• Journal of Forest and Environmental Science
• /
• v.27 no.3
• /
• pp.183-194
• /
• 2011

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.11
• /
• pp.1891-1907
• /
• 2016

Yeasts that are present in marine environments have evolved to survive hostile environments that are characterized by high exogenous salt content, high concentrations of inhibitory compounds, and low soluble carbon and nitrogen levels. Therefore, yeasts isolated from marine environments could have interesting characteristics for industrial applications. However, the application of marine yeast in research or industry is currently very limited owing to the lack of a suitable isolation method. Current methods for isolation suffer from fungal interference and/or low number of yeast isolates. In this paper, an efficient and non-laborious isolation method has been developed and successfully isolated large numbers of yeasts without bacterial or fungal growth. The new method includes a three-cycle enrichment step followed by an isolation step and a confirmation step. Using this method, 116 marine yeast strains were isolated from 14 marine samples collected in the UK, Egypt, and the USA. These strains were further evaluated for the utilization of fermentable sugars (glucose, xylose, mannitol, and galactose) using a phenotypic microarray assay. Seventeen strains with higher sugar utilization capacity than the reference terrestrial yeast Saccharomyces cerevisiae NCYC 2592 were selected for identification by sequencing of the ITS and D1/D2 domains. These strains belonged to six species: S. cerevisiae, Candida tropicalis, Candida viswanathii, Wickerhamomyces anomalus, Candida glabrata, and Pichia kudriavzevii. The ability of these strains for improved sugar utilization using seawater-based media was confirmed and, therefore, they could potentially be utilized in fermentations using marine biomass in seawater media, particularly for the production of bioethanol and other biochemical products.

• The Korean Journal of Mycology
• /
• v.52 no.1
• /
• pp.35-54
• /
• 2024

With a history spanning 9,000 years, yeast has played a central role in the traditional production of fermented foods, particularly alcohol and bakery. Recent research has highlighted the versatility of yeast in various industries, including the production of bioactive compounds, bioethanol, pigments, and enzymes, and as a host for molecular biology studies. In Korea, yeast isolation has traditionally focused on traditional fermented foods such as soybean paste. However, there is a growing trend in the isolation and characterization of yeasts from natural environments such as flowers and fruits for industrial applications. In this study, we isolated and identified 12 yeasts from various natural environments in Korea, including botanical gardens and parks that are not listed on the National Species List of Korea (NSLK). These newly discovered species included Sakaguchia oryzae, Cystobasidium raffinophilum, Meira argovae, Kazachstania humilis, Meyerozyma smithsonii, Anthracocystis trispicatae, Naganishia brisbanensis, Tremella yokohamensis, Kwoniella shandongensis, Kwoniella newhampshirensis, Aureobasidium proteae, and Rhodotorula dairenensis.

• Mycobiology
• /
• v.48 no.6
• /
• pp.501-511
• /
• 2020

Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host's indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 ℃, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.04a
• /
• pp.81-91
• /
• 2011

Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. Recently, a large amount of studies regarding the utilization of lignocellulosic biomass as a good feedstock for producing fuel ethanol is being carried out worldwide. The plant biomass is mainly composed of cellulose, hemicellulose and lignin. The main challenge in the conversion of biomass into ethanol is the complex, rigid and harsh structures which require efficient process and cost effective to break down. The isolation of microorganisms is one of the means for obtaining enzymes with properties suitable for industrial applications. For these reasons, crude cultures containing cellulosic biomass degrading microorganisms were isolated from rice field soil, cow farm soil and rotten rice straw from cow farm. Carboxymethyl cellulose (CMC), xylan and Avicel (microcrystalline cellulose) degradation zone of clearance on agar platefrom rice field soil resulted approximately at 25 mm, 24 mm and 22 mm respectively. As for cow farm soil, CMC, xylan and Avicel degradation clearancezone on agar plate resulted around at 24mm, 23mm and 21 mm respectively. Rotten rice straw from cow farm also resulted for CMC, xylan and Avicel degradation zone almost at 24 mm, 23 mm and 22 mm respectively. The objective of this study is to isolatebiomass degrading microbial strains having good efficiency in cellulose hydrolysis and observed the effects of different substrates (CMC, xylan and Avicel) on the production of cellulase enzymes (endo-glucanase, exo-glucanase, cellobiase, xylanase and avicelase) for producing low cost biofuel from cellulosic materials.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.2
• /
• pp.129-134
• /
• 2017

