• 제목/요약/키워드: aerobic bacteria

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Occurrence of acid producing bacteria in Meju leaves (재래식 메주중의 산생성균의 분포)

  • Hur, Sung-Ho;Ha, Duk-Mo
    • Applied Biological Chemistry
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    • v.34 no.2
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    • pp.130-133
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    • 1991
  • The distribution of acid producing bacteria and general bacteria in 23 samples of Korean traditional Meju loaves was investigated and the strains isolated from the samples identified. The acid producing bacteria occurred more in outer part than inner part and anaerobic acid producing bacteria showed higher tendency of occurrence compared with the aerobes in each part. The average number of nonhalophilic and halotolerant bacteria belonging to aerobes were counted as $24{\times}10^6$ and $33{\times}10^5$ and the average number of those belonging to anaerobes $10{\times}10^7$ and $58{\times}10^5$ cells/g, respectively. The general bacteria isolated more in outer part than inner part and its average number was $62{\times}10^7$ cells/g. In the isolates, 2 aerobic acid producing strains were identified as Micrococcus spp., 3 anaerobic acid producing strains as Streptococcus sp., Pediococcus sp. and Lactobacillus sp., and 2 strains of aerobic general bacteria as Bacillus spp.

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Changes of Chemical and Microbial Properties of Soils after Forest Fires in Coniferous and Deciduous Forests (침엽수와 활엽수 산림에서 산불 후 토양화학적 및 토양미생물학적 특성 변화)

  • Kim, Jong-Gap;O, Gi-Cheol
    • The Korean Journal of Ecology
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    • v.24 no.1
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    • pp.1-7
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    • 2001
  • This study was carried out to examine the recovery of forest ecosystem by changes of soil chemical properties and soil microorganism at the burned areas of coniferous (Mt. Chocdae) and broad leaved forest (Samsinbong in Mt. Chiri). In the soil chemical properties of the burned area of Samsinbong, pH was 5.8, and contents of organic matter, total nitrogen, available P₂O/sub 5/, exchangeable K/sup +/, exchangeable Ca/sup ++/ and exchangeable Mg/sup ++/ were 7.42%, 0.73%, 28.5 ㎎/㎏, 1.3 me/100g, 13.3 me/100g and 2.2 me/100g, respectively. But they showed a tendency to decrease with time. In the soil chemical properties of the burned area of Mt. Chocdae, pH was 5.3, and contents of organic matter, total nitrogen, available P2O5, exchangeable K/sup +/, exchangeabe Ca/sup ++/ and Exchangeable Mg/sup ++/ were 6.42%, 0.25%, 24.4 ㎎/㎏, 0.7 me/100g, 3.7 me/100g and 2.1 me/100g, respectively, and they also showed a tendency to decrease with time. In contrast, they were not changed with time at the unburned areas. At the burned area of Samsinbong, soil microorganism showed to order of fungi (69×10⁴ CFU), actinomycetes (523×10⁴ CFU) and aerobic bacteria (291×10⁴ CFU), and at the unburned area, showed to order of actinomycetes (745×10⁴ CFU), fungi (594×10⁴ CFUU), and aerobic bacteria (160×10/sup 4/ CFU). At the burned area of Mt. Chocdae, soil microorganism showed to order of fungi (676×10⁴ CFU), actinomycetes (434×10⁴ CFU) and aerobic bacteria (350×10⁴ CFU), and at the unburned area, showed to order of fungi (461 ×10⁴ CFU), aerobic bacteria (328×10⁴ CFU) and actinomycetes (319×10⁴ CFU). Soil microorganisms of the aerobic bacteria, actinomycetes and fungi appeared at the burned areas were much more abundant than unburned areas. The aerobic bacteria appeared at the coniferous forest were also much more than the broad-leaved forest. The actinomycetes and fungi appeared at the broad-leaved forest were much more abundant than the coniferous forest.

