13:45 〜 14:08
[MIS14-01] 海洋微生物によるセレン化鉛微粒子の合成
★招待講演
キーワード：バイオミネラリゼーション、セレン、生物産生ナノ微粒子
Calchogenic element distributing widely in biological components and biospheres. Furthermore, Se is also an essential element as a nutrient to maintain bioactivities of animals and microorganisms. So far, many specific biological processes regarding selenium metabolisms have been found in various organisms. Microbes also have the specific dissimilative pathway on anaerobic respiration of selenium oxyanions as terminal electron acceptor for growth [1]. Other hands, it is reported that several microorganisms can aerobically reduce selenium oxyanions into elemental selenium without using anaerobic respiration metabolism. Such microorganisms are expected to be able to utilize to the selenium bioremediation, biofabrication and biomineralization. . In this study, we report the isolation and characterization of a marine Shewanella sp. strain KND-1, capable of growing aerobically by selenium oxyanion reduction Moreover, synthesis of PbSe semi-conductive nano-spheres by the selenium reduction of strain KND-1 under anaerobic condition has been attempted.
Marine fishes inhabiting the sand mud sea bottom where is deeper than depth of the water 70 m, were harvested by a trawl fishing in East China sea. Strain KND-1, which was isolated from the intestines of a searobin, was able to grow both aerobically and anaerobically in marine broth with generating red precipitations by elemental selenium formation due to the selenate reduction. The phylogenetic analysis showed strain KND-1 belongs in genus Shewanella. TEM observation and EDS analysis of the biogenic nano-spheres demonstrated that strain KND-1 could synthesize amorphous nano-depositions that contained Se and metal such as Pb, Co and Ni by incubating the cells under selenate and heavy metal anion co-existing condition. In particular, well-crystallized nanospheres that are comprised of selenium and lead of the almost same amount were synthesized by the biological process. These results suggested that our isolate is a probable candidate for synthesis of Se and metal contained semi-conductive particles.
[1] R. S. Oremland, J. T. Hollibaugh, A. S. Maest, T. S. Presser, L. G. Miller and C. W. Culbertson, Appl. Environ. Microbiol., 55(9), 2333–2343, 1989.
Acknowledgement
This work was supported by the JSPS for financial supports of challenging Exploratory Research (subject number:15K13352) and JSPS KAKENHI Grant Number 21K18911.
Marine fishes inhabiting the sand mud sea bottom where is deeper than depth of the water 70 m, were harvested by a trawl fishing in East China sea. Strain KND-1, which was isolated from the intestines of a searobin, was able to grow both aerobically and anaerobically in marine broth with generating red precipitations by elemental selenium formation due to the selenate reduction. The phylogenetic analysis showed strain KND-1 belongs in genus Shewanella. TEM observation and EDS analysis of the biogenic nano-spheres demonstrated that strain KND-1 could synthesize amorphous nano-depositions that contained Se and metal such as Pb, Co and Ni by incubating the cells under selenate and heavy metal anion co-existing condition. In particular, well-crystallized nanospheres that are comprised of selenium and lead of the almost same amount were synthesized by the biological process. These results suggested that our isolate is a probable candidate for synthesis of Se and metal contained semi-conductive particles.
[1] R. S. Oremland, J. T. Hollibaugh, A. S. Maest, T. S. Presser, L. G. Miller and C. W. Culbertson, Appl. Environ. Microbiol., 55(9), 2333–2343, 1989.
Acknowledgement
This work was supported by the JSPS for financial supports of challenging Exploratory Research (subject number:15K13352) and JSPS KAKENHI Grant Number 21K18911.