• 제목/요약/키워드: Growth conditions

검색결과 6,785건 처리시간 0.034초

식품위생관련 세균에 대한 가열처리 조건의 최적화 (Optimization of Heating Conditions for Bacteria Associated with Food Hygiene)

  • 이보순
    • 한국식품영양학회지
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    • 제12권6호
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    • pp.569-574
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    • 1999
  • Response surface methodology(RSM) was applied to determine the optimum heating conditions(tem-perature and time) for the inactivation of bacteria associated with food hygiene. Coefficients of determinations(R2) for the cell growth were 0.9155(P<0.05) in Pseudomonas aeruginosa 0.8997(P<0.05) in Escherichia coli 0.9690(P<0.01) in Salmonella typhimurium 0.9393(P<0.05) in Enterobacter aerogenes and 0.7905 in Vibrio parahaemolyticus. The growth of strains was significantly affected by the temperature and time and reaction to temperature was most closely correlated to the inhibition of growth. On the basis of superimposed contour maps of cell growth the optimum range of heating conditions were 55.62-6$0^{\circ}C$ and 19.25-30 min.

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Optimal growth conditions and economic analysis of sea cucumber releasing

  • Lee, Cheol;Choi, Sang Duk
    • Fisheries and Aquatic Sciences
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    • 제23권4호
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    • pp.11.1-11.11
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    • 2020
  • We tried to find the optimal growth conditions of sea cucumber and to analyze the economic effectiveness of the sea cucumber seedling release project in Korea. We first examined the optimal growth conditions of sea cucumber in the relating literatures. Then, we analyzed the economic effectiveness of the sea cucumber seedling release project of the Woncheon fishing village union of Gyeongnam Province in 2016-2018 by using the cost benefit analysis method. The net income of the release project of the Woncheon fishing village union was 69,850 Korean won. The benefit to cost ratio of the sea cucumber seedling release project of the Woncheon fishing village union was estimated to be 1.7, indicating that the project was economically feasible. In order to improve the economic feasibility of the sea cucumber release project, as we see in the case of the Woncheon fishing village union, it is necessary to manage the purchase of the sea cucumber seedling, to improve the recapture rate of sea cucumber, and to manage marketing of sea cucumber.

도토리 가루가 미세조류 증식에 미치는 영향 (Effect of Acorn Powder on the Biomass Productivity of Microalgae)

  • 최희정
    • 한국물환경학회지
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    • 제31권2호
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    • pp.134-141
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    • 2015
  • The focus of this study was to observe the growth of Chlorella vulgaris and Botryococcus braunii under mixotrophic conditions (i.e., added acorn) with the aim of increasing biomass and triacylglycerols (TAGs) content. The result of investigation indicated that the acorn contains a lot of carbonate (87.29%) and glucose (97.99 mg%). A significant growth of biomass was obtained when grown in acorn rich environment comparing to autotrophic conditions. 3 g/L acorn yielded the highest biomass concentration for these strains. Thus, the biomass productivity with 3 g/L acorn was obtained 2.31 times and 2.10 times higher than that of authotrophic conditions for Chlorella vulgaris and Botryococcus braunii, respectively. The maximum amount of TAGs was reached 14.35% and 18.41% for Chlorella vulgaris and Botryococcus braunii, respectively, in the growth medium with 5 g/L acorn. The effect of acorn could enhance the investigated microalgae growth, biomass productivity and TAGs content. This provides a feasible way to reduce the cost of bioenergy production from microalgae.

Study on simultaneous heat and mass transfer during the physical vapor transport of Hg2Br2 under ㎍ conditions

  • Kim, Geug Tae
    • 한국결정성장학회지
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    • 제29권3호
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    • pp.107-114
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    • 2019
  • A computational analysis has been carried out to get a thorough and full understanding on the effects of convective process parameters on double-diffusive convection during the growth of mercurous bromide ($Hg_2Br_2$) crystals on earth and under ${\mu}g$ conditions. The dimensional maximum magnitude of velocity vector, ${\mid}U{\mid}_{max}$ decreases much drasticlly near Ar = 1, and, then since Ar = 2, decreases. The ${\mu}g$ conditions less than $10^{-2}g$ make the effect of double-diffusion convection much reduced so that adequate advective-diffusion mass transfer could be obtained.

Culture Conditions Affecting the Optimal Mycelial Growth of Cystoderma amianthinum

  • Shim, Sung-Mi;Oh, Yun-Hee;Lee, Kyung-Rim;Kim, Seong-Hwan;Im, Kyung-Hoan;Kim, Jung-Wan;Lee, U-Youn;Shim, Jae-Ouk;Shim, Mi-Ja;Lee, Min-Woong;Ro, Hyeon-Su;Lee, Hyun-Sook;Lee, Tae-Soo
    • Mycobiology
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    • 제33권1호
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    • pp.65-67
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    • 2005
  • Cystoderma amianthinum, one of edible fungi belongs to Agaricaceae of Basidiomycota, has a good taste and flavor. This study was carried out to obtain the basic informations for the optimum mycelial growth of C. amianthinum. The optimal conditions for the mycelial growth were $25^{\circ}C$ and pH 5 in potato dextrose agar (PDA). C. amianthinum showed the favorable growth in the PDA and yeast malt extract agar (YMA). The favorable carbon and nitrogen sources promoting mycelial growth were fructose and histidine, respectively. The optimum C/N ratio was about 30 : 1 in case that 1 % glucose was supplemented to the basal medium as a carbon source.

