Decolorization of oxygen-delignified bleaching effluent and biobleaching of oxygen-delignified kraft pulp by non-white-rot fungus Geotrichum candidum Dec 1.

Decolorization of oxygen-delignified bleaching effluent (abbreviated as OBE) and biobleaching of oxygen-delignified kraft pulp (OKP) were conducted using a non-white rot fungus Geotrichum candidum Dec 1 (abbreviated as Dec 1) which has ability to decolorize various synthetic dyes and molasses. Dec 1 decolorized up to 77% of OBE for 6 days. In addition, Dec 1 increased the brightness of OKP from 47.

Heterotrophic nitrification and aerobic denitrification of high-strength ammonium in anaerobically digested sludge by Alcaligenes faecalis strain No. 4.

Alcaligenes faecalis strain No. 4 which is capable of heterogeneous nitrification and aerobic denitrification, was used to remove high-strength ammonium (approximately 1 g NH4(+)-N/l) from digested sludge, the product of an anaerobic digestion reactor, in which methane was produced from excess municipal sewage sludge. Repeated batch operations were conducted at 20°C and 30°C for 550 h, using a jar fermentor.

Formation of highly twisted ribbons in a carboxymethylcellulase gene-disrupted strain of a cellulose-producing bacterium.

Cellulases are enzymes that normally digest cellulose; however, some are known to play essential roles in cellulose biosynthesis. Although some endogenous cellulases of plants and cellulose-producing bacteria are reportedly involved in cellulose production, their functions in cellulose production are unknown. In this study, we demonstrated that disruption of the cellulase (carboxymethylcellulase) gene causes irregular packing of de novo-synthesized fibrils in Gluconacetobacter xylinus, a cellulose-producing bacterium.

Removal of xylene by a mixed culture of Pseudomonas sp. NBM21 and Rhodococcus sp. BTO62 in biofilter.

Xylene (a mixture of o-, m-, p-xylenes and ethylbenzene) gas removal was conducted in the a biofilter inoculated with a mixture of the m- and p-xylene-degraders, Pseudomonas sp. NBM21 and an o-xylene degrader, Rhodococcus sp. BTO62 under non-sterile conditions at 20 degrees C.

Purification and characterization of two DyP isozymes from Thanatephorus cucumeris Dec 1 specifically expressed in an air-membrane surface bioreactor.

DyP isozymes (DyP2 and DyP3) from the culture fluid of the fungus Thanatephorus cucumeris Dec 1 by air-membrane surface bioreactor were purified and characterized. The characteristics of DyP2 were almost the same as those of a recombinant DyP reported previously, but different from DyP3.

Solid state fermentation of lipopeptide antibiotic iturin A by using a novel solid state fermentation reactor system.

A new solid state fermentation reactor (SSFR) for solid substrate was used for the production of lipopeptide antibiotic iturin A using Bacillus subtilis RB14-CS. Solid state fermentation (SSF) is the technique of cultivation of microorganisms on solid and moist substrates in the absence of free water. SSF has shown much promise in the development of several bioprocesses and products because of their several advantages like absence of free water that allows simplified downstream processing and low cost.

Efficient dye decolorization and production of dye decolorizing enzymes by the basidiomycete Thanatephorus cucumeris Dec 1 in a liquid and solid hybrid culture.

Thanatephorus cucumeris Dec 1, a basidiomycete, is a promising decomposer of several xenobiotics. Air-membrane surface bioreactor culture (AMS culture), a hybrid between solid-state and submerged culture, was used for Dec 1 growth. The optimum temperature for AMS culture (25 degrees C) was lower than that for submerged culture (30 degrees C).

Degradation pathway of an anthraquinone dye catalyzed by a unique peroxidase DyP from Thanatephorus cucumeris Dec 1.

