A contribution to the Fissidens Hedw. (Musci, Fissidentaceae) of Myanmar, including F. strictidens sp. nov. and F. pseudoanomalus sp. nov.
CRYPTOGAMIE BRYOLOGIE
Authors: Bruggeman-Nannenga, Maria A.; Mueller, Frank
Abstract
Fissidens strictidens Brugg.-Nann. & Frank Mull., sp. nov., belonging to Fissidens subg. Aloma Kindb., and Fissidens pseudoanomalus Brugg.-Nann. & Frank Mull., sp. nov., belonging to Fissidens subg. Pachyfissidens (Mull.Hal.) Kindb. sect. Pachyfissidens, are described and figured from material collected in Kachin State, Myanmar. Fissidens biformis Mitt., Fissidens crispulus var. robinsonii (Broth.) Z.Iwats. & Z.H.Li Fissidens guangdongensis Z.lwats. & Z.H.I.i, Fissidens linearis var. obscuriretis (Broth. & Paris) I.G.Stone, Fissidens pokhrensis Nork. ex S.S.Kumar, Fissidens serratus Mull.Hal., and Fissidens wichurae Broth. & M.Fleisch. are newly recorded for Myanmar.
Enhancement of microbial redox cycling of iron in zero-valent iron oxidation coupling with deca-brominated diphenyl ether removal
SCIENCE OF THE TOTAL ENVIRONMENT
Authors: Xu, Jingjing; Guo, Jun; Xu, Meiying; Chen, Xingjuan
Abstract
Iron-redox cycling microorganisms are important for understanding the biogeochemical iron and play key roles in zero-valent iron (ZVI) mediated environmental bioremediation. Their influence on ZVI oxidation coupling with organic contaminant removal is of particular interest but is still poorly understood. The objective of this research was to study microbial redox cycles of iron in ZVI oxidation and deca-brominated diphenyl ether (decaBDE) removal. It was found that iron-oxidizing bacteria (IOB) enhanced ZVI oxidation by using iron as the sole electron donor. Iron-reducing bacteria (IRB) with high activity of Fe (III) reduction, also significantly accelerated rather than inhibited ZVI oxidation. ZVI oxidation activity was increased from 3.42% to 2428% by IOB and 19.49% by IRB. When deca-BDE was present in the medium, ZVI oxidation activity by IOB and IRB was increased from 2.67% to 48.33% and 64.33%, respectively. However, no co-accelerating effect of IOB and IRB occurred but rather a neutralizing influence on ZVI oxidation was detected with iron-redox cycling bacteria (IORB). ZVI oxidation activity by IORB only increased to 13.14% and 37.0% in the absence and presence of deca-BDE, respectively. Meanwhile, IRB also exhibited the highest removal activity of deca-BDE. Approximately 71.67% of deca-BDE was removed by IRB, compared to 18.91% by IOB and 4324% by IORB. Deca-BDE significantly influenced the effects of iron-metabolizing microorganisms on ZVI oxidation by altering the composition of microbial communities. Pseudomonas, Paenibacillus, and Sporolactobacillus were the key genera influencing ZVI oxidation and deca-BDE removal. Sporolactobacillus was firstly reported to be able to stimulate both ZVI oxidation and deca-BDE removal. Pseudomonas accelerated ZVI oxidation but had no significant contribution to deca-BDE removal. However, Paeni bacillus inhibited both Fe(III) reduction and deca-BDE removal. It is expected that continuous integration of ZVI oxidation and organic contaminant removal can be achieved by regulating the key genera in iron-metabolizing microbial communities. (C) 2020 Elsevier B.V. All rights reserved.