• 제목/요약/키워드: Microbial protease

검색결과 167건 처리시간 0.034초

감마선 조사 고추장의 미생물 및 일반품질 특성 변화 (Changes of Microbiological and General Quality Characteristics of Gamma Irradiated Kochujang(Fermented Hot Pepper Paste))

  • 김동호;육홍선;연규춘;손천배;변명우
    • 한국식품과학회지
    • /
    • 제33권1호
    • /
    • pp.72-77
    • /
    • 2001
  • 고추장의 보존성 향상을 목적으로 고추장에 5, 10, 20 kGy의 선량으로 감마선을 조사하고 $25^{\circ}C$에 12주간 보존하면서 고추장의 미생물 및 일반품질 변화를 조사하였다. 고추장의 Bacillus는 감마선 조사에 대하여 3.94 kGy의 $D_{10}$값을 보여 감마선에 대한 저항성이 높았으며 효모와 젖산균은 10 kGy의 선량에서 완전 사멸에 가까운 살균효과를 보였다. 고추장 보존 중의 일반품질 평가 요소인 아미노산성질소, 총환원당, protease 및 amylase 활성, pH, 갈변도의 변화는 감마선 조사에 의하여 영향을 받지 않았다. 따라서 감마선 조사는 고추장의 품질에 영향을 주지 않고 미생물만을 선택적으로 사멸시켜 제품의 보존 유통 및 가공에서 미생물 관점의 품질을 유지하는데 유용한 방법이 될 것으로 평가되었다.

  • PDF

Ruminal Protein Degradation Characteristics of Cell Mass from Lysine Production

  • Seo, S.;Kim, H.J.;Lee, S.Y.;Ha, Jong K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제21권3호
    • /
    • pp.364-370
    • /
    • 2008
  • Chemical analysis and in vitro studies were conducted to investigate the nutritive value for ruminants of cell mass from lysine production (CMLP) which is a by-product of the lysine manufacturing process. Proximate analysis, protein fractionation, and in vitro protein degradation using protease from Streptomyces griseus and strained ruminal fluid were carried out to estimate ruminal protein degradability of CMLP with two reference feedstuffs-soybean meal (SBM) and fish meal (FM). Amino acid composition and pepsin-HCl degradability were also determined to evaluate postruminal availability. CMLP contained 67.8% crude protein with a major portion being soluble form (45.4% CP) which was composed of mainly ammonium nitrogen (81.8% soluble CP). The amount of nucleic acids was low (1.15% DM). The total amount of amino acids contained in CMLP was 40.60% DM, which was lower than SBM (47.69% DM) or FM (54.08% DM). CMLP was composed of mainly fraction A and fraction B2, while the protein fraction in SBM was mostly B2 and FM contained high proportions of B2 and B3 fractions. The proportion of B3 fraction, slowly degradable protein, in CP was the highest in fish meal (23.34%), followed by CMLP (7.68%) and SBM (1.46%). CMLP was degraded up to 51.40% at 18 h of incubation with Streptomyces protease, which was low compared to FM (55.23%) and SBM (83.01%). This may be due to the insoluble portion of CMLP protein being hardly degradable by the protease. The in vitro fermentation by strained ruminal fluid showed that the amount of soluble fraction was larger in CMLP (40.6%) than in SBM (17.8%). However, because the degradation rate constant of the potentially degradable fraction of CMLP (2.0%/h) was lower than that of SBM (5.8%/h), the effective ruminal protein degradability of CMLP (46.95%) was slightly lower than SBM (53.77%). Unavailable fraction in the rumen was higher in CMLP (34.0%) compared to SBM (8.8%). In vitro CP degradability of CMLP by pepsin was 80.37%, which was lower than SBM (94.42%) and FM (89.04%). The evaluation of protein degradability using different approaches indicated that soluble protein in CMLP may supply a large amount of ammonia in the rumen while insoluble protein can be by-passed from microbial attacks due to its low degradability. The results from this study suggest that CMLP can be used as a protein supplement to ruminants for supplying both non-protein nitrogen to rumen microbes and rumen undegradable protein to the host animal.

