• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.614-622
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• 2013

Daqu, a traditional fermentation starter, has been used to produce attractively flavored foods such as vinegar and Chinese liquor for thousands of years. Although Bacillus spp. are one of the dominant microorganisms in Daqu, more precise information is needed to reveal why and how Bacillus became dominant in Daqu, and next, to assess the impact of Bacillus sp. on Daqu and its derived products. We combined culture-dependent and culture-independent methods to study the ecology of Bacillus during Daqu incubation. Throughout the incubation, 67 presumptive Bacillus spp. isolates were obtained, 52 of which were confirmed by 16S rDNA sequencing. The identified organisms belonged to 8 Bacillus species: B. licheniformis, B. subtilis, B. amyloliquefaciens, B. cereus, B. circulans, B. megaterium, B. pumilus, and B. anthracis. A primer set specific for Bacillus and related genera was used in a selective PCR study, followed by a nested DGGE PCR targeting the V9 region of the 16S rDNA. Species identified from the PCR-DGGE fingerprints were related to B. licheniformis, B. subtilis, B. amyloliquefaciens, B. pumilus, B. benzoevorans, and B. foraminis. The predominant species was found to be B. licheniformis. Certain B. licheniformis strains exhibited potent antimicrobial activities. The greatest species diversity occurred at the Liangmei stage of Daqu incubation. To date, we lack sufficient knowledge of Bacillus distribution in Daqu. Elucidating the ecology of Bacillus during Daqu incubation would enable the impact of Bacillus on Daqu to be accessed, and the quality and stabilization of Daqu-derived products to be optimized.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.1-13
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• 1998

Seasonal variation of algae distribution were studied in the Chuam reservoir from August 1996 to July 1997. As a result, 127 taxa were observed, representing 6 classes, 14 orders, 5 suborders, 29 families, 2 subfamilies, 54 genus, 118 species, 7 variaties and 2 formula. The majors of them are Chlorophyceae (59 taxa), Bacillariophyceae(39 taxa) and Cyanophyceae(20 taxa). The number of species was that 35 and 31 taxa were occurred in August 1996 and April 1997, 11 and 17 taxa in July 1997 and October 1996 respectively at Dam station, 53 taxa were occurred in September, 18 taxa in November at Munduck station. The biomass composition of occurrence species were as fallowes; Cyanophyceae are 80%, Bacillariophyceae 14% and Chlorophyceae 5% at Dam station and Cyanophyceae are 90%, Bacillariophyceae 1.3% and Chlorophyceae 0.4% at Munduck at Munduk station. At Munduk station, water bloom occurred by Cyanophyceae(99.9%, 3.7 $\times$ 10$^{7}$ cells/L) in November 1996 and the major causing algae was Microcrystis aeruginosa. Microcystis aeruginosa was dominant species (dominant index : 0.72 - 0.99) during summer and autumn, Fragilaria crotonensis and Asterionella formasa (DI : 0.33 - 0.74) during winter and spring. The water quality factors of the Chuam reservoir were that the values of water temperature ranged of 3.6 - 31.4$\circ$C, pH 6.7 - 9.0, conductivity 69.6-118.2 $\mu $s/cm, and turbidity 1.0-22.5 NTU, and the proper temperature of water for algae growth was 15 and 16.7$\circ $C in April and November. Also the concentration of dissolved oxygen(DO) ranged of 6.8-15.5mg/L, total nitrogen(T-N) 0.54-1.78 mg/L, total phosphrous (T-P) 0.003-0.034 mg/L, and chlorophyll-a 0.9-23.2mg/m$^{3}$. The concentration of Chlorophyll-a was in inverse proportion T-N/T-P ratio.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.853-860
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• 2003

Plants sequester atmospheric CO$_2$, a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pinus densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO$_2$ uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of CO$_2$ exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO$_2$ uptake per unit leaf area ranged from 1.6-6.7 mg/d㎡/h for P. densiflora and from 3.7-8.9 mg/d㎡/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO$_2$ uptake by total leaf area per tree, which subtracted the CO$_2$ release (i.e. respiration) by leaves and woody organs from the gross CO$_2$ uptake (diurnal uptake and release by leaves). Annual CO$_2$ release by leaves and woody organs accounted for 58-73％ of the gross CO$_2$ uptake across tree specimens. Annual CO$_2$ uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. densiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO$_2$ uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO$_2$ reduction of woody plants by forest type and age class.

