scholarly journals Microbial Carbon Metabolic Functions in Sediments Influenced by Resuspension Event

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 7
Author(s):  
Miao Wu ◽  
Ming Zhang ◽  
Wei Ding ◽  
Lin Lan ◽  
Zhilin Liu ◽  
...  

Microorganisms in sediments are an important part of the aquatic ecosystem, and their functional activities are sensitive to external environmental pressure. Shallow lakes are characterized by frequent sediment resuspension events, leading to large amounts of nutrients being released. However, information about the potential impacts of sediment resuspension events on the functional activities of microbial communities is limited. In this study, the responses of microbial carbon metabolism in sediments under different wind–wave disturbance were analyzed by BIOLOG ECO microplates. The results showed that under four disturbance conditions (wind speeds of 0, 1.60, 3.62, and 14.10 m/s), the total carbon metabolism function of the sediment microbial community (represented as average well-color development, AWCD) remained unchanged (p > 0.05), and the final total AWCD value stabilized at about 1.70. However, compared with the control group, some specific carbon sources (e.g., amines and carboxylic acids) showed significant changes (p < 0.05). We found that short-term (8 h) resuspension events did not affect the total carbon metabolism of sediment microbial communities, while it affected the microbial utilization ability of some specific types of carbon sources. For example, we found that the microbial utilization capacity of polymers in the 14.10 m/s group was the best. This study provides a new insight into the carbon cycle process of shallow lake sediments that resuspension events will affect the carbon cycle process of sediments.

2019 ◽  
Author(s):  
Sven P. Tobias-Hünefeldt ◽  
Stephen R. Wing ◽  
Federico Baltar ◽  
Sergio E. Morales

AbstractFjords are semi-enclosed marine systems with unique physical conditions that influence microbial communities structure. Pronounced organic matter and physical condition gradients within fjords provide a natural laboratory for the study of changes in microbial phylogeny and metabolic potential in response to environmental conditions (e.g. depth). In the open ocean new production from photosynthesis supplies organic matter to deeper aphotic layers, sustaining microbial activity. We measured the metabolic diversity and activity of microbial communities in fjords to determine patterns in metabolic potential across and within fjords, and whether these patterns could be explained by community composition modifications. We demonstrated that metabolic potential and activity are shaped by similar parameters as total (prokaryotic and eukaryotic) microbial communities. However, we identified increases in metabolic diversity and potential (but not in community composition) at near bottom (aphotic) sites consistent with the influence of sediments in deeper waters. Thus, while composition and function of the microbial community in the upper water column was likely shaped by marine snow and sinking POM generated by new production, deeper sites were strongly influenced by sediment resuspension of benthic organic matter generated from this or other sources (terrestrial, chemoautotrophic, microbial carbon loop), uncoupling the community composition and function dynamics.


2013 ◽  
Vol 864-867 ◽  
pp. 140-144
Author(s):  
Shao Yan Jiang ◽  
Wen Xing Wang ◽  
Xiang Xin Xue

The oil shale in the Western Fushun Basin as research object was investigated by Biolog-ECO to explore the functional diversity in microbial carbon metabolism of the oil shale. The process of Biolog-ECO was that, first determining the microbial community level physiological patterns during the 7 consecutive days by ECO microplate, then analyzing the differences in microbial metabolism of different types of carbon. The results showed that there were significant differences of the rate and extent in different types of carbon metabolism. The metabolism of carbohydrates, amino acids and amines carbon were significantly better than other carbon sources in all microbial communities, while the metabolism of acid metabolite was poor. Through continuous multi-point measuring the diversity index of Shannon-wiener, Simpson and McIntosh, overall, the microbial diversity was good, but with the time passing, the functional diversity of the carbon metabolism decreased.


mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Andrew Oliver ◽  
Brandon LaMere ◽  
Claudia Weihe ◽  
Stephen Wandro ◽  
Karen L. Lindsay ◽  
...  

