• Feed Journal
• /
• v.4 no.12 s.40
• /
• pp.84-92
• /
• 2006

항생제(antibiotics)란 공생(symbiosis)의 반대 개념인 항생(antibiosis)에서 유래된 것으로 ‘생물, 특히 미생물에 의해 만들어진 물질로서 다른 미생물의 성장이나 생명을 막는 것’을 말한다. 축산에서 성장촉진용 항생제 사용은 성장률과 사료효율 및 특정 질병을 치유시켜준다는 장점이 있어 그 동안 대중적으로 많이 사용했던 것이 사실이다. 그러나 무분별한 항생제 사용으로 인해 내성 문제와 체내 잔류와 같은 문제가 발생하여 가축뿐만 아니라 사람에게도 부정적인 문제를 야기 시킬 수 있다고 하여 최근 각 국가별로 항생제의 사용을 전면 금지 또는 강력한 규제를 하고 있다. 이러한 국제적인 움직임 속에 전 세계는 항생제를 대체할 수 있는 대체 물질 개발 대체물질을 이용한 친환경 무항생제 사육 프로그램을 도입하여 소비자에게 고품질의 안전하고 위생적인 축산물을 공급하기 위해 노력을 기울이고 있다. 다라서 본고에서는 항생제 사용에 따른 문제점을 지적하고 최근 각광 받고 있는 항생제 대체물질에 대해 살펴보며 추후 이러한 대체 물질을 통해 친환경 무항생제 사육의 가능성은 얼마나 되는지 살펴보기로 한다.

• Microbiology and Biotechnology Letters
• /
• v.13 no.3
• /
• pp.311-314
• /
• 1985

Ganodema lucidum protoplasts were formed by the treatment of Novozym 234. The osmotic stabilizers such as mannitol were effective enough to produce protoplasts up to 10$^{6}$ $m\ell$. For regeneration, however, MgSO$_4$.7$H_2O$ was suitable. When inositol and sucrose were employed as osmotic stablizers, the regeneration ratio reached to 0.26％. Overlay of Streptomycin sulfate added agar was required to prevent bacterial contamination.

• Journal of Life Science
• /
• v.33 no.7
• /
• pp.593-604
• /
• 2023

The ocean accounts for over 70% of the Earth's surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.

• Journal of Food Hygiene and Safety
• /
• v.29 no.2
• /
• pp.117-122
• /
• 2014

Rice can be the contaminating with soil-borne bacteria. Furthermore, the contaminated bacteria can be grown during immersion process for produce wet-milled rice flour. Therefore, disinfectants can be added during the immersion process. Antibacterial activities of the natural disinfectant, fermented rice spent water (FRSW), and the chemical disinfectants, chlorine dioxide (CD) and sodium benzoate (SB), were respectively determined when added in pure cultures of target bacteria such as Salmonella typhimurium, Escherichia coli, and Bacillus cereus or when added to immersion water in the immersion process. In addition, rinsing effects for removing bacteria were determined when rice was rinsed with water before and after the immersion process. Antibacterial activities were rapidly increased as increasing amounts of the disinfectants are added to the pure cultures of the target bacteria. Antibacterial activity of CD was the most effective among the three tested disinfectants when added to the pure cultures of the target bacteria, respectively. Those of the same disinfectants were increased when they were increasingly added to the immersion water. However those of the disinfectants were less effective when added to the immersion water. On the other hand, rinsing effects for removing bacteria were the most effective when rice was rinsed only with water without the immersion process. Collectively, rinsing rice with water only was more effective than using disinfectants in the immersion water during rice flour production.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.4
• /
• pp.284-293
• /
• 2000

For the artificial removal of air pollutants such as pesticides, environmental toxicants, and pathogenic microorganisms in the greenhouse or the living environment, the accelerated photodegradation and the biocidal effects of some photosensitizers (PS)/photocatalysts (PC) were tested under the sunlight and/or artificial light. The selected photosensitizers/photocatalysts included the semiconductors (PC-1 and PC-2), the oxidizers (PC-3, PC-4, PC-5 and PC-6), the aromatic ketone (PS-7) and the aromatic amine (PS-8). In the case of dichlorvos, all the photocatalysts selected showed more accelerated photodegradation than the control without photocatalysts under both the sunlight and artificial light. Whereas, only the photocatalyst PC-1 accelerated the degradation of methyl tert-butyl ether about 17 times more than the control under both the sunlight and artificial light. Procymidone was much more degraded by the photosensitizer PS-8 and the two photocatalysts (PC-1, PC-6) than by PS-7. In the preliminary experiments to diminish the population of the microorganisms in the air, the photocatalyst PC-1 added to the suspensions of Pseudomonas putida, Phytophthora capsici, and Salmonella typhimurium obviously inhibited the microbial growth under the artificial light. The photocatalyst PC-1 showed a bactericidal activity against Salmonella typhimurium spread on the nutrient broth agar medium. These results suggest that the photosensitizers/photocatalysis under the light can remove some air pollutants and hence they can be used to reduce the exposure of the workers in the horticultural facilities and/or the public in the environment to the harmful pollutants.

