Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

Enhancement of beta-Glucosidase Activity from a Brown Rot Fungus Fomitopsis pinicola KCTC 6208 by Medium Optimization

beta-Glucosidase, which hydrolyzes cellobiose into two glucoses, plays an important role in the process of saccharification of the lignocellulosic biomass. In this study, we optimized the activity of beta-glucosidase of brown-rot fungus Fomitopsis pinicola KCTC 6208 using the response surface methodology (RSM) with various concentrations of glucose, yeast extract and ascorbic acid, which are the most significant nutrients for activity of beta-glucosidase. The highest activity of beta-glucosidase was achieved 3.02% of glucose, 4.35% of yeast extract, and 7.41% ascorbic acid where ascorbic acid was most effective. The maximum activity of beta-glucosidase predicted by the RSM was 15.34 U/mg, which was similar to the experimental value 14.90 U/mg at the 16th day of incubation. This optimized activity of beta-glucosidase was 23.6 times higher than the preliminary activity value, 0.63 U/mg, and was also much higher than previous values reported in other fungi strains. Therefore, a simplified medium supplemented with a cheap vitamin source, such as ascorbic acid, could be a cost effective mean of increasing beta-glucosidase activity.

Evaluación del pretratamiento con ácido sulfúrico diluido del pasto maralfalfa (Pennisetum glaucum x Pennisetum purpureum) para la producción de etanol / Dilute sulfuric acid pretreatment of goliath grass (Pennisetum glaucum x Pennisetum purpureum) for ethanol cellulosic

Evaluar la producción de etanol a partir de cultivos lignocelulósicos, específicamente pastos de rápido crecimiento en la región, constituye una alternativa a la demanda de biocombustibles. En la presente investigación se seleccionó el pasto Maralfalfa (Pennisetum glaucum x Pennisetum purpureum) utilizando el pretratamiento con ácido sulfúrico diluido a diferentes temperaturas (110, 130, 150, 170 y 190 °C) y concentraciones de ácido (0.8, 1.2 y 2.0% (p/p)), seguido de un proceso de hidrólisis enzimática utilizando celulasas y celobiosas comerciales y un proceso de hidrólisis y fermentación simultanea. La máxima producción de etanol obtenido fue 117 mg etanol/ g biomasa pretratada a 190 °C y 1,2 %(p/p) de ácido sulfúrico. El líquido hidrolizado fue caracterizado calculando el porcentaje de glucosa, xilosa y lignina solubilizadas y degradadas durante el pretratamiento.

The goliath grass (Pennisetum glaucum x Pennisetum purpureum) was pretreated with different sulfuric acid concentrations (0.8, 1.2 y 2.0% (w/w)) from low to high temperatures (110, 130, 150, 170 y 190 °C) followed by enzymatic hydrolysis and SSF of remaining solids. The maximum yield was 117 mg of ethanol/g biomass to 190 °C and 1.2 % (w/w) of sulfuric acid.

Mariannaea samuelsii Isolated from a Bark Beetle-Infested Elm Tree in Korea

During an investigation of fungi from an elm tree infested with bark beetles in Korea, one isolate, DUCC401, was isolated from elm wood. Based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer and 28S rDNA (large subunit) sequences, the isolate, DUCC401, was identified as Mariannaea samuelsii. Mycelia of the fungus grew faster on malt extract agar than on potato dextrose agar and oatmeal agar media. Temperature and pH for optimal growth of fungal mycelia were 25degrees C and pH 7.0, respectively. The fungus demonstrated the capacity to degrade cellobiose, starch, and xylan. This is the first report on isolation of Mariannaea samuelsii in Korea.

Biochemical Characterization of an Extracellular beta-Glucosidase from the Fungus, Penicillium italicum, Isolated from Rotten Citrus Peel

A beta-glucosidase from Penicillium italicum was purified with a specific activity of 61.8 U/mg, using a chromatography system. The native form of the enzyme was an 88.5-kDa tetramer with a molecular mass of 354 kDa. Optimum activity was observed at pH 4.5 and 60degrees C, and the half-lives were 1,737, 330, 34, and 1 hr at 50, 55, 60, and 65degrees C, respectively. Its activity was inhibited by 47% by 5 mM Ni2+. The enzyme exhibited hydrolytic activity for p-nitrophenyl-beta-D-glucopyranoside (pNP-Glu), p-nitrophenyl-beta-D-cellobioside, p-nitrophenyl-beta-D-xyloside, and cellobiose, however, no activity was observed for p-nitrophenyl-beta-D-lactopyranoside, p-nitrophenyl-beta-D-galactopyranoside, carboxymetyl cellulose, xylan, and cellulose, indicating that the enzyme was a beta-glucosidase. The kcat/Km (s-1 mM-1) values for pNP-Glu and cellobiose were 15,770.4 mM and 6,361.4 mM, respectively. These values were the highest reported for beta-glucosidases. Non-competitive inhibition of the enzyme by both glucose (Ki = 8.9 mM) and glucono-delta-lactone (Ki = 11.3 mM) was observed when pNP-Glu was used as the substrate. This is the first report of non-competitive inhibition of beta-glucosidase by glucose and glucono-delta-lactone.