ABSTRACT Microbes and their metabolic products influence early-life immune and microbiome development, yet remain understudied during pregnancy. Vaginal microbial communities are typically dominated by one or a few well-adapted microbes which are able to survive in a narrow pH range and are adapted to live on host-derived carbon sources, likely sourced from glycogen and mucin present in the vaginal environment. We characterized the cervicovaginal microbiomes of 16 healthy women throughout the three trimesters of pregnancy. Additionally, we analyzed saliva and urine metabolomes using gas chromatography-time of flight mass spectrometry (GC-TOF MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) lipidomics approaches for samples from mothers and their infants through the first year of life. Amplicon sequencing revealed most women had either a simple community with one highly abundant species of Lactobacillus or a more diverse community characterized by a high abundance of Gardnerella, as has also been previously described in several independent cohorts. Integrating GC-TOF MS and lipidomics data with amplicon sequencing, we found metabolites that distinctly associate with particular communities. For example, cervicovaginal microbial communities dominated by Lactobacillus crispatus have high mannitol levels, which is unexpected given the characterization of L. crispatus as a homofermentative Lactobacillus species. It may be that fluctuations in which Lactobacillus dominate a particular vaginal microbiome are dictated by the availability of host sugars, such as fructose, which is the most likely substrate being converted to mannitol. Overall, using a multi-“omic” approach, we begin to address the genetic and molecular means by which a particular vaginal microbiome becomes vulnerable to large changes in composition. IMPORTANCE Humans have a unique vaginal microbiome compared to other mammals, characterized by low diversity and often dominated by Lactobacillus spp. Dramatic shifts in vaginal microbial communities sometimes contribute to the presence of a polymicrobial overgrowth condition called bacterial vaginosis (BV). However, many healthy women lacking BV symptoms have vaginal microbiomes dominated by microbes associated with BV, resulting in debate about the definition of a healthy vaginal microbiome. Despite substantial evidence that the reproductive health of a woman depends on the vaginal microbiota, future therapies that may improve reproductive health outcomes are stalled due to limited understanding surrounding the ecology of the vaginal microbiome. Here, we use sequencing and metabolomic techniques to show novel associations between vaginal microbes and metabolites during healthy pregnancy. We speculate these associations underlie microbiome dynamics and may contribute to a better understanding of transitions between alternative vaginal microbiome compositions.


2015 ◽  
Vol 8 (2) ◽  
pp. 1787-1832 ◽  
Author(s):  
J. Heymann ◽  
M. Reuter ◽  
M. Hilker ◽  
M. Buchwitz ◽  
O. Schneising ◽  
...  

Abstract. Consistent and accurate long-term data sets of global atmospheric concentrations of carbon dioxide (CO2) are required for carbon cycle and climate related research. However, global data sets based on satellite observations may suffer from inconsistencies originating from the use of products derived from different satellites as needed to cover a long enough time period. One reason for inconsistencies can be the use of different retrieval algorithms. We address this potential issue by applying the same algorithm, the Bremen Optimal Estimation DOAS (BESD) algorithm, to different satellite instruments, SCIAMACHY onboard ENVISAT (March 2002–April 2012) and TANSO-FTS onboard GOSAT (launched in January 2009), to retrieve XCO2, the column-averaged dry-air mole fraction of CO2. BESD has been initially developed for SCIAMACHY XCO2 retrievals. Here, we present the first detailed assessment of the new GOSAT BESD XCO2 product. GOSAT BESD XCO2 is a product generated and delivered to the MACC project for assimilation into ECMWF's Integrated Forecasting System (IFS). We describe the modifications of the BESD algorithm needed in order to retrieve XCO2 from GOSAT and present detailed comparisons with ground-based observations of XCO2 from the Total Carbon Column Observing Network (TCCON). We discuss detailed comparison results between all three XCO2 data sets (SCIAMACHY, GOSAT and TCCON). The comparison results demonstrate the good consistency between the SCIAMACHY and the GOSAT XCO2. For example, we found a mean difference for daily averages of −0.60 ± 1.56 ppm (mean difference ± standard deviation) for GOSAT-SCIAMACHY (linear correlation coefficient r = 0.82), −0.34 ± 1.37 ppm (r = 0.86) for GOSAT-TCCON and 0.10 ± 1.79 ppm (r = 0.75) for SCIAMACHY-TCCON. The remaining differences between GOSAT and SCIAMACHY are likely due to non-perfect collocation (±2 h, 10° × 10° around TCCON sites), i.e., the observed air masses are not exactly identical, but likely also due to a still non-perfect BESD retrieval algorithm, which will be continuously improved in the future. Our overarching goal is to generate a satellite-derived XCO2 data set appropriate for climate and carbon cycle research covering the longest possible time period. We therefore also plan to extend the existing SCIAMACHY and GOSAT data set discussed here by using also data from other missions (e.g., OCO-2, GOSAT-2, CarbonSat) in the future.


