Decoloration of a Carpet Dye Effluent Using Trametes Versicolor

Although a non-sterile, undiluted carpet dye effluent (containing two anthraquinone dyes) did not support growth of Trametes versicolor, the pre-grown fungus removed 95% of its color in shake-flasks after 10 h of incubation. After decoloration, the COD of the cell-free supernatant increased and the toxicity was unchanged as determined by the Microtox assay using Vibrio fischeri. Decoloration rates decreased when either glucose alone or Mn2+ and glucose were added. T. versicolor, immobilized on jute twine in a rotating biological contacting reactor, also decolorized four successive batches of the effluent. There was no decoloration in any of the uninoculated, non-sterile controls.     

Amaranth decoloration by Trametes versicolor in a rotating biological contacting reactor

Sequential batch and continuous operation of a rotating biological contacting (RBC) reactor and the effects of dissolved oxygen on the decoloration of amaranth by Trametes versicolor were evaluated. Amaranth belongs to the group of azo dyes which are potential carcinogens and/or mutagens that can be transformed into toxic aryl amines under anaerobic conditions. Cultivation of T. versicolor in a stirred tank reactor was found to be unsuitable for amaranth decoloration due to significant biomass fouling and increase in medium viscosity. Assuming that decoloration follows first-order kinetics, amaranth was decolorized more rapidly when T. versicolor was immobilized on jute twine in a RBC reactor operated either in a sequential batch (k=0.25 h^–1) or in a continuous (0.051 h⁻¹) mode compared to a stirred tank reactor (0.015 h⁻¹). Oxygen was found to be essential for decoloration with the highest decoloration rates occurring at oxygen saturation. Although longer retention times resulted in more decoloration when the RBC was operated in the continuous mode (about 33% amaranth decoloration), sequential batch operation gave better results (>95%) under similar nutrient conditions. Our data indicate that the fastest decoloration should occur in the RBC using nitrogen-free Kirk’s medium with 1 g/l glucose in sequential batch operation at rotational speeds and/or aeration rates which maintain oxygen saturation in the liquid phase.     

Biodegradation of endocrine-disrupting bisphenol A by white rot fungus Irpex lacteus

Biodegradation of endocrine-disrupting bisphenol A was investigated with several white rot fungi (Irpex lacteus, Trametes versicolor, Ganoderma lucidum, Polyporellus brumalis, Pleurotus eryngii, Schizophyllum commune) isolated in Korea and two transformants of T versicolor (strains MrP 1 and MrP 13). I. lacteus degraded 99.4% of 50 mg/l bisphenol A in 3 h incubation and 100% in 12 h incubation. which was the highest degradation rate among the fungal strains tested. T. versicolor degraded 98.2% of 50 mg/l bisphenol A in 12 h incubation. Unexpectedly, the transformant of the Mn-repressed peroxidase gene of T. versicolor, strain MrP 1, degraded 76.5% of 50 mg/l bisphenol A in 12 h incubation, which was a lower degradation rate than wild-type T. versicolor. The removal of bisphenol A by I. lacteus occurred mainly by biodegradation rather than adsorption. Optimum carbon sources for biodegradation of bisphenol A by I. lacteus were glucose and starch, and optimum nitrogen sources were yeast extract and tryptone in a minimal salts medium; however, bisphenol A degradation was higher in nutrient-rich YMG medium than that in a minimal salts medium. The initial degradation of endocrine disruptors was accompanied by the activities of manganese peroxidase and laccase in the culture     

Effect of Auxin,Kinetin and Monosaccharide on Callus Cell wall Composition of Abutilon avicennae Gaertn

