Alkaline $\alpha$-amylase Production from Bacillus megaterium

Jia, Shiru,Lim, Chae-kyu,Seo, Gwang-Yeob,Nam, Hyung-Gun Korean Society for Environmental Sanitary Engineer 2009 대한환경위생공학회지 Vol.13 No.1

The enzyme expressed from strain L-49 was 2.01 times higher than that of original strain. Strain L-49 can grow on culture plate with $50{\mu}g/mL$ ampicillin. The synthesis of $\alpha$-amylase was greatly suppressed when strain L-49 was grown on monosaccharide such as glucose and polysaccharide at the same time cell concentration was low. Amylase production was enhanced when the bacterium was grown on starch and dextrin. Among different nitrogen sources tried, yeast extract was found to be the best followed by panpeptone, peptone, meat extract, bean meal, and corn steep liquor. The average rate of enzyme production was enhanced for 3~4 times in fermentation time from 24h to 44h. The sugar uptake rate has also increased. Low oxygen supply rate enhanced the rate of strain propagation but depressed the enzyme production. Hence it is benefit to obtain high enzyme activity that agitation speed maintained not lower than 400r/min and aeration rate maintained greater than 1:1vvm.

Characteristics and Model for Growth of Rhizopus oryzae on the Simulated Gas-solid Interface

( Shiru Jia ),( Ri Xiang Kong ),( Hui Jun Dong ),( Kyu Hyuk Kwun ),( Sun Il Kim ),( Ki An Cho ),( Du Bok Choi ) 한국환경생물학회 2004 환경생물 : 환경생물학회지 Vol.22 No.4

N/A In order to investigate the effect on morphology of Rhizopus oryzae and production of lactic acid, various interface materials were used. Morphology of fungal showed sheet and flock when resin was added. The production of lactic acid was increased dramatically when interface materials were added. Furthermore, the effect of resin was more significant than that of others. It was assumed that interface materials could absorb substrate and microorganism together, so microorganism was not inhibited by substrate. The effect of static electric field on the interface culture was studied. When the exerting potential was 6.78 voltage, the biomass y was obviously higher than that of zero voltage. A simulated gas-solid interface system was developed to study the growth and two phases model for the growth of Rhizopus oryzae was build up that depended on the symmetric branching theory. An important parameter F was researched. The results indicated that the value of F had obvious difference at exponential and deceleration period, respectively.

Characteristics and model for growth of Rhizopus oryzae on the simulated gas-solid interface

shiru Jia,김선일,권규혁,조기안,Rixiang Kong,Huijun Dong,최두복 한국환경생물학회 2004 환경생물 : 환경생물학회지 Vol.22 No.4

In order to investigate the effect on morphology of Rhizopus oryzae and production of lactic acid, various interface materials were used. Morphology of fungal showed sheet and flock when resin was added. The production of lactic acid was increased dramatically when interface materials were added. Furthermore, the effect of resin was more significant than that of others. It was assumed that interface materials could absorb substrate and microorganism together, so microorganism was not inhibited by substrate. The effect of static electric field on the interface culture was studied. When the exerting potential was 6.78 voltage, the biomass y was obviously higher than that of zero voltage. A simulated gas-solid interface system was developed to study the growth and two phases model for the growth of Rhizopus oryzae was build up that depended on the symmetric branching theory. An important parameter F was researched. The results indicated that the value of F had obvious difference at exponential and deceleration period, respectively.

Isolation and identification of Bacillus megaterium producing Alkaline ${\alpha}$-amylase

Jia, Shiru,Choe, Yong-Deok,Cho, Hoon Korean Society for Environmental Sanitary Engineer 2008 대한환경위생공학회지 Vol.23 No.1