The reactants produced by action of a purified unique dye-decolorizing peroxidase, DyP, on a commercial anthraquinone dye, Reactive Blue 5, were investigated using electrospray ionization mass spectrometry (ESI-MS), thin-layer chromatography (TLC), and (1)H- and (13)C- nuclear magnetic resonance (NMR). The results of ESI-MS analysis showed that phthalic acid, a Product 2 (molecular weight 472.5), and a Product 3 (molecular weight 301.

Stimulation of anaerobic digestion of thickened sewage sludge by iron-rich sludge produced by the fenton method.

In batch mesophilic anaerobic digestion of a mixture of iron-rich sludge collected from Fenton treatment of molasses wastewater (MWW) and thickened sewage sludge from a municipal wastewater treatment plant, the methane content in the gas from the mixture was significantly higher than that from thickened sewage sludge only. When minerals in iron-rich sludge obtained by incineration were fed to thickened sewage sludge in semi-continuous experiments, the methane content obtained by digestion of thickened sewage sludge only increased approximately from 53% to 64%. These results suggest that iron-rich sludge can enhance methane production for thickened sewage sludge.

Stable repeated-batch production of recombinant dye-decolorizing peroxidase (rDyP) from Aspergillus oryzae.

Recombinant Aspergillus oryzae expressing a dye-decolorizing peroxidase gene (dyp) was cultivated for repeated-batch production of recombinant dye-decolorizing peroxidase (rDyP) using maltose as a carbon source. High-level rDyP activity in limitation of carbon and nitrogen sources was maintained stably for 26 cycles of repeated 1-d batches of A. oryzae pellets without any additional pH control.

Bioremediation of oil-contaminated soil using Candida catenulata and food waste.

Even though petroleum-degrading microorganisms are widely distributed in soil and water, they may not be present in sufficient numbers to achieve contaminant remediation. In such cases, it may be useful to inoculate the polluted area with highly effective petroleum-degrading microbial strains to augment the exiting ones. In order to identify a microbial strain for bioaugmentation of oil-contaminated soil, we isolated a microbial strain with high emulsification and petroleum hydrocarbon degradation efficiency of diesel fuel in culture.

Removal of COD and color from livestock wastewater by the Fenton method.

The Fenton method was applied to the removal of chemical oxygen demand using chromate (CODcr) and color from high-strength livestock wastewater in which the initial CODcr was 5000-5700 mg/L. The optimum ratio of H2O2 (mg/L) to the initial CODcr was 1.05 and the optimum molar ratio of H2O2/Fe2+ was 2.

DyP, a unique dye-decolorizing peroxidase, represents a novel heme peroxidase family: ASP171 replaces the distal histidine of classical peroxidases.

DyP, a unique dye-decolorizing enzyme from the fungus Thanatephorus cucumeris Dec 1, has been classified as a peroxidase but lacks homology to almost all other known plant peroxidases. The primary structure of DyP shows moderate sequence homology to only two known proteins: the peroxide-dependent phenol oxidase, TAP, and the hypothetical peroxidase, cpop21. Here, we show the first crystal structure of DyP and reveal that this protein has a unique tertiary structure with a distal heme region that differs from that of most other peroxidases.

Removal of o-xylene using biofilter inoculated with Rhodococcus sp. BTO62.

Rhodococcus sp. BTO62 was isolated from activated sludge from a wastewater treatment plant as an o-xylene-degrading microorganism. BOT62 degraded not only o-xylene, but also benzene, toluene, ethylbenzene, m- and p-xylenes and styrene (BTEXS).

Medium optimization of antifungal lipopeptide, iturin A, production by Bacillus subtilis in solid-state fermentation by response surface methodology.

Iturin A, a lipopeptide antibiotic produced by Bacillus subtilis RB14-CS, suppresses the growth of various plant pathogens. Here, enhancement of iturin A production in solid-state fermentation (SSF) on okara, a soybean curd residue produced during tofu manufacturing, was accomplished using statistical experimental design. Primary experiments showed that the concentrations of carbon and nitrogen sources were the main factors capable of enhancing iturin A production, whereas initial pH, initial water content, temperature, relative humidity, and volume of inoculum were only minor factors.

