TY - JOUR A1 - Li, Shuang A1 - Abdulkadir, Nafi'u A1 - Schattenberg, Florian A1 - da Rocha, Ulisses Nunes A1 - Grimm, Volker A1 - Müller, Susann A1 - Liu, Zishu T1 - Stabilizing microbial communities by looped mass transfer JF - Proceedings of the National Academy of Sciences of the United States of America : PNAS N2 - Building and changing a microbiome at will and maintaining it over hundreds of generations has so far proven challenging. Despite best efforts, complex microbiomes appear to be susceptible to large stochastic fluctuations. Current capabilities to assemble and control stable complex microbiomes are limited. Here, we propose a looped mass transfer design that stabilizes microbiomes over long periods of time. Five local microbiomes were continuously grown in parallel for over 114 generations and connected by a loop to a regional pool. Mass transfer rates were altered and microbiome dynamics were monitored using quantitative high-throughput flow cytometry and taxonomic sequencing of whole communities and sorted subcommunities. Increased mass transfer rates reduced local and temporal variation in microbiome assembly, did not affect functions, and overcame stochasticity, with all microbiomes exhibiting high constancy and increasing resistance. Mass transfer synchronized the structures of the five local microbiomes and nestedness of certain cell types was eminent. Mass transfer increased cell number and thus decreased net growth rates mu'. Subsets of cells that did not show net growth mu'SCx were rescued by the regional pool R and thus remained part of the microbiome. The loop in mass transfer ensured the survival of cells that would otherwise go extinct, even if they did not grow in all local microbiomes or grew more slowly than the actual dilution rate D would allow. The rescue effect, known from metacommunity theory, was the main stabilizing mechanism leading to synchrony and survival of subcommunities, despite differences in cell physiological properties, including growth rates. KW - microbial ecology KW - metacommunity assembly KW - stability KW - microbial KW - community cytometry KW - single-cell analytics Y1 - 2022 U6 - https://doi.org/10.1073/pnas.2117814119 SN - 0027-8424 SN - 1091-6490 VL - 119 IS - 17 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Zhang, Yan-qiu A1 - Guo, Zeng-hui A1 - Chen, Dai-zhao T1 - Porosity distribution in cyclic dolomites of the Lower Qiulitag Group (Upper Cambrian) in northwestern Tarim Basin, China JF - China geology N2 - Increasing interests in hydrocarbon resources at depths have drawn greater attentions to the deeply-buried carbonate reservoirs in the Tarim Basin in China. In this study, the cyclic dolomite rocks of Upper Cambrian Lower Qiulitag Group from four outcrop sections in northwestern Tarim Basin were selected to investigate and evaluate the petrophysical properties in relation to depositional facies and cyclicity. The Lower Qiulitag Group includes ten lithofacies, which were deposited in intermediate to shallow subtidal, restricted shallow subtidal, intertidal, and supratidal environments on a carbonate ramp system. These lithofacies are vertically stacked into repeated shallowing-upward, meter-scale cycles which are further grouped into six third-order depositional sequences (Sq1 to Sq6). There are variable types of pore spaces in the Lower Qiulitag Group dolomite rocks, including interparticle, intraparticle, and fenestral pores of primary origin, inter crystal, and vuggy pores of late diagenetic modification. The porosity in the dolomites is generally facies-selective as that the microbially-originated thrombolites and stromatolites generally yield a relatively high porosity. In contrast, the high-energy ooidal grainstones generally have very low porosity. In this case, the microbialite-based peritidal cycles and peritidal cycle-dominated highstand (or regressive) successions have relatively high volumes of pore spaces, although highly fluctuating (or vertical inhomogeneous). Accordingly, the grainstone-based subtidal cycles and subtidal cycle-dominated transgressive successions generally yield extremely low porosity. This scenario indicates that porosity development and preservation in the thick dolomite successions are primarily controlled by depositional facies which were influenced by sea-level fluctuations of different orders and later diagenetic overprinting. KW - Dolomites KW - porosity KW - cyclicity KW - Upper Cambrian KW - stromatolite KW - microbial KW - build up KW - oil-gas basin KW - oil-gas exploration engineering KW - Tarim Basin KW - China Y1 - 2020 UR - http://en.cgsjournals.com/zgdzdcqkw-data/zgdzyw/2020/3/PDF/cg2020026.pdf SN - 2096-5192 SN - 2589-9430 VL - 3 IS - 3 SP - 425 EP - 444 PB - Elsevier CY - Amsterdam ER -