Bacillus subtilis HJ18-4를 이용하여 제조한 메밀 속성장의 품질특성 (Quality characteristics of buckwheat Soksungjang manufactured by Bacillus subtilis HJ18-4)

  • 박나영;이선영;김지연;최혜선
    • 한국식품저장유통학회지
    • /
    • 제20권5호
    • /
    • pp.699-704
    • /
    • 2013
  • 메밀 속성장은 메밀과 콩으로 제조된 별미장이다. 항균 및 효소활성이 우수한 B. subtilis HJ18-4 균주를 starter로 사용하여 메밀 속성장을 제조하였다. 메밀 속성장 제조과정 중, starter 첨가 시기는 메주 제조단계(Treat-1) 및 염수 첨가단계(Treat-2)로 접종시기를 달리하였다. 발효 중 아미노태질소 함량, 환원당, 효소활성(protease, amylase)의 이화학적 품질특성과 총균 수, 유산균 수 및B. cereus 양 변화 등의 미생물학적 특성을 분석하였다. 그 결과, 총균 수는 발효 15일부터 7~8 log CFU/mL로 증가되었고 아미노태 질소함량은 발효기간 동안 65.38~202.52 mg%로 증가되었다. 반면, 환원당과 효소활성(amylase, protease)은 모든 처리구 에서 감소하였다. 발효기간 중 PlcR 발현에 미치는 영향을 측정한 결과, Treat-1 처리구에서 발효 23일 이후 검출되지 않았다. 메주 제조단계에서 B. subtilis HJ18-4를 접종한 Treat-1이 발효관련 이화학적 특성과B. cereus 저해효과가 우수하였다. 단일 균을 접종하여 제조되는 개량식장 제조 시, 자연발효에 제조된 장의 품질을 재현하기가 매우 어려운 실정이다. 본 연구는 자연발효방법으로 제조되는 메밀 속성장에 항균 및 효소활성이 우수한B. subtilis HJ18-4 균주를 스타터 적용하여 장류 품질개선 방법을 제시하였다.

장수버섯 배양으로 제조한 발효옻 추출물이 장류 미생물의 증식 및 효소활성에 미치는 영향 (Effect of the Extracts from Fermented-Rhus verniciflua Stem Bark with Fomitella fraxinea on the Growth and Enzyme Activity of Soybean Product-fermenting Microorganisms)

  • 최한석;여수환;정석태;최지호;강지은;김명곤
    • 한국균학회지
    • /
    • 제40권4호
    • /
    • pp.235-243
    • /
    • 2012
  • 옻의 장류이용 가능성을 검토하기 위하여 urushiol이 제거된 발효옻 추출물이 장류발효미생물의 증식 및 효소활성에 미치는 영향에 대하여 확인하였다. 발효옻 알코올 추출물은 Bacillus 속과 Z. rouxii에 대하여 항균활성을 가지고 있었으나 열수 추출물은 Bacillus 속과 Z. rouxii를 포함한 젖산균, 효모, 대장균에 항균활성이 없었다. 발효 옻 열수 추출물은 L. plantarum, L. mesenteroides, S. cerevisiae의 균체성장에는 영향을 미치지 않았으나 Bacillus속에 특이적으로 작용하여 B. licheniformis, B. sutilis의 균체를 1.3-4.5배 증가시켰다. 그러나 Z. rouxii는 균체량을 감소시켰으며 유해 미생물인 B. cereus와 E. coli에 대한 증식억제 효과도 나타내지 않았다. 발효옻 열수 추출물은 B. licheniformis와 B. subtilis가 생산하는 amylase와 protease의 활성을 큰 폭으로 증가시켰으며, amylase는 B. licheniformis 11052P 균주에서 protease는 B. subtilis 10854에서 그 증가 폭이 가장 컸다. 지방 및 cellulose 분해활성은 B. licheniformis와 B. subtilis의 모든 균주에서 나타나지 않았다.

Airway Mucus: Its Components and Function

  • Lillehoj, Erik-P.;Kim, K.-Chul
    • Archives of Pharmacal Research
    • /
    • 제25권6호
    • /
    • pp.770-780
    • /
    • 2002
  • The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airborne enemies.

가열과 비가열 처리를 통한 액젓의 이화학적 특성 (Characteristics of Salt Fermented Anchovies with Heat Treatment)

  • 강현우;조영제
    • 동아시아식생활학회지
    • /
    • 제23권1호
    • /
    • pp.92-97
    • /
    • 2013
  • This study was conducted to understand the quality characteristics of salt fermented anchovies with heat treatment by measuring their chemical compositions. The heat-treated and non-heat treated salt fermented anchovies contained, respectively, 63.21 and 66.51% of moisture, 2.24 and 2.12% of total nitrogen (TN), and 1,537 and 1,520 mg/100 g of amino nitrogen (AN). In addition, heat-treated and non-heat-treated salt fermented anchovies contained 127 and 134 mg/100 g of volatile basic nitrogen (VBN), respectively. Moreover, measured the microbial level of heat-treated and non-heat-treated salt fermented anchovies was $2.58{\times}10^4$ and $3.61{\times}10^2$ CFU/mL, respectively. Also, the heat-treated and non-heat-treated salt fermented anchovies 3.65 and 0.30 units of protease activities, respectively. The total free amino acid contents in heat-treated and non-heat-treated salt fermented anchovies was 4,964 and 6,638 mg/100 g, respectively. The major free amino acid were glutamic acid, leucine, lysine, alanine, valine, isoleucine. Our results provide the characteristics of salt fermented anchovies and encourage their application for the food industry and cooking.

