This study was carried out to compare the toxicity of nano and micrometer particles with Cu and Zn on soil microbial community and metal uptake of buck wheat. In microcosm system, soil was incubated for 14 days after soil aliquots were artificially contaminated with 1,000 mg/kg Cu, Zn nano and micro particles, respectively. After then, buck wheat was planted in incubating soils and non incubating soils. After 14 days, we compared bioaccumulation of metal, and microbial carbon substrate utilization patterns between incubating soils and non-incubating soils. The enrichment factor (EF) values of incubating samples were greater than non-incubating soils. Dehydrogenase activity had been inhibited by Cu and Zn nanoparticles in non-incubating soil, as well as it had been inhibited by Zn micro particles in incubating soils. Results of biolog test, it was not significant different between nano particles and micro particles. It cannot be generalized that nanoparticles of metal are always more toxic to soil microbial activity and diversity than micrometer-sized particles and the toxicity needs to be assessed on a case-by-case basis.

본 연구에서는 이산화염소수를 이용한 계사 내 깔짚의 미생물 수 저감화를 통한 깔짚의 미생물학적 안전성 확보를 위하여 연구를 수행하였다. 사용하기 전의 깔짚에는 coliform, E. coli, Listeria spp., yeasts and molds 및 total aerobic bacteria가 높은 수준으로 검출되었으며 사용기간이 늘어남에 따라 미생물 수가 증가하였다. 500 ppm 이산화염소수를 이용한 살균처리에서는 coliform, E. c

전통 용기인 미세다공성의 옹기를 화병으로 활용하기 관행의 자기 및 유리 화병과 옹기 화병에 장미 절화를 꽂고 절화수명을 비교하였다. 절화보존제 용액과 수돗물이 들어있는 3가지 재질의 용기에 장미 ‘Aqua’와 ‘Covernet’의 절화를 꽂은 후 절화수명과 미생물수, 수분흡수량, 절화 생체중 등을 조사하였다. 그 결과, 두 품종 모두 옹기 화병에서 절화수명이 길었으며, 절화보존용액이 수돗물에 비해 절화수명을 연장시켰다. 특히 절화보존용액을 넣은 옹기 화병에서 두 품종 모두 절화수명이 14일 수준으로 가장 길었다. 10일간의 누적 수분 흡수량은 절화보존용제를 넣은 옹기 화병에서 ‘Aqua’가 17.0mL, ‘Covernet’가 15.1mL로, 수돗물의 13.6과 13.8mL보다 많았다. 생체중은 절화보존제 처리가 수돗물에 비해 생체중 감소를 크게 지연시켰으며, 옹기도 다른 재질의 화병에 비해 생체중 감소 지연 효과가 있었다. 특히 옹기에 절화보존제를 처리한 ‘Aqua’ 품종의 경우 처리 8일 후에도 초기 생체중의 88% 수준을 유지하여 상대적으로 수분흡수가 원활했음을 알 수 있었다. 반면, 자기 화병에 절화보존제를 처리한 경우 79%, 옹기 화병에 수돗물을 넣은 경우 72%였다. 미생물수 측정 결과, 옹기의 보존용액의 총 균수가 다른 용기에 비해 적게 나타났다. 8일째 옹기에 ‘Covernet’을 꽂은 보존액에서 유지할 경우, 자기나 유리의 용기에 비해 비교적 적은 수의 미생물이 검출되었지만 보존 용기 간의 차이보다는 절화보존제 처리구에서 무처리에 비해 미생물의 증식이 현저히 감소하였다. 옹기는 절화 장미의 물올림을 유지시켜 주기 때문에 도관 폐쇄에 의한 꽃목굽음 현상이 억제하고, 절화보존제를 병행하여 사용함으로써 미생물의 발생을 억제하여 절화수명을 연장할 수 있다.