Comparison of Dyes for Easy Detection of Extracellular Cellulases in Fungi

To evaluate which dye is effective in a plate assay for detecting extracellular cellulase activity produced by fungi, four chromogenic dyes including remazol brilliant blue, phenol red, congo red, and tryphan blue, were compared using chromagenic media. For the comparison, 19 fungal species belonging to three phyla, ascomycota, basidiomycota, and zygomycota were inoculated onto yeast nitrogen-based media containing different carbon substrates such as cellulose (carboxylmethyl and avicel types) and cellobiose labeled with each of the four dyes. Overall, the formation of clear zone on agar media resulting from the degradation of the substrates by the enzymes secreted from the test fungi was most apparent with media containing congo red. The detection frequency of cellulase activity was also most high on congo red-supplemented media. The results of this study showed that congo red is better dye than other three dyes in a plate assay for fungal enzyme detection.

Characterization of Fusarium oxysporum Isolated from Paprika in Korea

In the present study we first report in Korea the identification and characterization of Fusarium oxysporum isolated from rotten stems and roots of paprika (Capsicum annuum var. grossum) at Masan, Kyungsangnamdo in 2006. The fungal species produced white aerial mycelia accompanying with dark violet pigment on PDA. The optimal temperature and pH for the growth of the species was 25degrees C and pH 7, respectively. Microscopic observation of one of isolates of the species shows that its conidiophores are unbranched and monophialides, its microconidia have oval-ellipsoidal shape with no septate and are of 3.0~11 x 1.5~3.5 microm sizes, its macroconidia are of 15~20 x 2.0~3.5 microm sizes and have slightly curved or slender shape with 2~3 septate. The results of molecular analysis show that the ITS rDNA of F. oxysporum from paprika shares 100% sequence identity with that of known F. oxysporum isolates. The identified species proved it's pathogenicity by causing rotting symptom when it was inoculated on paprika fruits. The growth of F. oxysporum from paprika was suppressed on PDA by agrochemicals such as benomyl, tebuconazole and azoxystrobin. The identified species has the ability of producing extracelluar enzymes that degrade cellobiose and pectin.

Detection of Extracellular enzymes Activities in Various Fusarium spp

Thirty seven species of Fusarium were evaluated for their ability of producing extracellular enzymes using chromogenic medium containing substrates such as starch, cellobiose, CM-cellulose, xylan, and pectin. Among the tested species Fusarium mesoamericanum, F. graminearum, F. asiaticum, and F. acuminatum showed high beta-glucosidase acitivity. Xylanase activity was strongly detected in F. proliferatum and F. oxysporum. Strong pectinase activity was also found in F. oxysporum and F. proliferatum. Amylase activity was apparent in F. oxysporum. No clear activity in cellulase was found from all the Fusarium species tested.

Detection of Extracellular Enzyme Activity in Penicillium using Chromogenic Media

A total of 106 Penicillium species were tested to examine their ability of degrading cellobiose, pectin and xylan. The activity of beta-glucosidase was generally strong in all the Penicillium species tested. P. citrinum, P. charlesii, P. manginii and P. aurantiacum showed the higher ability of producing beta-glucosidase than other tested species. Pectinase activity was detected in 24 Penicillium species. P. paracanescens, P. sizovae, P. sartoryi, P. chrysogenum, and P. claviforme showed strong pectinase activity. In xylanase assay, 84 Penicillium species showed activity. Strong xylanase activity was detected from P. megasporum, P. sartoryi, P. chrysogenum, P. glandicola, P. discolor, and P. coprophilum. Overall, most of the Penicillium species tested showed strong beta-glucosidase activity. The degree of pectinase and xylanase activity varied depending on Penicillium species.