Production of dye-decolorizing peroxidase (rDyP) from complex substrates by repeated-batch and fed-batch cultures of recombinant Aspergillus oryzae.

We examined production levels of dye-decolorizing peroxidase (rDyP) by recombinant Aspergillus oryzae using wheat bran and rice bran powders in repeated-batch and fed-batch cultures. Similar average rDyP productivities were observed in repeated-batch cultures using wheat bran powder and rice bran powder. Average rDyP productivities in fed-batch cultures were slightly lower than those in repeated-batch cultures.

Improvement in ammonium removal efficiency in wastewater treatment by mixed culture of Alcaligenes faecalis no. 4 and L1.

To improve ammonium removal efficiency in wastewater treatment, a mixed culture of Alcaligenes faecalis no. 4 and its mutant L1, both of which have heterotrophic nitrification and aerobic denitrification abilities, was performed. In a batch culture, no.

Degradation of diesel oil in soil using a food waste composting process.

We investigated the simultaneous degradation of diesel oil in soil and the organic matter in food waste by composting in 8 l reactors. Using a 0.5 l/min air flow rate, and 0.

Removal of p-xylene with Pseudomonas sp. NBM21 in biofilter.

As a p-xylene (p-Xyl)-degrading microorganism, Pseudomonas sp. NBM21 was isolated from an activated sludge of a wastewater treatment plant. NBM21 degraded p-Xyl, m-xylene, benzene and toluene, but not o-xylene, ethylbenzene (Eb) and styrene.

Enhancement of styrene removal efficiency in biofilter by mixed cultures of Pseudomonas sp. SR-5.

The styrene-degrading bacterium Pseudomonas sp. SR-5 exhibited a high styrene removability in a biofilter. However, the styrene removal efficiency (RE) of SR-5 decreased with time.

Complete decolorization of the anthraquinone dye Reactive blue 5 by the concerted action of two peroxidases from Thanatephorus cucumeris Dec 1.

It is useful to identify and examine organisms that may prove useful for the treatment of dye-contaminated wastewater. Here, we report the purification and characterization of a new versatile peroxidase (VP) from the decolorizing microbe, Thanatephorus cucumeris Dec 1 (TcVP1). The purified TcVP1 after Mono P column chromatography showed a single band at 43 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Biofilm fermentation of iturin A by a recombinant strain of Bacillus subtilis 168.

Bacillus subtilis 168 produces thin and fragile biofilm in the static culture, however, it was found out that its transformant B. subtilis RM/iSd16 containing wild sfp, itu operon and degQ, which produced lipopeptide antibiotic iturin A, produced thick and much stable biofilm. Production of iturin A by RM/iSd16 in biofilm was almost two times higher compared to that in the submerged culture at 28 degrees C.

Piggery wastewater treatment using Alcaligenes faecalis strain No. 4 with heterotrophic nitrification and aerobic denitrification.

Alcaligenes faecalis strain No. 4, which has heterotrophic nitrification and aerobic denitrification abilities, was used to treat actual piggery wastewater containing high-strength ammonium under aerobic conditions. In a continuous experiment using a solids-free wastewater (SFW) mixed with feces, almost all of the 2000 NH4+ -N mg/L and 12,000 COD mg/L in the wastewater was removed and the ammonium removal rate was approximately 30 mg-N/L/h, which was 5-10 times higher than the rates achieved by other bacteria with the same abilities.

Second stage production of iturin A by induced germination of Bacillus subtilis RB14.

Bacillus subtilis RB14, a dual producer of lipopeptide antibiotics iturin A and surfactin undergoes sporulation in the submerged fermentation and the production of these secondary metabolites becomes halted. In this study, production of lipopeptide antibiotics was investigated by induced germination of the spores by heat-activation and nutrient supplementation. The induced spores became metabolically active vegetative state and produced lipopeptide antibiotic iturin A that added up the total production at the end of the fermentation.