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1.
The efficiency of two lypolytic enzymes (fungal cutinase, yeast esterase) in the degradation of dipropyl phthalate (DPrP)
was investigated. The DPrP-degradation rate of fungal cutinase was surprisingly high, i.e., almost 70% of the initial DPrP
(500 mg/l) was decomposed within 2.5 h and nearly 50% of the degraded DPrP disappeared within the initial 15 min. With the
yeast esterase, despite the same concentration, more than 90% of the DPrP remained even after 3 days of treatment. During
the enzymatic degradation of DPrP, several DPrP-derived compounds were detected and time-course changes in composition were
also monitored. The final chemical composition after 3 days was significantly dependent on the enzyme used. During degradation
with fungal cutinase, most DPrP was converted into 1,3-isobenzofurandione (IBF) by diester hydrolysis. However, in the degradation
by yeast esterase, propyl methyl phthalate (PrMP) was produced in abundance in addition to IBF. The toxic effects of the final
degradation products were investigated using various recombinant bioluminescent bacteria. As a result, the degradation products
(including PrMP) from yeast esterase severely caused oxidative stress and damage to protein synthesis in bacterial cells,
while in the fungal cutinase processes, DPrP was significantly degraded to non-toxic IBF after the extended period (3 days). 相似文献
2.
The efficiency of two lipolytic enzymes (fungal cutinase and yeast esterase) in the degradation of dipentyl phthalate (DPeP)
was investigated. The DPeP degradation rate of fungal cutinase was surprisingly high, i.e., almost 60% of the initial DPeP
(500 mg/L) was decomposed within 2.5 hours, and nearly 40% of the degraded DPeP disappeared within the initial 15 minutes.
With the yeast esterase, despite the same concentration, >87% of the DPeP remained even after 3 days of treatment. The final
chemical composition after 3 days was significantly dependent on the enzyme used. During degradation with cutinase, most DPeP
was converted into 1,3-isobenzofurandione (IBF) by diester hydrolysis. However, in the degradation by esterase, pentyl methyl
phthalate, in addition to IBF, was produced in abundance. Toxicity monitoring using various recombinant bioluminescent bacteria
showed that the degradation products from yeast esterase contained a toxic hazard, causing oxidative stress and damage to
protein synthesis.
Ji-Young Ahn, Yang-Hoon Kim are contributed equally to this work 相似文献
3.
Kim YH Seo HS Min J Kim YC Ban YH Han KY Park JS Bae KD Gu MB Lee J 《Journal of applied microbiology》2007,102(1):221-228
AIMS: This research aims to investigate the efficiency of two lipolytic enzymes--fungal cutinase and yeast esterase--upon the biodegradation of dihexyl phthalate (DHP). METHOD AND RESULTS: During the enzymatic degradation of DHP dissolved in methanol, several degradation products were detected and their time-course changes were monitored using GC/MS. The DHP-degradation rate of cutinase was surprisingly high; i.e. almost 70% of the initial DHP (500 mg l(-1)) was decomposed within 4.5 h. Although the same amount of esterase was employed, more than 85% of the DHP remained after 3 days. Almost all the DHP was converted by cutinase into 1,3-isobenzofurandione (IBF), whereas hexyl methyl phthalate and IBF were abundantly produced by esterase. In addition, the toxicities of the DHP-degraded products by esterase were evaluated using various recombinant bioluminescent bacteria, which caused oxidative and protein damage, whereas the hydrolysis products from cutinase never caused any cellular damage in the methanol-containing reaction system. CONCLUSIONS: Cutinase starts to act as a DHP-degrader much earlier and faster than esterase, with high stability in ester-hydrolytic activity, therefore a plausible approach to the practical application of cutinase for DHP degradation in the DHP-contaminated environments may be possible. SIGNIFICANCE AND IMPACT OF THE STUDY: This study describes the enhanced degradation and detoxification of DHP using Fusarium oxysporum f. sp. pisi cutinase. 相似文献
4.
Enhanced degradation of an endocrine-disrupting chemical,butyl benzyl phthalate,by Fusarium oxysporum f. sp. pisi cutinase 总被引:1,自引:0,他引:1
Compared to yeast esterase, fungal cutinase degraded butyl benzyl phthalate (BBP) far more efficiently; i.e., almost 60% of the BBP disappeared within 7.5 h. Also, the final chemical composition significantly depended on the enzyme used. Toxicity monitoring using bioluminescent bacteria showed that butyl methyl phthalate, a major product of degradation by esterase, was an oxidative toxic hazard. 相似文献
5.
