Measurement of Bacterial Biomass as Lipopolysaccharide

Watson, SW; Je, Hobbie

doi:10.1520/stp36006s

Cited by 11 publications

(6 citation statements)

References 5 publications

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“…The latter technique is particularly useful with sediments as bacteria do not have to be quantitatively released from the sediment before analysis. The Limulus amoebocyte technique, although rather operator dependent (Watson et al 1977), is very sensitive and, in an ocean water column below the euphotic zone, biomass estimates based on LPS were in good agreement with others, such as ATP and direct counts (Watson & Hobbie 1979). Biomass measurements based on LPS will give a good estimate of the total bacterial biomass in other environments were Gram-negative bacteria dominate, e.g.…”

Section: 2 Bacterial Cell W a L L Constituentsmentioning

confidence: 70%

Characterization of microbial populations in polluted marine sediments

Parkes

Taylor

1985

Journal of Applied Bacteriology

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Summary The sediment environment is both heterogeneous and complex, and so too are the bacterial communities which develop within it. There are no simple, universal techniques available to characterize sediment microbial communities. Each method, even ones purporting to measure the same parameter (e.g. total bacterial biomass by ATP, LPS or direct counts plus volume estimates), tends to quantify a specific aspect of the microbial community. Hence, methods used to characterize bacterial populations within sediments need to be chosen carefully and with full awareness of the principles and limitations involved. An important point which also has to be considered is that biomass estimates, which may be equatable to activity for higher organisms, do not necessarily reflect metabolic activity when applied to bacteria (Meyer‐Reil et al. 1978). A large number of techniques for quantifying microbial populations require that the basic data be multiplied by conversion factors in order to obtain information which is both understandable and comparable with other data. These factors have to be used with caution, as they are often derived from laboratory isolates which may have very different properties and compositions from sediment bacteria. Also, as bacterial types change with depth within a sediment (Fig. 4), so too may the appropriate conversion factors. In this context there is obviously a need for more basic physiological information concerning sediment bacteria. In addition, if the characterization of bacterial populations within sediments is to play an effective role in the study of the impact of pollutants on the system in general, information is needed about the variability of microbial populations in both polluted and non‐polluted sediments. With all the problems associated with quantifying bacterial activity and populations within sediments it is tempting to ask the question 'Why bother to include micro‐organisms in any pollution study? The answer is that because they are the organisms that will respond rapidly to even small environmental changes, they provide the potential for positive action to be taken before damage to the higher trophic levels becomes irreversible.

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Section: 2 Bacterial Cell W a L L Constituentsmentioning

confidence: 70%

Characterization of microbial populations in polluted marine sediments

Parkes

Taylor

1985

Journal of Applied Bacteriology

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“…These values for mean cell volume and carbon per cell are comparable to those of other freshwaters (Table I). Average values of 0.22 pg bacterium-' (Dale 1974) for biomass and 10 fg C cell-' for carbon content (Watson & Hobbie 1979) were used to estimate biomass and the contribution of bacteria to total particulate carbon for Jan-Sept.…”

Section: Direct Microscopical Counts Of Microorganismsmentioning

confidence: 99%

Seasonal variation of nutrients, organic carbon, ATP, and microbial standing crops in a vertical profile of Pyramid Lake, Nevada

Hamilton-Galat

Galat

1983

Hydrobiologia

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Previous studies of Pyramid Lake, Nevada, led to the hypothesis that detritus could be an important food source for zooplankton because abundance of palatable algal species did not seem to bc enough to support the zooplankton community throughout the year. Furthermore, a large portion of the annual primary productivity was attributed to a nonpalatable blue-green alga, Nodularia spumigena. We felt this alga became important to the Pyramid Lake aquatic community upon death, as edible detritus and a source of new nitrogen. Changes in pelagic detritus concentrations and microbial standing crops were monitored to determine the availability of these potential foods. Epilimnetic particulate organic carbon (POC) was primarily living phytoplankton. During holomixis and following spring primary production, hypolimnetic POC was 60-97% detrital, but these profundal POC concentrations were low (ca 650 pg I-'). Detritus-bacteria aggregates were observed only following the September cyanophyte bloom.Although pelagic detritus availability for zooplankton was low, bacterial populations were sufficient to be at least a supplemental food source. Bacteria numbers ranged from0.50 106 to 24.7 lo6 m l l and increased in response to photosynthetic peaks. Microbial diversity, contribution to POC, and particle association were notable after July. The percentage of living carbon (assessed with ATP measurements) attributable to bacteria was highest in late summer and fall hypolimnetic samples.Patterns of change in organic phosphorus and nitrogen, the presence of a nitrogen-fixing cyanophyte, the N:P ratio, and results of other research demonstrated that non-nitrogen-fixing algae of Pyramid Lake are limited by inorganic nitrogen. The importance of N. spumigena to the aquatic community appeared to be as a source of new nitrogen, rather than as a forage; its mineralization is critical for the growth of palatable diatoms and green algae following winter mixing.

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“…There are relatively few data available to estimate the average ratio of protozoan : bacterial biomass beneath the euphotic zone. Mel'nikov (1977) examined phytoplankton, microzooplankton, and bacteria by direct microscopy at several stations in the eastern Pacific Ocean and found no phyto-and microzooplankton deeper than 200 m. Watson and Hobbie (1979) compiled a summary of estimates of bacterial biomass obtained by two independent methods along with total microbial biomass (bacteria, protozoa, sinking algae, etc.) measured by ATP concentrations.…”

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confidence: 99%