• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.496-496
• /
• 2003

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.477-477
• /
• 2003

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.101-101
• /
• 2003

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2002년도 학술발표대회
• /
• pp.104-104
• /
• 2002

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVII)
• /
• pp.493-493
• /
• 2005

• Membrane and Water Treatment
• /
• 제11권3호
• /
• pp.195-200
• /
• 2020

In this study, a biocatalyst composite was prepared by immobilizing oxidoreductases onto Cu-activated zeolite to facilitate biochemical decomposition of 4-chlorophenol (4-CP). 4-CP monooxygenase (CphC-I) was cloned from a 4-CP degrading bacterium, Pseudarthrobacter chlorophenolicus A6, and then overexpressed and purified. Type X zeolite was synthesized from non-magnetic coal fly ash using acetic acid treatment, and its surfaces were coated with copper ions via impregnation (Cu-zeolite). Then, the recombinant oxidative and reductive enzymes were immobilized onto Cu-zeolite. The enzymes were effectively immobilized onto the Cu-zeolite (79% of immobilization yield). The retained catalytic activity of CphC-I after immobilization was 0.3423 U/g-Cu-zeolite, which was 63.3% of the value of free enzymes. The results of this study suggest that copper can be used as an effective enzyme immobilization binder because it provides favorable metalhistidine binding between the enzyme and Cu-zeolite.

• Journal of Microbiology and Biotechnology
• /
• 제25권3호
• /
• pp.375-380
• /
• 2015

Recently, methane has attracted much attention as an alternative carbon feedstock since it is the major component of abundant shale and natural gas. In this work, we produced methanol from methane using whole cells of Methylosinus trichosporium OB3b as the biocatalyst. M. trichosporium OB3b was cultured on NMS medium with a supply of 7:3 air/methane ratio at 30℃. The optimal concentrations of various methanol dehydrogenase inhibitors such as potassium phosphate and EDTA were determined to be 100 and 0.5 mM, respectively, for an efficient production of methanol. Sodium formate (40 mM) as a reducing power source was added to enhance the conversion efficiency. A productivity of 49.0 mg/l·h, titer of 0.393 g methanol/l, and conversion of 73.8% (mol methanol/mol methane) were obtained under the optimized batch condition.

• Journal of Microbiology and Biotechnology
• /
• 제17권7호
• /
• pp.1083-1089
• /
• 2007

Because of their selectivity and catalytic efficiency, BVMOs are highly valuable biocatalysts for the chemoenzymatic synthesis of a broad range of useful compounds. In this study, we investigated the microbial Baeyer-Villiger oxidation and sulfoxidation of thioanisole and bicyclo[3.2.0]hept-2-en-6-one using whole Escherichia coli cells that recombined with each of the Baeyer-Villiger monooxygenases originated from Pseudomonas aeruginosa PAOl and two from Streptomyces coelicolor A3(2). The three BVMOs were identified in the microbial genome database by a recently described protein sequence motif; e.g., BVMO motif(FXGXXXHXXXW). The reaction products were identified as (R)-/(S)-sulfoxide and 2-oxabicyclo/3-oxabicyclo[3.3.0]oct-6-en-2-one by GC-MS analysis. Consequently, this study demonstrated that the three enzymes can indeed catalyze the Baeyer-Villiger reaction as a biocatalyst, and effective annotation tools can be efficiently exploited as a source of novel BVMOs.

• Journal of Microbiology and Biotechnology
• /
• 제26권7호
• /
• pp.1234-1241
• /
• 2016

Methanol is a versatile compound that can be biologically synthesized from methane (CH₄) by methanotrophs using a low energy-consuming and environment-friendly process. Methylocella tundrae is a type II methanotroph that can utilize CH₄ as a carbon and energy source. Methanol is produced in the first step of the metabolic pathway of methanotrophs and is further oxidized into formaldehyde. Several parameters must be optimized to achieve high methanol production. In this study, we optimized the production conditions and process parameters for methanol production. The optimum incubation time, substrate, pH, agitation rate, temperature, phosphate buffer and sodium formate concentration, and cell concentration were determined to be 24 h, 50% CH₄, pH 7, 150 rpm, 30℃, 100 mM and 50 mM, and 18 mg/ml, respectively. The optimization of these parameters significantly improved methanol production from 0.66 to 5.18 mM. The use of alginate-encapsulated cells resulted in enhanced methanol production stability and reusability of cells after five cycles of reuse under batch culture conditions.

• 한국환경보건학회지
• /
• 제17권1호
• /
• pp.120-128
• /
• 1991

Saccharomyces cerevisiae was immobilized by incubating iron oxides with calcium alginate, and by polyacrylamide entrapment to use repeatedly for the conversion of glucose to ethanol. Magnetic and non-magnetic immobilized yeast and polyacrylamide immobilized yeast were compared with the native yeast a batch-fermentation of ethanol from glucose. Three kinds of immobilized yeast tended almost identically, having ethanol productivity as well as the final yield about the same to what was found for the native yeast. The long-term operational stability of three kinds of immobilized yeast were significant difference according as immobilized yeast activation or non-activation before ethanol fermentation. In the non-activation they lost their activity of fermentation rapidly in the beginning stage an slower at a later stage. On the other hand, in the activation with nutrient media, their activities were increased to some extent and stable in the later stage. The cell count of three kinds of immobilized yeast after activiation by incubating nutrient media, increased by a factor of about 45 to 48, whereas the fermenting capacity increased by a factor of 174 to 178. In the prearation of immobilized biocatalysts, magnetic matter does not seem to have any adverse affect on the properties of the microorganism. The immobilized biocatalysts by utilizing magnetic matter have some advantages, especially in application of viscous media or insoluble particle-containing media, for this work was linked with microbial utilization of environmental wastes and elimination of envirnmental pollutant.