• 신재생에너지
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• 제18권2호
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• pp.9-17
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• 2022

In this study, we used the Flux Balance Analysis (FBA) program to examine the behavior of hydrogen and organic acids according to seasonal changes in food wastewater collected from D city. The results showed that average hydrogen conversion rates in spring, summer, autumn, and winter were 1.06, 0.71, 1.21, and 1.13 mol H₂/mol of hexose_added, respectively, indicating a significantly lower hydrogen conversion rate in summer than in other seasons. This phenomenon is believed to occur because the carbohydrate concentration of the incoming food wastewater is low. In addition, Lactobacillus, the lactic acid-producing bacterium, was 21.3% in spring, 27.2% in summer, 17.5% in autumn, and 22.6% in winter. The most distinctive feature of the microbial community in summer was that 15.3% of the Ilyobacter was analyzed. It was confirmed that Ilyobacter, which is involved in the production of acetic acid and propionic acid, is closely associated with the tendency of increasing acetic acid and propionic acid and thus contributes to organic acid change. Clostridium, a hydrogen-producing bacterium, was 76.2%, 50.8%, 78.3%, and 74%, in spring, summer, autumn, and winter, respectively. It was confirmed that Clostridium dominates the microbial community by approximately 70% or more in all seasons except summer.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1252-1260
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• 2020

(R)-2-(4-hydroxyphenoxy)propionic acid (HPOPA) is a key intermediate for the preparation of aryloxyphenoxypropionic acid herbicides (R-isomer). In order to improve the HPOPA production from the substrate (R)-2-phenoxypropionic acid (POPA) with Beauveria bassiana CCN-A7, static cultivation and H₂O₂ addition were attempted and found to be conducive to the task at hand. This is the first report on HPOPA production under static cultivation and reactive oxygen species (ROS) induction. On this premise, the cultivation conditions and fermentation medium compositions were optimized. As a result, the optimal carbon source, organic nitrogen source, and inorganic nitrogen source were determined to be glucose, peptone, and ammonium sulfate, respectively. The optimal inoculum size and fermentation temperature were 13.3% and 28℃, respectively. The significant factors including glucose, peptone, and H₂O₂, identified based on Plackett-Burman design, were further optimized through Central Composite Design (CCD). The optimal concentrations were as follows: glucose 38.81 g/l, peptone 7.28 g/l, and H₂O₂ 1.08 g/l/100 ml. Under the optimized conditions, HPOPA titer was improved from 9.60 g/l to 19.53 g/l, representing an increase of 2.03-fold. The results obtained in this work will provide novel strategies for improving the biosynthesis of hydroxy aromatics.

• 한국식품영양학회지
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• 제18권2호
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• pp.109-114
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• 2005

[ $10\%$ ] 유청배지에 Lactobacillus acidophilus와 Propionibacterium freudereichii를 혼합 배양할 때 유청 발효물 중의 생균수의 변화, 유당 소모량, 프로피온산과 초산생성량 등을 측정하였고, 유청 발효물을 식빵 제조에 일정량 첨가하여 식빵의 부피, 조직감, 보존성 등을 분석하였다. 4일 배양동안 L. acidophilus의 생균수는 배양 36시간에 $2.4\ties10^9$ cfu/mL, P. freudenreichii는 배양 96시간에 $9.42\times10^8$ cfu/mL로 최대값을 나타냈고 L. acidophilus가 P. freudenreichii보다 빠르게 증식하였다. 유당의 소모율은 $87.5\%$이었고, 4일 배양 후 프로피온산은 18.5g/L, 초산은 4.8g/L 생성되었으며 그 비율은 3.8:1이었다. 식빵의 부피는 유청 발효물을 많이 첨가할수록 작았으나 조직감은 유청 발효물이 많이 첨가될수록 낮은 경도 값으로 부드럽게 나타났으며, 보존성은 유청 발효물을 $10\%$첨가하였을 때 대조구에 비하여 2일 이상의 효과가 있는 것으로 나타났다.