• ALGAE
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• v.21 no.1
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• pp.83-90
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• 2006

Phytoplankton community in the coastal waters off the northeastern Korean Peninsula were characterized from May 2002 to August 2003. Taxonomic composition, abundance and biomass were determined at two water depths at 10 sample sites. A total of 153 phytoplankton species including 121 diatoms, 28 dinoflagellates, 7 green algae and 7 other species were identified. The mean abundance of phytoplankton varied from 15 to 430 cells mL–1 in the surface layer and from 11 to 545 cells mL–1 in the bottom layer, respectively. Phytoplankton was more abundant in coastal stations relative to those in more open ocean. The most dominant species were marine diatoms such as Thalassionema nitzschioides, Licmorphora abbreviata, Chaetoceros affinis and Chaetoceros socialis. In addition, a few limnotic diatoms including Fragilaria capucina v. rumpens, the green alga Scenedesmus dimorphus, some marine dinoflagellates and Cryptomonas sp. appeared as dominant species. Mean concentration of total chlorophyll-a varied from 0.22 to 7.87 μg chl-a L–1 and from 0.45 to 6.79 μg chl-a L–1 in the surface and bottom layers, respectively. The contribution of phytoplankton each size-fractionated varied highly with season. The contribution of microphytoplankton to total biomass of phytoplankton in the surface and bottom layer was high in February and August 2003, and that of nano-phytoplankton was high in May 2002 in both surface and bottom layers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.224-229
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• 1987

The ecological studies of the benthic polychaetes of the Yellow Sea were carried out for five years from August 1982. The emphasis of the research were placed on clarification of the distributional pattern and characteristic species of environmental factors on the polychaete community. Based on the polychaete samples analysed during the study period, it was possible to divide the polychaetes into five ecological groups : 18 warm water, 22 cold water, 20 cosmopolitan, 29 endemic, and 7 amphi-pacific species, Anaitides koreana, Aglaophamus sinensis, Nephtys polyoranchia, Nephtys caeca, Glycera capitata, and Scoloplos armiger seem to be characteristic species of sand bottom, while Haploscoloplos elongatus and Ophelina aulogaster of mud bottom. A total of 6 benthic communities have been recognized from the dominant benthic fauna found. In each benthic communities, dominant and characteristic polychaete species were clarified according to their ecological types. In general, as echinoderms such as Ophiura kinbergi, Amphioplus megapomus, and Luidia quinaria are distributed widely and found in high density, their influence on the distribution of most polychaetes is clearly shown.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.53-60
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• 2016

Seasonal variations in seaweed communities were examined at Gwanmaedo and Yeongsando, Korea, from May 2014 to February 2015. Eighty-nine species were identified, including 11 green, 20 brown and 58 red algae. Seventy-three and 74 species were identified at Gwanmaedo and at Yeongsando, respectively. Sargassum thunbergii and Myelophycus simplex were the dominant species, comprising 60.89 and 39.50% of total biomass, respectively, and S. fusiforme was subdominant at the two sites. Of six functional seaweed forms, the coarsely-branched form was the most dominant, forming about 43% of the species number at Gwanmaedo and Yeongsando. Seasonal seaweed biomasses ranged between 53.10 and 172.85 g/m² (average 93.57 g dry wt./m²) and between 83.11 and 176.20 g (138.21 g/m²) at Gwanmaedo and Yeongsando, respectively. The vertical distribution from the high to low intertidal zone was S. thunbergii and Gloiopeltis furcata; M. simplex and S. thunbergii; and S. fusiforme at Gwanmaedo. Seaweed zonation was distinct at Yeongsando, with S. thunbergii and Gelidiophycus freshwateri; M. simplex and S. thunbergii; and S. thunbergii and S. fusiforme. Seaweed biomass, evenness index (J'), and diversity index (H') values were greater at Yeongsando (138.21 g/m², 0.51, 2.18 respectively) than at Gwanmaedo (93.57 g/m², 0.48, 2.04), indicating that the seaweed community at Yeongsando is more stable than that at Gwanmaedo.