2008 ◽  
Vol 190 (8) ◽  
pp. 2947-2956 ◽  
Author(s):  
Catalina Arango Pinedo ◽  
Ryan M. Bringhurst ◽  
Daniel J. Gage

ABSTRACT Sinorhizobium meliloti is a member of the Alphaproteobacteria that fixes nitrogen when it is in a symbiotic relationship. Genes for an incomplete phosphotransferase system (PTS) have been found in the genome of S. meliloti. The genes present code for Hpr and ManX (an EIIAMan-type enzyme). HPr and EIIA regulate carbon utilization in other bacteria. hpr and manX in-frame deletion mutants exhibited altered carbon metabolism and other phenotypes. Loss of HPr resulted in partial relief of succinate-mediated catabolite repression, extreme sensitivity to cobalt limitation, rapid die-off during stationary phase, and altered succinoglycan production. Loss of ManX decreased expression of melA-agp and lac, the operons needed for utilization of α- and β-galactosides, slowed growth on diverse carbon sources, and enhanced accumulation of high-molecular-weight succinoglycan. A strain with both hpr and manX deletions exhibited phenotypes similar to those of the strain with a single hpr deletion. Despite these strong phenotypes, deletion mutants exhibited wild-type nodulation and nitrogen fixation when they were inoculated onto Medicago sativa. The results show that HPr and ManX (EIIAMan) are involved in more than carbon regulation in S. meliloti and suggest that the phenotypes observed occur due to activity of HPr or one of its phosphorylated forms.


2018 ◽  
Author(s):  
Oswaldo C Villena ◽  
Bahram Momen ◽  
Joseph Sullivan ◽  
Paul T Leisnham

Environmental changes will alter many environmental factors in the coming years including temperature, precipitation, humidity, and the amount of solar radiation reaching the earth’s surface, which in turn will have an impact on living organisms like invertebrates. In this study, we assessed the effect of UV-B radiation upon the metabolic rate and upon three fitness parameters (survival, development time, and body size) of the mosquitoes Aedes albopictus and Culex pipiens, and upon the production of microbial resources on which mosquito larvae feed in aquatic microcosms. We set up three UV-B radiation treatments mimicking levels typically measured in full-sun (FS) and shade (S) conditions, as well as a control group with no UV-B radiation (NUV). The metabolic rate expressed as heat production (µwatts/ml) for larvae and microbial community was measured at days 1, 8, and 15. Our results indicated that UV-B radiation affected the metabolic rate of both Cx. pipiens and Ae. albopictus larvae; metabolic rates were significantly higher in full-sun (FS) compared to shade (S) and no-UV condition (NUV), at days 8 and 15 compared to day 1 (Figures 1A and 1B). Culex pipiens metabolic rates were significantly higher than Ae. albopictus at day 15 compared to days 1 and 8 (Figure 1B). Metabolic rates were significantly lower in microbial communities from vials with Ae. albopictus larvae, Cx. pipiens larvae, and no larvae in FS conditions compared to vials from S and NUV conditions, especially at day 8 (Figure 2A and 2B). There was a major effect of UV-B conditions only on the survival of Ae. albopictus and Cx. pipiens mosquitoes, with significantly lower survival in FS compared to S and NUV conditions. UV-B radiation at levels found in aquatic environments in open fields showed a negative impact on the metabolic rate of Ae. albopictus and Cx. pipiens larvae and on the microbial communities on which they feed. These negative impacts could have important implications for the distribution and abundance of these mosquitoes and for the transmission rate of illness caused by the pathogens that these two broadly distributed mosquitoes transmit.


2018 ◽  
Author(s):  
Manuel Kleiner ◽  
Xiaoli Dong ◽  
Tjorven Hinzke ◽  
Juliane Wippler ◽  
Erin Thorson ◽  
...  

