Accelerated degradation of plastic products via yeast enzyme treatment.

Biodegradable plastics can solve the problem of unwanted plastics accumulating in the environment if they can be given the contradictory properties of durability in use and rapid degradation after use. Commercially available agricultural biodegradable mulch films are made from formulations containing polybutylene adipate-co-terephthalate (PBAT) to provide mechanical and UV resistance during the growing season. Although used films are ploughed into the soil using a tiller to promote decomposition, it is difficult if they remain durable.

Rain-induced bioecological resuspension of radiocaesium in a polluted forest in Japan.

It is the conventional understanding that rain removes aerosols from the atmosphere. However, the question of whether rain plays a role in releasing aerosols to the atmosphere has recently been posed by several researchers. In the present study, we show additional evidence for rain-induced aerosol emissions in a forest environment: the occurrence of radiocaesium-bearing aerosols in a Japanese forest due to rain.

In Vitro Assessment of Biocontrol Effects on Fusarium Head Blight and Deoxynivalenol (DON) Accumulation by DON-Degrading Bacteria.

Fusarium head blight (FHB) of cereals is a severe disease caused by the species complex. It leads to the accumulation of the mycotoxin deoxynivalenol (DON) in grains and other plant tissues and causes substantial economic losses throughout the world. DON is one of the most troublesome mycotoxins because it is a virulence factor to host plants, including wheat, and exhibits toxicity to plants and animals.

Draft Genome Sequence of Deoxynivalenol-Degrading Actinomycete Nocardioides sp. Strain LS1, Isolated from Wheat Leaves in Japan.

Actinomycete Nocardioides sp. strain LS1, isolated from wheat leaf, is a bacterium that degrades and assimilates the mycotoxin deoxynivalenol (DON) as the carbon source. This is the first study of the genome sequence of the DON-degrading genus Nocardioides, and it facilitates the study of genes encoding the DON-degrading pathway.

A teleomorph of the ustilaginalean yeast Moesziomyces antarcticus on barnyardgrass in Japan provides bioresources that degrade biodegradable plastics.

The basidiomycetous yeast Moesziomyces antarcticus (often cited as Pseudozyma antarctica), originally isolated from a sediment sample obtained from Lake Vanda in Antarctica, was asexually typified but closely related to the smut fungus Moesziomyces bullatus (Ustilaginales). We found a smut fungus on an ovary of barnyardgrass (Echinochloa crus-galli) in Japan, which had been identified as M. bullatus.

Pretreatment with an esterase from the yeast Pseudozyma antarctica accelerates biodegradation of plastic mulch film in soil under laboratory conditions.

The yeast Pseudozyma antarctica secretes a concentrated biodegradable plastic (BP)-degrading enzyme when cultivated with xylose. Treatment with the culture filtrate reduced the puncture strength of commercial BP mulch films. After burying the film in soil, the residual amount of solid film was reduced significantly, and none was recovered after 5 weeks.

Enzymatic degradation of poly-butylene succinate-co-adipate film in rice husks by yeast Pseudozyma antarctica in indoor conditions.

Agricultural mulch films made from biodegradable polymers (BP) have been used to decrease the burden of plastic waste recovery and recycling. However, their degradations depend largely on environmental conditions and sometimes do not proceed as desired. Yeast strains of Pseudozyma antarctica often isolated from rice husks were found to secrete an esterase to degrade BP films.

Phyllosphere Methylobacterium bacteria contain UVA-absorbing compounds.

Microbes inhabiting the phyllosphere encounter harmful ultraviolet rays, and must develop adaptive strategies against this irradiation. In this study, we screened bacterial isolates originating from the phyllosphere of various plants which harbored absorbers of ultraviolet A (UVA), a wavelength range which is recognized as harmful to human skin. Of the 200 phyllosphere bacterial isolates we screened, methanol extracts from bacterial cells of seventeen isolates absorbed wavelengths in the range of 315-400nm.

Draft Genome Sequence of the Fungus Paraphoma sp. B47-9, a Producer of a Biodegradable Plastic-Degrading Enzyme.

Paraphoma sp. B47-9 is a producer of a biodegradable plastic-degrading enzyme. Here, we report the draft genome sequence of this strain.

