• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.504-507
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• 2001

The partial 16S gene sequences of six filamentous cyanobacterial strains, Oscillatoria lmosa KCTC AG10168, Oscillatoria princeps KCTC AG10153, Oscillatoria sp. KCTC AG 10184, Phormidium tenue KCTC AG10158, Phormidium parchydematicum KCTC AG10164, and Lyngbya hieronymusii KCTC AG10199, which were isolated in the late summer at Daecheong Reservoirs, were determined and assigned their phylogenetic and taxonomic position among taxa of order Ocillatoriales whose partial 16S rRNA gene sequences aligned in this suty, were very heterogeneously clustered with other taxa. The two strains, Oscillatoria limosa KCTC AG10168 and O. princeps KCTC AG10153, formed a cluster with O. sancta PCC7515, which supported 64% of the bootstrap trees with high similarity (19-96.15%). Strain Oscillatoria sp. KCTC AG10184, that was known to produce a nasty substance, was closely related to the toxic Oscillatoria group. The study on morphological variation in various environments and toxin production will confirm the taxonomic status of these species. Phormidium tenus KCTC AG10158 and Phormidium parchydematicum KCTC AG10164 made a cluster with other oscillatorian species of Phormidium, Oscillatoria, and Leptolynbya, which supproted 100% of the bootstrap trees with a very high sequence smilarity (96.8-99.8%) in thsi study. The sequence analysis in this study also supported that taxa of oscillatoriales are not monophyletic. Some of the fractures, such as the presence or absence of sheath and cell shape, which were used to define them, would be inadequate and should be reconfirmed. We suggest that sequences of partial 16S rRNA gene fragments aligned in this study should be more useful than morphological features in the identification and reconfirmation of the taxonomic status of these oscillactorian cyanobacteria.

• 한국물환경학회지
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• 제38권6호
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• pp.282-291
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• 2022

Since the efficiency of wastewater treatment using microalgae differs depending on the metabolic characteristics of the species, it is important to understand the characteristics of target algae prior to the application in wastewater treatment. In this study, for the application of Arthrospira platensis to wastewater treatment, which is a filamentous alkaliphilic cyanobacteria, basic species specificity was identified and the possibility of application to wastewater treatment was investigated. As a result of the species specificity investigation, the specific growth rate between pH 7.0 and 11.0 showed the highest value near pH 9 at 0.25/day. The reason for the relatively low growth(0.08/day) at pH 11 was thought to be the CA(carbonic anhydrase) enzyme that is involved in carbon fixation during photosynthesis has the highest activity at pH 8.0 to 9.0, and at pH 11, CA activity was relatively low. In addition, A. platensis showed optimal growth at 400 PPFD(photosynthetic photon flux density) and 30℃, and this means that cyanobacteria such as A. platensis have a larger number of PS-I(photosystem I) than that of PS-II(photosystem II). It was speculated that it was because higher light intensity and temperature were required to sufficiently generate electrons to transfer to PS-I. Regarding the applicability of A. platensis, it was suggested that if a system using the synergistic effect of co-culture of A. platensis and bacteria was developed, a more efficient system would be possible. And different from single cocci, filamentous A. platensis expected to have a positive impact on harvesting, which is very important in the latter part of the wastewater treatment process.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.199-205
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• 2002

활주운동은 편모의 작용없이 고체의 표면을 미끄러지듯이 이동하는 박테리아의 운동방식으로 분류학상 다양한 종의 박테리아에서 발견된다. 지금까지 밝혀진 바에 의하면 활주 운동은 type IV pili(Tfp)를 필요로 하는 경우와 이를 필요로 하지 않는 두 가지로 크게 구분될 수 있는데, Tfp를 필요로 하는 경우에는 T룰의 확장과 수축에 의해 이루어지는 twitching motility와 운동기작이 흡사할 것으로 추정된다 Tfp를 필요로 하지 않는 활주운동에 대해서는 여러 다양한 모델이 제시되었는데, 이중 한 모델은 활주박테리아가 점액을 분출함으로서 추진력을 얻어 앞으로 진행한다는 설명이며, 다른 모델들은 외벽에 세포 전체를 감싸는 운동기구가 존재한다는 것이다. 이와 같이 활주운동은 일반적으로 잘 알려진 편모에 의한 운동과는 전혀 다른 운동방식에 의해 이루어지는데, 그 작용 기작이 매우 흥미로운 반면에 많은 부분들이 풀어야 될 숙제로 남아있어 앞으로의 연구결과들이 기대된다.