Enhanced Degradation of an Endocrine-Disrupting Chemical, Butyl Benzyl Phthalate, by Fusarium oxysporum f. sp. pisi Cutinase 总被引:2,自引:0,他引:2 下载免费PDF全文
Yang-Hoon Kim Jeewon Lee Ji-Young Ahn Man Bock Gu Seung-Hyeon Moon 《Applied microbiology》2002,68(9):4684-4688
Compared to yeast esterase, fungal cutinase degraded butyl benzyl phthalate (BBP) far more efficiently; i.e., almost 60% of the BBP disappeared within 7.5 h. Also, the final chemical composition significantly depended on the enzyme used. Toxicity monitoring using bioluminescent bacteria showed that butyl methyl phthalate, a major product of degradation by esterase, was an oxidative toxic hazard. 相似文献
6.
Xin Li Hui-Ying Yu Yi-Feng Lin Hong-Mei Teng Lei Du Guo-Gang Ma 《Biotechnology letters》2010,32(10):1487-1495
The morphological effects of CF66I, an antifungal compound produced by Burkholderia cepacia, on growing hyphae of Fusarium oxysporum were studied by fluorescence microscopy (FM) and transmission electron microscopy (TEM). At 20 μg/ml, CF66I strongly inhibited
growth and induced significant changes of the hyphal morphology. These changes included swelling of hyphae with considerable
thickening cell wall and abnormal chitin deposition, which was indicative of the alterations in cell wall structure. Furthermore,
fluorescein diacetate (FDA) staining indicated the loss of intracellular esterase activity. CF66I probably inhibits fungal
growth by interfering with the cell metabolic pathways. At 120 μg/ml, CF66I killed F. oxysporum (accompanied by propidium iodide permeation, intracellular cytoplasm leakage and crushing of hyphal tips), probably by direct
damage to the cell membrane. Thus, there are two different antifungal mechanisms of CF66I, depending on its concentration,
and further studies on this compound might be useful for us to develop a new class of antifungal agents. 相似文献
7.
Skory CD 《Journal of industrial microbiology & biotechnology》2003,30(1):22-27
This work demonstrates the first example of a fungal lactate dehydrogenase (LDH) expressed in yeast. A L(+)-LDH gene, ldhA, from the filamentous fungus Rhizopus oryzae was modified to be expressed under control of the Saccharomyces cerevisiae adh1 promoter and terminator and then placed in a 2μ-containing yeast-replicating plasmid. The resulting construct, pLdhA68X,
was transformed and tested by fermentation analyses in haploid and diploid yeast containing similar genetic backgrounds. Both
recombinant strains utilized 92 g glucose/l in approximately 30 h. The diploid isolate accumulated approximately 40% more
lactic acid with a final concentration of 38 g lactic acid/l and a yield of 0.44 g lactic acid/g glucose. The optimal pH for
lactic acid production by the diploid strain was pH 5. LDH activity in this strain remained relatively constant at 1.5 units/mg
protein throughout the fermentation. The majority of carbon was still diverted to the ethanol fermentation pathway, as indicated
by ethanol yields between 0.25–0.33 g/g glucose. S. cerevisiae mutants impaired in ethanol production were transformed with pLdhA68X in an attempt to increase the lactic acid yield by
minimizing the conversion of pyruvate to ethanol. Mutants with diminished pyruvate decarboxylase activity and mutants with
disrupted alcohol dehydrogenase activity did result in transformants with diminished ethanol production. However, the efficiency
of lactic acid production also decreased.
Electronic Publication 相似文献
8.
The autolysis of yeast cells has practical implications in the production of fermented foods and beverages and flavourants
for food processing. Protein and RNA degradation during yeast autolysis are well described but the fate of DNA is unclear.
Yeast cells (Saccharomyces cerevisiae) were autolysed by incubating suspensions at 30–60°C (pH 7.0), and at pH 4.0–7.0 (40°C) for 10–14 days. Up to 55% of total
DNA was degraded, with consequent leakage into the extracellular environment of mainly 3′- and 5′-deoxyribonucleotides, and
lesser amounts of polynucleotides. The rate and extent of DNA degradation, composition of the DNA degradation products and
DNase activity were affected by temperature and pH. The highest amount of DNA degradation occurred at 40°C and pH 7.0, where
the highest DNase activity was recorded. DNase activity was lowest at 60°C and pH 4.0, where the proportion of polynucleotides
in the degradation products was higher.
Electronic Publication 相似文献
9.