Optimization of Cultural Conditions for Mycelial Growth and Exo-Polysaccharide Production in Jar Fermentation by Fomitopsis pinicola

  • Cha, Wol-Suk;Jilu, Ding;Lee, Choon-Beom;Nam, Hyung-Geun;Lee, Jun-Han;Maeng, Jeung-Moo;Lim, Hwan-Hee
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVI)
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    • pp.187-191
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    • 2005
  • 발효기에서의 균사체 생장과 세포외다당류의 생산을 위한 최적 배양조건을 조사하기 위하여 회분식 반응기를 이용하여 연구한 결과 최적 회전속도와 통기량은 각각 200 rpm과 1.5 vvm 었다. 최적 배양 환경하에서 5L발효기(working volume 2 L)에서 배양한 결과 각각 10.21 g/L 와 3.56 g/L의 mycelial growth와 exo- polysaccharide를 얻었다.

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Growth and Photosynthetic Responses of One C3 and Two C4 Chenopodiaceae Plants to Three CO2 Concentration Conditions

  • Ishikawa, Shin-Ichi
    • Journal of Ecology and Environment
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    • 제31권4호
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    • pp.261-267
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    • 2008
  • Growth and photosynthetic responses of one $C_3$ and two $C_4$ plants in the family Chenopodiaceae in three $CO_2$ concentration $([CO_2])$ conditions-low (about $243{\mu}mol\;mol^{-1}$, LC), present (about 378, PC), and high (about 465, HC)-were investigated in open top chambers. The relative growth rate (RGR) and net assimilation rate in the $C_3$ plant, Chenopodium album, increased with increasing $[CO_2]$, though the RGR was not enhanced significantly in the HC condition. The leaf area ratio and leaf weight ratio of the $C_3$ plant drastically decreased with increasing $[CO_2]$, suggesting that the $C_3$ plant invests more biomass to leaves in lower $[CO_2]$ conditions. The two $C_4$ plants, Atriplex glauca and A. lentiformis, showed relatively small changes in those growth parameters. These photosynthetic-pathway-dependent responses suggest that growth patterns of $C_3$ and $C_4$ plants have been altered by past increases in atmospheric $[CO_2]$ but that there will be relatively little further alteration in the future high-$CO_2$ world.

STS316L의 고온피로균열에 미치는 인장유지시간의 효과 및 결정립크기에 따른 크리프 거동에 관한 연구 (The Effect of Tensile Hold time on the Fatigue Crack Propagation Property and Grain Size on the Creep Behavior in STS 316L.)

  • 김수영
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.373-378
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    • 2000
  • The heat resistant material, in service, may experience static loading, cyclic loading, or a combination of two. An experimental study of crack growth behavior of STS 316L austenitic stainless steel under fatigue, and creep-fatigue loading conditions were carried out on compact tension specimens at various tensile hold times. In the crack growth experiments under hold times. In the crack growth experiments under hold time loading conditions, tensile hold times were ranged from 5 seconds to 100 seconds and its behavior was characterized using the $\Delta$K parameter. The crack growth rates generally increase with increasing hold times. However in this material, the trend of crack growth rates decreases with increasing hold times for short hold time range relatively. It is attributed to a decline in the cyclic crack growth rate as a result of blunting at the crack tip by creep deformation. The effect of grain size on the creep behavior of STS 316L was investigated. Specimens with grain size of 30, 65 and 125${\mu}{\textrm}{m}$ were prepared through various heat treatments and they were tested under various test conditions. The fracture mode of 316L changed from transgranular to intergranular with increasing grain size.

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Biological Control and Plant-Growth Promotion by Bacillus Strains from Milk

  • Nautiyal Chandra Shekhar;Mehta Sangeeta;Singh Harikesh Bahadur
    • Journal of Microbiology and Biotechnology
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    • 제16권2호
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    • pp.184-192
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    • 2006
  • Six-hundred bacterial strains from human milk and milk from Sahiwal cows, Holstein Friesian cows, and buffaloes were screened for their ability to suppress phytopathogenic fungi under in vitro conditions. A consortium of 3 strains, viz., Bacillus lentimorbus B-30486 (B-30486), B. subtilis B-30487 (B-30487), and B. lentimorbus B-30488 (B-30488), isolated from Sahiwal cow milk resulted in better biological control and plant-growth promotion than single-strain treatments. For commercial-scale production of a bioinoculant, the solid-state fermentation of sugarcane agro-industrial residues, i.e., molasses, press mud, and spent wash, using the consortium of B-30486, B-30487, and B-30488, resulted in a value-added product, useful for enhancing plant growth. The application of the consortium to sugarcane fields infested with Fusarium moniliforme and Colletotrichum falcatum resulted in a reduction of mortality and significantly higher (P=0.05) plant height, number of tillers, and cane girth when compared with the control. Furthermore, under field conditions, the treatment of sugarcane with the consortium resulted in significantly (P=0.05) greater plant growth compared with nonbacterized plants. Accordingly, this is the first report on the effective use of bacteria isolated from milk for biological control and enhancing plant growth under field conditions. Furthormore, a solid-state fermentation technology was developed that facilitates the economic utilization of agro-industrial residues for environmental conservation and improving plant and soil health.

Growth and nutrient bioextraction of Gracilaria chorda, G. vermiculophylla, Ulva prolifera, and U. compressa under hypo- and hyper-osmotic conditions

  • Wu, Hailong;Shin, Sook Kyung;Jang, Sojin;Yarish, Charles;Kim, JangKyun
    • ALGAE
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    • 제33권4호
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    • pp.329-340
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    • 2018
  • The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.