The effects of exogenous kinetin, IAA, glucose (the component of cellulose) and galactose (one of tile inhibiting compounds of cellulose synthesis) on callus cell wall composition of China jute (Abutilon avicennae Gaertn) were investigated. When the China jute callus materials were treated with 2 mg/l IAA and H3-glucose, there was a 437% increase of the Ha-glucose, as compared with control. When galactose was added simultaneously with H3-glucose, there was a 138% increase of the H3-glucose as compared with control. Galactose inhibited H3-glucose incorporate content in cellulose, and also in pectin and hemicellulose. In the experiment with 10 mg/l kinetin treatment of the callus materials, when galactose was added, the incorporation H3-glucose was inhibited. It is interesting that the kinetin enhanced H3-galactose incorporation into all cell wall components. When it was added simultaneously with glucose, glucose inhibited H3-galactose into the cell Wall components. Results showed that the hormones effect cell wall component, not only concerned with hormones, but also concerned with exogenous monosaccharides. When exogenous monosacchrides were added to the culture medium (as galactose, glucose) in combination or respectively, they are quite different in effecting hormone induced China jute callus cell wall. When the callus was treated by IAA, galactose inhibited H3-glucose incorporation into cell wall components. When it was treated by kinetin, glucose inhibited H3-galactose incorporation into cell wall components.     

Production of D-(--)-3-hydroxyalkanoic acid by recombinant Escherichia coli

Pathways for extracellular production of chiral D-(-)-3-hydroxybutyric acid (3HB) and D-(-)-3-hydroxyalkanoic acid (mcl-3HA) were constructed by co-expression of genes of beta-ketothiolase (phbA), acetoacetyl-CoA reductase (phbB) and 3-hydroxyacyl-ACP CoA transacylase (phaG), respectively, in Escherichia coli strain DH5alpha. The effect of acrylic acid and glucose on production of both 3HB and mcl-3HA was investigated. It was found that the addition of acrylic acid significantly increased production of 3HB and mcl-3HA consisting of 3-hydroxyoctanoic acid and 3-hydroxydecanoic acid in a ratio of 1:3 from 199 mg x l(-1) to 661 mg x l(-1) and from 27 mg x l(-1) to 135 mg x l(-1), respectively, in shake flask studies when glucose was present in the medium at the very beginning of fermentation. The timing of glucose addition had no effect on 3HB production. In contrast, mcl-3HA production was affected by glucose addition, an mcl-3HA concentration of 193 mg x l(-1) was obtained when glucose was added to the culture at 12 h. A more than seven-fold increase was obtained when compared with that in medium containing glucose at the beginning of fermentation. However, a decrease in production of 3HB and mcl-3HA was found when glucose was added at 12 h to the culture containing acrylic acid. The repressive effect of acrylic acid on acetic acid production was also evaluated and discussed.     

吲(口朶)乙酸、激动素和单糖对苘麻愈伤组织细胞壁组分的影响

本实验采用 H~3标记糖饲喂示踪分析法。将苘麻愈伤组织分别用吲哚乙酸和激动素处理,并在培养基中供给 H~3葡萄糖或 H~3半乳糖。——实验表明,激素对细胞壁组成分影响,不仅与激素的种类有关,也与供给的外源单糖有关。而外源单糖(半乳糖、葡萄糖)单独加入或同时加入,使激素对苘麻愈伤组织诱导的影响又有所不同。在吲哚乙酸作用下,促进了 H~3葡萄糖的掺入;而半乳糖的加入又抑制了 H~3葡萄糖掺入到细胞壁各组分。在激动素作用下,促进H~3半乳糖的掺入,而葡萄糖的加入又抑制了 H~3半乳糖掺入到壁的各组分。     

Application of low-cost algal nitrogen source feeding in fuel ethanol production using high gravity sweet potato medium