Biodegradable Plastic-degrading Activity of Various Species of Paraphoma.

The fungal strain B47-9, isolated from barley, was previously selected as an effective degrader of various biodegradable plastic (BP) films such as poly(butylene succinate-co-adipate) (PBSA) and poly(butylene succinate) (PBS). The strain has not been identified based on mycological methods because it does not form fruiting bodies, which are the key to morphological identification. Here, we performed molecular phylogenetic analyses of the nuclear ribosomal RNA gene regions and their internal transcribed spacer region of B47-9 and related fungi.

Enhancement of Biodegradable Plastic-degrading Enzyme Production from Paraphoma-like Fungus, Strain B47-9.

To improve the productivity of Paraphoma-like fungal strain B47-9 for biodegradable plastic (BP)-degrading enzyme (PCLE), the optimal concentration of emulsified poly(butylene succinate-co-adipate) (PBSA) in the medium was determined. Emulsified PBSA was consumed as a sole carbon source and an inducer of PCLE production by strain B47-9. Among the various concentrations of emulsified PBSA [0.

High-level recombinant protein production by the basidiomycetous yeast Pseudozyma antarctica under a xylose-inducible xylanase promoter.

Yeast host-vector systems are useful tools for the production of recombinant proteins. Here, we report the construction of a new high-level expression plasmid pPAX1-neo for the basidiomycetous yeast, Pseudozyma antarctica. pPAX1-neo harbours a xylose-inducible expression cassette under control of the xylanase promoter and terminator of P.

Simultaneous bioethanol distillery wastewater treatment and xylanase production by the phyllosphere yeast Pseudozyma antarctica GB-4(0).

Bioethanol production using lignocellulosic biomass generates lignocellulosic bioethanol distillery wastewater (LBDW) that contains a large amount of xylose, making it a potential inexpensive source of xylose for biomaterials production. The main goal of this study was the production of useful enzymes from LBDW during treatment of this wastewater. In this study, we found that xylose strongly induced two yeast strains, Pseudozyma antarctica T-34 and GB-4(0), to produce novel xylanases, PaXynT and PaXynG, respectively.

Application of yeast glycolipid biosurfactant, mannosylerythritol lipid, as agrospreaders.

The spreading property of mannosylerythritol lipids (MELs) was investigated in connection with our search for new application in agriculture. The wetting ability of MEL solutions for hydrophobic surfaces was evaluated based on contact angle measurements for several surfactant solutions on abiotic and biotic surfaces. The contact angle of MEL-A solution on a hydrophobic plastic surface at 100 s after placement decreased to 8.

Contribution of soil esterase to biodegradation of aliphatic polyester agricultural mulch film in cultivated soils.

The relationship between degradation speed of soil-buried biodegradable polyester film in a farmland and the characteristics of the predominant polyester-degrading soil microorganisms and enzymes were investigated to determine the BP-degrading ability of cultivated soils through characterization of the basal microbial activities and their transition in soils during BP film degradation. Degradation of poly(butylene succinate-co-adipate) (PBSA) film was evaluated in soil samples from different cultivated fields in Japan for 4 weeks. Both the degradation speed of the PBSA film and the esterase activity were found to be correlated with the ratio of colonies that produced clear zone on fungal minimum medium-agarose plate with emulsified PBSA to the total number colonies counted.

Mannosylerythritol lipids secreted by phyllosphere yeast Pseudozyma antarctica is associated with its filamentous growth and propagation on plant surfaces.

The biological function of mannosylerythritol lipids (MELs) towards their producer, Pseudozyma antarctica, on plant surfaces was investigated. MEL-producing wild-type strain and its MEL production-defective mutant strain (ΔPaEMT1) were compared in terms of their phenotypic traits on the surface of plastic plates, onion peels, and fresh leaves of rice and wheat. While wild-type cells adhering on plastic surfaces and onion peels changed morphologically from single cells to elongated ones for a short period of about 4 h and 1 day, respectively, ΔPaEMT1 cells did not.

Production of a biodegradable plastic-degrading enzyme from cheese whey by the phyllosphere yeast Pseudozyma antarctica GB-4(1)W.

