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Yuanyuan Zhang Masashi Kuroda Shunsuke Arai Fumitaka Kato Daisuke Inoue Michihiko Ike 《Frontiers of Environmental Science & Engineering》2019,13(5):68
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eransk Slavomr Urk Martin evc Jaroslav Khun Miloslav 《Environmental science and pollution research international》2007,14(1):31-35
Goal, Scope and Background
The aim of this work is to show the ability of several fungal species, isolated from arsenic polluted soils, to biosorb and volatilize arsenic from a liquid medium under laboratory conditions. Mechanisms of biosorption and biovolatilization play an important role in the biogeochemical cycle of arsenic in the environment. The quantification of production of volatile arsenicals is discussed in this article.Methods
Heat-resistant filamentous fungi Neosartorya fischeri, Talaromyces wortmannii, T. flavus, Eupenicillium cinnamopurpureum, originally isolated from sediments highly contaminated with arsenic (more than 1403 mg.l-1 of arsenic), and the non-heat-resistant fungus Aspergillus niger were cultivated in 40 mL liquid Sabouraud medium (SAB) enriched by 0.05, 0.25, 1.0 or 2.5 mg of inorganic arsenic (H3AsO4). After 30-day and 90-day cultivation under laboratory conditions, the total arsenic content was determined in mycelium and SAB medium using the HG AAS analytical method. Production of volatile arsenic derivates by the Neosartorya fischeri strain was also determined directly by hourly sorption using the sorbent Anasorb CSC (USA).Results
Filamentous fungi volatilized 0.025–0.321 mg of arsenic from the cultivation system, on average, depending on arsenic concentrations and fungal species. The loss of arsenic was calculated indirectly by determining the sum of arsenic content in the mycelium and culture medium. The amount of arsenic captured on sorption material was 35.7 ng of arsenic (22nd day of cultivation) and 56.4 ng of arsenic (29th day of cultivation) after one hour's sorption. Biosorption of arsenic by two types of fungal biomass was also discussed, and the biosorption capacity for arsenic of pelletized and compact biomass of Neosartorya fischeri was on average 0.388 mg and 0.783 mg of arsenic, respectively.Discussion
The biosorption and amount of volatilized arsenic for each fungal species was evaluated and the effect of initial pH on the biovolatilization of arsenic was discussed.Conclusions
The most effective biovolatilization of arsenic was observed in the heat-resistant Neosartorya fischeri strain, while biotransformation of arsenic into volatile derivates was approximately two times lower for the non-heat-resistant Aspergillus niger strain. Biovolatilization of arsenic by Talaromyces wortmannii, T. flavus, Eupenicillium cinnamopurpureum was negligible. Results from biosorption experiments indicate that nearly all of an uptaken arsenic by Neosartorya fischeri was transformed into volatile derivates.Recommendations and Perspective
. Biovolatilization and biosorption have a great potential for bioremediation of contaminated localities. However, results showed that not all fungal species are effective in the removal of arsenic. Thus, more work in this research area is needed.3.
In Rhodopseudomonas palustris, an arsM gene, encoding bacterial and archaeal homologues of the mammalian Cyt19 As(III)
S-adenosylmethionine methytransferase, was regulated by arsenicals. An expression of arsM was introduced into strains for the
methylation of arsenic. When arsM was expressed in Sphingomonas desiccabilis and Bacillus idriensis, it had 10 folds increase
of methyled arsenic gas compared to wild type in aqueous system. In soil system, about 2.2%–4.5% of arsenic was removed by
biovolatilization during 30 days. This study demonstrated that arsenic could be removed through volatilization from the contaminated
soil by bacteria which have arsM gene expressed. These results showed that it is possible to use microorganisms expressing arsM as an
inexpensive, efficient strategy for arsenic bioremediation from contaminated water and soil. 相似文献
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