AbstractMeasurements of the carbon stable isotope ratio (δ13C) are widely used in biology to address major questions regarding food sources and metabolic pathways used by organisms. Measurement of these so called stable carbon isotope fingerprints (SIFs) for microbes involved in biogeochemical cycling and microbiota of plants and animals have led to major discoveries in environmental microbiology. Currently, obtaining SIFs for microbial communities is challenging as the available methods either only provide limited taxonomic resolution, such as with the use of lipid biomarkers, or are limited in throughput, such as NanoSIMS imaging of single cells.Here we present “direct Protein-SIF” and the Calis-p software package (https://sourceforge.net/projects/calis-p/), which enable high-throughput measurements of accurate δ13C values for individual species within a microbial community. We benchmark the method using 20 pure culture microorganisms and show that the method reproducibly provides SIF values consistent with gold standard bulk measurements performed with an isotope ratio mass spectrometer. Using mock community samples, we show that SIF values can also be obtained for individual species within a microbial community. Finally, a case study of an obligate bacteria-animal symbiosis showed that direct Protein-SIF confirms previous physiological hypotheses and can provide unexpected new insights into the symbionts’ metabolism. This confirms the usefulness of this new approach to accurately determine δ13C values for different species in microbial community samples.SignificanceTo understand the roles that microorganisms play in diverse environments such as the open ocean and the human intestinal tract, we need an understanding of their metabolism and physiology. A variety of methods such as metagenomics and metaproteomics exist to assess the metabolism of environmental microorganisms based on gene content and gene expression. These methods often only provide indirect evidence for which substrates are used by a microorganism in a community. The direct Protein-SIF method that we developed allows linking microbial species in communities to the environmental carbon sources they consume by determining their stable carbon isotope signature. Direct Protein-SIF also allows assessing which carbon fixation pathway is used by autotrophic microorganisms that directly assimilate CO2.


2020 ◽  
Vol 69 (1) ◽  
pp. 27-37
Author(s):  
YUXI LING ◽  
WENYING LI ◽  
TONG TONG ◽  
ZUMING LI ◽  
QIAN LI ◽  
...  

Daqu made from raw wheat, barley or pea is used as an inoculum for the fermentation of Chinese Baijiu. In this study, the microbial communities of four different types of Daqus (sauce-flavor Wuling Daqu, sauce and strong-flavor Baisha Daqu, strong-flavor Deshan Daqu, and light-flavor Niulanshan Daqu) were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), phospholipid fatty acid (PLFA) analysis, and Biolog EcoPlates analysis (Biolog). Clear differences were seen between the microbial communities of the four Daqus. PCR-DGGE showed differences in the number and brightness of bands between the Daqus, indicating the presence of unique bacterial species in Deshan Daqu, Wuling Daqu, and Niulanshan Daqu. Lactobacillus sanfranciscensis, Bacillus thermoamylovorans, and some unclassified bacteria were unique to Wuling Daqu, Deshan Daqu, and Niulanshan Daqu, respectively. Moreover, some bacterial species were observed in all four Daqus. A total of 26 PLFAs between C12 to C20 were detected from the four Daqus by PLFA analysis. Wuling Daqu had the highest total and fungal biomasses, Baisha Daqu had the highest bacterial biomass, and Niulanshan Daqu had the highest ratio of fungal biomass to bacterial biomass. The Biolog results indicated differences in the carbon source use and mode of the four Daqus, and also demonstrated that each Daqu had varying abilities to utilize different types of carbon sources. The cluster analysis of the three methods showed that the microbial communities of the four Daqus were different. This study also demonstrates the applicability of the three analytical methods in the evaluating of the microbial communities of Daqus.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Paula C. J. Reis ◽  
Shoji D. Thottathil ◽  
Yves T. Prairie

AbstractPrevious stable isotope and biomarker evidence has indicated that methanotrophy is an important pathway in the microbial loop of freshwater ecosystems, despite the low cell abundance of methane-oxidizing bacteria (MOB) and the low methane concentrations relative to the more abundant dissolved organic carbon (DOC). However, quantitative estimations of the relative contribution of methanotrophy to the microbial carbon metabolism of lakes are scarce, and the mechanism allowing methanotrophy to be of comparable importance to DOC-consuming heterotrophy remained elusive. Using incubation experiments, microscopy, and multiple water column profiles in six temperate lakes, we show that MOB play a much larger role than their abundances alone suggest because of their larger cell size and higher specific activity. MOB activity is tightly constrained by the local methane:oxygen ratio, with DOC-rich lakes with large hypolimnetic volume fraction showing a higher carbon consumption through methanotrophy than heterotrophy at the whole water column level. Our findings suggest that methanotrophy could be a critical microbial carbon consumption pathway in many temperate lakes, challenging the prevailing view of a DOC-centric microbial metabolism in these ecosystems.


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