• 제목/요약/키워드: psychrophilic bacteria

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Distribution of Indicator Organisms and Incidence of Pathogenic Bacteria in Raw Beef Used for Korean Beef Jerky

  • Kim, Hyoun-Wook;Kim, Hye-Jung;Kim, Cheon-Jei;Paik, Hyun-Dong
    • Food Science and Biotechnology
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    • 제17권6호
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    • pp.1337-1340
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    • 2008
  • The objective of this study was to evaluate the microbial safety of raw beef used to produce Korean beef jerky, The raw beef samples harbored large populations of microorganisms. In particular, psychrophilic bacteria were found to be most numerous ($9.2{\times}10^3-1.0{\times}10^5\;CFU/g$) in the samples. Mesophilic bacteria and anaerobic bacteria were present in average numbers ($10^3-10^5\;CFU/g$). Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $2.2{\times}10^1-7.8{\times}10^2\;CFU/g$ in the raw beef. Ten samples of raw beef were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from sample B, G, and H. The B. cereus isolates from raw beef samples were identified with 99.8% agreement according to the API CHB 50 kit.

Carvacrol과 thymol을 병행처리한 키토산 코팅이 냉장저장 시 흰다리 새우의 미생물 및 품질 특성에 미치는 효과 (The Effect of Chitosan Coating Combined with Carvacrol and Thymol on Microbial and Quality Characteristics of Litopenaeus vannamei during Cold Storage)

  • 고봉수;박미정;곽승해;오세욱
    • 한국식품위생안전성학회지
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    • 제32권5호
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    • pp.363-370
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    • 2017
  • 본 실험에서는 냉동 새우(Litopenaeus vannamei)를 $4^{\circ}C$에서 12일동안 저온 저장하며, 키토산 코팅과 천연보존제의 병행처리(0.05% carvacrol, 0.05% thymol)가 미생물(중온균, 저온균, Pseudomonas spp., $H_2S$ 생성균)의 성장과 새우의 이화학적 특징(총 휘발성 질소화합물, pH) 및 관능적 품질(외관, 냄새, 전반적 수용도)에 미치는 영향을 살펴보았다. 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 모든 대상 미생물의 성장을 억제하였고 특히 중온균, 저온균, $H_2S$ 생성균의 경우 실험의 마지막 날인 12일째까지 유의적인 항균효과(p < 0.05)를 보였다. 이 처리구들은 총 휘발성 질소화합물과 관능적 특성(외관, 냄새, 전반적 수용도)에서도 12일째까지 유의적인 차이(p < 0.05)를 보였으나 pH에서는 유의적 차이가 없었다. 따라서 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 새우의 주요 부패 미생물의 성장을 효과적으로 억제하는 것으로 보이며 냉장 새우의 유통기간 연장에 활용할 수 있을 것으로 보여진다.

우유의 열처리가 우유품질과 영양가에 미치는 영향: II. 열처리에 의한 우유의 미생물 사멸효과 (Effects of Heat Treatment on the Nutritional Quality of Milk: II. Destruction of Microorganisms in Milk by Heat Treatment)

  • 김광현;박대은;오세종
    • Journal of Dairy Science and Biotechnology
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    • 제35권1호
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    • pp.55-72
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    • 2017
  • The second article of 'Effects of heat treatment on the nutritional quality of milk,' titled 'Destruction of microorganisms in milk by heat treatment' and authored by Dr. Seong Kwan Cha, who worked at the Korea Food Research Institute, covers the heat-stable microorganisms that exist in milk after pasteurization. The article focusses on the microbiological quality of raw milk and market milk following heat treatment, and is divided into four sub-topics: microbiological quality of raw milk, survey and measurement of microorganisms killed in raw milk, effect on psychrophilic and mesophilic microorganisms, and effect of heat treatment methods on thermoduric microorganisms. Bacillus spp. and Clostridium spp. are sporeforming gram-positive organisms commonly found in soil, vegetables, grains, and raw and pasteurized milk that can survive most food processing methods. Since spores cannot be inactivated by LTLT (low temperature long time) or HTST (high temperature short time) milk pasteurization methods, they are often responsible for food poisoning. However, UHT (ultra high temperature) processing completely kills the spores in raw milk by heating it to temperatures above $130^{\circ}C$ for a few seconds, and thus, the UHT method is popularly used for milk processing worldwide.