• 식품기술
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• 제24권2호
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• pp.206-211
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• 2011

• 분석과학
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• 제29권4호
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• pp.202-208
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• 2016

A novel and simple method for detecting seven organic acids (formic acid, malic acid, lactic acid, acetic acid, citric acid, fumaric acid and propionic acid) in animal feed using high performance liquid chromatography equipped with a photo-diode array detector (HPLC/PDA) was developed. The chromatographic peaks of the seven organic acids were successfully identified by comparing their retention times and UV spectra with reference standards. Method validation was performed in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs) for the instrument employed in these experiments ranged from 12 to 8,026 μg/kg, and the limits of quantification (LOQs) ranged from 43 to 26,755 μg/kg. Average recoveries of the seven organic acids ranged from 79.3 to 95.2 %. Method replication resulted in intra- day and inter-day peak area variation of <3.2 %. The developed method was specific and reliable and is therefore suitable for the routine analysis of organic acids in animal feed.

• 상하수도학회지
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• 제10권3호
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• pp.73-82
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• 1996

The removal efficiencies of organic substrates, nitrogen and phosphorus in the anaerobic-aerobic biological phosphorus removal process were investigated by addition of acetic acid, propionic acid and butyric acid which are normal volatile fatty acids contained in anaerobic digester supernatants. Substrate utilization coefficients for the phosphorus release and uptake were also estimated. The effect of a VFA, which showed higher phosphorus removal efficiency than the other VFAs did, was also studied in an anaerobic-aerobic-anoxic biological nutrient removal process. For the anaerobic-aerobic process added by VFA, the phosphorus removal efficiencies were up to about 68%, 55% and 61% for the reactors of acetic acid, propionic acid and butyric acid added, respectively, which indicates the efficiencies were increased by about 8-21%, comparing to that of 47% for the reactor with no VFA added. There were no significant difference in removal efficiencies for organic substrate and $NH_3-N$ without regard to addition of VFA. However, the removal efficiency of total nitrogen was increased in the case of VFA added, since $NO_3-N$ was less produced. For the anaerobic-aerobic-anoxic process added VFA, the removal efficiencies for $NH_3-N$ and $PO{_4}^{3-}-P$ were increased by 5% and 13%, respectively, comparing with them in the reactors not added VFA.

• 농업과학연구
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• 제32권2호
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• pp.233-241
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• 2005

본 연구는 친환경농자재로 선정된 유기성폐자 원인 목초액을 농 축산분야의 적용과 활용성 평가를 위해 돈분퇴비화 과정 중 발생되는 악취에 대한 저감효과를 조사하여 그 이용가치를 검증하고자 실시하였다. 이상의 결과에 대한 요약은 다음과 같다. 암모니아 가스의 분석결과 목초액을 처리한 PA-100과 PA-300 처리구에서 초기 암모니아가스 발생량이 관행구보다 높게 나타났으며, 목초액 처리구에서는 약 18일 이후부터는 측정되지 않았다. 반면, 관행구에서는 보다 오랫동안 나타났으며 약 25일후로 검출되지 않았다. 또한 달관적인 조사를 통하여 PA-100과 PA-300 처리구에서는 발생하는 암모니아가스 냄새의 정도가 현저히 낮았다. 이러한 결과는 목초액내에 함유된 초산성분에 의한 암모니아의 중화반응과 탄화된 목재의 특유의 향으로부터 가려지는 가리움효과(eclipsed effect)에 의한 것으로 해석된다. 휘발성 유기산의 발생량을 GC를 통해 분석한 결과 PA-100 처리구에서 가장 낮은 함량을 보였으며 휘발성 유기산 중에서 acetic acid와 propionic acid 및 butyric acid 등이 가장 많이 발생하였다. 특히, propionic acid와 butyric acid는 PA-100 > PA-300 > 관행구 순으로 퇴비화 과정중 감소효율이 높게 나타났다. 그러나 acetic acid는 관행구보다 다소 높은 경향을 보였는데 이는 목초액의 주성분인의 하나인 초산(acetic acid) 때문인 것으로 판단된다.

