Tamotsu Hoshino

National Institute of Advanced Industrial Science and Technology

Sclerotinia borealis is among the most psychrophilic snow mold pathogen, mainly attacking Poaceae crops such as winter wheat and forage grasses as well as non-Poaceae plants under snow. Isolates were collected through the extensive surveys from North Atlantic islands through European and Asian Russia to Japan. Morphological characterization as well...

Typhulaceae Jülich is one of the cold-adapted fungal families in basidiomycetes. The representative genera, Typhula (Pers.) Fr. and Pistillaria Fr., are distinguished by the discontinuity between stems and hymenia in the former and the continuity in the latter (Fries 1821). This taxonomic criterion is ambiguous, and consequently, the view of Karste...

Typhulaceae Jülich is one of the cold-adapted fungal families in basidiomycetes. Typhula (Pers.) Fr. and Pistillaria Fr. representing the family are distinguished from the morphology of a stipe to a hymenium (Fries 1821). The hymenium of Typhula is distinguishable from the stipe, but indistinguishable and consecutive in the genus Pistillaria. This...

Typhula ishikariensis and the related fungi were separated into three biological species by morphological and physiological characteristics, as well as DNA sequences and mating reactions. We propose that the T. ishikariensis complex should be divided into three species (T. ishikariensis, T. canadensis and T. hyperborea) and two varieties (T. ishika...

Globisporangium spp. are soil-inhabiting oomycetes distributed worldwide, including in polar regions. Some species of the genus are known as important plant pathogens. This study aimed to clarify the species construction of Globisporangium spp. and their long-term isolation pattern in Sanionia moss in Ny-Ålesund, Spitsbergen Is., Norway. Globispora...

The basidiomycetous yeast, Glaciozyma antarctica, was isolated from various terrestrial materials collected from the Sôya coast, East Antarctica, and formed frost-columnar colonies on agar plates frozen at −1 °C. Thawed colonies were highly viscous, indicating that the yeast produced a large number of extracellular polysaccharides (EPS). G. antarct...

An isolate of a novel fungus and an isolate of a novel fungus-like microbe were obtained during field research conducted in Kuujjuarapik-Whapmagoostui, Quebec, in subarctic Canada, located on the southeastern coast of Hudson Bay, from August to September 2016. The isolates were identified as a Typhula sp. and Globisporangium sp. (syn. Pythium sp.),...

Arctic ecosystems are altered profoundly by climate changes. However, the responses of Arctic marine and terrestrial ecosystems as well as their biodiversity to global warming remain largely unknown. This article provides comprehensive insights into the results and major findings from the Arctic Challenge for Sustainability (ArCS) Project – an Arct...

Basidiomycetous yeast species of the genus Mrakia have been reported from a variety of extreme cold environments such as polar regions, glaciers, and high mountains. Several reports indicate that fungal species within the genus Mrakia occupy a major mycoflora in Antarctic environments. These results strongly suggest that this genus is well adapted...

Thermotolerant yeast Kluyveromyces marxianus can assimilate xylose but cannot produce ethanol from xylose under anaerobic conditions. Here, we constructed two recombinant K. marxianus strains, DMB5 and DMB13, that express xylose reductase (XR), NAD+- or protein-engineered NADP+-dependent xylitol dehydrogenase (XDH), and xylulokinase (XK) from K. ma...

An aerobic, Gram-negative, non-sporulating, motile, rod-shaped and lignin-degrading bacterial strain, Pseudomonas sp. CCA1, was isolated from leaf soil collected in Japan. This strain grew at 20–45 °C (optimum 20 °C), at pH 5.0–10.0 (optimum pH 5.0), and in the presence of 2% NaCl. Its major cellular fatty acids were C16:0 and summed feature 8 (C18...

Various microbes, including fungi and bacteria, that live in cold environments produce ice‐binding proteins (IBPs) that protect them from freezing. Ascomycota and Basidiomycota are two major phyla of fungi, and Antarctomyces psychrotrophicus is currently designated as the sole ascomycete that produces IBP (AnpIBP). However, its complete amino acid...

Talaromyces cellulolyticus is expected to become an industrial cellulase producer. In this study, we performed deletion analysis of the promoter region of the GH7 endoglucanase gene (cel7B), which encodes one of the major cellulases, using a β-glucuronidase reporter system. To obtain strains that harbor each gene cassette at the same locus, we had...