Protein-rich bloom algae biomass was employed as nitrogen source in fuel ethanol fermentation using high gravity sweet potato medium containing 210.0 g l(-1) glucose. In batch mode, the fermentation could not accomplish even in 120 h without any feeding of nitrogen source. While, the feeding of acid-hydrolyzed bloom algae powder (AHBAP) notably promoted fermentation process but untreated bloom algae powder (UBAP) was less effective than AHBAP. The fermentation times were reduced to 96, 72, and 72 h if 5.0, 10.0, and 20.0 g l(-1) AHBAP were added into medium, respectively, and the ethanol yields and productivities increased with increasing amount of feeding AHBAP. The continuous fermentations were performed in a three-stage reactor system. Final concentrations of ethanol up to 103.2 and 104.3 g l(-1) with 4.4 and 5.3 g l(-1) residual glucose were obtained using the previously mentioned medium feeding with 20.0 and 30.0 g l(-1) AHBAP, at dilution rate of 0.02 h(-1). Notably, only 78.5 g l(-1) ethanol and 41.6 g l(-1) residual glucose were obtained in the comparative test without any nitrogen source feeding. Amino acids analysis showed that approximately 67% of the protein in the algal biomass was hydrolyzed and released into the medium, serving as the available nitrogen nutrition for yeast growth and metabolism. Both batch and continuous fermentations showed similar fermentation parameters when 20.0 and 30.0 g l(-1) AHBAP were fed, indicating that the level of available nitrogen in the medium should be limited, and an algal nitrogen source feeding amount higher than 20.0 g l(-1) did not further improve the fermentation performance.     

Effect of mixed organic substrate on α-tocopherol production by <Emphasis Type="Italic">Euglena gracilis</Emphasis> in photoheterotrophic culture

Effects of organic carbon sources on cell growth and alpha-tocopherol productivity in wild and chloroplast-deficient W14ZUL strains of Euglena gracilis under photoheterotrophic culture were investigated. In both strains, the increase in cell growth was particularly high when glucose was added as the sole organic carbon source. On the other hand, alpha-tocopherol production per dry cell weight was enhanced by adding ethanol. Ethanol addition also increased the chlorophyll concentration in wild strain and mitochondria activity in W14ZUL strain. For effective alpha-tocopherol production, the effects of mixture of glucose and ethanol were investigated. The results showed that, when a mixture of glucose (6 g/l) and ethanol (4 g/l) was used, alpha-tocopherol productivity per culture broth was 3.89 x 10(-2) mg l(-1) h(-1), which was higher than the value obtained without addition of organic carbon source (0.92 x 10(-2) mg l(-1) h(-1)). In addition, under fed-batch cultivation using an internally illuminated photobioreactor, the alpha-tocopherol production per culture broth was 23.43 mg/l, giving a productivity of 16.27 x 10(-2) mg l(-1) h(-1).     

Degradation of phenanthrene by Trametes versicolor and its laccase

Phenanthrene is a three-ring polycyclic aromatic hydrocarbon and commonly found as a pollutant in various environments. Degradation of phenanthrene by white rot fungus Trametes versicolor 951022 and its laccase, isolated in Korea, was investigated. After 36 h of incubation, about 46% and 65% of 100 mg/l of phenanthrene added in shaken and static fungal cultures were removed, respectively. Phenanthrene degradation was maximal at pH 6 and the optimal temperature for phenanthrene removal was 30 degrees C. Although the removal percentage of phenanthrene was highest (76.7%) at 10 mg/l of phenanthrene concentration, the transformation rate was maximal (0.82 mg/h) at 100 mg/L of phenanthrene concentration in the fungal culture. When the purified laccase of T versicolor 951022 reacted with phenanthrene, phenanthrene was not transformed. The addition of redox mediator, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) or 1-hydroxybenzotriazole (HBT) to the reaction mixture increased oxidation of phenanthrene by laccase about 40% and 30%, respectively.     

<Emphasis Type="Italic">Brettanomyces bruxellensis</Emphasis>: effect of oxygen on growth and acetic acid production

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production.     

