• Food Science and Biotechnology
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• v.15 no.2
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• pp.163-167
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• 2006

Pectin was enzymatically extracted from industrial lemon pomace by using an endo-polygalacturonase from Aspergillus niger as a processing aid and compared to pectin extraction by hot hydrochloric acid. The yield of pectin was 17.6 and 20.2% with enzymatic and acidic treatments, respectively. The molecular weight distribution did not vary greatly between the samples extracted with enzyme or acid. Large differences in charge density were observed, however, when the samples were analyzed by anionic-exchange chromatography. Pectin extracted by the enzymatic treatment indicated higher charge density than that obtained by hydrochloric acid. The higher charge density could due to the presence of endogenous lemon pectinesterase, which was activated at low pH 4.5 in situ conditions during the process of enzymatic extraction, leading to low methoxylated pectin with a higher charge density.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.5
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• pp.269-278
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• 2003

Gibberellic acid (GA$_3$) is a commercially important plant growth hormone, which is gaining much more attention all over the world due to its effective use in agriculture and brewing industry. Industrially it is produced by submerged fermentation technique using Ascomycetous fungus Gibberella fujikuroi. Solid state and immobilized cell fermentation techniques had also been developed as an alternative to obtain higher yield of GA$_3$. This review summarizes the problems of GA$_3$ fermentation such as production of co-secondary metabolites along with GA$_3$, substrate inhibition and degradation of GA$_3$ to biologically inert compound gibberellenic acid, which limits the yield of GA$_3$ in the fermentation medium. These problems can be overcome by various bioprocessing strategies e.g. two - stage and fed batch cultivation processes. Further research on bioreactor operation strategies such as continuous and / or extractive fermentation with or without cell recycle / retention system need to be investigated for improvement in yield and productivity. Down stream processing for GA$_3$ isolation is also a challenge and procedures available for the same have been critically evaluated.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.6-13
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• 2000

PCE(tetrachloroethylene) 분해능을 보유한 그람 양성, 내생포자 형성의 혐기성균이 일본 기후현의 한 전자제품공장으로부터 분리되었다. 이 균은 생화학적 특성 및 16S rRNA 분석결과에 의하여 C. bifermentans인 것을 거쳐 cDCE(cis-1,2-dichloroethylene)로 전환되었다. 전자공여체로서 효모엑기스는 PCE 분해에 있어 가장 효과적이었으며 효모엑기스를 공급한 조건에서의 PCE 탈염소화 속도는 0.41 $\mu$mol/h.mg protein 이었다. 한편 본 균주는 PCE 뿐만 아니라 각종 유기염소화합물에 대해서도 분해능을 보유하고 있는 신종의 PCE 분해균으로서 각종 유기염소화합물에 오염된 지하수 및 토양에서의 In situ bioremediation 적용에 있어 유용할 것으로 기대된다.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.65-74
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• 2000

The sensitivity of a mehtanogen and sulfate-reducing bacterium isolated from a sea-based landfill site Cd$^{2+}$ and CU$^{2+}$ was studied. Methanogens and sulfate-reducing bacteria in leachates of the waste disposal site were enumerated using the MPN method. Methanobacterium thermoautotrophicum KHT, isolated from the leachate, could not grow at 0.5 mM Cd$^{2+}$ or 1.0 mM CU$^{2+}$. Desulfotomaculum sp. RHT, isolated from the same leachate, was able to insolubilization 3.0 mM Cd$^{2+}$ or 2.0 mM CU$^{2+}$ by production of hydrogen sulfide. When strains KHT and RHT were cultured together in the presence of the heavy metals, strain KHT could grow at high heavy metal concentrations after insolubilization of the metals by strain RHT. strain RHT.

• Elastomers and Composites
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• v.30 no.3
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• pp.229-234
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• 1995

Membrane process has been applied widely to petroleum chemistry, fine chemistry, polymer, electronics, food, bioprocessing, and wastewater treatment process. Membrane process has advantage that there's no phase change through separation, energy consumption is smaller than other separation processes. And equipment investment and operation cost are inxpensive too. We prepared the silicone rubber membrane and then separated the heavy metal ion from wastewater. Silicone rubber membrane was prepared using a superitical fluid process and heavy metal ions were separated from the chromium nitrate, ferric sulfate, cupric sulfate, nickel sulfate aqueous solution. The pressure difference between top and bottom of separation apparatus was preserved by vacuum pump, and the removal amount of heavy metal at each separation step were analyzed by instrumental analysis, AAS. The surface and pore of silicone rubber membrane was investigated using SEM, and the capability of wastewater treatment using a silicone rubber membrane was proposed as calculated removal rate of heavy metal after comparing removal amount of heavy metal to amount of heavy metal in mother solution by AAS analysis.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1054-1057
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions including hydrolysis of triglycerides, transesterification, and chiral synthesis of esters under natural conditions. Although lipases from various sources have been widely used in industrial applications, such as in food, chemical, pharmaceutical, and detergent industries, there are still substantial current interests in developing new microbial lipases, specifically those functioning in abnormal conditions. We screened 17 lipase-producing yeast strains, which were prescreened for substrate specificity of lipase from more than 500 yeast strains from the Agricultural Research Service Culture Collection (Peoria, IL, U.S.A.), and selected Yarrowia lipolytica NRRL Y-2178 as a best lipase producer. This report presents new finding and optimal production of a novel extracellular alkaline lipase from Y. lipolytica NRRL Y-2178. Optimal culture conditions for lipase production by Y. lipolytica NRRL Y-2178 were 72 h incubation time, $27.5^{\circ}C$, pH 9.0. Glycerol and glucose were efficiently used as the most efficient carbon sources, and a combination of yeast extract and peptone was a good nitrogen source for lipase production by Y. lipolytica NRRL Y-2178. These results suggested that Y. lipolytica NRRL Y-2178 shows good industrial potential as a new alkaline lipase producer.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.819-824
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• 2001