Diversity of Deep-sea Piezophiles and Their Molecular Adaptations to High-pressure Environment

  • Kato, Chiaki;Sato, Takako;Tamegai, Hideyuki;Nakasone, Kaoru
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2007년도 International Meeting of the Microbiological Society of Korea
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    • pp.80-82
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    • 2007
  • We have isolated numerous cold deep-sea adapted microorganisms (piezophilic, formerly referred to as "barophilic" bacteria) using deep-sea research submersibles. Many of the isolates are novel psychrophilic bacteria, and we have identified several new piezophilic species, i.e., Photobacterium profundum, Shewanella violacea, Moritella japonica, Moritella yayanosii, Psychromonas kaikoi, and Colwellia piezophila. These piezophiles are involving to five genera in gamma-Proteobacteria subgroup and produce significant amounts of unsaturated fatty acids in their cell membrane fractions to maintain the membrane fluidity in cold and high-pressure environments. Piezophilic microorganisms have been identified in many deep-sea bottoms of many of the world oceans. Therefore, these microbes are well distributed on our planet. One of the isolated deep-sea piezophiles, Shewanella violacea strain DSS12 is a psychrophilic, moderately piezophilic bacterium from a sediment sample collected at the Ryukyu Trench (depth: 5,110 m), which grows optimally at 30 MPa and $8^{\circ}C$ but also grows at atmospheric pressure (0.1 MPa) and $8^{\circ}C$. We have examined this strain to elucidate the molecular basis for gene regulation at different pressure conditions because this strain is useful as a model bacterium for comparing the various features of bacterial physiology under pressure conditions. In addition, we completed the sequencing of the entire genome of this piezophilic bacterium and we expect that many biotechnologically useful genes will be identified from the genome information.

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초고온멸균유(超高溫滅菌乳)의 보존성(保存性)에 관한 연구(硏究) (Studies on the Keeping Quality of Ultra-High-Temperature Sterilized Milk)

  • 김종우
    • 농업과학연구
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    • 제9권2호
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    • pp.556-561
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    • 1982
  • 우리나라에서 처리(處理) 유통(流通)되고 있는 초고온멸균유(超高溫滅菌乳)의 선도(鮮度) 및 세균학적(細菌學的) 상태(狀態)를 확인(確認)함과 동시(同時)에 냉장(冷藏) 및 실온(室溫)에 있어서의 보존성(保存性)을 구명(究明)하기 위하여 3개지성(個地城)(천안(天安), 평택(平澤) 및 수원(水原))에서 처리(處理) 생산(生産)되고 있는 초고온멸균무균충전우유(超高溫滅菌無菌充塡牛乳)를 시료(試料)로 하여 신선도(新鮮度) 검사(檢査)와 세균학적(細菌學的) 상태(狀態)를 시험(試驗)한 결과(結果)는 다음과 같다. 1. 3개(個) 유처리장(乳處理場)에서 생산(生産)된 초고온멸균유(超高溫滅菌乳)를 $5^{\circ}C$에 보존(保存)할 때 6주(週)까지 0.16%의 산도(酸度)를 유지(維持)하고 10주(週)에 이르러서도 0.18% 이하(以下)의 산도(酸度)와 음성(陰性)의 주정검사(酒精檢査) 및 자비시험결과(煮沸試驗結果)를 나타내었다. 2. 초고온멸균유(超高溫滅菌乳)를 $25^{\circ}C$에 보존(保存)할 때에는 9 주(週)까지 0.18%이하(以下)의 산도(酸度)를 유지(維持)하고 주정검사(酒精檢査) 및 자비시험(煮沸試驗)에서도 전시료(全試料)가 음성(陰性)을 나타내었다. 3. 초고온멸균유(超高溫滅菌乳)는 $5^{\circ}C$ 보존(保存)의 경우 내열성균(耐熱性菌), 대장균(大腸菌)은 나타나지 않았으며 생균수(生菌數) 및 호냉성균(好冷性菌)은 5주(週), 6주(週) 및 10주등(週等)에 <10/ml의 균수(菌數)를 나타내었다. 4. 초고온멸균유(超高溫滅菌乳)를 $25^{\circ}C$에 보존(保存)할 때 내열성균(耐熱性菌) 및 대장균(大腸菌)은 나타나지 않았으며 생균수(生菌數) 및 호냉생균(好冷生菌) 3주(週)부터 10주(週)까지 사이에 간단적(間斷的)으로 <10/ml의 균수(菌數)를 표시(表示)하였다.

