• BMB Reports
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• v.37 no.4
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• pp.387-393
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• 2004

The L-asparaginase (E. C. 3. 5. 1. 1) enzyme was purified to homogeneity from Pseudomonas aeruginosa 50071 cells that were grown on solid-state fermentation. Different purification steps (including ammonium sulfate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C50) were applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified 106-fold and showed a final specific activity of 1900 IU/mg with a 43% yield. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed it was one peptide chain with $M_r$ of 160 kDa. A Lineweaver-Burk analysis showed a $K_m$ value of 0.147 mM and $V_{max}$ of 35.7 IU. The enzyme showed maximum activity at pH 9 when incubated at $37^{\circ}C$ for 30 min. The amino acid composition of the purified enzyme was also determined.

• Journal of Mushroom
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• v.19 no.3
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• pp.126-133
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• 2021

In this study, we investigated the effect of solid culture medium on the production of cordycepin in Cordyceps militaris. The regression equation was expressed as follows: Y₁ = 755.3-58.6625X₁+4.79432E-14X₂-46.6625X₃-5.66269E-14X₁X₂-0.025X₁X₃+1.62475E-14X₂X₃-160.6625X₁²+0.0125X₂²-206.9625X₃², where, Y represents the value of cordycepin content (㎍/g), X₁ corresponds to the weight of M. alternatus in solid culture medium (g/bottle), X₂ to the water content of the solid culture medium (%), and X₃ to the culture period (day). The solid culture medium was optimized using the response surface methodology, and the optimal medium composition was as follows: the weight of M. alternatus in solid culture medium and water content were 16.2% and 100.7% (20.14 mL water/20 g solid culture medium), respectively, with a culture period of 39 days. Under these conditions, the cordycepin content of the fruiting bodies reached 150.0 ㎍/g (actual value). The supplementation of M. alternatus in solid culture for improved cordycepin content of C. militaris seems to be a promising alternative to wild and solid cultivation.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.703-710
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• 2011

Enzymatic saccharification of corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum and subsequent fermentation of the saccharification products to ethanol by Saccharomyces cerevisiae and Escherichia coli K011 were achieved. Prior to simultaneous saccharification and fermentation (SSF) for ethanol production, solid-state fermentation was performed for four days on ground corn stover using either P. chrysosporium or G. trabeum to induce in situ cellulase production. During SSF with S. cerevisiae or E. coli, ethanol production was the highest on day 4 for all samples. For corn stover treated with P. chrysosporium, the conversion to ethanol was 2.29 g/100 g corn stover with S. cerevisiae as the fermenting organism, whereas for the sample inoculated with E. coli K011, the ethanol production was 4.14 g/100 g corn stover. Corn stover treated with G. trabeum showed a conversion 1.90 and 4.79 g/100 g corn stover with S. cerevisiae and E. coli K011 as the fermenting organisms, respectively. Other fermentation co-products, such as acetic acid and lactic acid, were also monitored. Acetic acid production ranged between 0.45 and 0.78 g/100 g corn stover, while no lactic acid production was detected throughout the 5 days of SSF. The results of our experiment suggest that it is possible to perform SSF of corn stover using P. chrysosporium, G. trabeum, S. cerevisiae and E. coli K011 for the production of fuel ethanol.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.175-175
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• 2003

• Bulletin of Food Technology
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• v.23 no.2
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• pp.177-189
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• 2010

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1279-1284
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• 2005

The effects of 3 different strains of Japanese koji (Aspergillus oryzae, A. sojae and A. awamori) in the solid-state fermentation (SSF) of sugarcane bagasse mixed with wheat bran on chemical composition, energy, in vivo digestibility and preference of the fermented bagasse feeds (FBF) in goats were investigated. Diets consisted of lucerne hay cube (basal diet) and unfermented bagasse feed (control), FBF with A. oryzae (O), FBF with A. sojae (S) or FBF with A. awamori (A), which were mixed in a total ration of 7:3 (w/w DM). Three Nubian does were fed each of the diets, i.e. control, O, S and A in the 4 consecutive periods for digestion trials (21-day each). The goats were also used for preference trials (30-min each) of O, S and A. The O was significantly higher in CP content than others (p<0.05). The crude fiber (CF), ADF and cellulose contents of control were significantly lower than those of other diets (p<0.05). The S had significantly higher CF digestibility than control (p<0.05), and it revealed the largest value of all. Digestibilities of NDF, ADF and cellulose in S were significantly higher than those of control (about 10, 18 and 18%, respectively, p<0.05). The DE of S was significantly higher than that of others (p<0.05), though there were no significant differences in DCP and TDN between control and S. The results of preference trials demonstrated that the average intake rate was not significantly different among diets, but O and S are likely to be preferable to A (p<0.1). It was concluded that the SSF of bagasse feeds by Japanese koji can improve the fiber digestion, especially NDF, ADF or cellulose in goats, and there is a marked effect in the feed containing A. sojae, which may lead to the improvement of DE.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.469-472
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• 2002