Cellobiose dehydrogenase production by the genus cladosporium

Cellobiose dehydrogenase [CDH; EC.1.1.5.1] is an extracellular enzyme that mainly produced by wood-degrading fungi. It oxidizes cellobiose to cellobionolactone using a wide spectrum of electron acceptors. The key roles of CDH in growth, metabolism, and some other important cellular processes such as cellulose degradation in fungi have been noted. Since the demands for finding new sources of CDH among different organisms have been dramatically increased, this study was focused on the presence of CDH in the genus Cladosporium as a well-known cellulolytic fungus. Twenty strains of Cladosporium isolated from soil samples from different geographical origin were evaluated for CDH-producing ability. The early screening of the fungus by zymogram method revealed the presence of CDH as an extracellular form in all of the examined isolates. Submerged cultivation of the best producer of CDH [selected from initial screening] on a specific medium showed the maximum amounts of enzyme produced in shaking cultures with pH 4.5 at 28°C for a 14-day period. The enzyme activity was determined in the range of 27.83 to 1284.84 unit/mg protein among the isolates. Our observations show that Cladosporium isolates with high CDH producing ability i.e. isolates No. 10 and No. 18 can be used as selective candidates for large-scale production of this industrially important enzyme in further research programs. This is the first documented report on the presence of CDH in the fungus Cladosporium

Studies on immobilized cellobiase / 生物工程学报

Cellulosic material is the most abundant renewable carbon source in the world. Cellulose may be hydrolyzed using cellulase to produce glucose, which can be used for production of ethanol, organic acids, and other chemicals. Cellulase is a complex enzyme containing endoglucanase (EC 3.2.1.4), exoglucanase (EC 3.2.1.91) and cellobiase (EC 3.2.1.21). The hydrolysis of natural cellulose to glucose depends on the synergism of these three components. The mostly used cellulase produced by Trichoderma reesei has high activity of endoglucanase and exoglucanase, but the activity of cellobiase is relatively low. Therefore, improving the activity of cellobiase in cellulase reaction system is the key to enhance the sacchrification yield of cellulosic resources. Aspergillus niger LORRE 012 was a high productivity strain for cellobiase production. It was found that the spores of this strain were rich in cellobiase. In this work, the cellobiase was immobilized efficiently by simply entrapping the spores into calcium alginate gels instead of immobilizing the pure cellobiase proteins. The immobilized cellobiase was quite stable, and its half-life was 38 days under pH 4.8, 50 degrees C. The thermal stability of the immobilized cellobiase was improved, and it was stable below 70 degrees C. The suitable pH range of the immobilized cellobiase was pH 3.0 - 5.0, with the optimal pH value 4.8. The Km and Vmax value of the immobilized cellobiase were 6.01 mmol/L and 7.06 mmol/min x L, respectively. In repeated batch hydrolysis processes, 50 mL of substrate (10 g/L cellobiose) and 10 mL of immobilized beads containing cellobiase were added into a 150 ml flask. After reacting at pH 4.8, 50 degrees C for several hours, the hydrolysate was harvested for assay, and the immobilized beads were used for the next batch hydrolysis with the fresh substrate. This process was repeated, and the yield of enzymatic hydrolysis kept higher than 97% during 10 batches. The continuous hydrolysis process was carried out in a column reactor (inside diameter 2.8 cm, inside height 40 cm) packed with the immobilized beads. Using 10 g/L cellobiose as substrate, the hydrolysis yield reached 98% under 0.4 h (-1) dilution rate and pH 4.8, 50 degrees C. After corncob was treated by 1% dilute acid, the cellulosic residue (100 g/L) was used as substrate, and hydrolyzed by the cellulase (15 IFPU/g substrate) from Trichoderma reesei, at pH 4.8, 50 degrees C for 48 h. The concentration of reducing sugar in the hydrolysate was only 48.50 g/L (hydrolysis yield 69.5%). When the hydrolysate was further treated by the immobilized cellobiase, the cellobiose was hydrolyzed into glucose, and the feedback inhibition caused by the cellobiose accumulation disappeared sharply. By the synergism of immobilized cellobiase and the cellulase from T. reesei left in the hydrolysate, other oligosaccharides were mostly converted to monosaccharides. At 48 h, the reducing sugar concentration was increased to 58.78 g/L, the hydrolysis yield of the corncob residue was improved to 84.2%, and the ratio of the glucose in the total reducing sugar was increased from 53.6% to 89.5%. The reducing sugars converted from corncob could be used further in the fermentation of valuable industrial products. This research results were meaningful in the conversion and utilization of renewable biomass.