A bacterial strain, Bacillus megaterium L-49 has been isolated and identified that produces alkaline ${\alpha}$-amylase. The cell is ellipsoidal, about $1.0-1.2{\times}3.0-3.6{\mu}m$ in diameter, Gram-positive, motile, and central partial central. Growth occurs in media containing 7% of NaCl. This strain could utilize D-glucose, lactose, xylose, sucrose, mannose, and maltose, and but it does not utilize D-fructose, and glycogen. Among the various concentrations of saturated ammonium sulfate, the retractation ratio in range of 70 to 100% was about 93%. However, in the case of acetone, it was about 98.7%. EDTA has activating effect and Ca2+ has no effect on alkaline ${\alpha}$-amylase activity. The alkaline ${\alpha}$-amylase has low thermal stability. The optimal temperature for reaction is $50^{\circ}C$. The alkaline ${\alpha}$-amylase activity maintained stabilizing at pH 6-11 and the optimal pH for reaction was 9-10.

Characterization of Extracellular Polysaccharides from Nostoc flagelliforme Cells in Liquid Suspension Culture

Shiru Jia,Haifeng Yu,Yongxian Lin,Yujie Dai 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.3

Nostoc flagelliforme cells were studied with regard to the physico-chemical characterization of the extracellular polysaccharides (EPS) secreted in a liquid suspension culture. The hydrolyzed EPS were determined to be composed of four neutral sugars, which were glucose (43.2%), xylose (20.6%), galactose (29.9%), and mannose (6.3%). The glucuronic acid was the only uronic acid identified in the residue. The apparent molecular weight was estimated at 2.79 × 105. The Fourier transform infrared spectra showed that the EPS evidenced characteristics typical of non-sulfated polysaccharides. The UV spectrum and Bradford reaction indicated that there were no nucleic acids and proteins in them. The thermal analysis showed a decomposition peak at 245oC on the thermogravimetric (TG) curves. The scanning electron microscope (SEM) analysis indicated that the EPS possessed a porous structure. The observed microstructural irregularities indicated that the polysaccharide was a type of amorphous solid. These results showed that the EPS of N. flagelliforme cells might be employed as a substitute for those normally derived from field colonies. The results of this study may prove to be beneficial to the protection of the natural resource represented by N. flagelliforme.

Fractionation and Characterization of ε-Poly-L-lysine from Streptomyces albulus CGMCC 1986

Shiru Jia,Yujie Dai,Baoqing Fan,Guoliang Wang,Yuanyuan Jia,Peng Peng 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

ε-Poly-L-lysine (ε-PLL) produced by Streptomyces albulus CGMCC 1986 was fractionated using ultra-filtration technique with 2 and 5 kDa cut-offs of membrane. The number-average molecular weight of each fraction was determined by 1H nuclear magnetic resonance (NMR)method. The number-average molecular weights of the cutoffs of 5 and 2 kDa and the filtrate are 4,230.95, 3,687.80,and 1,900.82 Da, respectively. 1H NMR indicates the chemical shifts of α-H, β-H, γ-H, δ-H, and ε-H are very similar to all the fractions. Fourier transform-infrared (FTIR)spectra showed that the ε-PLL solid samples obtained by freeze-drying at pH 5 with molecular weights higher than 2 kDa take on a β-turn conformation, however, the fraction with molecular weight smaller than 2 kDa adopts random coil structure. The antibacterial test proved that the fraction between 2 and 5 kDa of membranes behaves the highest antibacterial activity than other fractions for the test strains of Staphylococcus aureus, Micrococcus luteus,Bacillus subtilis, Escherichia coli, and Shigella.

Isolation and identification of Bacillus megaterium producing Alkaline α-amylase

Shiru Jia,Yong-Deok Choe,Hoon Cho 대한환경위생공학회 2008 대한환경위생공학회지 Vol.23 No.1

A bacterial strain, Bacillus megaterium L-49 has been isolated and identified that produces alkaline a-amylase. The cell is ellipsoidal, about 1.0-1.2 × 3.0-3.6 ㎛ in diameter, Gram-positive, motile, and central partial central. Growth occurs in media containing 7% of NaCl. This strain could utilize D-glucose, lactose, xylose, sucrose, mannose, and maltose, and but it does not utilize D-fructose, and glycogen. Among the various concentrations of saturated ammonium sulfate, the retractation ratio in range of 70 to 100% was about 93%. However, in the case of acetone, it was about 98.7%. EDTA has activating effect and Ca2+ has no effect on alkaline α-amylase activity. The alkaline a-amylase has low thermal stability. The optimal temperature for reaction is 50℃The alkaline a-amylase activity maintained stabilizing at pH 6-11 and the optimal pH for reaction was 9-10.