• Korean Journal of Microbiology
• /
• v.51 no.1
• /
• pp.81-85
• /
• 2015

Since the banning of antibiotic growth promoters (AGPs), the death of livestock has been increased, thus there is a strong demand for AGP-alternatives. Modulation of gut microbiota has been reported to affect host physiological functions and suggested to be a novel approach for developing AGP-alternatives. However, little has been understood about livestock gut microbiota compared to that of humans. We conducted preliminary study provide fundamental information regarding to regional differences in swine gut microbiota. Swine fecal samples were obtained from farms in Jeju (n=40), Gwangju (n=28), and Haenam (n=30). MiSeq was used to sequence 16S rRNA V4 region, and Mothur pipeline (Schloss et al., 2009) was used for data processing. A total of 5,642,125 reads were obtained and 3,868,143 reads were remained after removing erroneous reads. Analysis of taxonomic composition at the phylum level indicated greater abundance of Firmicutes among Jeju swine, and cluster analysis of distribution of operational taxonomic units also showed regional differences among swine gut microbiota. In addition, correlation analysis between non-metric multidimensional scaling and abundance of phyla suggested that the phyla Actinobacter, Verrucomicrobia, Firmicutes, and Fibrobacteres were driving factors for the regional differences. Livestock gut microbiota may be affected by diet and practices in farms. Our results indicated significant regional differences in swine gut microbiota, suggesting that future livestock gut microbiota studies should be designed with the regional differences in mind.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1975.07a
• /
• pp.110.2-110
• /
• 1975

성분이 동일한 완제품간장을 3$^{\circ}C$, 15$^{\circ}C$, 5$^{\circ}C$로 각각 달리하여 밑봉과 개봉상태로 1년이상 보존하면서 경시적으로 성분의 변화및 미생물의 동태를 관찰하고 동시에 시판 간장중에 생육하는 미생물을 계측한 결과는 아래와 같다. (1) 총질소, 색도, 비중, 석염의 함량은 저장기간의 경과에 따라 증가 현상을 나타내었으며 고온(3$0^{\circ}C$, 15$^{\circ}C$), 개봉방치 상태에서는 저온(5$^{\circ}C$)밀봉방치 상태에 비하여 증가현상은 현저하였다.(중략)

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.05a
• /
• pp.203-206
• /
• 2005

시중의 정육점 및 백화점 등에서 유통 중인 10종의 우육 원료에 대한 일반 세균수, 저온균수, 고온균, 혐기성균 및 진균류, 대장균군에 대한 미생물학적 분포와 병원성 미생물에 대한분리${\cdot}$동정을 실시하였다. 실험결과 원료 우육에서 중온균은 $3.8{\times}\;10^3{\sim}1.4{\times}\;10^5\;cfu/g$으로 높은 분포를 보였다. 저온균은 $9.2{\times}\;10^3{\sim}1.0{\times}\;10^5\;cfu/g$으로 지표세균 중에서 가장 높은 분포를 나타내었고, 혐기성균은 중온균, 저온균과 유사한 분포를 보였으나 상대적으로 적게 검출되었고, 고온균은 모든 검체에서 검출되지 않았다. 대장균군 또한 모든 시료에 대해서 검출되지 않았다. 효모와 곰팡이류는 $2.2{\times}\;10^1{\sim}7.8{\times}\;10^2\;cfu/g$으로 검출되었다. 병원성 미생물은 우육 sample B, G, H에서 B. cereus 만이 검출되었고, 동정결과 99.8%의 상동성을 보였다.

• Microbiology and Biotechnology Letters
• /
• v.17 no.1
• /
• pp.24-28
• /
• 1989

Effect of various fermentation parameter was investigated on the production of prednisolone by microbial $\Delta$'-dehydrogenation of hydrocortisone. The microbial conversion process was conducted by using pseudo-crystallo-fermentation techniques. The optimum temperature for the bioconversion process was found to be 35$^{\circ}C$. It was noted that the production rate of prednisolone was little affected within the initial pH range of 6.5-7.8, and also by the use of surfactant, Tween 80. Production rate of prednisolone was significantly reduced by the use of the antifoam agent, neolin. In a fermentor operation, however, large amount of antifoam agent should be used to remove foams generated by the high aeration rate, which resulted in n lower production rate of prednisolone than that from the shake flask experiment.

• Journal of Life Science
• /
• v.23 no.1
• /
• pp.79-83
• /
• 2013

A biofertilizer, BIOACTIVE, was manufactured by N-acetyl-thioproline (ATCA) and mineral phosphate solubilizing bacteria. The growth promoting effect of the biofertilizer on lettuce was evaluated under three different pot conditions, and its stability was assessed in the field. According to the results of the pot experiments, plant growth was improved compared with that of control: 128%, 122%, and 153% for the leaf number, leaf length, and leaf mass, respectively. Applying the manufactured biofertilizer increased the concentration of phosphate: 118% and 132% in the cultivation soil and plant cells, respectively. These show that BIOACTIVE may have potential as an effective biofertilizer in agriculture.