New Selective Medium for Rapid Identification of Vibrio vulnificus from Patients with V. vulnificus Sepsis / 대한피부과학회지

BACKGROUND: Vibrio(V.) vulnificus is a halophilic, gram-negative bacillus that causes a fatal sepsis in patients with underlying chronic disease such as liver cirrhosis and alcoholic abuse. Because V. vulnificus infection has a fulminant course and high mortality rate, early recognition and rapid diagnosis with prompt therapy are necessary to improve survival rate. OBJECTIVE: The purpose of this study was to develop a new selective medium for rapid identification of V. vulnificus through color change of medium according to pH from patients suspected of having V. vulnificus sepsis. METHODS: Rapid isolation and identification of V. vulnificus can be possible by modifying the component of PNC(5% peptone, 1% NaCl, and 0.08% cellobiose [pH 8.0]) broth medium. From this PNC broth, a basal broth(5% peptone+1% NaCl+cellobiose) was prepared and used to evaluate additional medium supplements(cellobiose concentration [0.08, 0.2, 0.1%], pH [6.8, 7.5, 8.0] and pH indicator dye [bromthymol blue, thymol blue, phenol red, bromcresol purple, crystal violet, cresol red, and neutral red]). To examine the rapid identification and selectivity of this basal medium according to various conditions, V. vulnificus was tested by using saline and normal human blood containing these bacteria(1, 000 bacteria/ml), respectively at 37degrees C. A positive reaction(V. vulnificus growth) appeared as color change. The selectivity and identification capacity of this new broth was tested by using other 6 Vibrio species and 14 strains of other bacteria. RESULTS: Color change appeared only in the medium including bromthymol blue and thymol blue as a pH indicator dye. It was called the basal medium containing blue dyes as PNCB(peptone, NaCl, cellobiose and blue dye) medium. It took an average time of 4.8hr for becoming aware of yellow color change in PNCB broth after cultivating with saline mixed with V. vulnificus and 6hr in PNCB broth after cultivating with blood mixed with V. vulnificus. One Vibrio species and another 3 bacteria produced color change. So we confirmed that the final composition and pH of PNCB broth medium was 5% peptone, 1% NaCl, 0.2% cellobiose, 0.0004% bromthymol blue and 0.0004% thymol blue [pH 7.5] CONCLUSIONS: PNCB broth could be used as a selective and differential medium for rapid isolation and identification of V. vulnificus in patients with V. vulnificus sepsis.

Production of Polysaccharide by the Edible Mushroom, Grifola frondosa

The production of polysaccharide according to various developmental stages (mycelium growth, primordium appearance, and fruiting-body formation) in the edible mushroom Grifola frondosa was studied. The cap of the mature mushroom showed the highest amount of polysacchride. Mycelial growth and polysaccharide synthesis were optimal at pH 5 and 20degrees C. Polysaccharide synthesis was maximal after 12 days of cultivation, whereas maximum mycelial growth was shown after 18 days. Mannose, cellobiose and starch increased the level of polysaccharide as well as growth in submerged culture. Glucose and sucrose appeared to be good substrates for fruiting of Grifola frondosa.

Comparison between some digistive Enzymes in the Midgut larvae of nasal Batfly: Cephalopina Titillator clark [Diptera: oestridae] and sheep blowfly lucilia cuprina wiedeman [Diptera: oestridae]

Activities of invertase [alpha-1-2 glucosidase] trehalase [alpha-1-1 glucosidase] cellobiase[beta-1-4 glucosidase] and proteases in the midgut of 3[rd] instar larvae of Cephalopina titillator and Lucilia cuprina were determined. Homogenates from third instar Larval midgut showed the invertase, trehalase, cellobiase, and proteases activity in L. cuprina were more than that of C.titillator and upon using T. test it was found that there was a very high significant difference between the activities of the mentioned enzymes in the two insects. The enzyme activities may be affected by the different habitats of the larvae

Isolation and identification of Vibrio vulnificus and Vibrio parahaemolyticus from coast of Pusan and Daechon

This study was focused on the isolation of pathogenic Vibrio species, V. vulnificus and V. parahaemolyticus from marine environment from May to July of 1999. Isolation sites were coast near by Pusan and Daechon. The results obtained were as follows: 1. Seventy strains of V. parahaemolyticus and 19 strains of V. vulnificus were isolated from a total of 120 specimens. 2. Nineteen strains of V. vulnificus did not fermented arabinose and salicin but fermented lactose and cellobiose. All of V. parahaemolyticus isolates did not fermented lactose and cellobiose. 47 strains of V. parahaemolyticus fermented arabinose but 53 strains did not fermented salicin. 3. V. vulnificus and V. parahaemolyticus isolates showed three different API index numbers with 5046105 and 4346107 dominant. 4. V. vulnificus did not grow on 0% and 8% NaCl containing medium. V. parahaemolyticus grew on 8% NaCl containing medium. 5. V. vulnificus isolates and V. parahaemolyticus revealed different outer membrane protein p rofiles on SDS-PAGE.

