AUTHORS: Kiwamu Shiiba, Ryotaro Matsui, Yasuyuki Kamata, Tomoko Abe

Download as PDF

ABSTRACT: Microbes capable of degrading pollutant such as 1,4-dioxane were selected from the seawater samples of four coastal areas of Okinawa located in the most southern islands of Japan using the developed method and a seawater-charcoal perfusion apparatus. Specifically, aerobic culture in the apparatus led to the selection of candidate 1,4-dioxane degraders. Among these, strain RM-31 and KY-3 exhibited the strongest 1,4-dioxane degradation ability. 16S rDNA sequencing and the similarity analysis of strain RM-31 and KY-3 suggested that this organism was most closely related to Pseudonocardia carboxydivorans and Rhodococcus erythropolis respectively. These species are similar to Pseudonocardia and Rhodococcus spp. which has previously been reported as a 1,4-dioxane degrader. However, it was probably first bacteria from the seawater that can exert a strong degrading ability. The biodegradation rate of 1,4-dioxane by these strains at 25°C in broth medium with 3% NaCl was almost 20% faster than that without NaCl. PCR amplification test indicated that isolated strains had the SDIMO (soluble di-iron monooxygenase) ɑ-subunit gene.

KEYWORDS: 1,4-dioxane, degrading microbe, seawater-charcoal perfusion apparatus, Psedonocardia, Rhodococcus, hydrophilic interaction chromatography, soluble di-iron monooxygenase

REFERENCES:

[1] S. Mahendra and LA. Cohen, Pseudonocardia dioxanivorans sp. Nov., a novel actinomycete that grows on 1,4-dioxane. Int. J. Sys. Evol. Microbiol., 55, 2005, pp. 593-598.

[2] A. Grostern, CM. Sales, WQ. Zhuang, O. Erbilgin, LA. Cohen, Glyoxylate metabolism is a key feature of the metabolic degradation of 1,4-dioxane by Pseudonocardia dioxanivorans strain CB1190. Appl. Environ. Microbiol., 78, 2012, pp. 3298-3308.

[3] CM. Sales, A. Grostern, JV. Parales, RE. Parales, LA. Cohen, Oxidation of the cyclic ethers 1,4-dioxane and tetrahydrofuran by a monooxygenase in two Pseudonocardia species. Appl. Environ. Microbiol., Doi:10. 1128/AEM. 02418-13, 2013.

[4] K. Sei, K. Miyagaki, T. Kakinoki, K. Fukugasako, D. Inoue, M. Ike, Isolation and characterization of bacterial strains that have high ability to degrade 1,4-dioxane as a sole carbon and energy source. Biodegradation, 2013, 24, pp. 665-674.

[5] PB. Gedalanga, P. Pornwongthong, R. Mora, SYD. Chiang, B. Baldwin, D. Ogles, S. Mahendra, Identification of biomarker genes to predict biodegradation of 1,4-dioxane. Appl. Environ. Microbiol., 80, 2014, pp. 3209-3218.

[6] R. Matsui, K. Takagi, F. Sakakibara, T. Abe, K. Shiiba, Identification and characterization of 1,4-dioxane-degrading microbe separated from surface seawater by the seawater-charcoal perfusion apparatus. Biodegradation, 2016, 27, pp.155–163.

[7] NV. Nicholas, NB. Bui, AJ. Holmes. Soluble di-iron monooxygenase gene diversity in soils, sediments and ethene enrichments. Environ. Microbiol., 8, 2006, pp. 1228-1239.

[8] L. Mengyan, M. Jacques, Y. Yu, F. Stephanie, D. Ye, H. Zhili, Z. Jizhong, JJA. Pedro. Widespread distribution of soluble di-iron monooxygenase (SDIMO) genes in Arctic groundwater impacted by 1,4-dioxane. Environ. Sci. Technol., 47, 2013, pp. 9950–9958