• 한국해양학회지
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• v.28 no.4
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• pp.305-312
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• 1993

This study was carried out to investigate the benthic polychaetous community in the coastal area near Samchunpo City, in September and October of 1989. Polychaete, the dominant faunal group occupying 61.7% in the total faunal density, comprised a total of 50 species with a mean density of 112 indiv.m/SUP -2/. The Number of species and density were higher on the coastal area near Samchunpo Harbor and Samyang Sang-do. The most dominant Polychaete was Terebellides horikoshii (17.1%), followed by Lumbrineris longifolia (14.7%), and Mediomastus sp. (11.5%). The cluster analysis revealed that the study area could be divided into two areas. Each area sustained its specific benthic Polychaete assemblage; Terebellides-Heterogamous assemblage was located in the inner area from Samyang-do, and Lumbrineris-Mediomastus assemblage in the outer area. Lumbrineris-Heterogamous assemblage had higher polychaetous density and species number. Heterogamous sp. was the characteristic species occurring only in Terebellides-Heteromastus assemblage, whereas Mediomastus sp. only in Lumbrineris-Mediomastus assemblage.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.491-507
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• 2010

This study focuses on the fauna, seasonal prevalence and altitudinal distribution of the flies from March to November, 2008 in Mt. Hallasan, Jejudo Island, Korea. The fauna of flies was 39 species belonging to 5 Families which consist of 12 Calliphoridae, 19 Muscidae, 5 Sarcophagidae, 1 Dryomyzidae 1, Scathophagidae and 1 Anthomyiidae. The total number of flies collected was 21,605 with sex ratio of 57.98% in Mt. Halla. The ratio is higher than that of the residential area and other mountain survey sites. The average number of per trap individuals collected on the trapping day is 267, which is similar with the average of Mts. Jiryong, Juwang, Palgong and Gumo. The five dominant species showed a distinctive seasonal prevalence of 92.6% of the total flies: Chrysomyia pinguis (34.2%), Calliphora lata (25.3%), Hydrotaea dentipes(23.1%), Fannia scalaris (5.1%), and Lucilia caesar (4.9%). The seasonal prevalence of the flies was from the beginning of March to the end of November, and the highest peak time of the whole flies, males and females were different respectively. In the similarity index of the flies collected in different altitude, that of between 1,000 meters and 1,500 meters was the highest among the indices of 500 meters and above 1,000 meters. The index at each altitude was above 80% because of the same area. The diversity index of fly species was between 0.00 and 0.88 through altitudinal traps monthly. The highest index in Trap 1 was 0.88 in October, in Trap 2, 0.82 in July and in Trap 3, 0.63 in July. The diversity above 1,000 meters was most various in July. The five dominant species of C. pinguis, C. lata, H dentipes, F. scalaris, and L. caesar showed distinctive seasonal prevalence, relative abundance and altitudinal distribution respectively.

• Ocean and Polar Research
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• v.27 no.2
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• pp.135-148
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• 2005

Macrobeilthic fauna were collected using a van Veen grab $(0.1m^2)$ to investigate the spatial characteristics of the macrobenthos community at 28 stations near the Nakdong River estuary, Southeast Korea, in September 2001. A total of 203 species were sampled with a mean density of $1,554 ind./m^2$ and a biomass of $252.3 gWWt/m^2$. Annelids were the dominant faunal group in terms of species and density, with 68 species and a mean density of $1,031ind./m^2$, which comprised 33.5% and 66.3% of the total benthic animals, respectively. Based on density, three Polychaetes were dominant Tharyx sp· $(420ind./m^2)$, Lumbrineris longifolia $(143ind./m^2)$, and Sternaspis scutata $(118ind./m^2)$, along with a bivalve Theora fragilis $(129 ind./m^2)$. On cluster analysis, the benthic community was classified into four groups based on the species composition: Group-1 occurred in disturbed areas, Group-II in coastal regions, Group-III in central mariculture grounds, and Group-IV offshore. Environmental factors (mean gain size, organic carbon, and depth) were primarily correlated with the macrobenthos community structure. A benthic pollution assessment based on the macrobenthos community structure showed that Group-I and Group-II were located in a coastal area that had been severely disturbed by construction of Busan new port and various pollutants, Group-III was gradually polluted, while offshore Group-IV was the most stable.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.356-362
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• 2007

The rhizobacterial diversity associated with 9 native plant species inhabiting coastal sand dunes in Tae-an area, Chungnam Province, was studied using the denaturing gradient gel electrophoresis (DGGE) fingerprinting analysis over three times from October 2003 to March 2004. One dominant band commonly occurred in all of the rhizosphere samples, which was identified as that of Lysobacter enzymogenes. The other common bands included those derived from species of Pseudomonas and Bacillus. It was notable that L. enzymogenes was dominant in all of the 9 plant species and such dominance was consistent throughout the whole sampling period, which confirms the previous study by Lee et al. (2006a). The Bacillus bands were detected in all of the three samplings, and those of Pseudomonas were notable in the samples of December 2003. By the DGGE analysis alone, the significance of Lysobacter to the sand dune plants is not clear. However, considering their presence in healthy plants and the dominance in all plant species, Lysobacter may have positive roles in the survival or growth of the plants in sand dune area.