• Title, Summary, Keyword: bacterial fermentation

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Bacterial Contamination and Its Effects on Ethanol Fermentation

  • Chang, In-Seop;Kim, Byung-Hong;Shin, Pyong-Kyun;Lee, Wan-Kyu
    • Journal of Microbiology and Biotechnology
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    • v.5 no.6
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    • pp.309-314
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    • 1995
  • Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

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Study on the Simultaneous Production of the Bacterial Cellulose and Vinegar by Gluconacetobacter persimmonis KJ145T (Gluconacetobacter Persimmonis KJ145T를 이용한 Bacterial Cellulose및 식초의 동시 생산에 관한 연구)

  • 정용진;여수환;이오석
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.7
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    • pp.981-985
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    • 2003
  • The changes of component through simultaneous production of bacterial cellulose and vinegars by G. persimmonis KJ145$^{T}$ were examined. As a results, pH was decreased to 3.22 at 8 days of fermentation and total acidity showed 4.66 which was the highest at the 8 days of fermentation. Brix didn't show any changes during the fermentation period. Free sugars of fermentation broth were consist of fructose, glucose and sucrose. The fructose concentration of fermentation broth was maintained highly during fermentation period (until the final 10 days) without a remarkable decrease. The cell growth of G. persimmonis KJ145$^{T}$ was very rapidly increased from the 2 days of fermentation and increased most at the 4 days of fermentation. The productivity of bacterial cellulose was increased in proportion to the fermentation period. Malic acid, succinic acid and oxalic acid were detected as a organic acid of vinegar. The concentration of acetic acid was rapidly increased from the 2 days and reached highest concentration at 8 days. In conclusion, the results indicated that the 8 days was the optimal fermentation period to produce the bacterial cellulose and vinegar by G. persimmonis KJ145$^{T}$ simultaneously.

Mass Spectrometry-Based Metabolite Profiling and Bacterial Diversity Characterization of Korean Traditional Meju During Fermentation

  • Lee, Su Yun;Kim, Hyang Yeon;Lee, Sarah;Lee, Jung Min;Muthaiya, Maria John;Kim, Beom Seok;Oh, Ji Young;Song, Chi Kwang;Jeon, Eun Jung;Ryu, Hyung Seok;Lee, Choong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1523-1531
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    • 2012
  • The metabolite profile of meju during fermentation was analyzed using mass spectrometry techniques, including GC-MS and LC-MS, and the bacterial diversity was characterized. The relative proportions of bacterial strains indicated that lactic acid bacteria, such as Enterococcus faecium and Leuconostoc lactis, were the dominant species. In partial least-squares discriminate analysis (PLS-DA), the componential changes, which depended on fermentation, proceeded gradually in both the GC-MS and LC-MS data sets. During fermentation, lactic acid, amino acids, monosaccharides, sugar alcohols, and isoflavonoid aglycones (daidzein and genistein) increased, whereas citric acid, glucosides, and disaccharides decreased. MS-based metabolite profiling and bacterial diversity characterization of meju demonstrated the changes in metabolites according to the fermentation period and provided a better understanding of the correlation between metabolites and bacterial diversity.

Fermentation Aspects of Fruit-Vegetable Juice by Mixed Cultures of Lactic Acid Bacteria Isolated from Kimchi and Yeast (김치 젖산균과 효모의 혼합배양 방법에 의한 과채류즙의 발효양상)

  • 최홍식;김현영;여경목;김복남
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.6
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    • pp.1059-1064
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    • 1998
  • Fermented beverage using lactic acid bacteria isolated from kimchi was investigated. Lactic acid bacteria KL 1, KD 6, KL 4 strains from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for single and mixed culture fermentation. During the fermentation by bacterial strain and yeast for 1~3 days at 30oC, various fermentation behaviors were observed. The growth rate of mixed culture of KL 1 and yeast was higher than that of single culture by KL 1 alone during the fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 day) or 0.58%(1 day) and with the final pH of 3.3(3 day) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. Among several bacterial strains, KL 1 was suitable for the mixed culture fermentation with yeast in terms of desirable fermentation behavior and organoleptical quality. The selected strain, KL 1 was identified as Leuconostoc spp. through the series of tests on carbohydrate fermentation and biochemical characteristics.

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Fermentative Characteristics and Anti-Proliferative Activity against Mouse Carcinoma Cell Line of Kimchi prepared with Functional Cabbage (기능성 배추 김치의 발효 특성과 암세포 증식저해능)

  • Yu, Kwang-Won;Lee, Seong-Hyun;Shin, Eun-Hae;Hwang, Jong-Hyun
    • The Korean Journal of Food And Nutrition
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    • v.30 no.5
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    • pp.1007-1014
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    • 2017
  • To compare functional Chinese cabbage('Amtak' baechu; F1 hybrid cultivar between Brassica rapa and B. perkinensis, AB) with general Chinese cabbage ('Chunkwang' baechu; general spring cultivar, CB), two kinds of kimchi(ABK and CBK) prepared with AB and CB cultivar were fermented at $10^{\circ}C$ for 10 days. Their fermentative characteristics and anti-proliferative activities against mouse carcinoma cell lines were investigated. General kimchi(CBK) showed mature pH on the $6^{th}$ day of fermentation, whereas functional kimchi(ABK) reached pH on the $9^{th}$ day. CBK also exhibited acidity of mature stage on the $6^{th}$ day, but ABK reached mature acidity on the $9^{th}$ day. Although ABK and CBK were salted in the same condition, ABK had lower salinity than CBK, throughout the fermentation time. The highest total bacterial and lactic bacterial counts of CBK showed on the $8^{th}$ day of fermentation, but ABK showed the highest total bacterial and lactic bacterial counts on the $10^{th}$ day. The texture of ABK was harder than CBK for fermentation time. This seems to be corrleated with the slower fermentation rate of ABK. ABK showed significantly higher anti-proliferative activity (54.6% cell viability of control) in B16BL6 at $1,000{\mu}g/mL$. ABK was also higher in anti-proliferative activity than CBK throughout the fermentation time. However, there was no significant difference in the anti-proliferative activity of ABK between the fermentation times. In conclusion, fermentation of ABK showed a better texture, due to the slow fermentation rate and more anti-proliferative activity against mouse carcinoma cell line than those of CBK.