Designing a tailor-made synergistic system is a promising strategy for developing an effective enzyme for saccharification of lignocellulosic materials. In this study, a cellulolytic enzyme mixture comprising selected core recombinant enzymes for hydrolysis of sugarcane bagasse pretreated by alkaline-catalyzed steam explosion was optimized using a...

Acetoin is used in the biochemical, chemical and pharmaceutical industries. Several effective methods for acetoin production from petroleum-based substrates have been developed, but they all have an environmental impact and do not meet sustainability criteria. Here we describe a simple and efficient method for acetoin production from oil palm mesoc...

Objective A lignin-degrading bacterium, Burkholderia sp. CCA53, was previously isolated from leaf soil. The purpose of this study was to determine phenotypic and biochemical features of Burkholderia sp. CCA53. Results Multilocus sequence typing (MLST) analysis based on fragments of the atpD, gltD, gyrB, lepA, recA and trpB gene sequences was perfo...

We collected snow blight of moss, Polytrichum juniperinum on King George Island, maritime Antarctica. Host died in a circle of about 10–30 cm after snow melts. Clamp connected hyphae and no sclerotia were observed on tip of host leaves. DNA sequence of ITS region from moss symptoms were perfectly matched with fruit bodies of Typhula sp. on Macquari...

A stable NADP⁺-dependent d-amino acid dehydrogenase (DAADH) was recently created from Ureibacillus thermosphaericus meso-diaminopimelate dehydrogenase through site-directed mutagenesis. To produce a novel DAADH mutant with different substrate specificity, the crystal structure of apo-DAADH was determined at a resolution of 1.78 Å, and the amino aci...

To generate an organism capable of producing D-lactate, NAD⁺-dependent D-lactate dehydrogenase was expressed in our pyruvate-producing strain, Escherichia coli strain LAFCPCPt-accBC-aceE. After determining the optimal culture conditions for D-lactate production, 18.4 mM D-lactate was produced from biomass-based medium without supplemental mineral o...

We previously showed that overexpression of IoGAS1, which was isolated from the multiple stress-tolerant yeast Issatchenkia orientalis, endows Saccharomyces cerevisiae cells with the ability to grow and ferment under acidic and high-salt conditions. The deduced amino acid sequence of the IoGAS1 gene product exhibits 60% identity with the S. cerevis...

The plasmodium of Badhamia alpina thrived at lower temperatures (4 °C), and formed fruiting bodies at 8 °C. The yellow sclerotium and plasmodium were found inside a hollow, dead herbaceous stem under melting snow in Apr, and was cultured in moist chambers at 4 °C. The plasmodium did not form fruiting bodies for 6 wk at 4 °C. Sporulation was observe...

A transformant of Moorella thermoacetica was constructed for thermophilic ethanol production from lignocellulosic biomass by deleting two phosphotransacetylase genes, pdul1 and pdul2, and introducing the native aldehyde dehydrogenase gene (aldh) controlled by the promoter from glyceraldehyde-3-phosphate dehydrogenase. The transformant showed tolera...

The pentose phosphate pathway (PPP) plays an important role in the efficiency of xylose fermentation during cellulosic ethanol production. In simultaneous saccharification and co-fermentation (SSCF), the optimal temperature for cellulase hydrolysis of lignocellulose is much higher than that of fermentation. Successful use of SSCF requires optimizat...

Pseudomonas sp. strain CCA1 was isolated from leaf soil collected in Higashi-Hiroshima City in Hiroshima Prefecture, Japan. Here, we present a draft genome sequence of this strain. The genome consists of 24 contigs for a total of 6,993,992 bp, 8,917 predicted coding sequences, and a GC content of 67.2%.

Microbial degradation of lignin releases fermentable sugars, effective utilization of which could support biofuel production from lignocellulosic biomass. In the present study, a lignin-degrading bacterium was isolated from leaf soil and identified as Burkholderia sp. based on 16S rRNA gene sequencing. This strain was named CCA53, and its lignin-de...

Typhula winter rot on overwintering carrots caused by Typhula variabilis is a newly confirmed disease, and no practical control measure is yet available. To develop a control method, here we researched the infection period of T. variabilis and the time that winter rot appeared on carrots. Using spore traps, we found that basidiospore rain occurred...

Here we describe the screening and characterization of a lignin-degrading bacterium from an environmental sample. The bacterium was isolated from leaf soil and identified as Pseudomonas sp. strain CCA1 based on 16S rRNA gene sequencing. Although identified as able to degrade lignin in our screen, the ligninolytic activityof this strain was weak. No...

