• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.5
• /
• pp.673-676
• /
• 1998

Preparative conditions of high-gel strength agar from Gelidium amansii have been studied, The effect of NaOH pretreatment on the quality and yields of agar extracted from Gelidium amansli was examined. The Bel strength of agar extracted from C. amansii pretreated with NaOH was higher than that of agar extracted from G. amansii non-pretreated with NaOH. The gel strength of agar extracted from G. amansii was influenced by concentration, temperature and time of pretreatment with NaOH. It was found that the proper concentration, temperature and time of NaOH pretreatment to produce high-gel strength agar was $6\%$ NaOH, $80^{\circ}C$ and 2$\~$3 hrs. The principal sugars of agar extracted from G. amansli were galactose and 3,6-anhydrogalactose.

• Microbiology and Biotechnology Letters
• /
• v.21 no.1
• /
• pp.82-87
• /
• 1993

Fourteen samples of kimchies and soy bean pastes were used to isolate strictly anaerobic bacteria on complex BL agar and on a selective BS agar for bifidus bacteria. About $10^7$ ~ $10^8$ colonies per g sample were developed on BL agar under strictly anaerobic conditions, while BS agar supported the growth of $10^3$ ~ $10^6$ colonies per gram sample at the same condition. All colonies developed on BS agar at anaerobic conditions grew in aerobic conditions and did not show fructose6-phosphate phosphoketolase activity. Type cultures of Bifidobacterium did not grow in PYG medium containig more than 3% NaCI. From these results it is conduded that salted fermented food cannot support the growth of strictly anaerobes induding Bifidobactenum.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.5
• /
• pp.716-721
• /
• 1996

To bring out the functional properties of Agar-agar extracted with 0.01N $H_2SO_4$ from Gellidium amansii produced in Che-ju Udo and its fluid properties were investigated. The yield of agar from Gellidium amansii produced was $32.7\%$, the content ratio of agarose and agaropectin was 79 to 21, gelation ability was $0.19\%$ and jelly strength was $413.8\;dyne/cm^2$. Agar-agar solution showed the movement of non-Newtonian fluid and pseudoplastic property was emerged as its concentration go higher. The yield stresses in the range of $0.5\~5\%$ agar-agar solution were $0.09\~1.21\;dyne/cm^2\;at\;80^{\circ}C,\;0.12\~5.29\;dyne/cm^2\;at\;60^{\circ}C\;and\;4.84\~58.37\;dyne/cm^2\;at\;50^{\circ}C$.

• Horticultural Science & Technology
• /
• v.17 no.6
• /
• pp.768-769
• /
• 1999

Experiments were conducted to find out the optimum condition for in vitro proliferation using shoot tip of Gypsophila paniculata. Formation and fresh weight of adventitious shoots were promoted by shoot culture with $0.2mg{\cdot}L^{-1}$ BA and $0.2mg{\cdot}L^{-1}$ NAA in 'Bristol Fairy', while were promoted with $0.2mg{\cdot}L^{-1}$ BA and $0.1mg{\cdot}L^{-1}$ NAA in 'Red Sea'. Vitrification was suppressed by using $7{\times}13cm $ $(diameter{\times}height)$ vessel. Aeration treatment on cap and agar concentration did not affect vitrification, but promoted the elongation of adventitious shoots. Formation of adventitious shoot was inhibited by increasing agar concentration in the medium.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.23 no.3
• /
• pp.109-124
• /
• 2018

In order to find the optimum culture condition for marine free-living nematoda in the laboratory, various agar media were developed and experiments were carried on nematodes. Nematodes have collected from the bottom of the sandy sediments' surface layer (about 5cm sediment) of Taean Mallipo beach's intertidal zone. Especially, with regard to agar medium, Killian medium was transformed slightly, density of agar had made a difference and this agar medium(height 2.0 mm on diameter 60 mm Petri dish) was divided. It was mixed with 5 different species of microorganism as nematodes' live food and added each culture medium. Five individuals of Enoplolaimus sp. on each culture medium were grown in a culture medium which was set on $20^{\circ}C$ and light blocked. Moreover, as a result of the optimum culture condition, 1.0% density of agar showed the highest survival rates (the average time of survival is 246.8 hours). On the other hand, the 0.4% density of agar adding Killian medium, bacto peptone and beef extract showed the lowest survival rates, which indicates the average time of survival is 27.6 hours. About Bathylaimus sp., on Killian medium's 1.0% density of agar(no feeding amount) showed the highest survival rates, which connects that the hatching rate 94.7% after 99.5 hours and it laid 7 eggs averagely on the spawning amount and the hatching rate experiment.

