• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1533-1541
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• 2016

Samples of doenjang (a fermented soybean paste) were prepared with different types of salts; purified salt (PS), 3-year-aged solar salt (SS3), 1-year-aged solar salt (SS1), and bamboo salt (BS, 3^rd processing product). For starter doenjang samples, selected starters comprising two bacilli, one yeast, and one fungus were inoculated, whereas for non-starter doenjang samples, microorganisms present in rice straw were inoculated after enrichment. The doenjang samples were fermented for 13 weeks at 25℃. During the fermentation period, SS and BS doenjang samples showed higher bacilli counts as well as much lower yeast counts than PS doenjang. At 13 weeks, yeast counts of starter doenjang samples were 7.75, 5.69, 6.08, and 4.74 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. For non-starter doenjang samples, counts were 7.17, 5.05, 5.92, and 4.54 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. SS and BS promoted growth of bacilli but inhibited growth of yeasts compared with PS. Debaryomyces hansenii was the dominant yeast in PS doenjang, whereas Candida guilliermondii and Pichia sorbitophila were dominant in SS and BS doenjang. In the sensory evaluation, SS and BS doenjang scored better than PS doenjang. In conclusion, SS and BS seem better than PS for production of high-quality doenjang.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.795-802
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• 2014

The aim of this study was to determine the effects of temperature and supplementation with skim milk powder (SMP) on the microbial and proteolytic properties during the storage of cottage cheese. Cottage cheese was manufactured using skim milk with 2% SMP and without SMP as the control, and then stored at $5^{\circ}C$ or $12^{\circ}C$ during 28 days. The chemical composition of the cottage cheese and the survival of the cheese microbiota containing starter lactic acid bacteria (SLAB) and non-starter culture lactic acid bacteria (NSLAB) were evaluated. In addition, changes in the concentration of lactose and lactic acid were analyzed, and proteolysis was evaluated through the measurement of acid soluble nitrogen (ASN) and non-protein nitrogen (NPN), as well as electrophoresis profile analysis. The counts of SLAB and NSLAB increased through the addition of SMP and with a higher storage temperature ($12^{\circ}C$), which coincided with the results of the lactose decrease and lactic acid production. Collaborating with these microbial changes, of the end of storage for 28 days, the level of ASN in samples at $12^{\circ}C$ was higher than those at $5^{\circ}C$. The NPN content was also progressively increased in all samples stored at $12^{\circ}C$. Taken together, the rate of SLAB and NSLAB proliferation during storage at $12^{\circ}C$ was higher than at $5^{\circ}C$, and consequently it led to increased proteolysis in the cottage cheese during storage. However, it was relatively less affected by SMP fortification. These findings indicated that the storage temperature is the important factor for the quality of commercial cottage cheese.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.250-257
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• 2001

An experiment was conducted to determine the effects of phytase supplementation to the diets containing different levels of non-phytate phosphorus (NPP). A $3{\times}2$ factorial arrangement of treatments was employed. There were three dietary NPP levels of control (C) (0.45% for starter diet and 0.35% for grower diet), C-0.1% NPP (0.35% for starter diet and 0.25% for grower diet), and C-0.2% NPP (0.25% for starter diet and 0.15% for grower diet) and two phytase levels (0 and 500 U/kg). Reduced dietary NPP decreased feed intake and weight gain and increased mortality whereas dietary phytase increased feed intake and weight gain and decreased mortality. Supplemental phytase improved availabilities of dry matter, crude fat, ash, P, Zn, Mg, and Cu whereas dietary NPP level did not affect availabilities of nutrients except decreased Zn availability and increased Cu availability in reduced NPP diets. Nutrient retention of N, ash, Ca, P, Mg, and Zn were linearly decreased as dietary NPP levels reduced but dietary phytase increased their retention. Reduced dietary NPP increased ash excretion but decreased P and Cu excretion while dietary phytase decreased N excretion. Weight, length, girth and contents of ash, Ca, P and Mg of tibia linearly decreased as dietary NPP levels reduced. Dietary phytase increased length and ash content of tibia. It is concluded that dietary phytase can reduce P excretion and alleviate adverse affects caused by feeding low dietary NPP. Effects of phytase were greater in the lower NPP diets.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.527-537
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• 2019

