• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.510-518
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• 1989

Most of orange peels are disposed from orange juice manufacturing process. Thus, our purpose is to utilize these orange peels as fermentation substrate. We have investigated culture conditions and factors influencing citric acid production by an isolated strain, Asp. niger. Citric acid production was much higher in semisolid culture than in submerged culture and the particle size of ground orange peels was favored at 20 mesh in semisolid culture. The optimal pH and temperature were 4.5-5.0 and 3$0^{\circ}C$ respectively and the temperature cycling at 35$^{\circ}C$ for 20 hrs durig exponential phase, 1$0^{\circ}C$ for 4 hrs and 3$0^{\circ}C$ during stationary phase showed higher citric acid production than did at fixed temperature, 3$0^{\circ}C$. The addition of NH$_4$NO$_3$0.2%, MgSO$_4$7$H_2O$ 0.1%, methanol 2.5%, ethanol 1.5%, to culture medium promoted citric acid production but the addition of trace metal ions as nutrients had not effect on the acid production in orange peel medium. Under the optimal culture conditions, maximum yield of citric acid was 80.4% in solid medium. Almost of all original components of citrus peel was consumed by Asp. niger during fermentation.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.5-13
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• 2019

This study is conducted to investigate the effects of anaerobic treatments of swine manure slurry alone and combination of livestock manure slurry and fruit pomace on biogas production. Anaerobic co-digestion was evaluated in mesophilic tank reactors for 96 day-incubation period. The organic matter loading of anaerobic digestion was 1 kg of volatile solids(VS) per $1m^3{\cdot}day$. The highest methane production was achieved from the combination of swine manure slury and mandarin pomace(70:30) treatment, whereas the lowest daily and cumulative methane yields was observed in swine manure slurry alone treatment. More than two-fold increase in bio-gas and methane production was obtained by combination of livestock manure slurry and mandarin pomace treatment, compared to the swine manure slurry alone treatment. The co-digestion of livestock manure and fruits pomace has advantages to enhance the production of methane gas, compared to digestion of swine manure slurry alone.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.806-811
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• 2012

This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle) were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2%) in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively) filled with $O_2$-free $N_2$ gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at $39^{\circ}C$ for 24 h. Total gas production in all plant extracts was higher (p<0.05) than that of the control, and total gas production of ginger extract was highest (p<0.05). The methane emission was highest (p<0.05) at control, but lowest (p<0.05) at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM). Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%). Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53) than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens community in added wormwood, garlic, mandarin orange and honeysuckle extracts increased more than that of the others. The addition of onion extract increased R. albus diversity, while other extracts did not influence the R. albus community. The R. flavefaciens population in added wormwood and garlic extracts decreased, while other extracts increased its abundance compared to the control. In conclusion, the results indicated that the plant extracts used in the experiment could be promising feed additives to decrease methane gas emission from ruminant animals while improving ruminal fermentation.

• SUVANNABHUMI
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• v.14 no.1
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• pp.193-228
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• 2022

This study investigates the production and perception of Vietnamese tones by Japanese, Lao, and Taiwanese second language (L2) learners [n=30], comparing their performance in an Imitation task to that of Identification and Read-Aloud tasks. The results show that the Imitation task is generally easier for L2 speakers than the Identification and Read-Aloud tasks, suggesting that imitation is performed without some of the skills required by the other two tasks. It is also found that Lao and Taiwanese speakers outperform Japanese speakers, suggesting that prior experience with one tone language facilitates the acquisition of tone in another language. The result on speakers' tonal range show that L2 leaners have significantly narrower tonal F0 range than control Vietnamese speakers [n=11]. The results of error pattern analysis and tonal transcription also suggest that non-modal voice (glottal stop and creakiness) and contour tones (bidirectional fall-rise) are more difficult for L2 learners than modal voice tones (e.g., unidirectional contours: rising, falling, and level).