• 한국생물공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.340-342
• /
• 2005

An agar degrading bacterium, This strain was isolated from sea water in Jeju. The strain is Gram-negative, rod and strictly aerobe for growth. The identification bases on the 16S rRNA gene sequencing showed that the strain was closely related to the genus Agariovarans sp. and named Agariovorans sp. JA1. The strain grew on agar as a sole carbon and energy source and produced an extra cellular agarase. For the increase of agarase productivity, 0.5% agar, yeast extract and $NaNO_3$ were used as carbon, organic and inorganic nitrogen source, respectively. For effective production of agarase and growth, the pH, temperature and NaCl concentration were was pH 7, $25^{\circ}C$ $^{\sim}$ $30^{\circ}C$ and 2%, respectively.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.5
• /
• pp.295-299
• /
• 1998

To detect the effects of gelling agent brands and concentration on rice anther culture, anthers of rice(O. sativa L. japonica, cv, Nagdongbyeo) were inoculated on N6-Y1 basic media supplemented with 0.4~1.6% Bacto agar(Difco, 04140-01), Agarose(Sigma, Type 1) and 0.2~0.8% Gelrite(Kelco, 143364) as gelling agents. On 0.4% Bacto agar and Agarose media, the frequency of callus formation which was significantly decreased in proportion to gelling agent's concentration was 39% and 55%, respectively. On 0.6% Gelrite media, the frequency of callus formation which was not statistically significant among the 0.2~0.8% concentration was 44%. Calli derived from the higher concentration of gelling agents showed embryogenic with slow growth, small, whitish and hard shape compare to that of the lower concentration. The frequency of green plant regeneration was high not only in calli derived from the higher concentration but also in plant regeneration medium with the higher concentration after callus transfer. Calli derived from the higher concentration was effective to maintain the frequency of green plant regeneration up to 60 days after anther inoculation. Introduction of 0.6~0.8% Geltite for callus formation, then transferred 1.6% Bacto agar and Agarose or 0.8% Gelrite for green plant regeneration was effective to increase anther culture efficiency.

• Journal of Life Science
• /
• v.27 no.8
• /
• pp.937-944
• /
• 2017

To investigate the beneficial effects of fiber derived from agar on the lipid and glucose metabolism of obese model mice, changes in the fat accumulation, lipid content, and insulin concentration were measured in C57BL/6N mice fed a high-fat diet (HFD) and treated with a beverage containing agar (BCA) for 9 weeks. The feed efficiency ratio was significantly decreased in the HFD+BCA treatment group, although the body weight and food intake were maintained a constant level. Also, the fat accumulation in the fatty tissue and liver were lower in the HFD+BCA treatment group than in the HFD+Vehicle treatment group. Furthermore, a significant decrease was detected in the levels of total cholesterol (TC) and LDL after the BCA treatment, while a constant HDL level was maintained in the same group. Moreover, the serum insulin concentration was significantly decreased in the HFD+BCALo (Low concentration) and HFD+BCAMi (Middle concentration) groups compared to the HFD+Vehicle group. Therefore, the results suggest that the long-term administration of dietary fiber from agar can improve fat accumulation in the fatty tissue and liver, the serum lipid profile, and the insulin concentration in the blood. Also, the results provide evidence that the inclusion of agar fiber in beverages results in significant hypolipidemic and hypoinsulinemic effects.

• KSBB Journal
• /
• v.14 no.5
• /
• pp.572-577
• /
• 1999

A marine bacterium with highly effective agar degrading activity was ioslated from the southern sea of Korea (Chonnam, YoChon) and identified as Cytophaga sp. and named as Cytophaga sp. AYK301. This strain produced an extracellular agarase which had a high activity with agar. The optimum culture conditions for the production of agarase have been determined. For the increase of agarase productivity, 0.2% agar, 0.3% beef extract, and 0.05% NH$_4$NO$_3$ were used as carbon, organic and inorganic nitrogen source, respectively. The optimal initial pH, NaCl, culture time and temperature for the agar degrading activity were 7.5, 7.0%, 36 hr and $25^{\circ}C$, respectively. In the optimal conditions, the agarase production was increased up to more than 4.0 folds as compared to that by the basal medium.

• Journal of Bio-Environment Control
• /
• v.22 no.3
• /
• pp.241-247
• /
• 2013

For in vitro minimal-growth conservation of S. sarmentosum, the in vitro shoots with 10 mm length were cultured on Murashige and Skoog's media (MS) containing different levels of agar (0.8, 1.2, 1.6, 2%), Gelrite (0.4, 0.6, 0.8, 1%), ABA (0, 5, 10, $20mg{\cdot}L^{-1}$), and sucrose (2, 3, 6, and 9%) without subculture at $4^{\circ}C$ and $25^{\circ}C$. All media were supplemented with $0.2mg{\cdot}L^{-1}$ BA, agar and Gelrite media, with 5% sucrose, sucrose media, with 1.2% agar, and ABA media, with 5% sucrose and 1.2% agar, respectively. In vitro minimal-growth conservation in room-temperature ($25^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 1.6% agar, and the healthy plantlets could be preserved for 10 months without subculture. After 12 months at $4^{\circ}C$, survival rate was 100% in all media. The in vitro minimal-growth conservation in low temperature ($4^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 6% sucrose, and the healthy plantlets could be preserved over 18 months without subculture. Especially, long-term conservation using minimal growth of S. sarmentosum was much more efficient in the medium containing high level sucrose at $4^{\circ}C$ compared to others.