Background: Although an understanding of the proliferation and differentiation of fish female germline stem cells (GSCs) is very important, an appropriate threedimensional (3D) research model to study them is not well established. As a part of the development of stable 3D culture system for fish female GSCs, we conducted this study to establish a 3D aggregate culture system of ovarian cells in marine medaka, Oryzias dancena. Methods: Ovarian cells were separated by Percoll density gradient centrifugation and two different cell populations were cultured in suspension to form ovarian cell aggregates to find suitable cell populations for its formation. Ovarian cell aggregates formed from different cell populations were evaluated by histology and gene expression analyses. To evaluate the media supplements, ovarian cell aggregate culture was performed under different media conditions, and the morphology, viability, size, gene expression, histology, and E2 secretion of ovarian cell aggregates were analyzed. Results: Ovarian cell aggregates were able to be formed well under specific culture conditions that used ultra-low attachment 96 well plate, complete mESM2, and the cell populations from top to 50% layers after separation of ovarian cells. Moreover, they were able to maintain minimal ovarian function such as germ cell maintenance and E2 synthesis for a short period. Conclusions: We established basic conditions for the culture of O. dancena ovarian cell aggregates. Additional efforts will be required to further optimize the culture conditions so that the ovarian cell aggregates can retain the improved ovarian functions for a longer period of time.

When used as a starter in the manufacture of Meju, it is expected that the quality of the soup products can be improved. In this study, we isolated Lactobacillus strain having possible safety and food-industrial benefits as a starter. Four hundred and seven isolates were screened from Meju, and chemically characterized for their antibacterial activity against Bacillus cereus, non-productivity of biogenic amine, and hemolysis. Eight of the isolates were selected upon chemical characterization, and their antioxidant and β-glucosidase activity was measured. Finally, we selected, and measured its enzyme activity and antibiotic resistance. Next, we investigated its cell growth, showed maximum biomass of 3.5 g/L after 28 h of culture. The ingredients of the medium to improve biomass were selected using the Plackett-Burman design (PBD) and central composite design (CCD). The results obtained using PBD revealed molasses, yeast extract, and maltose to be significant factors determining the biomass of the L. brevis SCML 432 strain. The CCD was then applied with three variables found from PBD and the optimum values were predicted to be 5.5% molasses, 1.5% yeast extract, and 2.0% maltose, and the maximum biomass was predicted to be 11.2 g/L. Through model verification, we confirmed that the predicted and actual results were similar, with about 3.2-fold improvement in the biomass from 3.5 g/L to 11.3 g/L when compared to that obtained in basal medium. These results suggest that SCML 432 has high potential in the food industry as a starter.

Background : Sea buckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values has wide spread distribution from Eurasia to South east Asia. In recent times the medicinal benefits of vitamin tree are inclining, hence, efforts were taken to propagate them in vitro to exploit their medicinal property. Methods and Results : The tissue culture potential of them was investigated for the ability to induce shoot organogenesis in leaf explant, and induction of direct somatic embryogenesis from leaf tissue. Moreover, we also determined the effective induction medium for callus and somatic embryo production from H. rhamnoides. To induce the callus form leaf tissue, several phytohormone combinations such as α-naphthalene acetic acid (NAA) and 6-benzyladenine (BA), 2,4-Dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA), and Kinetin (K) were tried with the Murashige and Skoog (MS) as well as woody plant medium (WPM). In MS basal medium, the combination of 2,4-D and K showed the best callus induction rate of 71%, whereas in WPM basal medium the combination of NAA and BA showed the best callus induction rate of 91%. The adventitious root induction form callus was also attempted by using MS and B5 medium with the phytohormone combinations of IBA 1 – 5 g/ℓ. In MS medium, root was induced only at 4 g/ℓ of IBA and 64%, 51% and 55% root induction results were obtained at 3 g/ℓ, 4 g/ℓ and 5 g/ℓ in B5 basal medium, respectively. The somatic embryos were induced only in half strength MS with the triple phytohormone ratio of 2:1:2 of NAA, BA, and K. Conclusion : The in vitro propagation of sea buckthorn was successfully employed by generating callus, adventitious roots as well as the induction of somatic embryos form the leaf tissues derived callus. Our results provided a valuable addition to the utilization of H. rhamnoides thus enabling their propagation.

Lysine is the first essential amino acid for optimal nutrient quality in rice grain. For the narrow genetic diversities of lysine contents in rice, somaclonal variation was the source of mutation in our breeding program. Biochemical selection was conducted using 1 mM S-(2-aminoethyl) cysteine followed by two passages of 5 mM lysine plus threonine in the callus subculture medium. The lysine contents in endosperm of all progenies recovered from the biochemical selection were higher than those of their donor cultivar 'Hwayeongbyeo'. These elevated lysine levels of mutants were successfully transmitted to M4 generation. The lysine contents in endosperm varied 3.85 to 4.80% compare to their donor cultivar 'Hwayeongbyeo' was 3.85%. Three of high-lysine germplasms, Lys-l, Lys-2 and Lys-7 were selected by biochemical selection and rapid screening methods. DNA analysis showed that a new insertion of Tos 17 which mapped to rice chromosome 11 on the high-lysine mutant, Lys-2.