Removal of azo dyes from the effluent generated by textile industries is rather difficult. Azo dyes represent a major class
of synthetic colorants that are both mutagenic and carcinogenic. Galactomyces geotrichum MTCC 1360, a yeast species, showed more than 96% decolorization of the azo dye Remazol Red (50 mg/L) within 36 h at 30°C
and pH 11.0 under static condition with a significant reduction in the chemical oxygen demand (62%) and total organic carbon
(41%). Peptone (5.0 g/L), rice husk (10 g/L extract), and ammonium chloride (5.0 g/L) were found to be more significant among
the carbon and nitrogen sources used. The presence of tyrosinase, NADH-DCIP reductase, riboflavin reductase and induction
in azo reductase and laccase activity during decolorization indicated their role in degradation. High performance thin layer
chromatography analysis revealed the degradation of Remazol Red into different metabolites. Fourier transform infrared spectroscopy
and high performance liquid chromatography analysis of samples before and after decolorization confirmed the biotransformation
of dye. Atomic absorption spectroscopy analysis revealed a less toxic effect of the metabolites on iron uptake by Sorghum vulgare and Phaseolus mungo than Remazol Red dye. Remazol Red showed an inhibitory effect on iron uptake by chelation and an immobilization of iron,
whereas its metabolites showed no chelation as well as immobilization of iron. Phytotoxicity study indicated the conversion
of complex dye molecules into simpler oxidizable products which had a less toxic nature. 相似文献
10.
Proteolytic degradation is the primary obstacle in the use of the yeast Pichia pastoris for the expression of recombinant proteins. During the production of a recombinant Plasmodium falciparum circumsporozoite protein in this system, the (NANP)
n
repeats region at the N-terminus were completely proteolytically degraded. To remove the potential proteolytic site within
the recombinant protein, different strategies were tried, including adjusting the cultivation conditions and mutating the
sequence at the junction of the repeat domain and C-terminal region, but the degradation continued. However, modification
of the N-terminal sequence by adding an epitope-based peptide to the N-terminus not only protected the repeat domain from
cleavage by native proteases during longer induction in the yeast host and purification process, but also stabilized this
recombinant protein emulsified with adjuvant ISA720 for at least 6 months. The results showed that proteolytic degradation
of the recombinant circumsporozoite protein produced in P. pastoris was amino acid sequence (NANP)-specific, and that this effect was likely dependent on the conformation of the recombinant
protein. 相似文献
11.
Some strains of white rot fungi, non-lignolytic fungi and litter-decomposing basidiomycetes have been recognized as PAH degraders.
The purpose of our research was to enlarge the scope of PAH-degrading fungi and explore the huge endophytic microorganism
resource for bioremediation of PAHs. In this study, phenanthrene was used as a model PAHs compound. Nine strains of endophytic
fungi isolated from four kinds of plant from Eupharbiaceae were screened for degradation of phenanthrene. The endophytic fungus Ceratobasidum stevensii (strain B6) isolated from Bischofia polycarpam showed high degradation efficiency and was selected for further studies. Into the fungal culture, 100 mg l−1 phenanthrene was added, and after 10 days of incubation, about 89.51% of the phenanthrene was removed by strain B6. Extracellular
ligninolytic enzyme activities of strain B6 were tested. The results showed that manganese peroxidase [MnP] was the predominant
ligninolytic enzyme and that its production was greatly induced by the presence of phenanthrene. To confirm the involvement
of MnP in phenanthrene degradation, promotion and inhibition studies on MnP in different concentration level of Mn2+ and NaN3 were performed. Additionally, fungal mycelium-free and resuspended experiments were carried out. The results showed no apparent
correlation between MnP activity and phenanthrene degradation. The mycelium and fresh medium were the crucial factors affecting
the degradation of phenanthrene. To date, this is the first report on PAH degradation by Ceratobasidum stevensii. This study suggests that endophytic fungi might be a novel and important resource for microorganisms that have PAH-degrading
capabilities. 相似文献
12.