Isolation and Characterization of Microbial Strains with Hydrolytic Enzyme Profile from Clay Minerals

  • Lee, Sulhee;Cho, Eui-Sang;Nam, Young-Do;Park, So-Lim;Lim, Seong-Il;Seo, Dong-Ho;Kim, Jae-Hwan;Seo, Myung-Ji
    • 한국미생물·생명공학회지
    • /
    • 제48권1호
    • /
    • pp.64-71
    • /
    • 2020
  • A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.

Citrinin Hydrate Inhibit Serotonin N-Acetyltransferase Catalyzing the Conversion of Serotonin to N-Acetylserotonin

  • Lee, In-Kyoung;Yun, Bong-Sik;Kim, Kyong-Tai;Choi, Bo-Hwa;Park, Tae-Ju;Kim, Young-Ho;Yoo, Ick-Dong
    • Journal of Microbiology and Biotechnology
    • /
    • 제11권6호
    • /
    • pp.1099-1101
    • /
    • 2001
  • In an attempt to search for serotonin N-acetyltransferase (arylalkylamine N-acetyltransferasem, AA-NAT) inhibitors from microbial metabolites, we fecund the culture broth of Penicillium sp. 80722 which showed a strong inhibitory activity against AA-NNT. The active principle has been identified as citrinin hydrate through bioassay-guided fractionation of cultural broth, and structure elucidation derived by spectroscopic analyses. Citrinin hydrate inhibits AA-NAT with an $IC_50$ value of $173{\mu}M$ in a dose-dependent manner. Although citrinin hydrate was previously isolated as human rhinovirus 3C-protease inhibitor, this was recognized as the first AA-NAT inhibitor isolated from natural sources.

  • PDF

순창지역 메주 발효 중 미생물과 효소역가의 변화 (Changes in Microflora and Enzyme Activities of Traditional Meju during Fermentation at Sunchang Area)

  • 유진영;김현규
    • 한국식품영양과학회지
    • /
    • 제27권3호
    • /
    • pp.448-454
    • /
    • 1998
  • Meju for doenjang and kochujang was prepared as a model at Sunchang areaand monitored with major changes. Kochujang meju was prepared on September 12 and doenjang meju on November 12, 1995. Kochjang meju was found to be naturally fermented at 80~90% RH, 15~2$0^{\circ}C$ and doenjang meju was at 80~90% RH and 0~5$^{\circ}C$. The shapes of kochujang meju and doenjang meju were doughnut-type and rectangular, respectively. Weight losses during fermentation were 48% and 28%, respectively. The pH drop and acip production of kochujang meju were negligible. However, pH of doenjang meju decreased from 6.29 to 5.88 and acidity increased from 0.08 to 0.23% as lactic acid. Protein in meju was found to be rapidly solubilized during the early stage of fermentation. Soluble protein cotents of kochujang meju after 7 days and 60 days were 8.23%, respectively. The doenjang mejus were 2.15% after 20 days and 5.72% after 60 days. Soluble suger content increased with the fermentation time. The soluble sugar content was higher in kochjang meju. Acidic protease was highly produced during meju fermentation. $\alpha$-Amylase and $\beta$-amylase were detected in the kochujang meju, of which glutinous rice consisted, but negligible in doenjang meju. Lipase was detected in kochujang meju, but was, negligible in doenjang meju. Microbial population increased drastically after 7 days of fermentation in kochujang meju and 20 days of fermentation in doenjang meju.

  • PDF

Quality Characteristics of Low-Salt Gochujang Added with Glycyrrhiza uralensis and Brassica juncea

  • Lee, So-Young;Park, So-Lim;Yi, Sung-Hun;Nam, Young-Do;Lim, Seong-Il
    • Preventive Nutrition and Food Science
    • /
    • 제16권4호
    • /
    • pp.348-356
    • /
    • 2011
  • The effects of Glycyrrhiza uralensis and Brassica juncea on the quality and palatability of low-salt gochujang were investigated in terms of the microbial characteristics, enzyme activities, pH, acidity, amino nitrogen and sensory evaluation during 40 days of fermentation. The proliferation of fungi in low-salt gochujang with added G. uralensis and B. juncea were inhibited, while the numbers of total viable bacteria and lactic acid bacteria were not affected. In terms of ${\alpha}$-amylase and ${\beta}$-amylase activity, no significant difference was observed by the salt concentration or additives. However, lowering the salt concentration increased protease activity. The amount of amino-nitrogen in low-salt gochujang at 20 days was similar to that in the control gochujang at 40 days. In the sensory test, low-salt gochujang was preferred compared to control gochujang (8.5% salt). Particularly, the 4.3% salt gochujang with additives was the most preferred.