The principal DNA modification systems of the amino-acid-producing bacteria Corynebacterium glutamicum AS019, Brevibacterium flavum BF4, and B. lactofermentum BL1 was investigated using two approaches; digestion of plasmid DNA isolated from these species TseI and Fnu4HI, and sequence analysis of the putative methyltransferase target sites following the derivatization of DNA using metabisulfite treatment. The C. glutamicum and B. flavum strains showed similar digestion patterns to the two enzymes, indicating that the target for cytidine methyltransferase recognizes 5'-GCSGC-3'(where S is either G or C). Mapping the methylated cytidine sites by bisulfite derivatization, followed by PCR amplification and sequencing, was only possible when the protocol included an additional step eliminating any underivatized DNA after PCR amplification, thereby indicating that the derivatization was not $100\%$ efficient. This may have been due to the high G0C content of this genus. It was confirmed that C. glutamicum AS019 and B. flavum BF4 methylated the cytidine in the $Gm^5CCGC$ sequences, yet there were no similar patterns of methylation in B. lactofermentum, which was consistent with the distinctive degradation pattern seen for the above enzymes. These findings demonstrate the successful application of a modified bisulfite derivatization method with the Corynebacterium species for determining methylation patterns, and showed that different species in the geneus contain distinctive restriction and modification systems.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1078-1085
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• 2018

A salt-tolerant cellulase secreted by a marine Bacillus sp. SR22 strain with wide resistance to temperature and pH was purified and characterized. Its approximate mass was 37 kDa. The endoglucanase, named as Bc22Cel, was purified by ammonium sulfate precipitation, gel filtration chromatography, and extraction from the gel after non-reducing sodium dodecyl sufate-polyacrylamide gel electrophoresis. The optimal pH value and temperature of Bc22Cel were 6.5 and $60^{\circ}C$, respectively. The purified Bc22Cel showed a considerable halophilic property, being able to maintain more than 70% of residual activity even when pre-incubated with 1.5 M NaCl for 1 h. Kinetic analysis of the purified enzyme showed the $K_m$ and $V_{max}$ to be 0.704 mg/ml and $29.85{\mu}mol{\cdot}ml^{-1}{\cdot}min^{-1}$, respectively. Taken together, the present data indicate Bc22Cel as a potential and useful candidate for industrial applications, such as the bioconversion of sugarcane bagasse to its derivatives.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.201-208
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• 2015

The role of RNA-binding proteins (RBPs) to regulate expression of genes seems to be very important. RBPs play important roles in RNA related bioprocess such as transcription, pre-mRNA splicing, polyadenylation, transport, localization, translation, turn over and maintenance of structure. Despite of many researches on RNA binding proteins, detailed mechanisms of these proteins have not been fully understood. It seems that many parts of RBPs remains unknown and should be characterized for the better understanding of gene expression. Recently, genetic, biochemical, and bioinformatic analysis of genomes revealed a vast array of RBPs and many parts are interesting to understand bioprocessing including gene expression.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.155-161
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• 2005

The inherent instability of metabolite production in plant cell culture-based bioprocessing is a major problem hindering its commercialization. To understand the extent and causes of this instability, this study was aimed at understanding the variability of anthocyanin accumulation during long-term subcultures, as well as within subculture batches, in Vitis vinifera cell cultures. Therefore, four cell line suspensions of Vitis vinifera L. var. Gamay Freaux, A, B, C and D, originated from the same callus by cell-aggregate cloning, were established with starting anthocyanin contents of $2.73\;\pm\;0.15,\;1.45\;\pm\;0.04,\;0.7\;\pm\;0.024\;and\;0.27\;\pm\;0.04$CV (Color Value)/g-FCW (fresh cell weight), respectively. During weekly subculturing of 33 batches over 8 months, the anthocyanin biosynthetic capacity was gradually lost at various rates, for all four cell lines, regardless of the significant difference in the starting anthocyanin content. Contrary to this general trend, a significant fluctuation in the anthocyanin content was observed, but with an irregular cyclic pattern. The variabilities in the anthocyanin content between the subcultures for the 33 batches, as represented by the variation coefficient (VC), were 58, 57, 54, and $84\%$ for V. vinifera cell lines A, B, C and D, respectively. Within one subculture, the VCs from 12 replicate flasks for each of 12 independent subcultures were averaged, and found to be $9.7\%$, ranging from 4 to $17\%$. High- and low-producing cell lines, VV05 and VV06, with 1.8-fold differences in their basal anthocyanin contents, exhibited different inducibilities to L-phenylalanine feeding, methyl jasmonate and light irradiation. The low-producing cell line showed greater potential in enhanced the anthocyanin production.