Antioxidant effect of two flavonoids from the bark of Ficus bengalensis Linn in hyperlipidemic rats.

Two flavonoid compounds, viz. 5,7-dimethyl ether of leucopelargonidin 3-0-alpha-L rhamnoside and 5,3'-dimethyl ether of leucocyanidin 3-0-alpha-D galactosyl cellobioside obtained from the bark of F. bengalensis were evaluated for their antioxidant action in hyperlipidemic rats. The results were compared with the activity of a structurally similar flavonoid, quercetin, a known antioxidant. The Ficus compounds showed significant antioxidant effects which may be attributed to their polyphenolic nature. The methylation of two hydrozyl groups in the Ficus flavonoids might have slowed down their antioxidant action as compared to quercetin.

Identification of Vibrio vulnificus in Pusan and Southern Sea of Korea in 1996 using API 20E Kit

The halophilic bacterium, Vibrio vulnificus, causes acute fulminating wound infections and septicemia in human. Especially the septicemia shows high mortality above 50%. In Korea, septicemia by V. vulnificus was reported at westem and southern coast in every year. Here, we try to isolate this V. vulnipcus at Kyoung-nam area and coast of Pusan during 1996. Purposed sites were Dadaepo, Songjung, Chungsapo and Mipo of Pusan and Kijang, Ilkuang, Juksoung, Dongam, Waljun and Chilam of southern sea. Total 40 strains of V. vulnipcus were isolated from sea samples. Biochemical characteristics of isolated V. vulnificus were almost same with reference strain V. vulnificus ATCC 27562 on Farmer's tests and on API 20E kit test. V. vulnificus isolates in 1996, fermented cellobiose and salicin but arabinose. and had resistance to 7% sodium chloride.

"Região cis-atuante reguladora da transcrição do gene que codifica celobiohidrolase I em Trichoderma reesei: expressão basal e induzida / Cis regulatory region of gene transcription which codify cellobiohydrolase I in Trichoderma reesei: induced and basal expression\"

A enzima celobiohidrolase I (CBHI) do fungo multicelular Trichoderma reesei catalisa a liberação de celobiose a partir das extremidades redutoras das cadeias de celulose. Esta enzima é um dos membros do sistema de celulases extracelular necessário para a hidrólise completa da celulose até glicose. A expressão do gene cbhl é controlada pela fonte de carbono energético usado no meio de cultura. O crescimento em presença de celulose - não de glicose ou glicerol - resulta na indução do transcrito de cbhl em pelo menos 1200 vezes. Esta indução parece requerer a expressão basal do sistema das celulases, as quais são necessárias para catalisar a formação do indutor solúvel a partir da celulose. A expressão do transcrito de cbhl também é controlada pelo estado metabólico da mitocôndria; os transcritos das celulases são regulados sob condições tidas como repressoras da respiração mitocondrial...

Aryl beta-galactosidase from Sclerotium rolfsii: physiological and biochemical studies.

Production of beta-galactosidase by Sclerotium rolfsii NCIM 1084 was studied under submerged fermentation conditions. The enzyme was produced extracellularly and constitutively on glucose. The enzyme production was enhanced when galactose, raffinose, cellobiose, sucrose, xylose, maltose, cellulose and pectin were used as carbon sources. Cellulose and diammonium hydrogen phosphate were best carbon and nitrogen sources, respectively. Surfactants such as Sag, Paraffin oil, Tween 20 and Tween 80 increased the enzyme production. Maximum yield of beta-galactosidase obtained was 3.8-4.2 nkat/ml. The optimum pH, optimum temperature and molecular weight of the beta-glactosidase were 2.7, 60 degrees C and 2,21,000 daltons, respectively. The enzyme is an aryl beta-glactosidase and did not hydrolyse lactose. The Km value for o-nitrophenyl beta-D-galactoside was 3.7 mM. Galactose and 2-mercaptoethanol inhibited the enzyme.

Amylolytic activity of humicola sp

The thermophylic and cellulolytic fungus Humicola sp. secretes amylases in the liquid culture medium. This activity is induced by starch, maltose and cellobiose. Glucose impairs accumlation of amylolitic activity in the culture medium. The enzyme hydrolyzes starch, maltose and pullulan to glucose as the endproduct