Geographic imprint and ecological functions of the abiotic component of periphytic biofilms

We revealed abiotic components (extracellular polymeric substances, EPSs) in the periphytic biofilms. Further, effect of microbial community on EPS, and geodistribution patterns ecological functions EPS were studied. In nature, most microorganisms grow as aggregates, flocs, or biofilms [1, 2], held together by a self-produced matrix extracellular substances (EPSs) [3]. Periphytic are typical example. Consisting autotrophs heterotrophs, these aggregates both natural aquatic ecosystems (e.g., streams, wetlands, rivers, etc.) constructed wetlands paddy fields), where they play multiple, crucial roles modulating element cycling [4]. Due to concerns about excessive fertilizer input fields, nitrogen (N) phosphorus (P) management based biofilm is receiving more attention [5]. For instance, accumulation P beneficial for minimizing its emigration from fields adjacent [6]. The component has been relatively well studied [4, 6], whereas received less attention. Little known content composition biofilm, potential this matrix. It established that an important grown ecosystems, sensitive factors define their local habitats, such light, temperature, nutrient availability [7, 8]. This leads hypothesis contents will vary greatly among growing those ecosystems. Generally, proteins polysaccharides, which account over 70%–80% total mass two main plus small amounts other compounds, eDNA [9]. However, little currently protein, fields. Geodistribution patterning one central themes macroecology biogeography. As habitats biofilms, China distributed six geographical regions [10]. differences physical geography have resulted regional Given primary affecting [9], second hypothesis, namely, characteristics different regions' show distinct patterns. so far, distribution Furthermore, whether how affected characteristics, precipitation, remains be investigated. importance determined functions. function skeleton protective barrier living [11, 12]. recent years, we conducted series studies into found shift behavior elements potentials regulating [6, 13]. Assuming there indeed dissimilarities between geographic regions, third guiding our work then variations associated with To evaluate above-mentioned hypotheses, collected 600 soil, floodwater samples nationwide scale address following questions: (1) What composition, fields? (2) Are along if any, what driving EPS? Quantifying 200 (Figure 1A), it was (dry weight) varied 11.3 64.9 g/kg average 19.1 g/kg. expected, polysaccharides EPS. Protein levels significantly higher (9.9–48.9 g/kg, Figure 1B) than polysaccharide (1.2–15.9 p < 0.001, 1B); ratios protein 1.8 20 (with value 5.4, 1A). small, varying 0.1 0.7 1B). These results indicate dominates Chinese showed significant pattern: decreased increasing latitude (r = 0.3294, 0.0001, red line 1C). Additionally, ratio also but contrary increased 0.2742, 0.0005, blue at grows, lower content, polysaccharide. Thereby, might verified. present samples, 130 genera prokaryotes 145 eukaryotes identified. mainly consist microeukaryotes, green algae meiofauna, nematodes 2A). Specifically, Heteromita, Desmodesmus, Aporcelaimellus, Paratripyla, Characiopodium, Chlorotetraedron, Tubificoides, Chaetomium, Rhabdolaimus, Pythium frequently individual top 10 abundant specific thus core eukaryotic communities 2A); prokaryotic Flavobacterium, Acinetobacter, Cyanobium_PCC-6307, Dinghuibacter, Massilia, UTCFX1, Bacteroides, Luteolibacter, Clostridium_sensu_stricto_13, Proteiniclasticum 2B). Thus, can concluded consists prokaryotes, meiofauna. On basis co-occurrence eukaryotes, 15 eight related 2C). Four (Prevotella_9, Dechloromonas, Paludibacterium, Azospira) positive correlations accumulation, while eleven (Sphingomonas, RB41, Nocardioides, Adhaeribacter, JGI_0001001.H03, Phreatobacter, Arcticibacter, Flavisolibacter, Nitrospira) had negative Notably, network prokaryotes. suggests effects may outweigh effects, potentially makes negatively affect Conversely, eukaryotes. Six (Pinnularia, Heterolepidoderma, Lepidochaetus, Sminthurides, Halichaetonotus, Chaetonotus) only (Rhogostoma Pythium) positive. Both prokaryote eukaryote direct distributions 2D). analyzed PLS-PM, (path coefficient −0.63, 2D) exerted 0.46, included weak 0.09, Supporting Information Table S1) strong indirect 0.37, suggest indirectly Climatic factors, components, climatic 0.55 0.69, respectively; soil were, respectively, 0.28 0.20, 0.45 0.40, respectively Combining each factor −0.41, −0.11, −0.23, (Supporting S1). By contrast, contribution three external order: > soil. conclude principal forces large-scale Among sunshine duration 0.91) radiation intensity 0.63) effective accumulated temperature −0.92, role especially determining Nutrient ways modulate cycles concentrations TN TP 0.8 12.5 0.3 6.3 3A). 