파프리카(Capsicum annuum var. angulosum)는 우리나라의 대표적인 수출농산물로서 지속적인 수출확대를 위해서는 안전성 확보가 중요하다. 지금까지 수출과채류의 생물학적 위해요소에 대한 연구는 많이 이루어 지지 않았다. 본 연구는 우리나라의 대표적인 수출 농산물인 파프리카를 대상으로 미생물오염실태를 모니터링하고, 보관온도에 따른 세균오염도 변화를 분석하였다. 파프리카의 평균 총호 기성균 수는 log CFU/g이었으며, 대장균군은

The effect of the variation of aeration time on the microorganisms was investigated in sequencing batch reactor (SBRs). The cycling time in four SBRs was adjusted to 12 hours and then included different aerobic times as 1 hr, 2.5 hr, 4 hr and 5.5 hr, respectively. Four SBR systems have been operated and investigated for over 40 days. As the increase of aeration time, the consumption of glycogen within sludge at the 1st non-aeration time a little bit was increased and the production of glycogen at the aeration time was increased. Also, the produced PHB amounts and PHB production rate at the 1st non-aeration time were increased as the decrease of aeration time, which showed the activation of the phosphorus removal. The ratios of nitrifying microorganisms' number and GAOs to the total microorganisms' number in SBRs was decreased as the decrease of the aeration time, however, the PAOs ratio was almost constant irrespective of the variation of aeration time.

This work was to improve antimicrobial activities of horseradish by encapsulated with edible biopolymers such as lecithin and gelatin since it has been difficult to directly use horseradish extracts into foods and food containers due to its strong and undesirable flavors. It was shown that most of the nanoparticles containing the extracts were well formed in round shape with below 400 nm diameter as well as fairly stable and less odd flavors in various pH ranges by measuring zeta potentials. The encapsulation efficiencies of nanoparticles were estimated as 66.6% and 53.4% for lecithin and gelatin, respectively. Minimal Inhibitory Concentration (MIC) of both nanoparticles against G(+), Listeria monocytogenes and G(-), Salmonella typhimurium were also measured as 79 ppm based on AIT concentrations in the extracts, whose activities were about 65% higher than the case of adding crude extract. It was also found that the nanoparticles efficiently penetrated into the cell membrane and started to destruct the cells after 6 hours cultivation under Transmision Electron Microscopy observation. These results prove that the nano-encapsulation of the horseradish extracts can be employed to directly treat into the foods and food containers for antimicrobial purposes with the aids of aerosolization system, by using small amounts of the extracts and having less flavors due to masking effects of nanoparticles.

This study was conducted to determine the effect of probiotics as an alternative for antibiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in growing piglets. A total of 96 piglets (22.5±1.3㎏ average body weight) were allotted to 3 different treatment groups and replicated 4 times with 8 piglets per replicate in randomized complete block design. Treatments were T1) (Control, basal diet+0.2% antibiotics), T2) 0.2% probiotics complex and T3) 0.3% Bacillus probiotics. During the whole experiment period, there were no differences (p>0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency. However, digestibility of dry matter, crude protein, ether extract, nitrogen free extract and crude ash were showed higher in probiotics groups (T2 and T3) than those of control. In noxious gas emission, ammonia, amine, hydrogen sulfide and mercaptan were significantly (p

Three biphenyl-degrading microorganisms were isolated from polluted soil samples in Sasang-gu, Busan. Among them, isolate DS-94 showing the strong degrading activity was selected. The morphological, physiological, and biochemical characteristics of DS-94 were investigated by API 20NE and other tests. This bacterium was identified as the genus Pseudomonas by 16S rDNA sequencing and designated as Pseudomonas sp. DS-94. The optimum temperature and pH for the growth of Pseudomonas sp. DS-94 were 25℃ and pH 7.0, respectively. This isolate could utilize biphenyl as sole source of carbon and energy. Biphenyl-degrading efficiency of this isolate was measured by HPLC analysis. As a result of biological biphenyl-degradation at high biphenyl concentration (500 mg/L), biphenyl-removal efficiency by this isolate was 73.5% for 7 days.

This study was carried out in order to observe how the bay sediment would be changed with microbial treatments and a chemical oxidant like CaO2. The sediment during the treatments was analyzed in terms of pH, ORP, volatile organics content, COD, AVS, T-N, and T-P. With CaO2 treatment, pH was kept over 9.66 and ORP ranged from +4.70～+46.0, which meant an aerobic state meanwhile with the microbial treatment those were worse. In addition the chemical treatment showed better environmental index values than the microbial one: volatile organics content and COD values in the former were 12.9% and 37.9% while those in the latter were 4.5% and 18.7%, respectively. AVS and T-P were 71.1% and 100% versus 56.5% and 85.8%, respectively. However, the microbial treatment was better for T-N(66% higher). On the other hand, both treatment at a time enhanced all the environmental indices but COD meantime pH and ORP values were lower than with the chemical treatment only. Thus additional input of an oxygen generator like CaO2 could improve the environmental state of a bay sediment where the biological treatment is going on.

