• 산업기술연구
• /
• 제20권A호
• /
• pp.39-44
• /
• 2000

Highly viscous biopolymer from alkali-tolerant Bacillus sp. was purified and its solution properties were investigated. The intrinsic viscosities for crude biopolymer and biopolymers purified by dialysis or CPC(cetylpyridinium chloride) treatment were 58.24, 73.60 and 42.18 dL/g, respectively. The intrinsic viscosity of biopolymer showed the maximum value at the neutral pH but it was decreased remarkably at the alkaline or acidic pH. Biopolymer exhibited the property of polyelectrolyte, showing the sharp decrease of intrinsic viscosity by the addition of NaCl. Intrinsic viscosity of dilute solution at the low NaCl concentration was exponentially dependent on temperature and its temperature dependency was increased with NaCl concentrations. The chain stiffness, coil overlap parameter, and critical concentration were 0.09, 5.25 and 0.07g/dL, respectively. Temperature dependency on intrinsic viscosity of biopolymer solution was different each other at $45^{\circ}C$. Flow activation energies at temperatures above $45^{\circ}C$ were constant, while those at temperatures below $45^{\circ}C$ increased with increase of added NaCl concentration.

• 한국미생물·생명공학회지
• /
• 제25권1호
• /
• pp.82-88
• /
• 1997

To produce biopolymer, Metarrhizium anisopliae (Metschn.) Sorok was cultured in a medium containing glucose 1.0%, sucrose 2.0% , soluble starch 1.0%, yeast extract 0.5%, polypeptone 0.05%, K$_{2}$HPO$_{4}$ 0.1% MgSO$_{4}$ $\CDOT $ 7H$_{2}$O 0.02%. The culture broth was centrifuged and the polymer was harvested by adding methanol to the culture supermatant. When three times of methanol was added, the polymer was coagulated and precipitated. Then it was further purified through successive SK-1B, SA-20P, HP-20 column chromatographies. This polymer was designated as Biopolymer YU-122.C:H ratio of this Biopolmer YU-122 was 1:2 and small amount of N is detected by CHN analyzer. Glucose and glactose are main components of this polymer. Average molecular weight of this biopolymer was 1.7%$\times $10$^{6}$ by Sepharose 4B gel permeation chromatography. Optimal condition for biopolymer production was investigated. When 5% of mannitol was used as a carbon source, and polypepton as a N source, highest productivity of biopolymer was achieved. C/N ratio as nutrient was also a major factor in polymer production and its optimal ratio was 3.

• Journal of Microbiology and Biotechnology
• /
• 제15권3호
• /
• pp.626-632
• /
• 2005

A new bacterium BL-2 excreting a novel cationic polyglucosamine biopolymer was isolated from the spoiled leaves of Chinese cabbage and identified as Enterobacter sp. BL-2. The isolated Enterobacter sp. BL-2 was cultivated in pH-stat fed-batch culture using acetic acid as the feeding stock at pH 8.0, resulting in 17.11 g/l of cells and 1.53 g/l of an extracellular biopolymer after 72 h. The excreted biopolymer was purified by a three-step procedure, involving ethanol precipitation and deproteinizations, to a nearly homogeneous state, and its molecular weight was found to be 106 kDa. It was composed of glucosamine, rhamnose, and galactose at a molar ratio of 86.4:1.6:1.0, respectively, indicating a rarely found novel high-glucosamine-containing biopolymer. The FT-IR and $^{13}C-NMR$ spectra of the novel cationic polyglucosamine biopolymer PGB-l revealed a close identity with chitosan from crab shell. It can effectively flocculate various suspended solids, including kaolin clay, $Ca(OH)_2,\;Al_{2}O_3$, active carbon, microbial cells, and acidic dyes.