Solid state fermentation was performed for the production of entomopathogenic fungus Metarhizium anisopliae HY-2 using wheat bran media containing rice bran. Fungal growth in a solid state fermentation system was estimated by viable cell count, spore count, and mycelial biomass. It was used chemical method measuring N-acetyl-glucosamine (chitin) content for estimating of mycelial biomass. In static flask culture, viable cell reached 2.40 ${\times}$ $10^8$ cfu/g at 23 days of culture at $27^{\circ}C$ and then mycelial biomass was 41.59 mg/g. Specific growth rate(${\mu}$ max) was 0.0418 $h^{-1}$ between 3 and 9 days when estimated by viable cell count and was 0.00976 $h^{-1}$ between 9 and 17 days when N-acetylglucosamine content was measured. Viable cells reached 1.12 ${\times}$ $10^8$ cfu/g in polypropylene-bag at 28 days of culture at $27^{\circ}C$. Formulated microbial pesticide containing M. anisopliae HY-2 were tested their bio-activity against Chestnut Brown Chafer (Adoretus tenuimaculatus). The protection rate of the liquid culture showed 13 ${\sim}$ 26 % with 1st to 3rd instar, and spore suspension of M. anisopliae HY-2 showed 56 ${\sim}$ 64%. Conidia produced by large scale solid-state fermentation showed 20 ${\sim}$ 27 % activity 60 ${\sim}$ 64 % with M. anisopliae HY-2.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.960-967
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• 2011

Tannin acyl hydrolase, also known as tannase, is an enzyme with important applications in the food, feed, pharmaceutical, and chemical industries. However, despite a growing interest in the catalytic properties of tannase, its practical use is very limited owing to high production costs. Several studies have already demonstrated the advantages of solid-state fermentation (SSF) for the production of fungal tannase, yet the optimal conditions for enzyme production strongly depend on the microbial strain utilized. Therefore, the aim of this study was to improve the tannase production by a locally isolated A. niger strain in an SSF system. The SSF was carried out in packed-bed bioreactors using polyurethane foam as an inert support impregnated with defined culture media. The process parameters influencing the enzyme production were identified using a Plackett-Burman design, where the substrate concentration, initial pH, and incubation temperature were determined as the most significant. These parameters were then further optimized using a Box-Behnken design. The maximum tannase production was obtained with a high tannic acid concentration (50 g/l), relatively low incubation temperature ($30^{\circ}C$), and unique low initial pH (4.0). The statistical strategy aided in increasing the enzyme activity nearly 1.97-fold, from 4,030 to 7,955 U/l. Consequently, these findings can lead to the development of a fermentation system that is able to produce large amounts of tannase in economical, compact, and scalable reactors.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.732-738
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• 2009

An acidic polygalacturonase (PG) from Aspergillus kawachii was produced by solid state fermentation employing a polyurethane foam support. The conditions used for the production of acidic PG were particle size of support (0.6 or 500 $mm^3$) and fermentation time. From the factors studied, the particle size had important influence on enzyme production. The best conditions for acidic PG production were $0.6\;mm^3$ particle size, 18 hr at $30^{\circ}C$ and initial pH of 5.0. In addition, pectin was extracted from citrus pomaces (grapefruit, lime, and tangerine) by acidic PG at $50^{\circ}C$ for 24 hr with citric acid solution. Infrared spectroscopy showed that lime pomace had more high-methoxylated (65%) endogenous pectin than was obtained than from grapefruit or tangerine pomaces. The enzymatically extracted pectin yield in dry basis (d.b.) for grapefruit and lime pectins were 6.95 and 4.25%, respectively. The citric acid solution alone also contributed to pectin extraction from citrus pomaces (7-9%, d.b.). Limited pectin extraction by acidic PG from tangerine pomace was most likely due to the presence of low-methoxylated endogenous pectin. The enzymatic method for pectin extraction using acidic PG from A. kawachii is a promising technique for releasing highly polymerized pectic substances from high-methoxylated lime or grapefruit pomaces.

• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.45-56
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• 2021

Improved amylases were developed from protoplast fusants of two amylase-producing Aspergillus species. Twenty regenerated fusants were screened for amylase production using Remazol Brilliant Blue agar. Crude enzyme extracts produced by solid state fermentation of rice bran were assayed for activity. Three variable factors (temperature, pH and enzyme type) were optimized to increase the amylase activity of the parents and selected fusants using rice bran medium and solid state fermentation. Analysis of this optimization was completed using the Central Composite Design (CCD) of the Response Surface Methodology (RSM). Amylase activity assays conducted at room temperature and 80℃ demonstrated that Aspergillus designates, T5 (920.21 U/ml, 966.67 U/ml), T13 (430 U/ml, 1011.11 U/ml) and T14 (500.63 U/ml, 1012.00 U/ml) all exhibited improved function making them the preferred fusants. Amylases produced from these fusants were observed to be active over the entire pH range evaluated in this study. Fusants T5 and T14 demonstrated optimal activity under acidic and alkaline conditions, respectively. Fusants T13 and T14 produced the most amylase at 72 h while parents TA, TC and fusant T5 produced the most amylase after 96 h of incubation. Response surface methodology examinations revealed that the enzyme from fusant T5 was the optimal enzyme demonstrating the highest activity (1055.17 U/ml) at pH 4 and a temperature of 40℃. This enzyme lost activity with further increases in temperature. Starch hydrolysis using fusant T5 gave the highest yield of glucose (1.6158 g/100 ml). The significant activities of the selected fusants at 28 ± 2℃ and 80℃ and the higher sugar yields from cassava starch hydrolysis over their parental strains indicate that it is possible to improve amylase activity using the protoplast fusion technique.