This README_Villegas-Mendoza_et_al_2021.txt file was generated on 2021-03-09 by Josué Villegas-Mendoza (JVM), Eliana Gómez-Ocampo (EGO), Diana Rodríguez-Escobar (DRE) and Jorge Velásquez-Aristizábal (JVA) GENERAL INFORMATION 1. Title of Dataset: Microbial Metabolic Activity in Two Basins of the Gulf of Mexico Influenced by Mesoscale Structures 2. Author Information A. Principal Investigator Contact Information Name: Josué Villegas-Mendoza (ORCID: https://orcid.org/0000-0001-5614-3375) Institution: Universidad Autónoma de Baja California Address: Carretera Tijuana-Ensenada km 106, Ensenada, Baja California 22860, Mexico Email: jvillegas18@uabc.edu.mx B. Alternate Contact Information Name: Diana Rodríguez-Escobar (ORCID: https://orcid.org/0000-0002-1590-8746) Institution: Universidad Autónoma de Baja California Address: Carretera Tijuana-Ensenada km 106, Ensenada, Baja California 22860, Mexico Email: drodriguez41@uabc.edu.mx C. Alternate Contact Information Name: Eliana Gómez-Ocampo (ORCID: https://orcid.org/0000-0001-5593-7595) Institution: Universidad Autónoma de Baja California Address: Carretera Tijuana-Ensenada km 106, Ensenada, Baja California 22860, Mexico Email: eliana.gomez.ocampo@uabc.edu.mx D. Alternate Contact Information Name: Jorge Velásquez-Aristizábal (ORCID: https://orcid.org/0000-0003-2842-0931) Institution: Universidad Autónoma de Baja California Address: Carretera Tijuana-Ensenada km 106, Ensenada, Baja California 22860, Mexico Email: velasquez.jorge@uabc.edu.mx 3. Date of data collection: First oceanographic campaign ("Malla fina 1": MMF-01) from 2021-03-04 to 2021-03-23. Second oceanographic campaign ("Malla fina 2": MMF-02) from 2021-09-19 to 2021-09-29. 4. Geographic location of data collection: Two Gulf of Mexico basin's, Perdido (~25–26°N, 95–96°W) and Coatzacoalcos (~19–21°N, 94–95°W) 5. Information about funding sources that supported the collection of the data: These data were obtained from a study that was funded by Secretaría de Educación Pública through grants SEP UABC‐PTC‐702: 511‐6/17‐8051 (to JVM) and grant PRODEP 511-6/2019.-11768 (to EGO), and by the Hydrocarbon Fund of Consejo Nacional de Ciencia y Tecnología – Secretaría de Energía, through grants No. 201441 and No. 201441. This is a contribution of the Consorcio de Investigación del Golfo de México (CIGOM). SHARING/ACCESS INFORMATION Recommended citation for this dataset: Villegas-Mendoza, J., Rodriguez-Escobar, D., Gomez-Ocampo, E., & Velasquez-Aristizabal, J. (2021) Microbial Dynamics in Mesoscale Structures in Two Basins of the Gulf of Mexico. Manuscript submitted for publication DATA & FILE OVERVIEW 1. File List: One EXCEL file: continuos data (CTD) and discrete data (bottle samples): Villegas-Mendoza_et_al_2021_Dataset.xlsx 2. Relationship between files, if important: discre 3. Additional related data collected that was not included in the current data package: 4. Are there multiple versions of the dataset? no METHODOLOGICAL INFORMATION Water samples were collected with Niskin oceanographic bottles at five depth levels (0.1% and 30% light, maximum fluorescence, minimum oxygen, and 500 m) at three stations in each of the study basins, Perdido and Coatzacoalcos. *CTD data Dissolved oxygen, practical salinity, chlorophyll fluorescence, and in-situ temperature data acquired with a CTD instrument from surface to 500 m. * Community and Bacterial Respiration Rates Water samples from different depth levels were incubated in triplicate in 100 mL BOD bottles previously rinsed with 3% hydrogen peroxide (H2O2) and fitted with oxygen-sensitive patches (SP-PSt3-NAU-YOP). Samples for assessing community respiration were collected directly from BOD bottles; samples for bacterial respiration were filtered through 1-µm pore size polycarbonate filters. All the bottles were incubated for 24 hours in the dark under controlled temperature (18 ± 1 °C) (Bondyale-Juez et al., 2017). Oxygen concentration at different times was recorded with optode sensors using the Fibox 4 system (PreSens, Regensburg, Germany) (Villegas-Mendoza et al., 2019). Oxygen optode sensors provide continuous measurements (at intervals of seconds to minutes) with high accuracy (± 0.14–2.83 µmol and ± 1.4–283.1 µmol; 15 ppb detection limit). Bacterial growth efficiency was calculated as the ratio between bacterial production and (bacterial production plus bacterial respiration). * Bacterial Abundance Bacterial abundance was determined in 10 mL samples from each depth; the samples were fixed with 2% formaldehyde solution. A 0.5–1.0 mL aliquot of the sample was incubated with DAPI and filtered immediately through 0.2 µm black polycarbonate filters (Poretics). Cells were counted with an Eclipse Ti-E inverted microscope (Nikon Instruments Inc.) and the image analysis software Nikon NIS-Elements (Kirchman D., 1993). * Bacterial Production Bacterial production was determined by estimating protein synthesis with the micro-centrifugation technique developed by Smith and Azam (1992). Triplicate 1.5 mL water samples were spiked with 3H-leucine (Perkin Elmer, specific activity 123 Ci mmol^-1) and incubated for at least 3.5 hours in the dark at 18°C; 100 μL of cold 100% TCA were spiked into the control replicates. Afterwards, 1 mL of EcoLume liquid scintillation cocktail (MP Biomedicals) was added and mixed; bacterial 3H emission was measured with a Beckman LS6500 counter to estimate organic carbon assimilation (bacterial production, in µg C L^-1 d^-1). A constant 0.073 value for the leucine/protein fraction was used, assuming that leucine is not transformed into other amino acids. This value was multiplied by the carbon-protein cell ratio (0.86) and the isotopic dilution (2) (Smith & Azam, 1992). References * Bondyale-Juez, D. R., Packard, T. T., Viera-Rodríguez, M. A., & Gómez, M. (2017). Respiration: comparison of the Winkler technique, O2 electrodes, O2 optodes and the respiratory electron transport system assay. Marine Biology, 164(12), 1–11. https://doi.org/10.1007/s00227-017-3271-1 * Kirchman D (1993) Statistical analysis of direct counts of microbial abundance. In:Kemp PF, Sherr BF, Sherr EB, Cole JJ (eds) Handbook of methods in aquatic microbial ecology. Lewis Publishers, Boca Raton, FL, p 117−119 * Smith, D. C., & Azam, F. (1992). A simple, economical method for measuring bacterial protein synthesis rates in seawater using 3H-leucine. Marine Microbial Food Webs, 6(2), 107–114. Retrieved from http://scrippsscholars.ucsd.edu/fazam/content/simple-economical-method-measuring-bacterial-protein-synthesis-rates-seawater-using-3h-leucine * Villegas-Mendoza, J., Cajal-Medrano, R., & Maske, H. (2019). The Chemical Transformation of the Cellular Toxin INT (2-(4-Iodophenyl)-3-(4-Nitrophenyl)-5-(Phenyl) Tetrazolium Chloride) as an Indicator of Prior Respiratory Activity in Aquatic Bacteria. International journal of molecular sciences, 20(3), 782. https://doi.org/10.3390/ijms20030782