Three types of meongge (Halocynthia roretzi) jeotgal (MJ) were prepared with 3 different types of salts (12%, w/v): purified salt (PS), solar salt aged for 3 years (SS), and bamboo salt that had been recrystalized 3 times (BS). One set of MJ was fermented with starters, Bacillus subtilis JS2 and Tetragenococcus halophilus BS1-37 (each 6 log CFU/g), and another set without starters for 42 days at $10^{\circ}C$. The LAB count of the SSMJ (non-starter) was highest at day 28 (2.30 log CFU/g). The pH of the PSMJ and SSMJ was 5.72-5.77 at day 0, and 5.40-5.50 at day 42. BSMJ showed higher pH and lower titratable acidities than other samples. Amino-type nitrogen (ANN) increased continuously, and SSMJ showed higher values than other samples from day 14. Bacterial species of non-starter MJ were examined by culture independent method. Clone libraries of 16S rRNA genes were constructed in Escherichia coli from total DNA from non-starter MJ samples at day 0, 14, and 28. Thirty clones per each sample were randomly selected and DNA sequences were analyzed. Variovorax sp., uncultured bacterium, and Acidovorax sp. were the most dominant group at day 0, 14, and 28, respectively. Lactobacillus sakei and Streptococcus sp. were the next dominant group in SSMJ at day 28. A Streptococcus sp. was detected from PSMJ at day 28. Sensory evaluation for MJ samples at day 28 showed that SSMJ got higher overall acceptability scores. These results showed that solar salt can cause desirable changes in the microbial community of fermented foods, thereby positively affecting their overall quality.

• 육가공
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• 통권35호겨울호
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• pp.46-55
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• 2008

본 연구의 목적은 시판 중인 스타터를 이용한 발효육제품과 스타터를 이용하지 않고 자연발효시킨 육제품의 발효 및 숙성 중 미생물학적, 이화학적인 특성에 미치는 영향을 연구하고, 원료육에서의 전자선 조사(2 kGy) 효과를 검증하고자 한다. 2 kGy로 전자선 조사한 스타터 첨가구는 발효 및 숙성 중 pH가 급격히 감소하였으며(p<0.05), 최종 pH 는 4.25를 나타내었다. 총균수와 젖산균수는 스타터 첨가에 의해 좌우되는데 발효가 진행됨에 따라 총균수와 젖산균수가 유사한 경향을 나타내었다. TBARS 값은 발효 및 숙성기간이 증가함에 따라 모든 처리구에서 증가하였다. 본 연구결과를 통해 발효육 생산 전 2 kGy로 전자선 조사처리한 경우 총균수를 감소시키고 젖산균수는 증식하는 것을 확인하였다. 조사처리 후 육에 스타터를 첨가하게 되면 발효육 생산에 매우 유용하게 이용될 수 있을 것으로 사료된다.

• 한국축산식품학회지
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• 제27권3호
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• pp.308-313
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• 2007

본 연구의 목적은 시판 중인 스타터를 이용한 발효육제품과 스타터를 이용하지 않고 자연발효시킨 육제품의 발효 및 숙성 중 미생물학적, 이화학적인 특성에 미치는 영향을 연구하고, 원료육에서의 전자선 조사(2 kGy) 효과를 검증하고자 한다. 2 kGy로 전자선 조사한 스타터 첨가구는 발효 및 숙성 중 pH가 급격히 감소하였으며(p<0.05), 최종 pH 는 4.25를 나타내었다. 총균수와 젖산균수는 스타터 첨가에 의해 좌우되는데 발효가 진행됨에 따라 총균수와 젖산균수가 유사한 경향을 나타내었다. TBARS 값은 발효 및 숙성기간이 증가함에 따라 모든 처리구에서 증가하였다. 본 연구결과를 통해 발효육 생산 전 2 kGy로 전자선 조사처리한 경우 총균수를 감소시키고 젖산균수는 증식하는 것을 확인하였다. 조사처리 후 육에 스타터를 첨가하게 되면 발효육 생산에 매우 유용하게 이용될 수 있을 것으로 사료된다.

• 한국식품저장유통학회지
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• 제19권6호
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• pp.951-956
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• 2012