Márcia Maria Rosa Sâmia Maria Tauk-Tornisielo Pedro Eduardo Rampazzo Sandra Regina Ceccato-Antonini 《World journal of microbiology & biotechnology》2010,26(8):1491-1502
The yeasts are microorganisms with great potential for biotechnological applications in diverse areas. The biological control
of phytopathogens by yeasts has showed satisfactory results under laboratory conditions, and it has already produced commercial
formulations. With this as focus, this work aims to perform in vitro and in vivo evaluations of the action of a Torulaspora globosa yeast strain (1S112), isolated from sugarcane rhizosphere, against the phytopathogenic mold Colletotrichum sublineolum, the causative agent of anthracnose in sorghum. In vitro experiments included the antagonism test in Petri dishes with morphological
hyphal evaluation; yeast killer activity; siderophore, volatile compound and hydrolytic enzyme production. In vivo experiments
were conducted in greenhouse conditions with a sorghum variety susceptible to C. sublineolum by evaluating the anthracnose disease for 6 weeks. The results indicated that the yeast strain significantly controlled the
fungal growth, either in vitro or in vivo. The strain of T. globosa exhibited killer activity against two sensitive strains, which is a novel capacity for this species. The yeast did not produce
siderophores, volatile compounds or hydrolytic enzymes, although it has reduced the mycelial growth, resulting in hyphal deformities
but not cell death. The yeast controlled the anthracnose disease in sorghum, either inoculated before or after the fungal
spores, suggesting that the competition for space and nutrients to dominate the mold and killer toxin production, altering
the hyphal morphology, are mechanisms utilized by the yeast in the biocontrol. 相似文献
13.
Dibutyl phthalate (DBP) was more efficiently degraded by cutinase compared to yeast esterase; i.e. almost 80% of initial DBP (500 mg l−1) was decomposed within 7.5 h, and nearly 50% of the degraded DBP disappeared within the initial 30 min. The toxicity of the final DBP degradation products were investigated using various recombinant bioluminescent bacteria. Butyl methyl phthalate, the major product of degradation by the esterase, was an oxidative toxic hazard that damaged protein synthesis. 相似文献
14.
Irbe I Andersone I Andersons B Noldt G Dizhbite T Kurnosova N Nuopponen M Stewart D 《Biodegradation》2011,22(4):719-728
In our study, early period degradation (10 days) of Scots pine (Pinus sylvestris L.) sapwood by the brown-rot fungus Coniophora puteana (Schum.: Fr.) Karst. (BAM Ebw.15) was followed at the wood chemical composition and ultrastructurelevel, and highlighted
the generation of reactive oxygen species (ROS). An advanced decay period of 50 days was chosen for comparison of the degradation
dynamics. Scanning UV microspectrophotometry (UMSP) analyses of lignin distribution in wood cells revealed that the linkages
of lignin and polysaccharides were already disrupted in the early period of fungal attack. An increase in the lignin absorption
A280 value from 0.24 (control) to 0.44 in decayed wood was attributed to its oxidative modification which has been proposed to
be generated by Fenton reaction derived ROS. The wood weight loss in the initial degradation period was 2%, whilst cellulose
and lignin content decreased by 6.7% and 1%, respectively. Lignin methoxyl (–OCH3) content decreased from 15.1% (control) to 14.2% in decayed wood. Diffuse reflectance Fourier-transform infrared (DRIFT)
spectroscopy corroborated the moderate loss in the hemicellulose and lignin degradation accompanying degradation. Electron
paramagnetic resonance spectra and spin trapping confirmed the generation of ROS, such as hydroxyl radicals (HO∙), in the early wood degradation period. Our results showed that irreversible changes in wood structure started immediately
after wood colonisation by fungal hyphae and the results generated here will assist in the understanding of the biochemical
mechanisms of wood biodegradation by brown-rot fungi with the ultimate aim of developing novel wood protection methods. 相似文献
15.
16.
Narukjaporn Thammajaruk Nongluksna Sriubolmas Duangnate Israngkul Vithaya Meevootisom Suthep Wiyakrutta 《Journal of industrial microbiology & biotechnology》2011,38(6):679-685
Culture media and fermentation conditions for cultivation of an endophytic fungus Phomopsis sp. Hant25 were investigated in order to improve the yield of mycoepoxydiene, a novel fungal metabolite having potent cytotoxic
activity against many cancer cell lines. Mycoepoxydiene accumulated in the culture broth during the stationary phase of fungal
growth. Modified M1D medium was superior to malt Czapek, and Czapek yeast autolysate broths in supporting mycoepoxydiene production.
Pellet growth was the morphological form that favored biosynthesis of mycoepoxydiene. This could be achieved by incubating
the culture statically for 6 days before shaking at 120 rpm. Incorporation of a cellulose paper disc into the culture flask
promoted fungal growth at the liquid surface, which accelerated mycoepoxydiene production and maximized the final yield to
a level of 354 mg l−1, though fungal attachment to the solid support was not required. Since the peak concentration of mycoepoxydiene in the culture
broth was followed by a steeply declining phase, the harvest time had to be precisely determined for maximum product yield.
Understanding the factor(s) involved in rapid degradation of mycoepoxydiene could lead to improved final yields. 相似文献
17.
