniłłowicz-Kowalska ◽  
Kamila Rybczyńska-Tkaczyk

Abstract The study characterizes the anamorphic Bjerkandera adusta strain CCBAS 930, including growth conditions, physiological properties, and enzymatic activities related to basic metabolism and specific properties coupled with the fungal secondary metabolism. It was established that the fungus grows in a wide pH range (3.5–7.5), up to 3% of salt concentration and a temperature of 5–30 °C. Media rich in natural organic components (potato, maize extracts, whey) are optimal for biomass propagation. Minimal media, containing mineral salts and glucose as well as static growth conditions, are required to obtain idiophasic mycelium, equivalent to the secondary metabolism of the fungus. Of the 7 complex C, N, and energy sources tested, the strain did not utilize only fibrous cellulose. Lipolytic activity reached the highest values of the enzymatic activities corresponding to those capabilities. The specific properties of strain B. adusta CCBAS 930 determined by the production of HRP-like peroxidase were related to the decolorization and biodegradation of anthraquinone derivative daunomycin. The decolorization of 30% of daunomycin effluents occurred most rapidly in iso-osmotic medium and non-enriched with nitrogen, containing 0.25% glucose, pH = 5.0–6.0, and 25–30 °C. In agitated cultures, the strain decolorized solutions of daunomycin by biosorption, which coincided with the inhibition of aerial mycelium production and HRP-like biosynthesis. Based on knowledge, potential and real possibilities of using the strain in bioremediation of colored industrial sewage were discussed.


1998 ◽  
Vol 64 (6) ◽  
pp. 2020-2025 ◽  
Author(s):  
Lee A. Beaudette ◽  
Stephen Davies ◽  
Phillip M. Fedorak ◽  
Owen P. Ward ◽  
Michael A. Pickard

ABSTRACT Two methods were used to compare the biodegradation of six polychlorinated biphenyl (PCB) congeners by 12 white rot fungi. Four fungi were found to be more active than Phanerochaete chrysosporium ATCC 24725. Biodegradation of the following congeners was monitored by gas chromatography: 2,3-dichlorobiphenyl, 4,4′-dichlorobiphenyl, 2,4′,5-trichlorobiphenyl (2,4′,5-TCB), 2,2′,4,4′-tetrachlorobiphenyl, 2,2′,5,5′-tetrachlorobiphenyl, and 2,2′,4,4′,5,5′-hexachlorobiphenyl. The congener tested for mineralization was 2,4′,5-[U-14C]TCB. Culture supernatants were also assayed for lignin peroxidase and manganese peroxidase activities. Of the fungi tested, two strains ofBjerkandera adusta (UAMH 8258 and UAMH 7308), one strain ofPleurotus ostreatus (UAMH 7964), and Trametes versicolor UAMH 8272 gave the highest biodegradation and mineralization. P. chrysosporium ATCC 24725, a strain frequently used in studies of PCB degradation, gave the lowest mineralization and biodegradation activities of the 12 fungi reported here. Low but detectable levels of lignin peroxidase and manganese peroxidase activity were present in culture supernatants, but no correlation was observed among any combination of PCB congener biodegradation, mineralization, and lignin peroxidase or manganese peroxidase activity. With the exception of P. chrysosporium, congener loss ranged from 40 to 96%; however, these values varied due to nonspecific congener binding to fungal biomass and glassware. Mineralization was much lower, ≤11%, because it measures a complete oxidation of at least part of the congener molecule but the results were more consistent and therefore more reliable in assessment of PCB biodegradation.


Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.


Author(s):  
T. S. Kuan

Recent electron diffraction studies have found ordered phases in AlxGa1-xAs, GaAsxSb1-x, and InxGa1-xAs alloy systems, and these ordered phases are likely to be found in many other III-V ternary alloys as well. The presence of ordered phases in these alloys was detected in the diffraction patterns through the appearance of superstructure reflections between the Bragg peaks (Fig. 1). The ordered phase observed in the AlxGa1-xAs and InxGa1-xAs systems is of the CuAu-I type, whereas in GaAsxSb1-x this phase and a chalcopyrite type ordered phase can be present simultaneously. The degree of order in these alloys is strongly dependent on the growth conditions, and during the growth of these alloys, high surface mobility of the depositing species is essential for the onset of ordering. Thus, the growth on atomically flat (110) surfaces usually produces much stronger ordering than the growth on (100) surfaces. The degree of order is also affected by the presence of antiphase boundaries (APBs) in the ordered phase. As shown in Fig. 2(a), a perfectly ordered In0.5Ga0.5As structure grown along the <110> direction consists of alternating InAs and GaAs monolayers, but due to local growth fluctuations, two types of APBs can occur: one involves two consecutive InAs monolayers and the other involves two consecutive GaAs monolayers.


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