동치미에서 분리한 유산균 Leuconostoc mesenteroides와 Lactobacillus brevis를 무주스에 접종하여 에서 2일간 혼합 배양하여 와 8에서 각각 30분, 15분으로 열처리하여 25, 15, 5에서 8주동안 저장하면서 품질변화를 조사하였다. 열처리한 무주스에서는 미생물이 전혀 검출되지 않아 모두 사멸되었음을 알수 있었으며 이화학적 품질의 변화가 거의 일어나지 않았으나, 열처리를 하지 않은 무주스의 경우는 저장온도가 높
Lactic aicd bacteria(LAB)는 전통적으로 식품의 발효과정 중에 사용되는 미생물이다. Lactic acid bacteria를 이용한 bacteriocinogenic culture와 lactic acid bacteria에서 생산되는 산물은 식품의 부패에 원인이 되는 미생물과 병원성균에 대한 생육억제효과을 지니고 있다. 이러한 이유로 생선제품, 유제품. 육제품과 발효되지 않은 냉장식품 등의 식품저장에 lactic acid bacter
In order to study the natural preservation of food, sixteen kinds of medicinal plants were extracted by 80% methanol and then antimicrobial activity of the extracts was investigated against various kinds of microorganisms. The extracts of medicinal plants showed good effects of antimicrobial activity against bacteria except Bacillus cereus, Escherichia coli O-157. Especially, the extracts of Artemisia annua, Aster scaber, Solidago virganrea shower good inhibitory effects on the growth of bacteria to the cooling preservation foods, and Artemisia annua was decreased of the TMA(Trimethylamine) test. the result thus indicate that Artemisia annua, Aster scaber, Solidago fischeri extract inhibitory effects on cooling preservation foods, so that it may be potential as a natural preservatives.
폴리시알린산 (polysialic acid)은 미생물로부터 인간에 이르기까지 다양한 세포의 세포 표면 복합당사슬에 공유 결합하는 당사슬의 일종이다. 최근 성게 난자의 젤리층과 성게 난자의 표면에서 폴리시알린산이 연결된 당단백질이 발견됨으로써 폴리시알린산의 생합성과 그 기능에 대한 의문이 제기되었다. 둥근성게의 난자와 배에서 추출한 효소액과 CMP-[ C]Neu5Ac를 기질로 사용하여 Neu5Ac를 endogenous acceptor에 전달하는 CMP-N
전통민속주 제조에 널리 사용되어온 국화꽃잎에서 에탄올 추출하여 식품부패에 관련된 미생물을 대상으로 항균활성을 검색하고 에탄올 추출물의 농도별 항균활성과 최저 생육저해 농도를 조사하였다. 국화 에탄올 추출물의 항균활성은 산국이 B. subtilis에 대해 항균활성이 높게 나타난 반면, 소국은 E.coli에 대한 항균활성이 산국보다 다소 높게 나타났다. 8종의 부패균에 대한 에탄올 추출물의 항균활성은 산국이 소국에 비하여 높게 나타났으며, 산국 에탄
부패하는 두부에서부터 각종 미생물 18종을 분리하여 동정한 결과, B. cereus, X. luminescens, A. calcoaceticus, Kl. pneumoniae, S. typhimurium, Pantoea sp., Bacillus sp., Cardiobacterium sp., E. coli, St. aureus, Yersinia sp. 등 11종의 각기 다른 미생물로 나타났다. 실온에서 두부의 부패 과정중 이들 미생물의 존재 함량은
This paper discussed about the effect of Zoogloea ramigera on the initial microorganism attachment and the biofilm growth. The additions of 5, 10 and 15%(w/w) of Zoogloea ramigera were facilitated for the initial attachment on the surface of the acryl disk. At biofilm growth, the more Zoogloea ramigera added to the activated sludge, the more biofilm dry weight was obtained.
In order to get the stable biofilm and to minimize the start-up periods, initial biofilm formation using activated sludge with floe forming microorganisms like Zoogloea ramigera was recommended rather than that without floe forming microorganisms.
In order to develop of support media for biofilm reactor, physicochemical properties and attachability of surface of activated carbon, clay mineral, non-clay mineral, and waste mold sand were examined. Measured physicochemical properties of materials were surface roughness, mean particle size, surface area, hydrophobicity, and surface charge. At a tested materials, activated carbon was the best attachable material and microorganisms were attached 20.1 × 10^7 CFU/㎠ at surface, compared with diatomaceous earth which were attached of 9.2 × 10^7 CFU/㎠. In our research, surface area and hydrophobicity showed more influence than any other factor on attachment of microorganisms.
This paper discussed effect of the surface roughness and the hydrophobicity of support material on the microbial attachment in a rotating biological contactor. The hydrophobicity of each support material was determined by the measurement of contact angle of water and the surface roughness was measured by the surface roughness instrument. Microorganisms have well attached on the surface of more hydrophilic support material like Nylon6 than that of the hydrophobic support material like PE. When the relatively hydrophilic surface was roughen, the microbial attachment was increased but when the relatively hydrophobic surface was roughen, the attachment was slightly increased because the hydrophobicity of support material was increased by roughening the hydrophobic surface. Although both variables, the surface hydrophobicity and the surface roughness, have influenced the microbial attachment, the influence of the surface roughness overruled that of the surface hydrophobicity. Support material whose surfaces were roughened about l㎛, 6㎛ and 11㎛ were allowed for attached 3, 7 and 24hr, but the differences of maximum and minimum attachment of each material gave nearly constant values and similar trend with time.
The clogging phenomenon in the fixed film reactor is shown when biomass growth is excessive for long operating time. In addition, effluent water quality gets worse because of detachment of biomass. In this study, we conducted air - backwashing to sustain biomass in reactor to complement these defects. The results of experimental are showed in the following conclusion.
The detachment rate was 19.5 - 38.0 % when the organic loading rate was 0.40 - 1.32 ㎏ COD/㎥/day, the air - backwashing intensity was 2 L/min(6.7 ㎥/㎡/hr) and the backwashing time was 15 - 19 seconds.
And the detachment rate was 32.2 - 58.6 % when the organic loading rate was 1.37 - 2.27 ㎏ COD/㎥/day, the backwashing time was 1 - 12 minutes. As organic loading rate and backwashing time are increased, detachment of fixed biomass is increased. The detachment equation with detachment rate(DR, %), backwashing time(BWT, min), fixed biomass concentration(FB, ㎎/L), and organic loading rate(OLR, ㎏ COD/㎥/day) through multiple linear regression was given by the following equation:
DR = 17.964 BWT^0.41407 FB^0.0597 OLR^0.1945