• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.83-93
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• 2011

Biochemical and enzymatic characterization for extracellular protease isolated from Cordyceps militaris cultivated on rice bran medium was investigated. C militaris produced proteolytic enzymes from 10 days after inoculation, maximum enzyme production was found at 25 days. The optimum temperature and pH of proteases production was at $25^{\circ}C$ and pH 7.0, respectively. The protease activity was observed in the four peaks (Pro-I, Pro-II, Pro-III, and Pro-IV) separated through Sephadex G-100 column chromatography. The separated protease was optimally active at $25^{\circ}C$. Optimum pH of the protease was between 7 and 8. Enzyme was also stable over at $30-80^{\circ}C$. The enzyme was highly stable in a pH range of 4-9. Protease activity was found to be slightly decreased by the addition of $Mg^{2+}$, $Mn^{2+}$, $Zn^{2+}$, $Fe^{2+}$ and $Cu^{2+}$, whereas inhibited by the addition of $Ca^{2+}$ and $Co^{2+}$ Protease activity was inhibited by protease inhibitor PMSF. On the other hand, the partially purified protease was investigated on proteolytic protease activity by zymogram gel electrophoresis using three substances (casein, gelatin and fibrin). Four active bands (F-I, FII, F-III, and F-IV) of fibrin degradation were revealed on fibrin zymogram gels. Both of F-II and FIII showed caseinolytic, fibrinolytic and gelatinolytic activities in three gels. Thermostability, pH stability, and pH-thermostability of the enzyme determined the residual fibrinolytic activity also displayed on fibrin zymogram gel. The only one enzyme (F-II) displayed over a broad range of temperature at $30-90^{\circ}C$. The FII displayed fibrinolytic activity in the pH range 3-5, but was inactivated in the range of pH 6-11. The F-I and F-III showed enzyme activity in the pH range of 6-11. In the pH-thermostability, the F-II only kept fibrinolytic activity after heating at $100^{\circ}C$ for 10, 20 and 30 min at pH 3 and pH 7, respectively. On the other hand, the F-II was retained activity until heating for 10 min under pH 11 condition. By using fibrin zymogram gel electrophoresis, extracellular fibrinolytic enzyme F-II from C. militaris showed unusual thermostable under acid and neutral conditions.

• BMB Reports
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• v.30 no.2
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• pp.101-105
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• 1997

Extracellular phospholipase $A_2$ activity has been detected in urine of patients with acute pyelonephritis (APN). This enzyme required micromolar $Ca^{2+}$ ion for its maximum activity and showed a broad range of pH (4.5~10) optimum. Urine enzyme hydrolyzed phosphatidylethanolamine (PE) and phosphatidylserine (PS) more effectively than phosphatidylcholine (PC). $PLA_2$ activity in the urine of patients with APN was about 5-fold higher than that of healthy individuals. When urine was subjected to heparinSepharose column chromatography, phospholipase $A_2$ activity was detected in both heparin-non-binding and binding fractions. Both phospholipase $A_2$ activities were sensitive less than a micromolar calcium concentration and did not react with anti-human 14-kDa group II phospholipase $A_2$ monoclonal antibody, HP-l. These findings suggest that two kinds of novel extracellular phospholipase $A_2$. which may not belong to the 14-kDa group II phospholipase $A_2$ family, exist in the urine of patients with APN.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.164-167
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• 2005

The culture condition and medium composition for the enhanced mycelial growth of Lepista nuda DGUM 26501 were investigated. The optimal temperature and pH for the mycelial growth were $24^{\circ}C$ and $7.0\~8.0$, respectively. The partial pressure of oxygen for the enhanced mycelial growth was more than $10\%\;O_2$. When Czapek-Dox medium was used as a minimal medium, manitol and xylitol were very good carbon sources. Organic nitrogen sources were better than inorganic ones for mycelial growth. As the nitrogen source tested, com steep liquor, soytone and protease peptone were the best as a source of organic nitrogen sources. When ammonium phosphate as phosphorus sources was used, the enhanced mycelial growth was shown. Nicotinic acid was proved to be the most appropriate source of vitamin. After the mycelia of L. nuda DGUM 26501 was cultivated at $24^{\circ}C$ for 10 days in LNM broth (pH 7.0), the activities of extracellular enzyme were determined. The specific activity of $\alpha-amylase$ was much higher than those of other enzymes. However, little or no enzyme activities of $\beta-glucosidase$, CMCase, laccase and lipase were found.

• Journal of Microbiology
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• v.42 no.4
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• pp.267-277
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• 2004

Effects of elevated $CO_2$ on soil microorganisms are known to be mediated by various interactions with plants, for which such effects are relatively poorly documented. In this review, we summarize and syn­thesize results from studies assessing impacts of elevated $CO_2$ on soil ecosystems, focusing primarily on plants and a variety the of microbial processes. The processes considered include changes in microbial biomass of C and N, microbial number, respiration rates, organic matter decomposition, soil enzyme activities, microbial community composition, and functional groups of bacteria mediating trace gas emission such as methane and nitrous oxide. Elevated $CO_2$ in atmosphere may enhance certain micro­bial processes such as $CH_4$ emission from wetlands due to enhanced carbon supply from plants. How­ever, responses of extracellular enzyme activities and microbial community structure are still controversy, because interferences with other factors such as the types of plants, nutrient availabilitial in soil, soil types, analysis methods, and types of $CO_2$ fumigation systems are not fully understood.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.245-249
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• 1989