Pervaporative Butanol Fermentation Using a New Bacterial Strain

  • Park, Chang-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.1 no.1
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    • pp.1-8
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    • 1996
  • Fermentation processes for the production of butanol had an economic importance in the first part of this century. Today butanol is commercially produced from the Oxo reaction of propylene because relatively low priced propylene during the cracking of petroleum. Efforts have been made during the past decade or two to improve the productivity of butanol fermentation processes. It includes strain improvements, continuous fermentation processes, cell immobilization and simultaneous product separation. This review introduces a new butanol fermentation process using pervaporative product separation and a new bacterial strain producing less amount of organic acids. This review also compares the new process with chemical processes. This kind of new fermentation process may be able to compete with the chemical synthesis of butanol and revitalize the butanol fermentation process.

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Effects of Lactic Acid Bacterial Fermentation on the Antioxidant and Anti-inflammatory Activity of Brown Algae Eisenia bicyclis Extract (대황(Eisenia bicyclis) 추출액의 항산화 및 항염증 활성에 대한 유산균 발효의 영향)

  • Han, Hae-Na;Eom, Sung-Hwan;Kim, Ji-Hoon;Kim, Deok-Hoon;Kim, Song-Hee;Kim, Yunhye;Yeom, Seung-Mok;Kim, Young-Mog
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.2
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    • pp.151-157
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    • 2015
  • This study was conducted to evaluate the effect of lactic acid bacterial fermentation on the antioxidant and anti-inflammatory activity of an edible brown alga, Eisenia bicyclis. Lactic acid bacteria were inoculated into and cultivated in E. bicyclis water extract. The antioxidant activity of the extract was assayed before and following fermentation. Antioxidant activity was determined by assaying the levels of radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical and alkyl radical. The lactic acid bacterial fermentation of E. bicyclis extract resulted in enhanced antioxidant activity. The greatest enhancement of antioxidant activity was seen in the DPPH radical scavenging assay, in which E. bicyclis extract was fermented by Pediococcus pentosaceus MBP-34 strain for 12 h. This fermented extract also exhibited higher inhibitory activity (96.66%) on nitric oxide production compared with other lactic acid bacterial fermented extracts or raw extract (189.60%). In conclusion, fermentation by bacterial strain is an attractive strategy for developing value-added food ingredients.

Determination of Microbial Community as an Indicator of Kimchi Fermentation (김치발효의 지표로서 미생물군집의 측정)

  • Han, Hong-Ui;Lim, Chong-Rak;Park, Hyun-Kun
    • Korean Journal of Food Science and Technology
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    • v.22 no.1
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    • pp.26-32
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    • 1990
  • Attempts were made to define the characteristics of microbial community as an indicator of Kimchi fermentation. Determination of communities was carried out by simple Gram-stain, followed by direct microcopic counts. In room-temperature $(15^{\circ}C)$ fermentation, microbial succession was occurred in the order of communities of Gram-positive bacteria, yeasts and Gram-negative bacteria. It was characteristic that Gram-positive bacterial community was developed during the production of lactic acid, yeasts community was developed to cause rancidity, and Gram-negative bacterial community was relevant to maceration (or softening) as well as rancidity. The fluctuation of apparent Gram-negative reaction group might be used as a criterion of death or aging of Gram-positive bacterial populations. In low-temperature fermentation $(5^{\circ}C)$, however, it was found that yeasts and Gram-negative bacterial communities did not developed but only Gram-positive bacterial community did. It follows from these results mentioned above that maturity of Kimchi depends on the development of Cram-positive bacterial community. Thus, the size and occurrence of microbial community are avaiable for an indicator of Kimchi fermentation, and also determination of community could be a useful method to predict the maturity.

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Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content

  • Li, Yanbing;Nishino, Naoki
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.9
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    • pp.1304-1312
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    • 2013
  • The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages.

Changes in Physicochemical components and Bacterial Count during the Fermentation of Onion Kimchi (양파 김치류의 숙성중 이화학적 성분 및 세균수의 변화)

  • 이종임;조영숙;손미예;강갑석;서권일
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.5
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    • pp.419-424
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    • 2000
  • To develop a functional Kimchi utilizing onion, 5 different Kimchi with onion used as a major ingredient were formulated. The changes in pH. titratable acidity, reducing sugar. total bacterial count, and the number of lactic acid bacteria in the process of fermentation were studied A. onion Kimchi Control. B : onion Kimchi added with oyster, C : onion Kimchi added with salted shrimp, D : onion Kimchi added with oyster, cucumber, and a bit of radish, E : onion Kimchi added with salted shrimp, cucumber, and a bit of radish. pH of onion Kimchi decreased during storage, but titratable acidity increased. The pH values of onion Kimchi were not significantly different among groups, the changes in pH during fermentation were the lowest in A, and changes in B and D were lower than those of C and E. Salt concentration tended to decrease during the fermentation process, and the changes in salt concentration were lower in D and E than in B and C. Reducing sugar content maximized at 4 days of fermentation and decreased after 12 days. The number of lactic acid bacteria increased during first 4 days of fermentation and decreased after 12 days. Total lactic acid bacterial count were the most lowest in A.

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