0.372, 3B) 0.272, 3C) contents, partly explain why could accumulate considerable N P. TOC biofilm; amount 6.4 94.6 (blue bar correlation 0.302, 3D). biofilm. shaping accumulation. Previously, even basic information not systematically available. quantitatively comprehensively China. substantiated field varies rice-growing provinces generally [14, 15]. some (oligotrophic) environments (such oceans Everglades), EPSs primarily composed [9]; eutrophic component. trophic status habitat extends similar observation Durmaz Sanin [16] who reported carbon wastewater affects activated sludge flocs. terms function, functional groups 14], largely [15]. tempting speculate high rice paddies possibly promotes sequester process formation [17]. research test should scientifically interesting practical applications. Microorganisms producers consumers biofilms; activity directly change Here dominated various phototrophic [18]. chemotrophic microorganisms, result supply phosphorus, limited light caused canopy shading. Prokaryotes exert indicated (cf. because although bacteria produce EPS-producing apparently accounted part whole population good substrate due abundance monosaccharides, maltose, d-xylose, mannose, d-fructose autotrophic cyanobacteria) do require energy sources, heterotrophic dominate 2A,B), need consume growth [19]. Therefore, consuming versus few producing overall negative. Eukaryotes 2D), supported pattern parts: through being reason maintain microenvironment [20]. A possible observed predatory feeding [21], control reducing consumption increase Studying biodiversity contributes addressing scientific issues biogeography [22]. Here, employed multiple regression analysis [23] Then, Partial Least Squares Path Modeling [24] synthesize data analyze impact including principally drive Theoretically, latitude, longer is, are, production agrees results. previous findings [25, 26], protecting against adverse conditions 27]. example, secrete help them resist stress posed low temperatures [28, 29]. maybe certain would lead synthesis resulting difference planting areas. addition, lighting microbes shifting structure 18]. climate-induced structures 2A,B) another (biomass content) across spite quantitative above analyses notwithstanding, conclusive evidence significance still lacking. Accumulation efficient way nutrients/elements 6]. study, quantified C, N, shapes nutrients. conditions, water stress, heavy metals, pesticides, insecticides [11]. new First, instrumental groups, carboxyl, carbonyl, forth [30], providing binding sites P, facilitating Second, [11], source soils expects improve fertility [31]. components. effects. shows imprint: decrease opposite trend. Temperature beyond skeleton, propensity Sampling areas China, ranging 22°25′ 47°16′ S1A). sampled located northeast, central, south covering 93% All 7–15 days after transplanting. total, sampling selected; per area, randomly chosen within radius 1 km; sample, corresponding separately site. floodwater, (sunshine duration, intensity, temperature) retrieved http://data.cma.cn/site/index.html. Regarding sample collection: (about 50 g wet softly scraped surface using sterilized stainless-steel knife; minimize contamination distinct, visible clods washed several times running remove adhering until effluent no turbid. Water drained sealed plastic bags S1B). 100 ml bottled, (0–20 cm without biofilm) collected. transported ice laboratory stored −20°C further analysis. extracted modified alkaline extraction method, Bradford assay bovine serum albumin standard (Bio-Rad) phenol–sulfuric acid assay, microspectrophotometer (Bei Jing Kai Ao K5600). Part pretreated 60°C constant weight oven (GZX-9140ME) before all, 0.5 5 digested HNO3–H2O2 digestion (JKXZ06-8B) subsequently used measure (TN) (TP) contents; flow analyzer (FS3700, OI Analytical). Total organic (TOC) potassium dichromate method. pH measured meter (Mettler Toledo FE28). 2 was, taken mixed well, divided parts communities. values relative calculated summarize area. via 16S 18S rDNA high-throughput sequencing HiSeq. 2500 platforms, respectively. methods DNA purification, sequencing, quality control, sequence analysis, sequences deposition National Center Biotechnology (NCBI) database, forth, described previously Microbial deposited NCBI under accession number PRJNA854262, Genome Warehouse Genomics Data [32, 33], Beijing Institute Genomics, Academy Sciences/China Bioinformation, GWHBOSZ00000000. generated R “psych” package, interaction visualized software Gephi 0.9.2 (France). nutrients (C, P) [34]. Statistical “vegan” package. (TOC, TN, TP) (pH, TP), (including eukaryotes) conjunction latter [21]. statistical procedures SPSS 16.0 (SPSS Inc.). abundances Circos (http://circos.ca/), figures SigmaPlot 10.0 (Systat Software Yonghong Wu Pengfei Sun conceived study. Rui data. wrote draft. Wu, Yingyao Liu, Sun, Jan Dolfing gave advice experimental design revised manuscript. authors reviewed manuscript draft discussion study Key Research Development Program (2021YFD1700803), Natural Science Foundation (41825021, 42177232, 41961144010, 41701301), Jiangsu Province (BZ2019015, BK20200057, BE2020731), Original Innovation Project Sciences (ZDBS-LY-DQC024). declare conflict interest. support openly available (repository name, e.g., “figshare”). Center, GWHBOSZ00000000 publicly accessible https://ngdc.cncb.ac.cn/gwh, BioProject PRJCA012051, submission PRJNA854262. scripts saved GitHub https://github.com/SunPFei/PLS-PM-for-EPS.git https://gitee.com/pengfei-sun0913/pls-pm-for-eps.git. Supplementary materials (figures, tables, scripts, graphical abstract, slides, videos, translated version, update materials) online DOI iMeta http://www.imeta.science/. Please note: publisher responsible functionality any supporting supplied authors. 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