Characterization of Extracellular Polysaccharides from Nostoc flagelliforme Cells in Liquid Suspension Culture

Jia, Shiru,Yu, Haifeng,Lin, Yongxian,Dai, Yujie Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.3

Nostoc flagelliforme cells were studied with regard to the physico-chemical characterization of the extracellular polysaccharides (EPS) secreted in a liquid suspension culture. The hydrolyzed EPS were determined to be composed of four neutral sugars, which were glucose (43.2%), xylose (20.6%), galactose (29.9%), and mannose (6.3%). The glucuronic acid was the only uronic acid identified in the residue. The apparent molecular weight was estimated at $2.79{\times}10^5$. The Fourier transform infrared spectra showed that the EPS evidenced characteristics typical of non-sulfated polysaccharides. The UV spectrum and Bradford reaction indicated that there were no nucleic acids and proteins in them. The thermal analysis showed a decomposition peak at $245^{\circ}C$ on the thermogravimetric (TG) curves. The scanning electron microscope (SEM) analysis indicated that the EPS possessed a porous structure. The observed microstructural irregularities indicated that the polysaccharide was a type of amorphous solid. These results showed that the EPS of N. flagelliforme cells might be employed as a substitute for those normally derived from field colonies. The results of this study may prove to be beneficial to the protection of the natural resource represented by N. flagelliforme.

Alkaline α-amylaseProduction from Bacillus megaterium

Shiru Jia,Chae-kyu Lim,Gwang-yeob Seo,Hyung-Gun Nam 대한환경위생공학회 2009 대한환경위생공학회지 Vol.24 No.1

The enzyme expressed from strain L-49 was 2.01 times higher than that of original strain. Strain L-49 can grow on culture plate with 50㎍/mL ampicillin. The synthesis of α-amylase was greatly suppressed when strain L-49 was grown on monosaccharide such as glucose and polysaccharide at the same time cell concentration was low. Amylase production was enhanced when the bacterium was grown on starch and dextrin. Among different nitrogen sources tried, yeast extract was found to be the best followed by panpeptone, peptone, meat extract, bean meal, and corn steep liquor. The average rate of enzyme production was enhanced for 3~4 times in fermentation time from 24h to 44h.. The sugar uptake rate has also increased. Low oxygen supply rate enhanced the rate of strain propagation but depressed the enzyme production. Hence it is benefit to obtain high enzyme activity that agitation speed maintained not lower than 400r/min and aeration rate maintained greater than 1:1vvm.

Characterization of Bacteriostatic Sausage Casing: A Composite of Bacterial Cellulose Embedded with ε-Polylysine

Huixia Zhu,Shiru Jia,Hongjiang Yang,Weihua Tang,Zhilei Tan,Yuanyuan Jia 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.6

The feasibility of a novel bacteriostatic sausage casing made of bacterial cellulose (BC) embedded with ε-polylysine (ε-PL) was evaluated. The ε-PL/BC composite was prepared by immersing BC tubes in ε-PL solution and its characteristics were analyzed with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD),and atomic force microscopy (AFM) techniques, respectively. The results suggested that ε-PL molecules were incorporated into the cellulose fiber networks and the ε-PL/BC composite might have a novel unique structure. No significant loss of antimicrobial activity was observed even after autoclaving at 121℃ for 30 min and the oxygen permeability was far below than that of polyethylene (PE) and polyvinyl alcohol (PVA) membrane. Its tensile strength was 51.8 MPa. The ε-PL/BC composite exhibits bacteriostatic and/or bacteriocidal activities against a broad spectrum of Gram-positive and Gram-negative bacteria; as a result, an extended shelf life than controls was observed for sausage packaged with the ε-PL/BC composite.