• 한국환경농학회지
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• 제13권3호
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• pp.311-320
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• 1994

농축산(農畜産) 폐기물(廢棄物)의 혐기적(嫌氣的) 처리공정(處理工程)에 적용하기 위하여 아한대(亞寒帶) 지역(地域)으로 부터 분리(分離)한 clostridia의 생화학적(生化學的) 특성(特性)을 조사(調査)한 결과(結果)는 다음과 같았다. 1. Cellulose 배지로 저온(低溫)에 집적배양(培養)한 결과 $CH_4$ 생성이 왕성(旺盛) 하였던 늪지 퇴적물(堆積物)(Canada, $56.9^{\circ}N$), 호수퇴적물(堆積物) Ⅳ(Canada, $55.0^{\circ}N$) 그리고 갯벌흙 Ⅱ(Korea, $37.0^{\circ}N$)에서 산생성능(酸生成能)이 우수하고 동시에 메탄을 생성하는 Clostridia, 즉 Clostridium botulinum SRC-64, Clostridium scatologens SRC-91 및 Clostridium tyrobutyricum SRC-100 을 각각 분리(分離)하였다. 분리(分離)된 clostridia 3균주(菌株)의 최적(最適) 생육온도(生育溫度)는 $37^{\circ}C$이었고 최저(最低) 생육온도(生育溫度)는 $10^{\circ}C$ 정도 이었으며, 그리고 이들 균주(菌株)는 특이적 메탄 생성균(生成菌)의 조효소(組酵素)인 $F_{420}$을 함유 하였다. 2. 포도당의 혐기분해(嫌氣分解) 생성물(生成物)로서 SRC-64 는 $H_2$, acetic, isovaleric, caproic acid 를 생성(生成)하였으며, SRC-91 은 $H_2$, propionic, butyric, valeric, caproic acid 를, SRC-100 은 acetic 과 propionic acid 를 주로 생성(生成) 하였다. 또한 3 균주(菌株) 모두 $13^{\circ}C$, 2 일(日) 배양조건(培養條件)에서 2.6-8.68 n moles/ml 범위(範圍)의 $CH_4$ 생성능력(生成能力)을 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제11권3호
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• pp.217-233
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• 1998

Milk yield and its composition is governed by level of nutrition and the composition of diet. Higher concentrate input improves milk yield, whereas its input at moderate levels improves yield of milk fat. High level of dietary protein improves dry matter intake and milk production, however, CP content above 14% has less advantage. Milk yield is enhanced by the feeding of cottonseed and soyabean meal, whereas milk fat increases by the supplementation of cottonseed. Dietary fat increases energy intake, production of milk and milk fat. Quality and quantity of feeds consumed affect fermentation patterns in rumen. Among the rumen metabolites, volatile fatty acids (VFA) content and propionate proportion have been related positively with milk yield, whereas proportion of acetate and butyrate have been related positively with milk fat content. Dietary carbohydrates through the source of sugar, starch, roughage and fibre affect VFA concentration in rumen. Therefore, concentration of volatile fatty acids could be altered to the advantage of consumer through judicious manipulation of diet.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1274-1280
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• 2015

This study was conducted to assess the effects of microbial and chemical combo additives on nutritive values, fermentation indices and aerobic stability of whole crop barley silage. Barley forage (Youngyang) was harvested at about 30% dry matter (DM) by treatments, chopped to 5 cm length and treated with distilled water only (CON), Lactobacillus plantarum (INO), propionic acid (PRO) or an equal mixture of INO and PRO (MIX). Barley forages were ensiled in 4 replications for 0, 2, 7, and 100 days. On 100 days of ensiling, MIX silage had higher (p<0.05) in vitro DM digestibility than CON silage, but lower (p<0.05) acid detergent fiber concentration. The pH in all treated silages was lower (p<0.05) than CON silage. The MIX silage had higher (p<0.05) lactate concentration and lactate to acetate ratio than in CON, but lower (p<0.05) yeast count. Aerobic stability in CON, PRO, and MIX silages were higher (p<0.05) than in INO silage. It is concluded that microbial and chemical combo additives using L. plantarum and propionic acid could efficiently improve nutritive values of barley silage in terms of increased in vitro DM digestibility compared to other treatments. In addition, all treatments except CON reduced yeast count which is the initiate microorganism of aerobic spoilage.