This study was carried out to investigate the effect of KEM and SAF appication on contents change of fatty acids and organic acid of perilla(Perilla Frutescens Britton). Contenst of squalene in perilla leaves on control and KEM/SAF treated were 3.39 mg and 4.22 mg, respectively. Therefore the squalene quantity of KEM/SAF treated leaves was 24.2% more than that of control. A total 6 fatty acids in perilla leaves were analyzed in this study. Percentage of the saturated and unsaturated fatty acid in perilla leaves were 20 and 80%, respectively. Contents of phytosterols in perilla leaf such as campesterol and sitosterol were 2.0 and 20.0 mg, respectively. Therefore sitosterol content was 10 fold more than that of campesterol. The KEM/SAF application on perilla leaf was effective on the change of squalene or phytosterol contents. However effect of that was negligible on the change of fatty acid content.

This study was carried out to compare and analyze the effect of Korean effective microorganism(KEM) and seafood amino acid fertilizer(SAF) application on apple on functional substances of fruit. Vitamin C in fruit of control and KEM/SAF treated were 29.3 and, 39.8 ㎎, respectively. Also active oxygen scavenging ability of those treatments measured with DPPH method were 40.6 and 54.1%, respectively. Vitamin E contents of those treatments were 2.51 and 2.50 ㎎, respectively. Sitosterol, a phytosterol, contents of those treatments were 4.79 and 5.41 ㎎, respectively. Proportion of sugars, fructose, glucose, and sucrose in the fruit of control were 36.1, 15.3 and 17.8%, respectively. Those of the fruit of KEM/SAF treated were 45.9, 13.2 and 18.8%, respectively. Malic acid contents of control and KEM/SAF treated fruits were 53.7 and 43.8%, respectively.

본 연구는 천연 식품보존료 개발의 일환으로 한약 재료로 이용되고 있는 개머루덩굴을 에탄올로 추출하여 식품부패 및 병원성 미생물에 대한 항균활성을 조사하였다. 개머루덩굴 에탄올 추출물은 식품부패 및 병원성 미생물에 대해 농도 의존적으로 항균효과를 보였으며, 그 중에서 Escherichia coli O157:H7 균에 대해 가장 높은 항균효과를 보였다. 또 개머루덩굴 에탄올 추출물이 식중독 유발세균의 성장에 미치는 효과를 검정하기 위해 Salmonella typhimurium, Yersinia enterocolitica, Staphylococcus aureus, Escherichia coli O157:H7 균들의 배양액에 개머루덩굴 에탄올 추출물의 농도를 250, 500, 1,000, 2,000 mg/L 각 농도별로 첨가하여 생육을 조사한 결과 250 mg/L까지는 대조군과 별 차이를 보이지 않았으나 500 mg/L 이상에서는 유의적인(p<0.05) 감소를 관찰할 수 있었다. 본 연구결과는 개머루덩굴 에탄올 추출물이 식중독을 유발시키는 세균에 대하여 우수한 항균작용을 나타내고 있으며, 따라서 개머루덩굴이 효과적인 천연보존료로서 이용될 수 있음을 시사하고 있다.

본 연구의 목적은 대구 경북지역 초등학교에 공급되는 전처리 채소와 가공식품의 유통단계를 분석하고, 유통과정에서의 미생물 변화와 학교급식에 이용되는 식재료의 미생물 품질을 평가하기 위하여 실시되었다. 유통 중 박피도라지에서 일반세균 CFU/g, 대장균군 CFU/g, E. coli < , S. aureus < CFU/g, B. cereus < CFU/g이 검출되었다. 전처리 양파에서는 일반세균 CFU/g, 대장균군 CFU/g이 검출되

마즙의 위생성 및 보존성 향상을 목적으로 0, 1, 3 및 5 kGy의 선량으로 감마선을 조사하고 에서 보관하면서 8일간 마즙의 미생물학적, 일반품질 및 관능평가를 실시하였다. 마즙의 호기성세균 및 대장균군은 각각 1.26 및 1.34 kGy의 값을 보였으며, 저장에 따라 3 및 5 kGy 조사구의 경우 검출한계 이하의 균수를 유지하였다. 효모 및 곰팡이의 D10값은 0.29 kGy로 일반호기성균 및 대장균군 보다 감마선에 높은 감수성을 보였으