• Journal of Ecology and Environment
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• 제40권1호
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• pp.66-74
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• 2016

Background: When developing water quality improvement strategies for eutrophic lakes, questions may arise about the relative importance of point sources and nonpoint sources of phosphorus. For example, there is some skepticism regarding the effectiveness of partial reductions in phosphorus loading; because phosphorus concentrations are too high in hypertrophic lakes, in-lake phosphorus concentrations might still remain within typical range for eutrophic lakes even after the reduction of phosphorus loading. For this study, water quality and the phytoplankton and zooplankton communities were monitored in a hypertrophic reservoir (Lake Wangsong) before and after the reduction of phosphorus loading from a point source (a sewage treatment plant) by the installation of a chemical phosphorus-removal process. Results: Before phosphorus removal, Lake Wangsong was classified as hypertrophic with a median phosphorus concentration of $0.232mg\;L^{-1}$ and a median chlorophyll-a concentration of $112mg\;L^{-1}$. The dominant phytoplankton were filamentous cyanobacteria for the most of the ice-free season. Following the installation of the advanced treatment process, phosphorus concentrations were reduced to $81mg\;L^{-1}$, and the N/P atomic ratio increased from 42 to 102. Chlorophyll-a concentrations decreased to $42{\mu}g\;L^{-1}$, and the duration of cyanobacterial dominance was confined to the summer season. Cyanobacteria in spring and autumn were replaced by diatoms and cryptomonads. Filamentous cyanobacteria in summer were replaced by colony-forming unicellular Microcystis spp. It was remarkable that zooplankton biomass increased despite the decrease in phytoplankton biomass, and especially cladoceran zooplankton which increased drastically. These responses to the reduction of point source P loading to Lake Wangsong imply that reducing the point source P loading can have a big impact even when nonpoint sources account for a large fraction of the total annual phosphorus loading. Conclusions: Our results also show that the phytoplankton community can shift to decreased cyanobacterial dominance and the zooplankton community can shift to higher cladoceran dominance, even when phosphorus concentrations remain within the typical range for eutrophic lakes following the reduction of phosphorus loading.

• 생명과학회지
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• 제26권10호
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• pp.1202-1206
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• 2016

Subsection I과 II의 시아노박테리아 균주들은 단세포성이며, Subsection III의 시아노박테리아 균주들은 섬유상의 다계통성, 이형 사이토시스 형성성 균주들인 반면, Subsections IV와 V는 단일계통성으로 보고되어있다. 본 연구에서 13 균주의 시아노박테리아의 the small subunit rRNA (16S rRNA) 염기서열들이 - Subsection III의 Oscillatoria nigro-viridis PCC7112, Subsection IV에 속하는 Anabaena, Nostoc, Tolypothrix, Calothrix 및 Scytonema속을 포함한 6 균주, Subsection V에 속하는 Hapalosiphon, Fischerella and Chlorogloeopsis 속의 6 균주 - 결정되었다. 결정된 16S rRNA 염기서열을 이용하여 시아노박테리아의 분자계통분석을 수행하였다. 그러나, 16S rRNA의 염기서열 결정을 근거로 한 본 연구의 계통분석결과 Subsection IV는 단일 계통성이 아닌 다계통성이며, 반면 Subsection V는 이전에 보고되어진 것처럼 단일 계통성임을 나타내었다. 또한, 본 연구 결과는 Scytonema속이 이형 사이토시스 형성성 시아노박테리아인 Subsection IV 및 V의 공통 조상일 수 있음을 강력하게 나타낸다. 부가적으로, 본 연구의 분자계통 분석을 통해 Anabaena속은 다계통성으로 계통학적으로 다양한 종들로 구성되어 있음을 나타내고 있다. 본 연구 결과는 Anabaena속이 좀 더 세밀하게 재분류 되어져야 함을 나타낸다.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.205-214
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• 2020

남세균은 수계나 토양 생태계에서 질소 고정 능력으로 인해 질소순환 과정에 중요한 역할을 하는 미생물로 다양한 산업분야에서 활용될 수 있는 유용 물질을 생산할 수 있다. 또한 일부 종은 수생태계에서 유해조류 번성을 일으켜 수자원의 이용을 제한한다. 일반적으로 생물소재은행은 관련 연구를 위해 남세균 배양주를 제공하는 역할을 한다. 하지만 국내 생물소재은행에서는 남세균의 체계적인 보존이 미비한 실정이다. 본 연구에서는 국내에서 분리한 Trichormus variabilis (syn. Anabaena variabilis)를 대상으로 알긴산 마이크로캡슐을 이용한 동결보존기술을 개발하였다. 동결보존제만 사용하는 일반 동결보존법과 세포를 마이크로캡슐에 포집한 후 동결보존제를 혼합하는 두 가지 방법으로 실험을 수행하였고 각각의 효율을 비교하였다. T. variabilis 동결보존 후 35일간 재배양하여 세포수를 비교한 결과 두 가지 동결보존법 모두 재생에 성공하였으며, 초기 농도 1.0 × 10⁵ cells에서 마이크로캡슐 방법은 6.7 × 10⁶ cells로, 일반 동결 보존법은 1.1 × 10⁷ cells로 증가되었다. 또한 배양 14일 후 T. variabilis 세포의 부정형 형태를 발견하였다. 세포 소기관을 관찰하기 위해 투과전자현미경(TEM) 분석을 하였고 lacunae와 lipid body의 크기가 줄어든 것을 확인하였다. 세포 형태와 관련된 mreB 유전자가 동결보존 전에 비해 동결 보존 후 발현량이 54.7%로 감소된 것을 확인하였다. 본 연구결과를 통해 향후 사상성 남조류에 대하여 보존제와 마이크로캡슐을 이용한 동결보존이 가능할 것으로 기대된다.

