Ice core bacteria data from RVIB Nathaniel B. Palmerand ARSV Laurence M. Gould cruises NBP0104, LMG0106, NBP0204,and LMG0205 in the Southern Ocean from 2001-2002 (SOGLOBEC project; Sea Ice Microbes project)

<h2>Bacteria Abundance, Biomass and Chlorophyll <em>a</em> in Ice Cores</h2>

<p><strong>NOTES:</strong><br />
NBP0104: Cores labelled with \"DNA\" were collected for DNA analysis.</p>

<pre>

<strong>Contributor:</strong>
Dr. Christian Fritsen
University and Community College System of Nevada
Desert Research Institute
Div. of Earth and Ecosystem Sciences
2215 Raggio Parkway
Reno, NV 89512

Office: 775/673-7487

</pre>

<h3>BG 235 - Methods used for chlorophyll <em>a</em> (chla) analysis and bacteria biomass determination</h3>

<p><strong>Core Sampling techniques:</strong></p>

<p>Sampling methods for recovery of chlorophyll <em>a</em> and bacteria from sea ice cores follows those described in:<br />
Garrison, D.L. and K.R. Buck(1986), Organism losses during ice melting: a serious bias in sea ice community studies. <em>Polar Biol.</em>, <strong>6</strong>:237-239.</p>

<p>Recommendations for reporting were used as outlined by:<br />
Horner, R. <em>et al.</em>,(1992), Ecology of Sea Ice Biota. I: Habitat, Terminology and Methodology. <em> Polar Biol.</em> <strong>12</strong>:417-427</p>

<p><strong>Analytic Techniques:</strong></p>

<p>Chla (mg m^-3):</p>

<ul>
<li>determined fluorometrically (Turner Designs 10AU Fluorometer) following extraction in 90% acetone (Parsons <em>et al</em>., 1984)</li>
<li>ice core chla corrected to account for chla in filtered sea water (FSW) added to core sections during melting</li>
</ul>

<p>Bacteria cell abundance (cells m^-3) and biomass (mg C m^-3):</p>

<p>LMG 0106</p>

<ul>
<li>preserved (0.5% glutaraldehyde) samples stained with 4',6-diamidino-2-phenylindole (DAPI; 0.1 to 0.3% final concentration), filtered through 0.2 mm black, polycarbonate membrane filters, and mounted onto glass microscope slides on the ship (within 24 hours following collection)</li>
<li>bacteria enumerated using epifluorescence microscopy and sized using digital images taken with Image Pro Plus</li>
<li>bacteria biomass determined using cell abundance, cell biovolume (BV; mm³; as determined from mean length and width measurements), and an allometric conversion factor for bacterial carbon per volume specific for DAPI-stained bacteria (cellular carbon = 218 X BV^0.86; Loferer-Kribacher <em>et al.</em>, 1998).</li>
<li>ice core samples corrected for FSW dilution</li>
</ul>

<p>NBP 0104</p>

<ul>
<li>preserved (0.5% glutaraldehyde) samples stained with Sybri Gold (0.01% final concentration), filtered through 0.2 mm Anodisc filters (Whatman), and mounted onto glass microscope slides at home institution (~1-2 months following collection)</li>
<li>bacteria enumerated using epifluorescence microscopy and sized using digital images taken with Image Pro Plus</li>
<li>bacteria biomass determined using cell abundance, cell biovolume (BV; mm³), and an allometric conversion factor for bacterial carbon per volume specific for Acridine Orange-stained bacteria (cellular carbon = 89.9 X BV^0.59; Simon and Azam, 1989). Note: an AO-specific carbon per volume conversion factor was used in calculating biomass in Sybri Gold-stained samples because both AO and Sybri Gold stain bacteria cells similarly relative to DAPI (unpublished data).</li>
<li>ice core samples corrected for FSW dilution</li>
</ul>

<p>Loferer-Kribacher, M., Klima, J., and R. Psenner. 1998. Determination of bacterial cell dry mass by transmission electron microscopy and densitometric image analysis. Applied and Environmental Microbiology. 64:688-694.</p>

<p>Parsons,T.R., Maita, Y., and C.M. Lalli. 1984. A manual of chemical and biological methods for seawater analysis. Pergamon Press. Elmsford, New York.</p>

<p>Simon, M., and F. Azam. 1989. Protein content and protein synthesis rates of planktonic marine bacteria. Marine Ecology Progress Series. 51, 201-213.</p>

<p><em>updated: April 20, 2006</em></p>