본 연구는 국내산 천일염(장판염, 토판염)의 성분 비교와 이를 이용하여 무 절임을 제조할 때 첨가한 스타터와 함께 발효기간 동안의 변화를 알아보고자 수행하였다. 그 결과 두 소금간의 일반성분 중 수분함량은 차이를 보였지만 회분 함량은 그룹간의 차이를 보이지 않아, 생산시기가 동일한 점을 고려할 때 천일염 생산방식에 따른 차이라고 판단된다. 이들의 무기성분 함량은 소금의 주성분인 Na 함량은 큰 차이를 보이지 않았고, Ca, K 그리고 Mg 함량은 장판염이 높게 측정된 반면, Fe 그리고 Zn 함량은 토판염이 높게 측정되었지만, Ca 함량을 제외하고 크게 차이를 보이지 않았다. 천일염의 당도 측정 결과 10.70 Brix로 높은 함량을 나타내어 어떤 종류의 당으로 구성되었는지에 대한 정성 분석 연구가 요구된다. 무 절임 중 천일염과 스타터 첨가에 의한 발효 변화를 관찰하였을 때 스타터를 첨가한 그룹이 스타터를 첨가하지 않은 그룹보다 활발하게 유리당, 유기산 등 2차 대사산물을 생성하여, 우점종으로서 초기 미생물 조절에 영향을 끼쳤다고 판단된다. 그리하여 실험에 사용된 Leuconostoc mesenteroides B-512F 균주의 스타터 첨가가 발효과정 중 미생물 균총 변화에 큰 영향을 주므로, 발효 식품 제조 시 초기미생물 조절자로서의 명확한 역할 구명이 필요할 것으로 생각된다.

• 한국유기농업학회지
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• 제22권3호
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• pp.491-502
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• 2014

본 연구는 천연물질에서 유래한 반추위 메탄저감용 친환경 첨가제 개발을 위해 각기 다른 종균을 이용하여 발효한 세신 추출물의 항균활성, 항산화활성 및 in vitro 반추위 발효시험을 체계적으로 실시하였다. 접종된 균주들의 성장효율을 알아보기 위해 실시한 생균수측정 결과 L. curvatus NJ40 균주에서 유의적으로 높은 균주성장을 나타냈다(p<0.05). 항균활성측정 결과는 대조구 대비 L. curvatus NJ40 및 L. plantarum NJ45 균주와 발효된 세신 추출물이 병원균에 대한 항균효과를 나타내는 것으로 조사되었다. In vitro 반추위 발효실험에 세신 및 발효 세신 추출물을 적용한 결과, 휘발성 지방산 생성량 대비 반추위 메탄 저감효과가 나타났다. 특히 반추위 미생물 활력 및 사료이용 효율을 대표할 수 있는 휘발성 지방산 생성효율에 대한 부정적 효과 없이, 오히려 휘발성지방산 생성효율을 향상시키면서 반추위 메탄 저감효과를 가져올 수 있는 것으로 나타났다.

• Journal of Animal Science and Technology
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• 제64권1호
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• pp.10-22
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• 2022

We studied the effects of Saccharomyces cerevisiae boulardii CNCM I-1079 (LSB) supplemented to lactating sows on reproductive traits and farrowing duration and to piglets from day 7 of life on post-weaning performance and IgG concentration. Ninety-six Landrace × Yorkshire sows started the trial 5 days before the expected farrowing date. Sows were distributed into 2 groups according to parity number and backfat thickness: control (CON: regular lactation diet) and LSB (CON + LSB at 2 × 10⁹ colony forming units [CFU]/kg of feed). Seven days after birth, litters were randomly selected from each group and supplemented creep feed with or without LSB at 2 × 10⁹ CFU/kg. At weaning, piglets from CON sows were shifted to a commercial farm and allocated to 14 pens in groups of 25 piglets/pen according to the creep feed supplemented during lactation. Piglets followed a 3-phase feeding program: creep, pre-starter and starter, with or without LSB at 2 × 10⁹ CFU/kg LSB in creep and pre-starter, and 1 × 10⁹ CFU/kg LSB in starter. The piglets were vaccinated against classical swine fever on days 41 and 72 of life. One day before each vaccination and at the end of the trial, blood samples were collected from 15 randomly selected piglets per treatment and assessed for total IgG. Supplemented sows with non-supplemented litters displayed the lowest backfat thickness loss during lactation (p < 0.05). The LSB supplementation shortened farrowing duration (p < 0.05) and increased feed intake (p < 0.05) during the first week of lactation. The LSB-fed piglets were heavier at the end of creep (p < 0.05), pre-starter (p < 0.05), and the trial (p < 0.05); grew faster during creep (p < 0.05), starter (p < 0.05), and overall (p < 0.05); and displayed an improved feed conversion ratio during creep (p < 0.05). Total IgG content was higher at days 40 (p < 0.05) and 71 (p < 0.05) in LSB-fed piglets. We conclude that supplementing sows with Saccharomyces cerevisiae boulardii CNCM I-1079 from late gestation until weaning shortens farrowing duration, increases feed intake, and minimizes backfat losses during lactation. When supplemented to piglet diet, post-weaning performance is improved. This improvement observed could be linked to a better immune status, as suggested by the higher IgG.