• 환경생물
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• 제35권3호
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• pp.296-304
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• 2017

Samples were collected between August 2016 and May 2017 at Sangju-si, Gyeongsangbuk-do, Jeju-do, and Uljin-gun, Gangwon-do. As a result, one genus and six species were newly recorded in Korea. The unrecorded indigenous genus was Borzia, and the six species were Anagnostidinema acutissimum, Komvophoron bourrellyi, Hydrocoleum stankovicii, Borzia trilocularis, Phormidium tinctorium and Pseudanabaena lohchoides. Phormidium tinctorium and Pseudanabaena lohchoides had been reported to inhabit freshwater, but in this study, these were found in brackish water. It had also been reported that B. trilocularis trichomes are composed of up to 8 cells, but in this study, a maximum of 10 cells was observed.

• ALGAE
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• 제33권4호
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• pp.291-304
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• 2018

Lyngbya C. Agardh ex Gomont is a nonheterocytous cyanobacterial genus whose evolutionary history is still poorly known. The traditionally defined Lyngbya has been demonstrated to be polyphyletic, including at least five distinct clades, some of which have been proposed as new genera. Intraspecific diversity is also clearly underestimated in Lyngbya due to the lack of unique morphological characters to differentiate species. In this study, we describe the new genus Capillus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes from benthic marine environments, including two new Brazilian species (here described as C. salinus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes, and C. tropicalis T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes), and two species yet to be described, one of them from India (Capillus sp. 2.1), and the other from United States of America, based on strain PCC 7419. Capillus species presented cross-wise diagonal fragmentation, assisted or not by necridic cells, which has not been previously mentioned for Lyngbya. Ultrastructural analyses showed that C. salinus and C. tropicalis have numerous gas vesicles, which are rarely described for benthic marine species. The new genus formed a well-supported clade, and the D1-D1' and Box B secondary structures of internal transcribed spacer also supported the proposal of its new species. These findings help to clarify the diversity of species in the Lyngbya complex and the taxonomy of the group, and highlight the need of further floristic surveys in tropical coastal environments, which remain poorly studied.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.645-658
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• 2021

Porins are essential for the viability of Gram-negative bacteria. They ensure the uptake of nutrients, can be involved in the maintenance of outer membrane integrity and define the antibiotic or drug resistance of organisms. The function and structure of porins in proteobacteria is well described, while their function in photoautotrophic cyanobacteria has not been systematically explored. We compared the domain architecture of nine putative porins in the filamentous cyanobacterium Anabaena sp. PCC 7120 and analyzed the seven candidates with predicted OprB-domain. Single recombinant mutants of the seven genes were created and their growth capacity under different conditions was analyzed. Most of the putative porins seem to be involved in the transport of salt and copper, as respective mutants were resistant to elevated concentrations of these substances. In turn, only the mutant of alr2231 was less sensitive to elevated zinc concentrations, while mutants of alr0834, alr4741 and all4499 were resistant to high manganese concentrations. Notably the mutant of alr4550 shows a high sensitivity against harmful compounds, which is indicative for a function related to the maintenance of outer membrane integrity. Moreover, the mutant of all5191 exhibited a phenotype which suggests either a higher nitrate demand or an inefficient nitrogen fixation. The dependency of porin membrane insertion on Omp85 proteins was tested exemplarily for Alr4550, and an enhanced aggregation of Alr4550 was observed in two omp85 mutants. The comparative analysis of porin mutants suggests that the proteins in parts perform distinct functions related to envelope integrity and solute uptake.

• Membrane and Water Treatment
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• 제15권1호
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• pp.11-19
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• 2024

This study presents the characteristics of growth and morphology of Anabaena sp., a representative filamentous cyanobacterium, depending on temperature variation from 10 to 30 ℃. Both the filament density (or number) and its length of Anabaena were highly affected by temperature, as well as growth stage. Rapid growth at a higher temperature led to an increase in Anabaena filament density, as well as optical density at 680 nm (OD₆₈₀). However, the number of vegetative cells within a single filament of Anabaena grown at 30 ℃ was smaller than those grown at lower temperatures, due to the intercalary division of the filament. Of the three different cells comprising a single Anabaena filament, the vegetative cell marginally affects the growth of Anabaena. The main dimensions of the vegetative cell, i.e., length and width, depend on the temperature and growth stage. The length-to-width (L/W) ratios of vegetative cells and akinetes were relatively consistent regardless of the temperature. However, in vegetative cells with dichotomous growth, the L/W ratio shows clear differences depending on their growth stage. It has been demonstrated that the L/W ratio could be used as an indicator to indirectly predict the growth stage of on-sit Anabaena samples.