Ambient climate determines the directional trend of community stability under warming and grazing

2021 ◽  
Author(s):  
Peipei Liu ◽  
Wangwang Lv ◽  
Jianping Sun ◽  
Caiyun Luo ◽  
Zhenhua Zhang ◽  
...  
2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yongyi Liang ◽  
Qihong Lu ◽  
Zhiwei Liang ◽  
Xiaokun Liu ◽  
Wenwen Fang ◽  
...  

AbstractObligate and non-obligate organohalide-respiring bacteria (OHRB) play central roles in the geochemical cycling and environmental bioremediation of organohalides. Their coexistence and interactions may provide functional redundancy and community stability to assure organohalide respiration efficiency but, at the same time, complicate isolation and characterization of specific OHRB. Here, we employed a growth rate/yield tradeoff strategy to enrich and isolate a rare non-obligate tetrachloroethene (PCE)-respiring Geobacter from a Dehalococcoides-predominant microcosm, providing experimental evidence for the rate/yield tradeoff theory in population selection. Surprisingly, further physiological and genomic characterizations, together with co-culture experiments, revealed three unique interactions (i.e., free competition, conditional competition and syntrophic cooperation) between Geobacter and Dehalococcoides for their respiration of PCE and polychlorinated biphenyls (PCBs), depending on both the feeding electron donors (acetate/H2 vs. propionate) and electron acceptors (PCE vs. PCBs). This study provides the first insight into substrate-dependent interactions between obligate and non-obligate OHRB, as well as a new strategy to isolate fastidious microorganisms, for better understanding of the geochemical cycling and bioremediation of organohalides.


Biosfera ◽  
2015 ◽  
Vol 32 (2) ◽  
pp. 83 ◽  
Author(s):  
Utojo Utojo

This study aims to estimate the wealth and stability of traditional and intensive brackishwater pond waters through biological index calculation (diversity, uniformity and dominance of plankton) in traditional and intensive brackishwater pond waters of Probolinggo Regency, East Java Province. Sampling plankton and water from the site, considered to represent the diversity of plankton and water stability of traditional and intensive brackishwater pond. Plankton was collected using a plankton net no. 25, then preserved using 1% lugol solution. Measurement of water quality variables include temperature, salinity, dissolved oxygen and pH, whereas the laboratory analyzes that Total Organic Matter (TOM), NO2, NO3, NH3, PO4, Total Suspended Solids (TSS), and Fe. Plankton identification using microscope and calculation with cell counting method. The results of analysis of plankton in intensive brackishwater pond waters are obtained as much as 23 genera consisting of 16 genera of phytoplankton were included into three classes, namely Bacillariophyceae as much as 5 genera, Cyanophyceae 3 genera, Dinophyceae and Chlorophyceae, each of the four genera, whereas zooplankton consisting of 7 genera are included into two classes, namely Crustaceae 6 genera and Rotatoria 1 genus. In traditional brackishwater pond earned as much as 13 genera consisting of 8 genera of phytoplankton were included into Bacillariophyceae 5 genera, Cyanophyceae 2 genera, and Dinophyceae 3 genera, whereas zooplankton consisting of three genera are included into class Crustaceae 2 genera and Rotatoria 1 genus. Plankton abundance in intensive brackishwater pond ranges 702 - 4269 ind./L, diversity index of 0.26 -2.38, uniformity index of 0.10 - 1.5, and dominance index of 0.02 - 0.68. In traditional brackishwater pond have an abundance of plankton range 134 - 776 ind./L, diversity index of 0.10 - 1.97, uniformity index of 0.08 - 1.0, and dominance index of 0.01 - 0.75. Traditional and intensive brackishwater pond waters condition still within the limits that can be tolerated by the culture organism. Based on the index value of biological, diversity of genus in the intensive brackishwater pond is relatively higher than traditional brackishwater pond and the community stability moderate, whereas traditional brackishwater pond unstable. On average, the uniformity of the genus in both  brackishwater ponds are relatively evenly and genus of plankton to dominate the others genus.


Ecology ◽  
2021 ◽  
Author(s):  
Hamish S. Greig ◽  
Peter A. McHugh ◽  
Ross M. Thompson ◽  
Helen J. Warburton ◽  
Angus R. McIntosh

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