Advantages and disadvantages of various radioisotopic methods for measuring bacterial production are reviewed. To unraval the problems of each method, a new technique for measuring bacterial phospholipid-phosphorus (PL-P) production using $\sp{32}$P was developed. The major findings in developing the PL-P method are that: (1) specific activity of the phospholipids is the same as that of the medium, indicating that $\sp{32}$P is incorporated into PL-P at the same rate as the phosphorus in the medium, and (2) the labeling pattern of $\sp{32}$P into the phospholipids follows the macromolecular labeling pattern. / Bacterial production in the hydrocarbon seep area on the Louisiana slope, measured by the PL-P method, was strikingly high with the range from 0.03 to 1.16 g C m$\sp{-3}$ per generation. The methanotrophic or methylotrophic bacterial production related to methane and other hydrocarbon seepage seem to be a major contributing factor for the high bacterial production. Pulse-labeling experiments using size fractionation showed that bacterial growth and relative biomass were associated with particles larger than 64 $\mu$m in the hydrocarbon seep. The large and metabolically active bacterial aggregates suggest that the aggregates may serve as a trophic intermediate between bacterial carbon and seep heterotrophic benthic fauna. / Unrelated to the previous topics, the microbial aspect of polonium-210 solubilization from phosphogypsum, was also studied. Polonium-210, the last $\alpha$ emitting radionuclide in the natural uranium-238 decay series, is toxic when ingested or inhaled. Several laboratory column experiments demonstrated that polonium release in the phosphogypsum was clearly related to the bacterial activity. Sulfate reducing bacteria (SRB) play a significant role in the Po release. However, the accumulation of sulfide caused by the respiration of SRB removed the released Po by forming metal sulfide co-precipitation. Nutrient depletion in the ground water causes a decline of bacterial activity, and therefore the Po release in the ground water is probably controlled by nutrient availability affecting bacterial growth. / Source: Dissertation Abstracts International, Volume: 55-11, Section: B, page: 4736. / Major Professor: Paul A. LaRock. / Thesis (Ph.D.)--The Florida State University, 1994.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_77298 |
| Contributors | Hyun, Jung-Ho., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 142 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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