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입상 활성탄 여과지에서 세균의 재성장과 생물막 형성 세균의 분리 및 동정 (Bacterial regrowth in biofilms formed in granular activated carbon filter adsorbers and the bacterial isolation and identification)

  • 이규철;권순복;이병기;박종근
    • 상하수도학회지
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    • 제22권2호
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    • pp.205-212
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    • 2008
  • This study aimed to investigate the biofilm formation, bacterial regrowth, and bacterial community structure in the granular-activated carbon (GAC) filter adsorbers (FAs) used in water treatment plants. In 2005 and 2006, raw water, settled water, GAC FA by depth, and filtered water were collected twice a year from water treatment plants (WTPs) B and S. The number of heterotrophic bacteria, including mesophilic and psychrophilic bacteria, in such collected waters was investigated along with the total number of coliforms therein. Heterotrophic bacteria were detected in most samples, mainly at the surface layers of the GAC FAs, and fewer such bacteria were found in the lower and bottom layers. An increase in the bacterial number, however, was observed in the samples from various depths of the GAC FAs in WTPs B and S compared with the surface layers. An increase in the bacterial number was also detected in the filtered water. This may indicate that there is a regrowth of the bacteria in the GAC FA. Considering, however, that heterotrophic bacteria were not found in the filtered water, it can be deduced that most bacteria are removed in the chlorination process. Coliforms were detected at the surface layer of the GAC FAs, but their regrowth was not observed. MicroLog systems were used to identify the bacteria community distribution. Eight genera and 14 species, including Pseudomonas spp., were detected in WTP B, and 8 genera and 9 species, including Aeromonas spp., in WTP S. Further studies are required to elucidate their role in the biofilms in water treatment processes.

Pseudomonas spp.에 의한 부패 (Food Spoilage by Pseudomonas spp.)

  • 김경미;이희영;이수민;박범영;오미화;윤요한
    • Journal of Dairy Science and Biotechnology
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    • 제31권2호
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    • pp.179-186
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    • 2013
  • Pseudomonas spp. are Gram-negative psychrophilic bacteria, which can proliferate at refrigeration temperature. The bacteria produce heat-stable enzymes that can degrade fat and protein in foods. Hence, Pseudomonas spp. are related to the spoilage of milk, dairy products, and meat products under cold storage, causing economic loss. In the food industry, various methods have been used to remove bacteria including Pseudomonas spp. in food-related conditions, but they can be resistant to antimicrobials and sanitizers because they form biofilms regulated by quorum sensing (cell density-dependent cell-to-cell signaling). Since Pseudomonas cells in biofilms can cross-contaminate foods resulting in food spoilage and the survival of food-borne pathogens in food-related conditions, efficient decontamination technology and microbiological criteria should be established to reduce the occurrence of food spoilage by Pseudomonas spp.

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Determination of the Effect of Different Ground Mustard Seeds on Quality Characteristics of Meatballs

  • Caglar, Muhammed Yusuf;Gok, Veli;Tomar, Oktay;Akarca, Gokhan
    • 한국축산식품학회지
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    • 제38권3호
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    • pp.530-543
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    • 2018
  • This study investigated the effect of yellow, black, and brown mustard seeds on color, lipid oxidation (thiobarbituric acid-reactive substances [TBARS]), and microbiological and sensory qualities of meatballs during storage. Heat treatment of mustard seeds affected the TBARS value of meatball samples (p<0.0001). The addition of mustard seeds decreased TBARS value of meatball samples (p<0.0001). Heat treatment of mustard seeds decreased the $L^*$, $a^*$ and $b^*$ values of meatball samples (p<0.0001). The meatball samples with mustard seeds increased $b^*$ value of meatball samples however it decreased $a^*$ value of meatball samples (p<0.0001). The addition of mustard seeds decreased aerobic mesophilic bacteria count (p<0.0001), Enterobacteriaceae count (p<0.0001), psychrophilic bacteria count (p<0.0001) and yeast and mold count of meatball samples (p<0.0001). On a given storage day, the yellow mustard added meatballs sample was given higher color, appearance, flavor, acceptability ratings than those added black and brown mustard. Regarding sensory and microbiological properties, mustard seed contributed to microbiological quality and sensorial properties of meatball samples.