Extracellular proteases of Bacillus licheniformis were partially purified using ammonium sulfate fractionation and Sephadex G-75 gel filtration chromatography. The partial purification permited the weparation of two different protease activities, type I and type II. Protease type I is an enzyme with rather high protealytic activity toward dasein and was highly susceptible to organofluoride and EDTA inhibitions. It showed maximal proteolytic activity at pH 7.5 and was rapidly denatured at $71^{\circ}C$. Protease type II is a protease with relatively lower proteolytic activity than the type I. It was also inhibited by 10mM of EDTA and 1mM of PMSF by 30 min incubation. The enzyme showed maximal activity at pH 8.0 and was denatured relatively slowly at $71^{\circ}C$.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.121-128
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• 2022

L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.326-330
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• 2002

A wetland soil was sterilised by two methods and changes in microbial enzyme activities were assessed. The short-term effects were determined by toluene addition, while the longer-term effects of elimination was monitored by ${\gamma}$-radiation. The changes in ${\beta}$- glucosidase, ${\beta}$-xylosidase, cellobiohydrolase, phosphatase, arylsulphatase, and N-acetylglucosaminidase activities were determined by using methylumbelliferyl model substrates and comparing with the activities of control samples. Toluene addition induced different responses of enzymes. For example, phosphatase activity increased by the treatment while ${\beta}$-glucosidase and arylsulphatase activities decreased. In contrast, ${\gamma}$-radiation decreased all enzyme activities compared to control by 40-80%. The overall results of the toluene and ${\gamma}$-radiation experiments indicate that the large amounts of enzymes are stabilised outside of living cells, at least in the short term, but that the persistence of enzymes is maintained by de-novo synthesis of microbes.

• Journal of Microbiology and Biotechnology
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• v.4 no.1
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• pp.49-55
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• 1994

A fungal strain capable of producing extracellular cellulase was isolated from farmland. It was identified as Aspergillus niger, and named Aspergillus niger KKS. Production of cellulase and xylanase by the A. niger KKS was studied through a shake-flask culture. The effects of culture conditions such as inoculum size, temperature, pH, and medium composition on the cellulase and xylanase production were examined. The optimum temperature and pH for the enzyme production were $30^{\circ}C$ and pH 7.0, respectively. The optimized medium was composed of 2.0% (w/v) rice straw, 0.5% (w/v) proteose peptone, 0.5% (w/v) $KH_2 PO_4$, 0.05% (w/v) yeast extract, 0.01% (w/v) $CoSO_4 \cdot 7H_2O$, and 0.05% (w/v) $CuSO$_4$\cdot 5H_2O$. When the strain was incubated with the optimized medium, it gave the activities of endoglucanase, $\beta$-glucosidase, $\beta$-xylosidase, xylanase were 3.80, 4.20, 4.00, 80.0 (IU/mL), respectively. Filter paper and cotton activities were 0.68 and 0.045 (IU/mL), respectively. The results of this study show that A. niger KKS is a potential organism with a wide spectrum of enzyme activities, such as those of $\beta$-glucosidase, $\beta$-xylosidase, and xylanase.

• Korean Journal of Microbiology
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• v.14 no.1
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• pp.17-24
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• 1976

Celluloytic microorgnasims were isolated form the various sources and four of them were identified as Trichoderma roningi, Aspergillus niger, Penicillium chrysogenum, and Streptomyces sp. The induction of extracellular5 cellulase of these species in the liquid culture media containing carboxymethylcellulose (CMC) or Avicel as inducer showed that CMC was a better effective inducer for the production of CMCase(Cx cellulase component) as well as Avicelase(C$_{1}$ cellulase component) than Avicel. It is believed that certain hydrolysis products of cellulose(CMC) could serve as an inducer for an enzyme synthesis. In T. roningi, Asp. niger, and Strptomyces sp., the optimum temperature of CNCase on CMC-culture medium was 50.deg. but temperature around 40.deg.C was found to be optimum for the activities of CMCase prepared from P.ehrysogenum. The optimum temperature for Avicelase activitiles on Avicel-culture media of T. roningi and P. chrysogenum was $40{\circ}C$ whereas temperature $50{\circ}C$ was found to be optimum for Avicelase from A.niger and Streptomyces sp. The optimal activities of these CNCase and Avicelase prepared from. T. ronigi, Pen.chrysogenum and Streptomyces sp. were found similarly to be at pH's around 5.4 and 6.0 while pH 4.8 was optimum for the activities of CMCase and Avicelase from A.niger, indicating that A.niger in acidic media would yield an enzyme of high activity.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.379-384
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• 2010

We isolated microorganisms presenting high enzymatic activities for amylase, cellulase, protease, lipase or fibrinolysis from Korean traditional soybean sauce and paste. Then, the physiological properties and 16S rRNA sequences of isolated microorganisms were analyzed. All of the isolated 13 strains possessing high extra cellular enzyme activities have higher amylase and cellulase activities than Bacillus subtilis KACC 10114. All the selected strains have protease activities except for D2-14. Except D8-8 and K4-1, other strains have lipase activity. D2-7, D8-8 and K4-1 strains have higher fibrinolytic activities than others, while D8-2 strain has no activity. Most of the selected strains showed antibacterial activity even in gram positive and gram negative bacteria and yeast. Gene sequence analysis of 16S rRNA from isolated strains revealed that all the selected strains were member of Bacillus species.