• 한국식품과학회지
• /
• 제23권2호
• /
• pp.161-166
• /
• 1991

미생물을 이용한 유용물질 생산연구의 일환으로 토양으로부터 생물고분자 생산균주를 분리하고, 이 분리균에 대한 균학적 성질 및 생성 생물고분자의 이화학적 성상을 검토하였다. 분리균주는 Bacillus속의 한 균종으로 동정 하였으며, 알칼리 내성균주의 특징을 나타내었다. 이 균주로부터 생성된 생물고분자는 성분분석, 정색반응 및 I.R. spectrum 분석결과 단백질 함량이 높고, 일부 amino sugar가 존재하나 uronic acid는 함유하지 않았다. 그러나 cetyl pyridinium chloride에는 침전되어 산성의 생물고분자인 것으로 추정되었다.

• Ecology and Resilient Infrastructure
• /
• 제5권3호
• /
• pp.180-188
• /
• 2018

하천 제방의 토양 안정화 물질의 하나로, 미생물 유래 베타글루칸과 잔탄검 계열 바이오폴리머를 사용하고자 하는 연구가 현재 진행중이다. 본 연구의 목적은 바이오폴리머 신소재의 생태성 평가의 일환으로, 바이오폴리머가 국내 하천에 자생하는 식물의 씨앗 발아 및 생육에 미치는 영향을 평가하는 것이다. 낙동강과 영산강에 자생하는 총 9종의 식물을 대상으로 시험한 결과, 발아율, 총 건중량, 지상부 건중량, specific leaf area 등 지상부 형질에서는 식물종 별로 다양한 바이오폴리머에 대한 반응을 나타냈다. 애기똥풀의 총 건중량과 지상부 건중량은 감소한 반면 타 식물종들은 건중량을 유지하거나 다소 증가시켰다. 반면 대상 식물종들의 뿌리 생장 (뿌리 길이, 지상부 대비 지하부 건중량)은 바이오폴리머가 처리된 토양에서 증가하는 경향을 보였다. 이러한 결과로 보아, 본 연구에서 시험된 바이오폴리머는 토양 강화 효과와 함께 자생 식물의 뿌리 생장을 촉진시켜, 제방을 강화시키는 역할을 할 것으로 기대된다. 그러나 화학물질들에 대한 식물 반응의 종 특이성을 고려할 때, 보다 광범위한 식물종을 대상으로 하는 연구가 필요할 것이다.

• Ecology and Resilient Infrastructure
• /
• 제6권4호
• /
• pp.304-313
• /
• 2019

미생물 유래 베타글루칸과 잔탄검 계열의 바이오폴리머는 식물 성장에 효과적이고 토양의 강도를 증진시키는 기능을 지니고 있어 하천 제방의 토양 보강 및 안정화 재료로서 활용이 가능하다. 본 연구의 목적은 분사 공법을 이용하여 바이오폴리머 신소재를 실규모 제방에 시공하는 경우 바이오폴리머에 의해 하천 제방 표면 토양의 강도 증진 및 식생 효과를 검증하는 것이다. 실규모 하천제방에서 바이오폴리머를 이용하여 제방 표면을 피복하였고, 혼합재료에 대한 강도 측정 결과 바이오폴리머를 처리한 구역에서 강도가 높게 나타났다. 그리고 큰김의털과 호밀풀을 대상으로 식물 생장을 조사하였으며, 두 식물종의 지상부 생장에 긍정적인 효과를 확인하였다. 반면 대상 식물종의 지하부 생장은 바이오폴리머가 처리된 토양에서 감소하는 경향을 보였다. 바이오폴리머를 처리한 토양에서는 토양이 수분을 보유하는 능력이 증가하여 바이오폴리머로 처리로 인해 오히려 지하부 성장을 더디게 하는 것으로 판단된다. 본 연구의 결과에 따라 분사공법을 이용한 바이오폴리머 시공은 토양의 강도 증진 효과와 하천 제방의 녹화에 사용하기 충분한 것으로 판단된다. 그러나 하천 제방에 식재하는 광범위한 식물 종에 대한 바이오폴리머의 효과와 식물 종 별로 적정 바이오폴리머 농도에 대한 연구가 필요할 것이다.