Biodegradation of endocrine-disrupting phthalates by Pleurotus ostreatus

Biodegradation of endocrine-disrupting phthalates [diethyl phthalate (DEP), dimethyl phthalate (DMP), butylbenzyl phthalate (BBP)] was investigated with 10 white rot fungi isolated in Korea. When the fungal mycelia were added together with 100 mg/l of phthalate into yeast extract-malt extract-glucose (YMG) medium, Pleurotus ostreatus, Irpex lacteus, Polyporus brumalis, Merulius tremellosus, Trametes versicolor, and T. versicolor MrP1 and MrP13 (transformant of the Mn-repressed peroxidase gene of T. versicolor) could remove almost all of the 3 kinds of phthalates within 12 days of incubation. When the phthalates were added to 5-day pregrown fungal cultures, most fungi except I. lacteus showed the increased removal of the phthalates compared with those of the nonpregrown cultures. In both culture conditions, P. ostreatus showed the highest degradation rates for the 3 phthalates tested. BBP was degraded with the highest rates among the 3 phthalates by all fungal strains. Only 14.9% of 100 mg/l BBP was degraded by the supernatant of P. ostreatus culture in YMG medium in 4 days of incubation, but the washed or homogenized mycelium of P. ostreatus could remove 100% of BBP within 2 days even in distilled water, indicating that the initial BBP biodegradation by P. ostreatus may be attributed to mycelium-associated enzymes rather than extracellular enzymes. The biodegradation rate of BBP by the immobilized cells of P. ostreatus was almost the same as that in the suspended culture. The estrogenic activity of 100 mg/l DMP decreased during biodegradation by P. ostreatus.     

Uptake of cadmium ions in white-rot fungus Trametes versicolor: effect of cd (II) ions on the activity of laccase

The effects of cadmium Cd (II) ions on the physiology and biological activity of Trametes versicolor, a strain belonging to white-rotting Basidiomycetes, were examined. Cd (II) ions were added to 10-day-old cultures grown on a liquid medium, or at the time of inoculation. Our experiments showed that T. versicolor is a good cadmium biosorbent from aqueous solution, this strain removing almost all the Cd (ll) ions over the first 2h of incubation by what appears to be a rapid, energy-independent surface binding phenomenon, at the rate of approximately 2mg Cd per g mycelial dry weight. An additional slower and energy-dependent transport mechanism was also present, taking in approximately 0.3mg Cd (II) perg dry weight. It is also shown that these Cd (II) ions significantly stimulate the activity of extracellular laccase when added to 10-day-old cultures.     

Degradation of pentachlorophenol by a Flavobacterium species grown in continuous culture under various nutrient limitations

A Flavobacterium sp. was grown in continuous culture limited for growth with ammonium, phosphate, sulfate, glucose, glucose + pentachlorophenol (PCP) (0.065 h -1), or PCP. Cells ere harvested, washed, and suspended to 3 x 10(7) cells ml (-1) in shake flasks containing a complete mineral salts medium without added carbon or supplemented with 50 mg of PCP ml(-1) or 50 mg of PCP ml(-1) + 100 mg of glucose ml(-1). The PCP concentration and the viable cell density were determined periodically. Cells that were grown under phosphate, glucose, or glucose + PCP limitation were more sensitive to PCP and took longer to degrade 50 mg of PCP ml(-1) than did cells that very were grown under ammonium, sulfate, or PCP limitation. Glucose stimulated viability and PCP degradation in all cases except when the cells were grown under carbon limitation with glucose and PCP added together as the carbon source. These results indicate that there is a relationship between nutrient limitation, phenotypic variation, and the sensitivity to and degradation of PCP by this organism.     

Degradation of pentachlorophenol by a Flavobacterium species grown in continuous culture under various nutrient limitations.