BACKGROUND: Yeasts are used in a variety of industries. However, most industries are biased toward Saccharomyces cerevisiae ; so we sought to explore non-conventional yeasts (NCY). This study aimed to isolate yeasts from seawater collected from the East Sea of Korea and to analyze the NCY. METHODS AND RESULTS: We first collected seawater and performed pure isolation using four kinds of medium (GPY, DOB + CSM, DG18, and SCG). In total, 314 strains and 17 genera were isolated by ITS sequencing, including Aureobasidum pullulans (236 strains), Cryptococcus (19 strains), Cystobasidium (18 strains), and Rhodotorula (9 strains). Upon in-depth analysis, A. pullulans, the most dominant genus (236 strains), was divided into Group II (147 strains), Unknown I (8 strains), and Unknown II (49 strains). CONCLUSION: In this study, a total of 314 strains were isolated from seawater; many of these yeasts have been found and reported in seawater previously. In-depth analysis of A. pullulans, showed the dominance of Group I (21 strains) and Group II (147 strains) We also discovered Unknown I (8 strains) and Unknown II (49 strains), which have not been reported previously.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.4
• /
• pp.828-834
• /
• 2010

An ethanol-producing yeast strain, CHFY0201, was isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w/v) ethanol at $30^{\circ}C$. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1+2 regions, suggested that the CHFY0201 was a novel strain of Schizosaccharomyces pombe. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. pombe CHFY0201 in YPD media containing 9.5% total sugars were $0.59{\pm}0.01$ g/l/h and $88.4{\pm}0.91%$, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) powder in a 5-l lab-scale jar fermenter at $32^{\circ}C$ for 66 h with an agitation speed of 120 rpm. Under these conditions, S. pombe CHFY0201 yielded a final ethanol concentration of $72.1{\pm}0.27$ g/l and a theoretical yield of $82.7{\pm}1.52%$ at a maximum ethanol productivity of $1.16{\pm}0.07$ g/l/h. These results suggest that S. pombe CHFY0201 is a potential producer for industrial bioethanol production.

• Microbiology and Biotechnology Letters
• /
• v.40 no.1
• /
• pp.1-9
• /
• 2012

This study's aim was to isolate microorganisms producing agarase with a high activity, with possible applications in improving the performance of the pretreatment processes for bioethanol production. Marine algaes were collected from the south coast of Korea, from which three kinds of microorganisms were isolated. After a 4-day culture of these strains at $25^{\circ}C$, crude enzymes were obtained from culture supernatant or cell-free extract by ammonium sulfate precipitation and membrane dialysis. Agarase activity was observed in these crude enzymes. Notably higher specific activity was observed in the crude enzyme obtained from the culture supernatant rather than that from the cell-free extract. This indicates that a secreted enzyme has a much greater activity than a cellular enzyme. Crude enzymes from the GNUM08122 strain were inferred to have ${\alpha}$-agarase activity because release of p-nitrophenol was observed, possibly due to the cleavage of p-nitrophenyl-${\alpha}$-D-galactopyranoside. The 16S rRNA sequence of GNUM08122 showed a close relationship to Pseudoalteromonas issachenkonii KMM 3549 (99.8%) and Pseudoalteromonas tetraodonis IMA 14160 (99.7%), which led us to assign it to the genus Pseudoalteromonas. Biochemical and physiological study revealed that this strain can grow well at $40^{\circ}C$ under a wide range of pH (pH 4~8) in high-salt conditions (10% NaCl).

• Korean Journal of Microbiology
• /
• v.55 no.3
• /
• pp.234-241
• /
• 2019

An intensive interaction between yeasts and insects has highlighted their relevance for attraction to food and for the insect's development and behavior. Yeast associated in the gut of insects secretes cellulase which aided in the food digestion (cellulose degradation). Three strains of cellulose-degrading yeast were isolated from the gut of adult grasshoppers collected in Gyeonggi Province, South Korea. The strains $ON22^T$, $G10^T$, and $G15^T$, showed positive cellulolytic activity in the carboxymethyl cellulose (CMC)-plate assay. The phylogenetic tree based on sequence analysis of D1/D2 domains of the large subunit rRNA gene and the internal transcribed spacer (ITS) regions revealed that the strains $ON22^T$ (100 and 98.4% sequence similarities in D1/D2 domains and ITS) and $G10^T$ (99.8 and 99.5% in D1/D2 domain and ITS region) were most closely related to the species Moesziomyces aphidis JCM $10318^T$; $G15^T$ (100% in D1/D2 domains and ITS) belongs to the species Moesziomyces antarcticus JCM $10317^T$, respectively. Morphology and biochemical test results are provided in the species description. Cellulase with its massive applicability has been used in various industrial processes such as biofuels like bioethanol productions. Therefore, this is the first report of the cellulolytic yeast strains $ON22^T$, $G10^T$, and $G15^T$ related to the genus Moesziomyces in the family Ustilaginaceae (Ustilaginales), in Korea.