Assessment and sources identification of microplastics, PAHs and OCPs in the Luoyuan Bay, China: Based on multi-statistical analysis.

Luoyuan Bay is a mariculture influenced water body located in southeastern China. Multi-statistical techniques were applied to 21 sampling locations in the bay to identify the sources of microplastics and other pollutants in the sediment. In microplastics detection, fragment was the most abundant shape (~36%), and rayon was the dominant polymer (~59%). The size of more than 48% of total microplastics observed was less than 200 µm. The study showed that the upper part of Luoyuan Bay was dominated by microplastic pollution, while the lower part of the bay was dominated by persistent organic pollutants (PAHs, OCPs). Mariculture is one of the main sources of pollution in Luoyuan Bay. Apart from mariculture, there were additional sources such as industry, land reclamation, port, and so on; industry and land reclamation were the leading sources of microplastics, while port, industry, and mariculture were the primary sources of PAHs and OCPs.

Nioella ostreopsis sp. nov., isolated from toxic dinoflagellate, Ostreopsis lenticularis.

A novel short-rod-shaped bacterial strain with poly-ß-hydroxybutyric acid granules inside, designated as Z7-4T, was isolated from a culture of a marine dinoflagellate with palytoxin-producing capacity, Ostreopsis lenticularis OS06, collected from the East China Sea. Cells of Z7-4T were Gram-stain-negative, non-motile, strictly aerobic, 0.9-1.2 µm wide and 2.0-3.9 µm long. Growth occurred in 1-4 % (w/v) NaCl, at 15-37 °C and at pH 5.0-10.0, with optimum growth in 3.5 % (w/v) NaCl, at 30 °C and at pH 7.0. Analysis of 16S rRNA gene sequence revealed that Z7-4T shared the highest 16S rRNA gene sequence similarities with Nioella aestuarii JCM 30752T (98.8 %), followed by Nioella sediminis KCTC 42144T (98.6 %) and Nioella nitratireducens KCTC 32417T (96.9 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that Z7-4T clearly represented a member of the genus Nioella within the family Rhodobacteraceae. The respiratory quinone of Z7-4T was identified as Q-10. Polar lipids of Z7-4T were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The DNA G+C content of Z7-4T was 63.0 mol%. DNA-DNA hybridization values of the isolate against the closely related type strains were far below the 70 % limit for species delineation. The average nucleotide identity and in silico DNA-DNA genome hybridization relatedness between Z7-4T and the closely related members of the genus Nioella, N. sediminis KCTC 42144T and N. nitratireducens KCTC 32417T, were 91.1 and 46.3 %, and 79.3 and 19.4 %, respectively. On the basis of the results of polyphasic analysis, Z7-4T is proposed to represent a novel species of the genus Nioella, for which the name Nioella ostreopsis sp. nov. is proposed. The type strain of Nioella ostreopsis is Z7-4T (=KCTC 62459T=CCTCC AB 2017231T).