Pyruvate plays an essential role in the central carbon metabolism of multiple organisms and is used as a raw material in the chemical, biochemical and pharmaceutical industries. To meet demand, large amounts of pyruvate are produced through fermentation processes. Here we describe a simple and efficient method for producing pyruvate in Escherichia...

The use of yeasts tolerant to acid (low pH) and salt stress is of industrial importance for several bioproduction processes. To identify new candidate genes having potential roles in low-pH tolerance, we screened an expression genomic DNA library of a multiple-stress-tolerant yeast, Issatchenkia orientalis (Pichia kudriavzevii), for clones that all...

Inoculation of carrot roots with Typhula spp. revealed that T. variabilis Riess and T. japonica Terui cause decay of carrot roots under snow, with rotting of the root crown. T. variabilis was more virulent than T. japonica. These fungi and T. incarnata Lasch: Fr., also attacked rapeseeds during the winter, and rapeseed leaves became blighted, bleac...

Burkholderia sp. strain CCA53 was isolated from leaf soil collected in Higashi-Hiroshima City in Hiroshima Prefecture, Japan. Here, we present a draft genome sequence of this strain, which consists of a total of 4 contigs containing 6,647,893 bp, with a G+C content of 67.0% and comprising 9,329 predicted coding sequences.

We obtained strains with the xylanase regulator gene, xlnR, overexpressed (HXlnR) and disrupted (DXlnR) derived from Talaromyces cellulolyticus strain C-1, which is a cellulase hyperproducing mutant. Filter paper degrading enzyme activity and cellobiohydrolase I gene expression was the highest in HXlnR, followed by C-1 and DXlnR. These results indi...

Based on the results of DNA-DNA hybridization and 16S rRNA gene sequence analyses, it was ascertained that the type strain of Moorella thermoautotrophica does not exist in any established culture collection or with the authors who originally described this species. Therefore, this species cannot be included in any further scientific studies. It is...

In the present study, a fungal strain isolated from the Antarctic soil was identified as Penicillium sp. CHY-2 based on its 5.8S rRNA gene sequence analysis. Furthermore, its biodegradation ability towards 13 different toxic compounds such as 4-butylphenol (4-BP), 4-sec-butylphenol (4-s-BP), 4-tert-butylphenol (4-t-BP), 4-nonylphenol (4-NP), 4-tert...

Despite feather fungi being an important component of the Arctic fungal flora, their ecological role and diversity is not fully known. In the current study, fungal cultures were isolated from feathers (barnacle goose, common eider and glaucous gull) collected in the Ny-Ålesund region, Svalbard. Isolates were identified by ITS region sequences, whic...

The open reading frame YGL157w in the genome of the yeast Kluyveromyces marxianus strain DMB1 encodes a putative uncharacterized oxidoreductase. However, this protein shows 46% identity with the Saccharomyces cerevisiae S288c NADPH-dependent methylglyoxal reductase, which exhibits broad substrate specificity for aldehydes. In the present study, the...

Moorella thermoacetica is an anaerobic thermophilic acetogen that is capable of fermenting sugars, H2/CO2 and syngas (H2/CO). For this reason, this bacterium is potentially useful for biotechnology applications, particularly the production of biofuel from CO2. A soil isolate of M. thermoacetica, strain Y72, produces both ethanol and acetate from H2...

The Saccharomyces cerevisiae HAP4 gene encodes a transcription activator that plays a key role in controlling the expression of genes involved in mitochondrial respiration and reductive pathways. This work examines the effect of knockout of the HAP4 gene on aerobic ethanol production in a xylose-utilizing S. cerevisiae strain. A hap4-deleted recomb...

Twenty-seven strains of basidiomycetous yeast Mrakia spp. were collected from lake sediment and soil surrounding the lakes in the Skarvsnes area, East Antarctica. Based on sequence similarity of their ribosomal internal transcribed spacer regions and D1/D2 domains, the isolated strains were classified into three species; Mrakia blollopis (18 strain...

Two genes from Kluyveromyces marxianus strain DMB1, YGL039w1 and YGL039w2, encode putative uncharacterized oxidoreductases that respectively share 42% and 44% identity with the Saccharomyces cerevisiae S288c NADPH-dependent methylglyoxal reductase (EC 1.1.1.283). To determine the enzymatic characteristics of their products, the two genes were expre...

We have redefined Typhula variabilis, T. laschii, T. intermedia, and T. japonica on the basis of morphological and molecular evidence. Typhula variabilis, T. laschii, and T. intermedia, hitherto regarded as synonymous, were compared by critical observations of sclerotial rind cells. Rind cells of T. variabilis were thick and plateaued in the center...

