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Volume 46 (2010)
- Issue 4 Pages 161-
- Issue 3 Pages 119-
- Issue 2 Pages 71-
- Issue 1 Pages 1-
Volume 46, Issue 3
Displaying 1-5 of 5 articles from this issue
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ORIGINALS
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KEN SASAKI, CHIHIRO HARA, KENJI TAKENO, HIROSHI OKUHATA, HITOSHI MIYAS ...Article type: ORIGINALS
2010 Volume 46 Issue 3 Pages 119-127
Published: 2010
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSRemoval of metals related to radionuclides (Sr, U) and heavy metals (Co, Cu, Hg, Cr and As) present in aqueous solutions using photosynthetic bacteria immobilized porous ceramic, which can be recovered with an electromagnet, were carried out under aerobic dark condition. Among the photosynthetic bacteria tested, Rhodobacter sphaeroides SSI showed the highest removal activity for such metals with immobilized ceramic. The percentage of removal of 20 mg/l of Sr, Co and U were as high as 82%, 58 and 95, respectively after 6 days of treatment. The COD and phosphate present in the aqueous solution were simultaneously removed at high efficiency of over 90%. With a pure culture system, strain SSI can adsorb 98% of U on and/or in the cells from culture liquid during 6 days of aerobic growth. These pieces of immobilized porous ceramic could also remove Cu, Hg, Cr and As in the same system.View full abstractDownload PDF (3164K) -
HIROAKI MATSUZAWA, YASUHIRO TANAKA, KAZUHIRO MORIArticle type: ORIGINALS
2010 Volume 46 Issue 3 Pages 129-136
Published: 2010
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSRhizoremediation, one of phytoremediation strategy, restores polluted site using collaborating interactions between plants and rhizosphere microbes. In order to enhance the remediation activity, many researches to introduce pollutant-degrading microbes into rhizosphere have been extensively implemented. Most of the researches have been targeting the terrestrial plants, while there is a little information about that in aquatic plants. In present study, 11 strains derived from the rhizosphere of giant duckweed (Spirodela polyrrhiza) were used, and we aimed to screen suitable microbes for introduction into rhizosphere of S. polyrrhiza in terms of root periphytic property and rhizosphere survivability. We investigated which microbes could attach tightly to the roots and dominate in microbial community of 11 strains inhabiting the rhizosphere of sterilized S. polyrrhiza. As a result, Asticcacaulis sp. strain RS59G dominated in the microbial community of 11 strains, and the strain had high root periphytic property. Survivability of 3 strains in the rhizosphere of S. polyrrhiza was evaluated using recombinants of the each strain in the presence of competition between the recombinants and environmental microbes. All of the recombinants inhabited stably in the rhizosphere of S. polyrrhiza, and Asticcacaulis sp. strain RS59G maintained large population in the rhizosphere for 3 days. These results suggest that introduction of pollutant-degrading microbes into rhizosphere of aquatic plants could be promising strategy for aquatic environmental purification.View full abstractDownload PDF (2127K) -
DAISUKE INOUE, NAOKI NOMOTO, KAZUNARI SEI, SATOSHI SODA, MICHIHIKO IKEArticle type: ORIGINALS
2010 Volume 46 Issue 3 Pages 137-144
Published: 2010
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSTo evaluate the biodegradation potential of bisphenol A (BPA) and bisphenol F (BPF) in the seawater environment, biodegradation tests of these compounds were performed using seawater microbes obtained from various parts of Japan. BPA was biodegraded in 7 out of 11 seawater samples, and BPF was biodegraded in 4 out of 5 seawater samples, suggesting that biodegradation potentials of BPA and BPF distribute widely in the seawater environment. Multiple metabolites appeared during the biodegradation of BPA and BPF, and some of them seemed to be different from those detected in the biodegradation by previously reported BPA－ and BPF－degrading bacteria. Thus, biodegradation pathways of BPA and BPF by seawater microbes may include novel ones that are distinct from already－known pathways. Although 30 bacterial strains were isolated from enrichment cultures constructed from seawater samples with BPA biodegradation potential, none exhibited BPA－degrading ability. Similarly, only 2 of 19 strains isolated from enrichment cultures from seawater samples with BPF biodegradation potential showed BPF－degrading ability. Thus, most of BPA－ and BPF－degrading microbes in seawater may require certain nutrients or symbiotic relationship with other microbes for their growth on BPA and BPF, respectively. However, 2 BPF－degrading isolates included both gram－positive and gram－negative bacteria, suggesting the presence of taxonomically－diverse BPF－degrading bacteria in the seawater environment.View full abstractDownload PDF (1206K) -
ZHIGANG LI, YONGGUANG MA, LI ZHANG, JIACHUN YANG, DAISUKE HIRA, TAKAO ...Article type: ORIGINALS
2010 Volume 46 Issue 3 Pages 145-153
Published: 2010
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSThe characteristics of granular anammox sludge were studied through long-term continuous cultivation in a stirred tank reactor. The reactor was operated steadily with stirring speeds of 70–120 rpm. A maximum nitrogen loading rate of 9.52 kg/m3/d was obtained after 318 days of continuous treatment. The particle size of anammox granules ranged primarily from 2.0–4.0 mm, the wet density was 1.04 g/ml, and the settling velocity was 152.7 m/h, indicating satisfactory settling of the granules. The sludge contained high amounts of organic matter with a volatile to total solids mass percent of 0.91. Observations by scanning electron and stereo microscopy showed that the anammox granules were relatively regular in shape and had a very clear outline. Furthermore, the bacterial composition of the mature community was investigated by amplifying the 16S rRNA sequences by PCR. Results showed that Planctomycete KSU–1 was dominant in the reactor and played a significant role in the anammox process.View full abstractDownload PDF (3781K)
NOTE
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TAKANORI FUJIMOTO, TOSHIHIRO KOBORI, TAKASHI MIZOGUCHI, KEITARO WATANA ...Article type: NOTES
2010 Volume 46 Issue 3 Pages 155-159
Published: 2010
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSBiogradation of solubilized supernatant with high speed mixer and alkaline solution was investigated using activated sludge. Protein profiles and biodegradation rate were investigated on the various solubilized supernatant with different alkaline concentration. Biodegradation by activated sludge was increased with increase of alkaline concentration. Large amount of proteins was analyzed by lowry method compared with those of Bradford method due to the no reaction to low molecule protein of less than 10 KDa in Bradford method. Biodegradation might be effected by the protein concentration and low molecule of protein of less than 10 KDa.View full abstractDownload PDF (1209K)
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