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Aerobic Liquid Fermentation of Residual Food Waste by Thermophilic Bacteria (고온세균을 이용한 남은 음식물의 호기적 액상발효)

  • Ryu, Seung-Yong;Park, Myoung-Ju;Kim, So-Young;Lee, Ki-Young
    • Journal of the Korea Organic Resources Recycling Association
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    • v.10 no.3
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    • pp.126-131
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    • 2002
  • For the probiotic feed production from residual food waste, aerobic liquid fermentation was conducted by thermophilic bacteria. 11 Strains of bacteria were isolated from several soil sources and residual food waste. Screening was carried by shaking incubator for the separation of thermophilic strain at $55^{\circ}C$. The isolated strains were tested for enzyme activities such as ${\alpha}$-amylase and protease. 6 Bacterial strains were chosen and were adapted by repeated fermentation processes in food waste substrate. The viable cell count of them at final fermentation stages were shown as $3-7{\times}10^9/ml$ in 2L-jar fermenter. Among them B3, B6 showed higher enzyme activity. By the mixed fermentation of B3, B6 and Bacillus stearothermophilus, the highest viable cell count reached to $1.4{\times}10^{10}/ml$ in 8 hours.

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Effect of Garlic Concentrations on Growth of Microorganisms during Kimchi Fermentation (마늘의 농도가 김치 미생물에 미치는 영향)

  • Cho, Nam-Chul;Jhon, Deok-Young;Shin, Mal-Shik;Hong, Youn-Ho;Lim, Hyun-Sook
    • Korean Journal of Food Science and Technology
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    • v.20 no.2
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    • pp.231-235
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    • 1988
  • Population changes of aerobic bacteria, yeasts, and lactic acid bacteria ware investigated during the fermentation of Kimchis containing 0, 1, 2, 4, and 6% garlic at $21^{\circ}C$. The numbers of aerobic bacteria increased during the first 2 days and decreased thereafter. The higher the garlic concentration of the Kimchis was, the smaller the increase of the aerobic bacterial population was during the initial periods of the fermentations. Garlic concentrations that showed the largest population difference between them after 2-days fermentation were 1% and 2%. The population of lactic acid bacteria also increased only during the first 2 days and was held thereafter. Lactic acid bacterial population increased more at higher garlic concentrations during the initial period of the fermentations and major microorganisms contributed to the increase were Lactobacillus brevis and low acid-producing lactbacilli. Changes of yeasts at the different garlic concentrations during the fermentations were not apparent.

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Gender and Age Differences in Hand Hygiene Practices among the General Population (성별 및 연령별 손 위생관리의 비교)

  • Kim, Jong-Gyu
    • Journal of Environmental Health Sciences
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    • v.45 no.3
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    • pp.213-221
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    • 2019
  • Objective: This study was performed to evaluate gender and age differences in hygienic behavior among the general population, focusing on hand-washing habits and the microbial load of hands. Methods: A self-administered questionnaire survey and a separate microbial examination were performed. The Pearson's correlation between hand-washing habits and microbial load was analyzed. Results: In the questionnaire survey on hand-washing habits, gender differences were found in hand-washing frequency, use of hand-washing agents, and hand drying methods (p<0.05). Age differences were found in numbers of washing parts of the hands and also in hand drying methods (p<0.05). Females showed better habits washing hands than did males, as did older people compared to younger. In the microbial examination of indicator bacteria on their hands, younger people tended to show a higher load of total aerobic bacteria than did the older, and females showed a higher load of total coliforms than did males (p<0.05). There were significant relationships between the load of total aerobic bacteria and hand-washing frequency, duration, and method of turning-off water (p<0.05). Conclusions: Although females were expected to show a better practice of hand-washing than were males based on the survey results, they showed a higher level of total coliforms in the hand examination. The older age group showed better hand-washing habits than did the younger age group and had less total aerobic bacteria on their hands. These inter-gender and age differences highlight the need for development and implementation of gender-and age-specific educational programs or campaigns.

Composition and Diversity of Gut Bacteria Associated with the Eri Silk Moth, Samia ricini, (Lepidoptera: Saturniidae) as Revealed by Culture-Dependent and Metagenomics Analysis