Milk fat curdle is difficult to remove from sewage. In an attempt to identify an appropriate agent for bio-remediation of milk fat curdle, Mrakia strains were collected from the Skarvsnes ice-free area of Antarctica. A total of 27 strains were isolated and tested for their ability to decompose milk fat at temperatures ranging from 4°C to 15°C. All...

Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free myce...

Mrakia blollopis strain SK-4 was isolated from an algal mat of Naga-ike, a lake in Skarvsnes, East Antarctica. Here, we report the draft genome sequence of M. blollopis SK-4. This is the first report on the genome sequence of any cold-adapted fungal species.

Isobutanol is attracting attention as a potential biofuel because it has higher energy density and lower hygroscopicity than ethanol. To date, several effective methods for microbial production of isobutanol have been developed, but they require expensive reagents to maintain expression plasmids and induce expression, which is not suitable for prac...

In this study, we describe a novel method for producing valuable chemicals from glucose and xylose in Escherichia coli. The notable features in our method are avoidance of plasmids and expensive inducers for foreign gene expression to reduce production costs; foreign genes are knocked into the chromosome, and their expression is induced with xylose...

Flocculation is a desirable property in industrial yeasts and is particularly important in the fuel ethanol industry because it provides a simple and cost-free way to separate yeast cells from fermentation products. In the present study, the effect of pH and lignocellulose-derived sugars on yeast flocculation was investigated using a flocculent Sac...

We determined the genome sequence of a thermotolerant yeast, Kluyveromyces marxianus strain DMB1, isolated from sugarcane bagasse hydrolysate, and the sequence provides further insights into the genomic differences between this strain and other reported K. marxianus strains. The genome described here is composed of 11,165,408 bases and has 4,943 pr...

Metagenomic screening and conventional cultivation have been used to exploit microbial lipolytic enzymes in nature.We used an indigenous forest soil (NS) and oil-fed enriched soil (OS) as microbial and genetic resources. Thirty-four strains (17 each) of lipolytic bacteria were isolated from the NS and OS microcosms. These isolates were classified i...

We examined three specimens of sclerotia from Tashkent Province, Uzbekistan collected in April 1957. Phylogenetic results suggested that the collected fungi were highest homology (98.0%) to snow mold, Typhula sp. in Iran. Rind cells of collected fungi were lobate and gently rough closely morphologically similar to Typhula subvariabilis.

There has been much research on the bioconversion of xylose found in lignocellulosic biomass to ethanol by genetically engineered Saccharomyces cerevisiae. However, the rate of ethanol production from xylose in these xylose-utilizing yeast strains is quite low compared to their glucose fermentation. In this study, two diploid xylose-utilizing S. ce...

A psychrophilic yeast species was isolated from glacier cryoconite holes of Svalbard. Nucleotide sequences of the strainswere studied using D1/D2 domain, ITS region and partial sequences of mitochondrial cytochrome b gene. The strains belonged to a clade of psychrophilic yeasts, but showed marked differences from related species in the D1/D2 domain...

The Antarctic basidiomycetous yeast Mrakia blollopis SK-4 can quite uniquely ferment various sugars under low temperature conditions. When strain SK-4 fermented lignocellulosic biomass using the direct ethanol fermentation (DEF) technique, approximately 30% to 65% of the theoretical ethanol yield was obtained without and with the addition of the no...

A term «psychrophilic» or «psychrotolerant» to describe the low-temperature fungi widely applied in mycology. The term was introduced to describe the low-temperature bacteria by Morita. Quite recently, Japanese scientists Tamotsu Hoshino and Naoyuki Matsumoto proposed a new term for the low-temperature fungicryophilic fungi, including some oomycete...

The cellulase producing fungal strain Y-94, isolated in Japan and invalidly described as Acremonium cellulolyticus nom. nud. strain Y-94, seldom forms enteroarthric conidia under nutrient starvation conditions. Phylogenetic analysis using ITS1-5.8S-ITS2 and RNA polymerase II large subunit gene sequences revealed that strain Y-94 is closely related...

The Antarctic basidiomycetous yeast Mrakia blollopis SK-4 fermented ethanol between pH 5.0 and pH 10.0 with optimum pH at 8.0-10.0. Knowledge of ethanol fermentability as to the genus Mrakia remains incomplete. Further experiments are required to elucidate the ethanol fermentability of genus e.g., as to optimum fermentation pH, optimum fermentation...