Xylanases are industrially important enzymes for xylan digestion. We experimentally screened over 114 Sec and 24 Tat pathway signal peptides, with two different promoters, for optimal production of an alkaline active xylanase (XynBYG) from Bacillus pumilus BYG in a Bacillus subtilis host. Though both promoters yielded highly consistent secretion levels (0.97 Pearson correlation coefficient), the Sec pathway was found to be more efficient than the Tat pathway for XynBYG secretion. Furthermore, the optimal signal peptide (phoB) for XynBYG secretion was found to be different from the optimal peptides for cutinase and esterase reported in previous studies. A partial least squares regression analysis further identified several statistically important variables: helical properties, amino acid composition bias, and the discrimination score in Signal P. These variables explain the observed 23 % variance in the secretion yield of XynBYG by the different signal peptides. The results also suggest that the helical propensity of a signal peptide plays a significant role in the beta-rich xylanase, but not in the helix-rich cutinase, suggesting a coupling of the conformations between the signal peptide and its cargo protein for optimal secretion. 相似文献
18.
Nehme N Mathieu F Taillandier P 《Journal of industrial microbiology & biotechnology》2008,35(7):685-693
This study examines the interactions that occur between Saccharomyces cerevisiae and Oenococcus oeni strains during the process of winemaking. Various yeast/bacteria pairs were studied by applying a sequential fermentation strategy which simulated the natural winemaking process. First, four yeast strains were tested in the presence of one bacterial strain leading to the inhibition of the bacterial component. The extent of inhibition varied widely from one pair to another and closely depended on the specific yeast strain chosen. Inhibition was correlated to weak bacterial growth rather than a reduction in the bacterial malolactic activity. Three of the four yeast strains were then grown with another bacteria strain. Contrary to the first results, this led to the bacterial stimulation, thus highlighting the importance of the bacteria strain. The biochemical profile of the four yeast fermented media exhibited slight variations in ethanol, SO(2) and fatty acids produced as well as assimilable consumed nitrogen. These parameters were not the only factors responsible for the malolactic fermentation inhibition observed with the first bacteria strain. The stimulation of the second has not been reported before in such conditions and remains unexplained. 相似文献
19.
Sui Sheng T. Hua Maria T. Brandl Bradley Hernlem Jeffrey G. Eng Siov Bouy L. Sarreal 《Mycopathologia》2011,171(2):133-138
The metabolic activity of the aflatoxigenic fungus, Aspergillus flavus co-cultured with the biocontrol yeast, Pichia anomala was examined using several viability stains. Both the FUN-1 stain and the combined use of DiBAC4(5) with CDFA-AM stains were applied in this study. The results suggest that the ATP-generating system in A. flavus was inactivated as the ratio of yeasts to fungi increased in the dual culture. A decrease in hyphal membrane potential and
esterase activity was substantiated by the combined stains of DiBAC4(5) and CDFA-AM. Reduced metabolic function in conjunction with cell wall damage of A. flavus hindered the growth and biomass production of this fungus. Viability stains such as FUN-1 and DiBAC4(5) with CDFA-AM may assist in elucidating the biocontrol mechanism by allowing for the visualization of the antagonistic
effect of yeast species on target fungi in situ, as well as for screening potent biocontrol yeast agents against fungal pathogens. 相似文献
20.
Aromatic compounds are abundant in aqueous environments due to natural resources or different manufacturer’s wastewaters. In this study, phenol degradation by the yeast, Trichosporon cutaneum ADH8 was compared in three forms namely: free cells, nonmagnetic immobilized cells (non-MICs), and magnetically immobilized cells (MICs). In addition, three different common immobilization supports (alginate, agar, and polyurethane foams) were used for cell stabilization in both non-MICs and MICs and the efficiency of phenol degradation using free yeast cells, non-MICs, and MICs for ten consecutive cycles were studied. In this study, MICs on alginate beads by 12 g/l Fe2O3 magnetic nanoparticles had the best efficiency in phenol degradation (82.49%) and this amount in the seventh cycle of degradation increased to 95.65% which was the highest degradation level. Then, the effect of magnetic and nonmagnetic immobilization on increasing the stability of the cells to alkaline, acidic, and saline conditions was investigated. Based on the results, MICs and non-MICs retained their capability of phenol degradation in high salinity (15 g/l) and acidity (pH 5) conditions which indicating the high stability of immobilized cells to those conditions. These results support the effectiveness of magnetic immobilized biocatalysts and propose a promising method for improving the performance of biocatalysts and its reuse ability in the degradation of phenol and other toxic compounds. Moreover, increasing the resistance of biocatalysts to extreme conditions significantly reduces costs of the bioremediation process. 相似文献