• The Plant Pathology Journal
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• v.40 no.2
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• pp.115-124
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• 2024

Citrus cultivation plays a pivotal role, making a significant contribution to global fruit production and dietary consumption. Accurate identification of viral pathogens is imperative for the effective management of plant viral disease in citrus crops. High-throughput sequencing serves as an alternative approach, enabling comprehensive pathogen identification on a large scale without requiring pre-existing information. In this study, we employed HTS to investigate viral pathogens infecting citrus in three different regions of South Korea: Jejudo (Jeju), Wando-gun (Wando), and Dangjin-si (Dangjin). The results unveiled diverse viruses and viroids that exhibited regional variations. Notably, alongside the identification of well-known citrus viruses such as satsuma dwarf virus, citrus tatter leaf virus, and citrus leaf blotch virus (CLBV), this study also uncovered several viruses and viroids previously unreported in Korean citrus. Phylogenetic analysis revealed that majority of identified viruses exhibited the closest affilations with isolates from China or Japan. However, CLBV and citrus viroid-I-LSS displayed diverse phylogenetic positions, reflecting their regional origins. This study advances our understanding of citrus virome diversity and regional dynamics through HTS, emphasizing its potential in unraveling intricate viral pathogens in agriculture. Consequently, it significantly contributes to disease management strategies, ensuring the resilience of the citrus industry.

• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.1-7
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• 2017

It was shown in speech production studies that the preparation unit of spoken word production is language particular, such as onset phonemes for English and Dutch, syllables for Mandarin Chinese, and morae for Japanese. However, there have been inconsistent results on whether the onset phoneme is a planning unit of spoken word production in Korean. In this study, two sets of experiments investigated possible influences of task demands on the phonological preparation in native Korean adults, namely, implicit priming and word naming with the form preparation paradigm. Only the word naming task, but not the implicit priming task, showed a significant onset priming effect, even though there were significant syllable priming effects in both tasks. Following the attentional theory ($O^{\prime}S{\acute{e}}aghdha$ & Frazer, 2014), these results suggest that task demands might play a role in the absence/presence of onset priming effects in Korean. Native Korean speakers could maintain their attention to the shared onset phonemes in word naming, which is not very demanding, while they have difficulties in allocating their attention to such units in a more cognitive-demanding implicit priming, even though both tasks involve accessing phonological codes. These findings demonstrate that there are cross-linguistic differences in the first selectable unit in preparation of spoken word production, but within a single language, the preparation unit might not be immutable.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.137-143
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• 2008

Production of Indian citrus ringspot virus (ICRSV)-free plants from an infected plant of kinnow mandarin (Citrus nobilis Lour ${\times}$ C. deliciosa Tenora) is reported. The shoot apices of different sizes (0.2-1.0 mm) excised from the ICRSV-infected plant were micrografted onto decapitated rootstock seedlings of rough lemon (C. jambhiri). Micrograft survival depended on the size of shoot apex and the sucrose concentration of the culture medium. Increase in scion size from 0.2 to 0.7 mm resulted in an increase in micrografting success rate from 30.55 to 51.88%. Further, micrograft survival obtained with 0.2 mm was improved from 30.55 to 38.88% by increasing sucrose concentration in the culture media from 5 to 7.5%. The micrografted plants were tested for ICRSV using ELISA and RT-PCR. All plants raised from 0.2-mm scion were found negative with both ELISA and RT-PCR whereas only 20% of the ELISA negative plants raised from 0.3-mm scion were found negative for ICRSV with RT-PCR. The outcome of this research is the successful establishment, acclimatization and virus testing of micrografted plants.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.147-151
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• 1999