  • MsangoSoko, Kondwani;Gandotra, Sakshi;Chandel, Rahul Kumar;Sharma, Kirti;Ramakrishinan, Balasubramanian;Subramanian, Sabtharishi
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1367-1378
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    • 2020
  • The polyphagous eri silk moth, Samia ricini, is associated with various symbiotic gut bacteria believed to provide several benefits to the host. The larvae of S. ricini were subjected to isolation of gut bacteria using culture-dependent 16S rRNA generic characterization, metagenomics analysis and qualitative enzymatic assays. Sixty culturable aerobic gut bacterial isolates comprising Firmicutes (54%) and Proteobacteria (46%); and twelve culturable facultative anaerobic bacteria comprising Proteobacteria (92%) and Firmicutes (8%) were identified inhabiting the gut of S. ricini. The results of metagenomics analysis revealed the presence of a diverse community of both culturable and un-culturable gut bacteria belonging to Proteobacteria (60%) and Firmicutes (20%) associated with seven orders. An analysis of the results of culturable isolation indicates that these bacterial isolates inhabited all the three compartments of the gut. Investigation on persistence of bacteria coupled with metagenomics analysis of the fifth instar suggested that bacteria persist in the gut across the different instar stages. In addition, enzymatic assays indicated that 48 and 75% of culturable aerobic, and 75% of anaerobic gut bacterial isolates had cellulolytic, lipolytic and nitrate reductase activities, thus suggesting that they may be involved in food digestion and nutritional provision to the host. These bacterial isolates may be good sources for profiling novel genes and biomolecules for biotechnological application.

Influence of microbial additive on microbial populations, ensiling characteristics, and spoilage loss of delayed sealing silage of Napier grass

  • Cai, Yimin;Du, Zhumei;Yamasaki, Seishi;Nguluve, Damiao;Tinga, Benedito;Macome, Felicidade;Oya, Tetsuji
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.7
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    • pp.1103-1112
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    • 2020
  • Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.

Microbial Hazard Analysis of the Manufacturing Processes for Frozen Korean Cold Noodle, Naengmyeon (냉동 냉면류의 제조공정별 미생물학적 위해요소 평가)

  • Kim, YuJung;Kim, HyeJin;Lim, Youngeun;Yang, HuiJie;Park, Seulgi;Cheong, Jin-Sook;Om, Ae-Son
    • Journal of the FoodService Safety
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    • v.3 no.1
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    • pp.38-44
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    • 2022
  • This study investigated the microbiological hazards in the manufacturing processes of Naengmyeon. Sanitary indicative bacteria, such as aerobic plate counts and coliforms as well as pathogenic bacteria, were examined from raw materials, manufacturing processes, working area, 17 utensils and equipment. The aerobic plate counts for raw materials and arrowroot starch estimated as 0.77±0.68~5.02±0.28 and 5.02±0.28 log CFU/g, respectively. Coliforms were detected from wheat flour, buckwheat flour, and potato starch. Staphylococcus aureus was detected to be 0.61±1.06 log CFU/g in wheat flour and 0.20±0.35 log CFU/g in buckwheat flour. During the manufacturing process, aerobic plate counts for kneading process were 4.54±0.34 log CFU/g. But after the press out and heat process, contamination of aerobic plate counts and coliforms decreased and remained at a low level until the release process. Aerobic plate counts before washing disinfection of screw were 3.28±0.62 log CFU/100 cm2, the level of which was high in utensils and equipment that had contact with employees or water. These results represent not only an important indicator for the hygienic level but also a scientific basis for analyzing biological hazards, which lead to the introduction of HACCP for the production of safe and hygienic cold noodles processed by manufacturers.

Microbial and Chemical Changes of Kimchies Containing Different Ingredients During Fermentation (재료를 달리한 김치의 발효중 미생물학적 및 화학적 변화)

  • 유영균
    • The Korean Journal of Food And Nutrition
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    • v.9 no.3
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    • pp.289-293
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    • 1996
  • Population changes of aerobic bacteria and lactic acid bacteria and changes of pH, acidity, and total sugar content were creased from initial period of fermentation. Lactic acid bacteria Increased during the first one nay rapidly and thereafter they creased slowly thereafter. Acidity increased on the third day of fermentation. Acidity was very low In Kimchi containing both Total sugar content decreased gradually from initial period to late period of fermentation.

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Change of Total Bacteria, Lactic bacteria and Textural Parameters during Kimchi Preservation (김치저장중 총세균.유산균 및 물성변화에 관한 연구)

  • 임국이
    • Journal of the Korean Home Economics Association
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    • v.25 no.4
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    • pp.57-62
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    • 1987
  • To obtain basic data for the decvelopment of Kimchi preservation method, optimal ripening Kimchi was air-packaged with polyethylene bag, and followed by the microbiological, firmness and sensory evaluations during storage at 5$^{\circ}C$. 1. Total aerobic count increased in the beginning of storage and then decreased slowly as the number of total Lactic bacteria(anaerobe) in creased. 2. Textural parameters were remarkably changed according to the elapse of storage period. 3. Sensory evaluation showed that the score was decreased considerably 10 days after storage.

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