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Many scholars have explored the treatment effect of biofilters with different packing media. However, there is little report on the microbial communities of the packing media. Therefore, this paper attempts to disclose the differences between two popular packing media of biofilter, namely, volcanic rock and ceramiste, in terms of the attached bacteria. Firstly, two multi-layer biofilters (MBFs) were designed, and respectively packed with volcanic rock and ceramiste. The packing media were collected after the MBFs entered stable operation. The DNA was extracted from the media and pyro-sequenced. After that, the community structure and diversity of the microorganisms were analyzed in details. The main results are as follows: The values of ACE estimator, Chao1 estimator, and Simpson's diversity show that volcanic rock had the higher bacterial diversity. The libraries with volcanic rock and ceramsite respectively consist of 1,810 and 1,352 operational taxonomic units (OTUs). Surprisingly, the Venn diagram of OTUs indicates that the two-packing media only share 13.2 % OTUs. The volcanic rock contained sequences in 16 phyla while ceramiste only covered sequences in 11 phyla. Among all phyla, Tenericutes was unique to ceramiste, while Chloroflexi, GN02, NKB19, Thermi, Chlorobi and TM7 were only observed in volcanic rock. Ceramiste contained more Proteobacteria (67.06 % vs. 64.12 %), Bacteroidetes (25.11 % vs. 22.72 %) andFirmicutes (6.20 % vs. 4.55 %) than volcanic rock. The research findings clarify the research direction and provide the theoretical basis for improving ceramiste technology and developing alternatives for volcanic rock. [ABSTRACT FROM AUTHOR]

Three new species and one subspecies of the genus Amynthas are described from Guangxi Zhuang Autonomous Region, China: The new species are: Amynthas maximus Qiu & Dong, sp. nov. and Amynthas tortuosus Qiu & Dong, sp. nov., and Amynthas shengtangmontis Dong & Jiang, sp. nov., the subspecies is Amynthas shengtangmontis minusculus subsp. nov. All have four pairs of spermathecal pores in 5/6-8/9, which indicates that they should belong to the corticis-group. Their morphological characteristics are compared to other similar species in the corticis-group from China and other Asian countries, such as Amynthas pulvinus Sun & Jiang, 2013, Amynthas homosetus (Chen, 1938), Amynthas corticis (Kinberg, 1867), Amynthas dorsualis Sun & Qiu, 2013, and Amynthas carnosus (Goto & Hatai, 1899). In addition, the results presented are confirmed by the pairwise comparison of COI barcode sequences. The pairwise distances between each new species and the other eighteen corticis-group species are greater than 14.7% on average. Furthermore, the pairwise distance between A. shengtangmontis shengtangmontis and A. shengtangmontis minusculus is 10.7-11.4%. [ABSTRACT FROM AUTHOR]