• 한국약용작물학회지
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• 제17권1호
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• pp.26-32
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• 2009

The region containing 18S rRNA gene, ITS 1 and part of the 5.8S rRNA gene of the Atractylodes japonica Koidz was amplified by PCR and the product cloned in a pBluescript SK II plasmid. DNA sequence of the cloned DNA was determined and submitted to the GenBank (accession number EU678363). Phylogenetic analysis of the ITS 1 DNA showed close similarity with the other plant species of the family Compositae. The extract of the plant materials of five different members of the family Compositae was analyzed by HPLC to detect atractylon. Extract of the A. japonica Koidz showed presence of significant amount of atractylon. However, noticeable amount of atractylon was not detected by the same analyses from the extracts of the other plants belonging to the family Compositae including Artemisia capillaris, Chrysantemum zawadskii, Eclipta prostrata or Taraxacum platycarpum.

• 한국환경농학회지
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• 제39권1호
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• pp.26-35
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• 2020

BACKGROUND: Microbes that govern a unique biochemical process of oxidizing ammonia into dinitrogen gas, such as anaerobic ammonium oxidation (anammox) have been reported to play a pivotal role in agricultural soils and in oceanic environments. However, limited information for anammox bacterial abundance and distribution in the terrestrial habitats has been known. METHODS AND RESULTS: Phylogenetic and next-generation sequencing analyses of bacterial 16S rRNA gene were performed to examine potential anammox bacteria in paddy soils. Through clone libraries constructed by using the anammox bacteria-specific primers, some clones showed sequence similarities with Planctomycetes (87% to 99%) and anammox bacteria (94% to 95%). Microbial community analysis for the paddy soils by using Illumina Miseq sequencing of 16S rRNA gene at phylum level was dominated by unclassified Bacteria at 33.2 ± 7.6%, followed by Chloroflexi at 20.4 ± 2.0% and Acidobacteria at 17.0 ± 6.5%. Planctomycetes that anammox bacteria are belonged to was 1.5% (± 0.3) on average from the two paddy soils. CONCLUSION: We suggest evidence of anammox bacteria in the paddy soil. In addition to the relatively well-known microbial processes for nitrogen-cycle, anammox can be a potential contributor on the cycle in terrestrial environments such as paddy soils.

• Mycobiology
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• 제48권2호
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• pp.122-132
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• 2020

Citric acid is a commercially valuable organic acid widely used in food, pharmaceutical, and beverage industries. In this study, 260 yeast strains were isolated from soil, bread, juices, and fruits wastes and preliminarily screened using bromocresol green agar plates for their ability to produce organic acids. Overall, 251 yeast isolates showed positive results, with yellow halos surrounding the colonies. Citric acid production by 20 promising isolates was evaluated using both free and immobilized cell techniques. Results showed that citric acid production by immobilized cells (30-40 g/L) was greater than that of freely suspended cells (8-19 g/L). Of the 20 isolates, two (KKU-L42 and KKU-L53) were selected for further analysis based on their citric acid production levels. Immobilized KKU-L42 cells had a higher citric acid production rate (62.5%), while immobilized KKU-L53 cells showed an ~52.2% increase in citric acid production compared with free cells. The two isolates were accurately identified by amplification and sequence analysis of the 26S rRNA gene D1/D2 domain, with GenBank-based sequence comparison confirming that isolates KKU-L42 and KKU-L53 were Candida tropicalis and Pichia kluyveri, respectively. Several factors, including fermentation period, pH, temperature, and carbon and nitrogen source, were optimized for enhanced production of citric acid by both isolates. Maximum production was achieved at fermentation period of 5 days at pH 5.0 with glucose as a carbon source by both isolates. The optimum incubation temperature for citric acid production by C. tropicalis was 32 ℃, with NH₄Cl the best nitrogen source, while maximum citric acid by P. kluyveri was observed at 27 ℃ with (NH₄)₂ SO₄ as the nitrogen source. Citric acid production was maintained for about four repeated batches over a period of 20 days. Our results suggest that apple and banana wastes are potential sources of novel yeast strains; C. tropicalis and P. kluyveri which could be used for commercial citric acid production.

• 생명과학회지
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• 제18권12호
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• pp.1723-1727
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• 2008

클로렐라의 생리활성 물질을 활용하여 기능성 식품을 개발하기 위한 기초 자료를 얻기 위하여 클로렐라 배양장에서 생육이 빠른 클로렐라를 분리하여 동정하고 이화학적 특성을 조사하였다. 분리된 클로렐라는 전형적인 둥근 모양과 $3{\mu}m$ 크기로 주름진 형태를 취하고 있었다. 분리된 클로렐라의 동정을 위하여 18S rRNA sequences를 실시한 결과 Chlorella sp. IFRPD 1018와 99%의 높은 상동성을 보여 Chlorella sp.와 거의 일치하여 Chlorella sp. CMS-1로 명명하였다. 클로렐라 열수 추출물에 조단백질 함량이 59.21%로 많이 함유되어 있었고, 조지방 함량은 0.01%로 미량 함유되어 있었다. 클로렐라 CMS-1의 무기질 농도는 K 2.52%, P 2.25%, Mg 0.63%, Ca 0.63% 순으로 함유되어 있었다. 클로렐라 CMS-1의 주요 구성 아미노산은 glutamic acid 6.21%, alanine 5.76%, aspartic acid 5.44% 순이였으며, 특히 유리아미노산 중 ${\gamma}$-aminobutyric acid (GABA)의 함량은 7.13%로 전체 유리아미노산의 63.8% 비율로 차지하였고 그 다음으로 L-alanine 1.44%, L-glutamic acid 0.90%, L-leucine 0.26%, L-glycine 0.20% 순으로 함유되어 있었다.

• 생명과학회지
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• 제29권2호
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• pp.248-255
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• 2019

국내 삼천포 및 서천에서 채집한 갯장어(Muraenesox cinereus)의 장내기관으로부터 분리된 미생물들의 다양성 및 특성에 관하여 조사하였다. 장내 미생물의 순수 분리를 위하여 marine agar 배지를 사용하였으며 $37^{\circ}C$에서 호기적으로 배양하였다. 순수 분리 후, 49 균주를 분리하였으며 16S rRNA 염기서열 분석 결과를 바탕으로 계통학적 분석을 실시한 결과, 3문, 13과, 14속, 34종으로 구성되어 있는 것을 확인하였다. 특히, Proteobacteria 문은 83.7%의 분포를 나타내었으며 8과, 8속, 26종으로 Aeromonadaceae, Pseudoalteromonadaceae, Shewanellaceae, Enterobacteriaceae, Morganellaceae, Moraxellaceae, Pseudomonadaceae와 Vibrionaceae로 분포하는 것을 확인하였다. 그리고 분리한 균주들이 amylase, lipase, protease와 같은 산업적으로 유용한 효소를 생산하는지 확인하기 위하여 효소 활성 평가를 실시하였으며, 39 균주가 최소 한 종류 이상의 효소 활성을 가지고 있는 것을 확인하였다. 특히 Aeromonas 속의 균주들은 테스트한 모든 효소의 활성을 나타내는 것을 확인하였다. 이러한 결과는 본 연구를 통하여 분리한 미생물들의 산업적 활용 가능성을 나타내었다. 그러므로 이번 연구는 국내 유전자원 확보 및 갯장어의 장내마이크로비옴의 과학적 지식 확장에 도움이 될 것으로 생각된다.