We determined a draft genome sequence for Moorella thermoacetica strain Y72, a syngas-assimilating bacterium with high transformation efficiency. This strain was confirmed to be M. thermoacetica because its overall genome sequence characteristics were similar to those of M. thermoacetica strain ATCC39073. Y72 was confirmed to carry all the genes en...

The Antarctic sea ice diatom Navicular glaciei produced ice-binding protein (NagIBP) that is similar to the antifreeze protein (TisAFP) from snow mold Typhula ishikariensis. In the thermal hysteresis range of NagIBP, ice growth was completely inhibited. At the freezing point, the ice grew in a burst to 6 direction perdicular to the c-axis of ice cr...

Hokkaido, the northernmost island of Japan, may roughly be divided into the Sclerotinia area in eastern part and the Typhula area in western part based on the occurrence of snow molds. The Sclerotinia area is characterized by deep soil frost and thin snow cover and the Typhula area by unfrozen soil and thick snow cover. The distinction is not absol...

Snow molds attack dormant plants, such as forage crops, winter cereals, and conifer seedlings, at low temperatures under snow cover. These fungi belong to various taxa (oomycetes, ascomycetes, and basidiomycetes). Oomycetes, Pythium spp. were reported to be less tolerant to chilling and freezing temperatures than other fungal taxa. Free mycelia and...

Phytopathogenic fungi and fungal-like microbes occur frequently on moss and vascular plant species in polar regions. Characterization of the pathogens is important because they can affect individual growth and community structure in many wild plants. This review documents taxonomical and ecological features of phytopathogenic fungi and fungal-like...

Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified to date. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) buta...

A total of 71 isolates were collected from lake sediment and soil surrounding lakes in the Skarvsnes area, Antarctica. Based on ITS region sequence similarity, these isolates were classified to 10 genera. Twenty-three isolates were categorized as ascomycetous fungi from five genera (Embellisia, Phoma, Geomyces, Tetracladium or Thelebolus) and 48 is...

We constructed a xylose-fermenting recombinant strain of thermotolerant yeast Kluyveromyces marxianus, DMB3-7. Both xylose consumption and ethanol production were remarkably increased in DMB3-7 compared to the control strain at 30°C. Furthermore, DMB3-7 produced ethanol from xylose at both 42°C and 45°C, above which xylose metabolic activity decrea...

In the present study, comprehensive, quantitative metabolome analysis was carried out on the recombinant glucose/xylose-cofermenting S. cerevisiae strain MA-R4 during fermentation with different carbon sources, including glucose, xylose, or glucose/xylose mixtures. Capillary electrophoresis time-of-flight mass spectrometry was used to determine the...

The yeast Kluyveromyces marxianus is considered as a potential alternative to Saccharomyces cerevisiae in producing ethanol as a biofuel. In this study, we investigated the ethanol fermentation properties of novel K. marxianus strain DMB1, isolated from bagasse hydrolysates. This strain utilized sorbitol as well as various pentoses and hexoses as s...

Antarctic basidiomycetous yeast Mrakia blollopis SK-4 has unique fermentability for various sugars under a low temperature condition. Hence, this yeast was used for ethanol fermentation from glucose and also for direct ethanol fermentation (DEF) from cellulosic biomass without/with Tween 80 at 10°C. Maximally, 48.2 g/l ethanol was formed from 12% (...

Ganoderic acid A and α- and β-D-glucan content were compared among morphologically different basidiocarps of the medicinal mushroom Ganoderma lucidum. Ginkgo leaf-shaped basidiocarps gradually hardened from the base to the pileus and accumulated a higher amount of bioactive components than normal (kidney-shaped) and antler/deer horn-shaped basidioc...

Milk fat curdle in sewage is one of the refractory materials for active sludge treatment under low temperature conditions. For the purpose of solving this problem by using a bio-remediation agent, we screened Antarctic yeasts and isolated SK-4 strain from algal mat of sediments of Naga-ike, a lake in Skarvsnes, East Antarctica. The yeast strain sho...

Effect of yeast extract on lipase production. Mrakia blollopis SK-4 was cultivated by lipase production medium (♦) and lipase production medium without yeast extract (•). (TIF)

SDS-PAGE of purified lipase from Mrakia blollopis SK-4. Lane 1. Molecular weight marker; 2. Purified lipase. (TIF)

The application of microbial catalysts to syngas from the gasification of lignocellulosic biomass is gaining interest. Acetogens, a group of anaerobic bacteria, can grow autotrophically on gaseous substrates such as hydrogen and carbon dioxide or syngas and produce acetate via the acetyl-CoA pathway. Here, we report the isolation from a soil sample...