• Journal of Microbiology and Biotechnology
• /
• 제14권4호
• /
• pp.658-664
• /
• 2004

To find a new utilization of rice bran, nine higher fungi were examined for the production of exo-biopolymer with macrophage stimulating activity from rice bran. Among the exo-biopolymers produced from submerged cultures, Lentinus edodes showed the highest activity, followed by Grifola frondosa, Schizophyllum commune, and Coriolus versicolor. L. edodes also had the most potent macrophage stimulating activity in a liquid culture rather than in a solid culture. In order to improve rice bran utilization and the yield of exo-biopolymer with macrophage stimulating activity, the treatment of Rapidase effectively increased the macrophage stimulating activity (about 30% increase), whereas the other enzymes (Econase, Viscozyme, Ultraflo, Celluclast, and Thermylase) treatments did not increase the macrophage stimulating activity. Exo-biopolymer with macrophage stimulating activity from L. edodes contained mainly neutral sugars (58.7%) with considerable amounts of uronic acid (32.2%) and a small amount of proteins (9.1%). Component sugars of exo-biopolymer consisted of mainly arabinose, galactose, glucose, mannose, and xylose (0.95:0.81:0.96:1.00:0.39, respectively). When the exo-biopolymer was treated with $NaIO_4, NaClO_2$, and pronase, the $NaClO_2$ treatment and pronase digestion had little effect, whereas $NaIO_4$ oxidation significantly decreased the macrophage stimulating activity (47.6% reduction at $100\mug/ml$). Therefore, the carbohydrate moiety in exo-biopolymer from L. edodes plays an important role in the expression of the macrophage stimulating activity.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 춘계학술발표대회
• /
• pp.199-202
• /
• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica was studied. Maltose, yeast extract and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in flask culture were pH 5.0, $25^{\circ}C$ and 150 rpm in a meidum containing of 30 g maltose, 6 g yeast extract, 2 g polypeptone, 0.5 g $K_2HPO_4$, 0.2 g $KH_2PO_4$, 0.2 g $MnSo_4\;{\cdot}\;5H_2O$, 0.2 g $MgSO_4\;{\cdot}\;7H_2O$ in 1-L distilled water. Exo-biopolymer production and mycelial growth in the suggested medium were significantly increased in a 2.5-L jar fermentor, where the maximum biopolymer concentration was 8 g/1.

• Food Science and Biotechnology
• /
• 제16권5호
• /
• pp.691-709
• /
• 2007

Concerns on environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer's demand for high quality food products has caused an increasing interest in developing biodegradable packaging materials using annually renewable natural biopolymers such as polysaccharides and proteins. However, inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low water resistance are causing a major limitation for their industrial use. By the way, recent advent of nanocomposite technology rekindled interests on the use of natural biopolymers in the food packaging application. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to their nanometer size dispersion. These improvements include increased mechanical strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Consequently, natural biopolymer-based nanocomposite packaging materials with bio-functional properties have huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of natural biopolymer-based nanocomposite films, and their potential use in food packaging applications are addressed.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.317-320
• /
• 2000

The optimal temperature and pH for both mycelial growth and exe-biopolymer production by Cordyceps millitaris in shake flask culture were found to be $20^{\circ}C$ and 6.0, respectively. Sucrose (4%) and corn steep powder (1%) were the most suitable carbon and nitrogen source for mycelial growth and exo-biopolymer production. The maximum specific growth rate $(0.142h^{-1})$ was achieved when sucrose was used as the sole carbon source. Exo-biopolymer production was increased with the increase in C/N molar ratio concentration, probably due to the facilitated carbon uptake. Under the optimal culture conditions, the maximum mycelial growth exe-biopolymer concentration were reached to around 13.3 g dry cell weigh/l and 3.33 g/l, respectively.