A Flavobacterium sp. was grown in continuous culture limited for growth with ammonium, phosphate, sulfate, glucose, glucose + pentachlorophenol (PCP) (0.065 h -1), or PCP. Cells ere harvested, washed, and suspended to 3 x 10(7) cells ml (-1) in shake flasks containing a complete mineral salts medium without added carbon or supplemented with 50 mg of PCP ml(-1) or 50 mg of PCP ml(-1) + 100 mg of glucose ml(-1). The PCP concentration and the viable cell density were determined periodically. Cells that were grown under phosphate, glucose, or glucose + PCP limitation were more sensitive to PCP and took longer to degrade 50 mg of PCP ml(-1) than did cells that very were grown under ammonium, sulfate, or PCP limitation. Glucose stimulated viability and PCP degradation in all cases except when the cells were grown under carbon limitation with glucose and PCP added together as the carbon source. These results indicate that there is a relationship between nutrient limitation, phenotypic variation, and the sensitivity to and degradation of PCP by this organism.     

Natural cytotoxic activity in seabream (Sparus aurata L.) and its modulation by vitamin C

Growth of pathogen bacterium. Enterococcus was not affected in tryptic soy broth (TSB) medium containing ammonia-N concentration in the range of 0-5.14 mg l(-1). Giant freshwater prawn Macrobrachium rosenbergii (8-12 g) were challenged with Enterococcus which had been incubated for 24 h in TSB medium containing different concentrations of ammonia-N at 0-5.14 mg l(-1) Cumulative mortality of M. rosenbergii was higher for the bacteria incubated in TSB medium having ammonia-N at 0 and 0.26 mg l(-1), than those incubated in TSB medium having 1.28, 2.57 and 5.14 mg l(-1) ammonia-N after 24 h of challenge. However, cumulative mortality of prawn was significantly higher for the bacteria incubated in TSB medium with no ammonia added after 120 h of challenge. The prawns (8-12 g) were challenged with Enterococcus previously incubated in TSB medium for 24 h, then placed in water having concentrations of ammonia-N at control (0.06 mg l(-1)), 0.55, 1.01, 1.68 and 3.18 mg l(-1). Mortality of prawns increased directly with ammonia-N concentrations after 72 h challenge. The pranws (20-30 g) which had been exposed to control, 0.55, 1.68 and 3.18 mg (-1) ammonia-N for 7 days were examined for the total haemocyte count (THC), differential haemocyte count (DHC), phenoloxidase activity and respiratory burst of haemocytes. Phenoloxidase activity decreased when the prawns were exposed to ammonia-N greater than 0.55 mg l(-1). The respiratory burst increased significantly at 0.55 mg l(-1) but decreased significantly at 1.68 and 3.18mg (-1) ammonia-N. No significant difference in haemocyte count was observed among the prawns at different ammonia-N concentrations. It is suggested that ammonia in water decreases the virulence of Enterococcus, and reduces the immune resistance of M. rosenbergii.     

Decoloration of Amaranth by the white-rot fungus Trametes versicolor. Part I. Statistical analysis

The white-rot fungus Trametes versicolor decolorized the mono-azo-substituted naphthalenic dye Amaranth. The relationship between the amount of enzymes present in the system and the efficiency of the decoloration process was investigated. The two responses used to quantify the process of decoloration (i.e., initial decoloration rate, v0, and the percent concentration of dye decolorized in 1 h, %c) were correlated with the amount of three enzymes considered for the study (lignin peroxidase, manganese peroxidase, and laccase) and analyzed through stepwise regression analysis (forward, backward, and mixed). The results of the correlation analysis and those of the regression analysis indicated that lignin peroxidase is the enzyme having the greatest influence on the two responses.     