Cheese whey is a by-product of cheese production and has high concentrations of lactose (about 5%) and other nutrients. Pseudozyma antarctica produces a unique cutinase-like enzyme, named PaE, that efficiently degrades biodegradable plastics. A previous study showed that a combination of 1% oil and 0.

Purification, characterization, and cloning of the gene for a biodegradable plastic-degrading enzyme from Paraphoma-related fungal strain B47-9.

Paraphoma-related fungal strain B47-9 secreted a biodegradable plastic (BP)-degrading enzyme which amounted to 68 % (w/w) of the total secreted proteins in a culture medium containing emulsified poly(butylene succinate-co-adipate) (PBSA) as sole carbon source. The gene for this enzyme was found to be composed of an open reading frame consisting of 681 nucleotides encoding 227 amino acids and two introns. Southern blot analysis showed that this gene exists as a single copy.

Xylose induces the phyllosphere yeast Pseudozyma antarctica to produce a cutinase-like enzyme which efficiently degrades biodegradable plastics.

There is a need to speed up the degradation of used agricultural mulch films that are made of biodegradable plastics (BPs) in the field. Treating them with BP-degrading enzymes could be a solution to this problem. A cutinase-like enzyme of yeast Pseudozyma antarctica (PaE) has wide specificity of BPs degradation, but needs to be produced efficiently.

Bacterial cytochrome P450 system catabolizing the Fusarium toxin deoxynivalenol.

Deoxynivalenol (DON) is a natural toxin of fungi that cause Fusarium head blight disease of wheat and other small-grain cereals. DON accumulates in infected grains and promotes the spread of the infection on wheat, posing serious problems to grain production. The elucidation of DON-catabolic genes and enzymes in DON-degrading microbes will provide new approaches to decrease DON contamination.

Affinity purification and characterization of a biodegradable plastic-degrading enzyme from a yeast isolated from the larval midgut of a stag beetle, Aegus laevicollis.

Two yeast strains, which have the ability to degrade biodegradable plastic films, were isolated from the larval midgut of a stag beetle, Aegus laevicollis. Both of them are most closely related to Cryptococcus magnus and could degrade biodegradable plastic (BP) films made of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) effectively. A BP-degrading enzyme was purified from the culture broth of one of the isolated strains employing a newly developed affinity purification method based on the binding action of the enzyme to the substrate (emulsified PBSA) and its subsequent degradative action toward the substrate.

Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants.

To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth indicated that it secreted a BP-degrading enzyme, and has directly contributing to accelerating the degradation of film.

Biodegradable plastic-degrading enzyme from Pseudozyma antarctica: cloning, sequencing, and characterization.

Pseudozyma antarctica JCM 10317 exhibits a strong degradation activity for biodegradable plastics (BPs) such as agricultural mulch films composed of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). An enzyme named PaE was isolated and the gene encoding PaE was cloned from the strain by functional complementation in Saccharomyces cerevisiae. The deduced amino acid sequence of PaE contains 198 amino acids with a predicted molecular weight of 20,362.

A novel actinomycete derived from wheat heads degrades deoxynivalenol in the grain of wheat and barley affected by Fusarium head blight.

Deoxynivalenol (DON) is a hazardous and globally prevalent mycotoxin in cereals. It commonly accumulates in the grain of wheat, barley and other small grain cereals affected by Fusarium head blight (caused by several Fusarium species). The concept of reducing DON in naturally contaminated grain of wheat or barley using a DON-degrading bacterium is promising but has not been accomplished.

Specificity of Pseudomonas isolates on healthy and Fusarium head blight-infected spikelets of wheat heads.

The specificity of culturable bacteria on healthy and Fusarium head blight (FHB)-infected spikelets of wheat heads was investigated to find a candidate of biocontrol agents against FHB. The bacterial genus Pseudomonas was commonly isolated from the tissues, and phylogenetic analysis using 16S ribosomal RNA gene sequences of isolates of the genera revealed that particular phylogenetic groups in the genus specifically inhabited either healthy or infected spikelet tissues. The specificity of each group was suggested to be due to differences in the ability to form biofilms and colonize spikelet tissues; isolates originated from healthy spikelets formed biofilms on polyvinyl chloride microplate wells and highly colonized the spikelet tissues.