• Title/Summary/Keyword: Microbial Biotechnology

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Synthesis and Characterization of Fructooligosaccharides Using Levansucrase with a High Concentration of Sucrose

  • Seo Eun-Seong;Lee Jin-Ha;Choi Jae-Young;Seo Mi-Young;Lee Hee-Sun;Chang Seuk-Sang;Lee Hyung-Jong;Choi Jeong-Sik;Kim Doman
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.5
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    • pp.339-344
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    • 2004
  • A method for synthesizing branched fructo-oligosaccharides (BFOS) with a high concentration of sucrose ($1{\~}3$ M) was developed using levansucrase prepared from Leuconortoc mesenteroides B-1355C. The degree of polymerization of oligosaccharides synthesized according to the present method ranged from 2 to over 15. The synthesized BFOS were stable at a pH ranges of 2 to 4 under $120^{\circ}C$. The percentage of BFOS in the reaction digest was $95.7\%$ (excluding monosaccharides; $4.3\%$ was levan). BFOS reduced the insoluble glucan formation by Streptococcus sobrinus on the surfaces of glass vials or stainless steel wires in the presence of sucrose. They also reduced the growth and acid productions of S, sobrinus. Oligosaccharides can be used as sweeteners for foods such as beverages requiring thermo- and acid-stable properties and 3s potential inhibitors of dental caries.

Relationship between Chemical Property and Microbial Activity of Reclaimed Tidal Lands at Western Coast Area in Korea

  • Ko, Eun-Seong;Joung, Ji-An;Kim, Chang-Hwan;Lee, Su Hwan;Sa, Tongmin;Choi, Joon-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.4
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    • pp.254-261
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    • 2014
  • The scientific information between microbial activities and chemical properties of reclaimed tidal soil is not enough to apply for reclamation projects. This study was conducted to investigate the relation between chemical properties and microbial activities of reclaimed tidal lands located at western coastal area (25 samples from Nampo, Ewon, Sukmoon and Shihwa sites). Most of the reclaimed soils showed chemical characteristics as salinity soil except Nampo site. The major component influenced the salinity of reclaimed soil was identified as a sodium from the relationship between EC and exchangeable cation. With an increase in EC of soil, the population of mesophilic bacteria decreases whereas halotolerant and halophilic bacteria increases. The population of mesophilic bacteria increased with an increase in both organic matter and dehydrogenase activity. However, the population of halotolerant and halophilic bacteria decreased with an increase in organic matter. Based on the relation between chemical property and microbial activity of reclaimed tidal soil, electrical conductivity and organic matter as chemical properties of soil, population of mesophilic bacteria, halotolerant and halophilic bacteria and dehydrogenase activity as microbial activities could be the major parameters for reclamation process.

Divergence of Granular Sludges and Microbial Communities in Two Types of Anaerobic Reactors Treating Different Wastewaters

  • Qin, Xianchao;Li, Chunjie;Gao, Yueshu;Zhang, Zhenjia;Zhang, Xiaojun
    • Journal of Microbiology and Biotechnology
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    • v.29 no.4
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    • pp.633-644
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    • 2019
  • An advanced anaerobic expanded granular sludge bed (AnaEG) and an internal circulation (IC) reactor, which were adopted to treat starch processing wastewater (SPW) and ethanol processing wastewater (EPW), were comprehensively analyzed to determine the key factors that affected the granules and microbial communities in the bioreactors. The granule size of $900{\mu}m$ in the AnaEG reactor was smaller than that in the IC reactor, and the internal and external morphological structures of the granular sludge were also significantly different between the two types of reactors. The biodiversity, which was higher in the AnaEG reactor, was mainly affected by reactor type. However, the specific microbial community structure was determined by the type of wastewater. Furthermore, the dominant methanogens of EPW were mainly Methanosaeta and Methanobacterium, but only Methanosaeta was a major constituent in SPW. Compared with the IC reactor, characteristics common to the AnaEG reactor were smaller granules, higher biodiversity and larger proportion of unknown species. The comparison of characteristics between these two reactors not only aids in understanding the novel AnaEG reactor type, but also elucidates the effects of reactor type and wastewater type on the microbial community and sludge structure. This information would be helpful in the application of the novel AnaEG reactor.

Performance and Spatial Succession of a Full-Scale Anaerobic Plant Treating High-Concentration Cassava Bioethanol Wastewater

  • Gao, Ruifang;Yuan, Xufeng;Li, Jiajia;Wang, Xiaofen;Cheng, Xu;Zhu, Wanbin;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1148-1154
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    • 2012
  • A novel two-phase anaerobic treatment technology was developed to treat high-concentration organic cassava bioethanol wastewater. The start-up process and contribution of organics (COD, total nitrogen, and $NH_4^+$-N) removal in spatial succession of the whole process and spatial microbial diversity changing when sampling were analyzed. The results of the start-up phase showed that the organic loading rate could reach up to $10kg\;COD/m^3d$, with the COD removal rate remaining over 90% after 25 days. The sample results indicated that the contribution of COD removal in the pre-anaerobic and anaerobic phases was 40% and 60%, respectively, with the highest efficiency of 98.5%; TN and $NH_4^+$-N had decreased to 0.05 g/l and 0.90 g/l, respectively, and the mineralization rate of total nitrogen was 94.8%, 76.56% of which was attributed to the anaerobic part. The microbial diversity changed remarkably among different sample points depending on the physiological characteristics of identified strains. Moraxellaceae, Planococcaceae, and Prevotellaceae were dominant in the pre-anaerobic phase and Bacteroidetes, Campylobacterales, Acinetobacter, Lactobacillus, Clostridium, and Bacillus for the anaerobic phase. Methanosarcinaceae and Methanosaeta were the two main phylotypes in the anaerobic reactor.