Effects of Rapeseed Oil on Activity of Methylmalonyl-CoA Carboxyltransferase in Culture of Streptomyces fradiae

To investigate why more tylosin was produced when Streptomyces fradiae T1558 was cultured in a rapeseed oil medium than in a glucose or starch medium, we measured the activity of methylmalonyl-CoA carboxyltransferase (EC 2.1.3.1) and intracellular propionic acid. The activity of the enzyme, which catalyzes the formation of the precursor of tylosin, protylonolide, was 0.19 U/mg protein in 5 days of culture in rapeseed oil medium, which was 2.5- and 1.3-fold that with the glucose or starch medium, respectively. The intracellular propionic acid concentration was 1.2 g/g of dry weight, which was 4.3- and 2.1-fold that with the glucose or starch medium, respectively. The addition of propionic acid increased tylosin production in batch culture: when 0.2 g/l (final concentration) propionic acid was added to the glucose medium, 3.8 g/l tylosin was produced in 10 days of culture, 4.7-fold the amount without propionic acid. These findings suggest that in glucose medium, intracellular propionic acid is a limiting factor because of the low activity of methylmalonyl-CoA carboxyltransferase of the tylosin biosynthesis pathway.     

Contribution of manganese peroxidase and laccase to dye decoloration by Trametes versicolor

During dye decoloration by Trametes versicolor ATCC 20869 in modified Kirk’s medium, manganese peroxidase (MnP) and laccase were produced, but not lignin peroxidase, cellobiose dehydrogenase or manganese-independent peroxidase. Purified MnP decolorized azo dyes [amaranth, reactive black 5 (RB5) and Cibacron brilliant yellow] in Mn²⁺-dependent reactions but did not decolorize an anthraquinone dye [Remazol brilliant blue R (RBBR)]. However, the purified laccase decolorized RBBR five to ten times faster than the azo dyes and the addition of a redox mediator, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), did not alter decoloration rates. Amaranth and RB5 were decolorized the most rapidly by MnP since they have a hydroxyl group in an ortho position and a sulfonate group in the meta position relative to the azo bond. During a typical batch decoloration with the fungal culture, the ratio of laccase:MnP was 10:1 to 20:1 (based on enzyme activity) and increased to greater than 30:1 after decoloration was complete. Since MnP decolorized amaranth about 30 times more rapidly than laccase per unit of enzyme activity, MnP should have contributed more to decoloration than laccase in batch cultures.     

Kinetics of growth and ethanol production on different carbon substrates using genetically engineered xylose-fermenting yeast

Saccharomyces cerevisiae 424A (LNH-ST) strain was used for fermentation of glucose and xylose. Growth kinetics and ethanol productivity were calculated for batch fermentation on media containing different combinations of glucose and xylose to give a final sugar concentration of 20+/-0.8 g/L. Growth rates obtained in pure xylose-based medium were less than those for media containing pure glucose and glucose-xylose mixtures. A maximum specific growth rate micro(max) of 0.291 h(-1) was obtained in YPD medium containing 20 g/L glucose as compared to 0.206 h(-1) in YPX medium containing 20 g/L xylose. In media containing combinations of glucose and xylose, glucose was exhausted first followed by xylose. Ethanol production on pure xylose entered log phase during the 12-24h period as compared to the 4-10h for pure glucose based medium using 2% inoculum. When glucose was added to fermentation flasks which had been initiated on a pure xylose-based medium, the rate of xylose usage was reduced indicating cosubstrate inhibition of xylose consumption by glucose.     

Structural changes of plant residues during decomposition in a compost environment

The degradation of plant material during composting was investigated qualitatively by scanning electron microscopy (SEM) and quantitatively by chemical methods. Decomposition of Miscanthus (Miscanthus oogiformis L.), hemp (Cannabis sativa L.) and wheat (Triticum aestivum L.) straw was observed by placing litterbags containing these materials in compost piles. Hemp and Miscanthus straw were more stable than wheat straw, but the two materials differed in the way they were degraded despite similar chemical compositions. Hemp straw was broken down in more flexible structures compared to the rigid breakdown of Miscanthus straw. It was concluded that the anatomical arrangement of the tissue is just as important as the content of recalcitrant compounds in determining decomposition rate. Thus, when using composted plant materials as growing medium, the choice of material must depend not only on nutritional quality but also on structural quality. This study indicated that hemp material might be a good structural component in a compost to be used as a growing medium.