시판 식물성 식품의 오염지표세균 분포 및 저장온도, 기간별 오염지표세균의 변화 (Distribution of Indicator Organisms and Influence of Storage Temperature and Period in Commercial Plant Food)

  • 이용욱;박석기
    • 한국식품위생안전성학회지
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    • 제14권1호
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    • pp.1-8
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    • 1999
  • There were few data for the distribution of the indicator organisms in the commercial plant foods, and for the normal flora and for the foodborne agents within the country. First of all it must be investigated the distribution of the indicator organisms. And also it is very important to prepare the sanitation criteria for the plant foods through the microbiological examination and the investigation of tendency to change of the indicator organisms according to the storage temperature and period. The average number of total viable counts for grains was 2.9$\times$105/g, psychrophilic bacteria 2.9$\times$105/g, heterotrophic bacteria 3.1$\times$105/g, heat-resistant bacteria 2.1$\times$103/g, Pseudomonas aeruginosa 23/g. That for beans was 6.3$\times$102/g, psychrophile 34/g, heterotroph 1.7$\times$102/g. That for sesames was 1.4$\times$105/g, coliform 350/g, psychrophile 7.4$\times$104/g, heterotroph 5.8$\times$104/g, Pseud. aeruginosa 2.3$\times$103/g. heat-resistant bacteria 150/g. That for potatoes was 2.0$\times$107/g, coliform 5.0$\times$104/g, psychrophile 1.8$\times$107, heterotroph 1.4$\times$107/g, heat-resistant bacteria 3.3$\times$104/, Staphylococcus 2.7$\times$105/g, fecal streptococcus 4.5$\times$103/g, Pseud. aeruginosa 7.0$\times$103/g. That for mushrooms was 1.2$\times$108/g, psychrophile 9.4$\times$107/g, heterotroph 1.0$\times$109/g, heat-resistant bacteria 1.6$\times$105/g, Pseud. aeruginosa 1.3$\times$103/g. That for vegetables was 5.9$\times$1011/g, coliform 1.8$\times$106g/, Staphylococcus 1.1$\times$1012/g, heterotroph 8.4$\times$1011/g, heat-resistant bacteria 7.6$\times$106/g, Staphylococcus 1.1$\times$107/g, fecal streptococcus 1.1$\times$104/g, Pseud. aerugniosa 5.2$\times$104/g. That for nuts 3.9$\times$104/g, coliform 3.9$\times$103/g, psychrophile 4.0$\times$104/g, heterotroph 3.2$\times$104/g, heat-resistant bacteria 400/g. In commercial grains and beans, SPC, psychrophile, heterotroph and heat-resistant bacteria stored at 1$0^{\circ}C$, 2$0^{\circ}C$, 3$0^{\circ}C$ were constant. Staphylococcus, coliform, Pseud. aeruginosa were decreased a little n grains, but were not detected in beans. In mushrooms, all indicator organisms were increased as time goes on and were increased rapidly at 2$0^{\circ}C$. In sesames, coliform was not detected at all temperature. psychrophile was increased for 7 days, the others were constant. In potatoes, SPC, psychrophile, heat-resistant bacteria, heterotroph had a tendency to increase and the others were constant. In vegetables, indicator organisms were had a tendency to increase, psychrophile, heterotroph were rapidly increased after 7 days. In nuts, SPC, coliform, psychrophile heterotroph, heat-resistant bacteria, Pseud. aeruginosa were constant, staphylococcus and fecal streptococcus were not detected.

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바이칼 호수에 서식하는 담수 스폰지 내 공생세균의 분리 (Isolation of Bacteria Associated with Fresh Sponges in Lake Baikal)

  • 조안나;김주영;안태석
    • 생태와환경
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    • 제47권spc호
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    • pp.39-47
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    • 2014
  • 바이칼호에 서식하는 2종의 스폰지 체내 및 주변 물로부터 92개의 저온성 균주를 분리하고 각 균주들의 기질 분해능을 조사하였다. 그 결과 섬유소와 지방에 대한 분해 활성도를 갖는 균주는 38.0, 34.8%로 비교적 적었으나 전분과 단백질 분해 활성도를 갖는 균주는 78.3, 57.6%로 높은 비율로 나타났다. 분리한 세균을 염기서열의 유사도에 따라 분류하기 위하여 Genomic Fingerprinting을 실시한 후 31개 균주를 선별하여 동정한 결과, Baikalospongia sp.에서 분리한 13균주는 모두 Pseudomonas속으로 확인된 반면, Lubomirskia sp.에서 분리한 14균주는 Pseudomonas ssp., Buttiauxella agrestis, Pseudomonas fluorescens, Yersinia ruckeri, Bacillus ssp., Paenibacillus ssp., Bacillus thuringiensis, Bacillus simplex, Brevibacterium ssp., Acinetobacter lwoffii로 다양하게 동정되었다. 그러나 총 31개 균주 중 18개가 Pseudomonas속으로 동정된 것은 타감작용에 의한 다른 세균 성장의 방해 때문으로 평가되며, 이러한 일반적인 배양 방법의 한계점을 극복하기 위해서는 스폰지의 서식처와 세균의 검출 방법에 대하여 보다 다양한 심층적인 연구가 이루어져야 할 것으로 생각된다.