Quality characteristics of Satsuma mandarin (Citrus unshiu Marc. var. okitsu) harvested in early December according to production areas and sea level altitude of Cheju were investigated. Soluble solids and flesh ratio were $9.06{\sim}12.98,\;77.32{\sim}81.27%$ on citrus fruits harvested in orchards located below 100 m sea level (lower area), and were $10.16{\sim}12.26,\;75.00{\sim}81.55%$ in orchards 150 m sea level altitude (higher area), respectively. Acid content of citrus juice was $0.83{\sim}1.21%$ in fruits harvested in lower area, and was $0.94{\sim}1.34%$ in higher area except Hankyung-myun area. The differences of soluble solids and acid contents by harvesting periods for 10 days were 0.91 and 0.82 for soluble solids; 0.15 and 0.13% for acid contents, respectively. In proportion to late harvesting, Brix/acid ratio and fruit quality were improving. Soluble solids of fruits harvested from lower area were higher than those of fruits from higher area, but acid contents were lower in fruits from lower area than in fruits from higher area. In sensory evaluation on fruit appearence, the differences between two altitudes were not clear, but panelists marked higher points on fruits harvested in main production areas, Seogwipo-si and Namwon-eup which are southern areas. Fruit quality harvested in Seogwipo-si areas showed better quality than fruits from other harvested areas.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.665-676
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• 2016

As high temperature during citrus growing season has caused a serious problems including inferior coloration in production of mandarins in Korea, we were to investigate the expression pattern of several genes related with coloration during the ripening in high temperature condition of citrus fruits. The expression of genes related with sugar metabolism, cell wall degradation, and flavonoid synthesis in high temperature conditions was investigated in fruits of 'Haryejosaeng' (Citrus unshiu) and 'Shiranuhi' mandarin (C. reticulata). While the expression of beta-amylase (BMY), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and flavanone 3-hydroxylase (F3H) was differently induced, expression of polygalacturonase (PG) decreased dependently on temperature conditions. In 'Haryejosaeng' mandarin, while the expression of genes related to the skin coloration, such as CHS and F3H genes increased at $25^{\circ}C$, the expression of PAL and stilbene synthase (STS) genes were induced at $30-35^{\circ}C$ in all ripening stages. In 'Shiranuhi' mandarin, the expression of the BMY gene decreased at early time point in all temperature condition and then increased at $30-35^{\circ}C$ than at $25^{\circ}C$ in the ripening stage 2 to 3 of fruits. F3H and STS genes also showed the tendency to decrease at $30-35^{\circ}C$. Although the expression levels of genes in ripening stage 1 and stage 2 of fruits showed similar patterns in both 'Haryejosaeng' and 'Shiranuhi', the expression levels of genes were down-regulated in late ripening stage of 'Shiranuhi' fruits compared to 'Haryejosaeng'. In general, the mRNA levels of seven tested genes were higher in 'Haryejosaeng' than in 'Shiranuhi' mandarin, and expression of genes by high temperature was regulated sensitively in 'Haryejosaeng' compared to 'Shiranuhi' mandarin. Further investigations of expression of various genes based on transcriptome analysis in early ripening stage can provide valuable information about the responses to climatic changes in ripening citrus fruits.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.259-265
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• 2005

Indian citrus ringspot virus (ICRSV)-free plants of Kinnow mandarin (Citrus nobilis Lour x C. deliciosa Tenora) were raised from virus-infected plants using unfertilised ovules as explants. Plants were tested by indirect ELISA and RT-PCR before using their explant. An amplified product of 539 bp was obtained by RT- PCR in ICRSV infected plants. Unfertilized ovules were excised from unopened flower buds of plants tested postive for virus and were cultured on Murashige and Skoog's (MS) basal medium supplemented with various concentrations of kinetin (KN) or malt extract (ME). Maximum induction (31.94%) of embryogenic callus was observed on MS medium supplemented with KN ($9.29\;{\mu}M$). Transfer of embryogenic calli to similar media composition resulted in somatic embryogenesis in all cultures, with an average number of 60.36 globular, 17.39 heart and 7.71 cotyledonary-shaped somatic embryos per culture. All cotyledonary shaped embryos developed into complete plantlets within 60 days on transfer to similar medium. Embryogenic callus induction, somatic embryo formation, maturation, germination and plantlet formation were achieved on MS medium supplemented with KN ($9.29\;{\mu}M$) alone. The plantlets derived from somatic embryos were transferred to sterilized soil, sand and vermiculite (3:1:1) mixture. After acclimatization, the plantlets were transferred to screen house and were indexed for ICRSV employing indirect ELISA and RT-PCR and found free of virus. A distinct feature of this study is the induction of somatic embryogenesis from unfertilised ovules to produce virus-free plants.