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Sasidhorn Innok Masatoshi Matsumura Nantakorn Boonkerd Neung Teaumroong 《World journal of microbiology & biotechnology》2005,21(8-9):1559-1568
Summary Microcystis, which are toxic microcystin-producing cyanobacteria, normally bloom in summer and drop in numbers during the winter season
in Senba Lake, Japan. Recently, this lake has been treated by ultrasonic radiation and jet circulation which were integrated
with flushing with river water. This treatment was most likely sufficient for the destruction of cyanobacterial gas vacuoles.
In order to confirm whether Microcystis viridis was still present, a molecular genetic monitoring technique on the basis of DNA direct extraction from the sediment was applied.
Three primer sets were used for polymerase chain reaction (PCR) based on rRNA intergenic spacer analysis (RISA), the DNA dependent
RNA polymerase (rpoC1) and a Microcystis sp.-specific rpoC1 fragment. The results from each primer were demonstrated on the basis of single strand conformation polymorphisms (SSCP).
Using the RISA primer showed different results from the rpoC1 and Microcystis sp.-specific rpoC1 fragment; meanwhile, the rpoC1 Microcystis sp.-specific fragment was more specific than the RISA primer. Therefore, the Microcystis sp.-specific rpoC1 fragment was further analysed by denaturing gradient gel electrophoresis (DGGE). The DNA pattern representing M. viridis could not be detected in any of the sediment samples. However, the results were confirmed with another technique, terminal
restriction fragment length polymorphisms (T-RFLP). Although T-RFLP patterns of 16S rDNA in sediment at 91 bp and 477 bp lengths
were matched with the T-RFLP of M. viridis (HhaI and MspI endonuclease digestion, respectively), the T-RFLP pattern of 75 bp length was not matched with M. viridis (both of HhaI and MspI endonuclease digestion) which were the major T-RFLP pattern of M. viridis. Therefore, the results most likely indicated that M. viridis seems to have disappeared because of the addition of the ultrasonic radiation and jet circulation to the flushing treatment. 相似文献
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Teaumroong Neung Innok Sasidhorn Chunleuchanon Somporn Boonkerd Nantakorn 《World journal of microbiology & biotechnology》2002,18(7):673-682
The diversity among 853 isolates of nitrogen-fixing cyanobacteria obtained from soil samples collected from different ecosystems including mountainous, forest and cultivated areas in the central, northern and northeastern regions of Thailand was examined. Most isolates showed slow growth rate and had filamentous, heterocystous cells. The percentage of heterocysts in the filaments of different isolates varied from 8.3 to 9.6. Only a few strains showed high nitrogen-fixing potential, while most of the strains exhibited low capacity for nitrogen fixation. Anabaena and Nostoc were the dominant genera among these isolates. One hundred and two isolates were randomly selected from this diverse collection to determine the extent of genetic diversity on the basis of DNA fingerprinting using the PCR method. Based on the PCR products obtained by using a combination of three primers, all strains could be distinguished from one another. When a subset of 45 isolates of Nostoc and a subset of 44 isolates of Anabaena were further analysed by PCR, a wide range of diversity was observed within each of these genera. 相似文献
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Cyanobacterial akinete induction and its application as biofertilizer for rice cultivation 总被引:1,自引:0,他引:1
Sasidhorn Innok Somporn Chunleuchanon Nantakorn Boonkerd Neung Teaumroong 《Journal of applied phycology》2009,21(6):737-744
Nostoc sp. VICCR1-1 was induced in order to form akinetes on the basis of nutrient modification. Phosphorus and iron were found
to be the critical for akinete differentiation, especially when both elements were omitted. The number of akinete cells increased
up to 20% when compared with culturing in BG110 medium (without N source). In addition, CaCl2 played a role in heterocyst differentiation, and was able to induce heterocyst ranging between 30% and 46%. In order to prepare
akinetes as inoculum, the dried form of akinetes was prepared by mixing it with montmorillonite clay. The inoculum with the
amount of 2.8 × 106 cells m−2 was applied to rice (Oryza sativa) fields. After harvesting, the grain yields from chemical N fertilizer, vegetative cells, and akinete inoculum treatments
were not significantly different. To monitor the persistence of Nostoc sp. VICCR1-1 after harvesting, the most probable number-denaturing gradient gel electrophoresis technique using 16S rRNA
gene was employed. The results indicated that the remaining population is at 2.5 × 105 and 1.62 × 106 cells m−2 in treatments supplied with vegetative cells and akinete inocula, respectively. Akinete induction might be one of the appropriate
approaches for producing cyanobacterial inoculum. 相似文献
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