Chemistry and Metabolism of Intracellular Reserves

Preiss, Jack

doi:10.1007/978-1-4613-0803-4_3

Cited by 34 publications

(14 citation statements)

References 303 publications

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“…The occurrence of polyphosphates in these sediments indicates P storage by algae and/or bacteria under conditions of excess phosphate, a phenomenon referred to as "luxury consumption" (Dawes & Senior, 1973;Kulaev, 1979;Preiss, 1989). Intracellular polyphosphate accumulation can be large, accounting for up to 20% of cell dry weight (Deinema et al, 1980).…”

Section: Polyphosphates: Indicators Of Luxury P Consumptionmentioning

confidence: 99%

Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation

Laarkamp¹

2000

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Phosphorus, an essential nutrient, is removed from the oceans only through burial with marine sediments. Organic phosphorus (Po,g) constitutes an important fraction (ca. 25%) oftotal-P in marine sediments. However, given the inherent lability of primary Po,g biochemicals, it is a puzzle that any Pm, is preserved in marine sediments. The goal of this thesis was to address this apparent paradox by linking bulk and molecular-level Po" information.A newly-developed sequential extraction method, which isolates sedimentary Po" reservoirs based on solubility, was used in concert with 3lp nuclear magnetic resonance spectroscopy (31p_NMR) to quantify Po,g functional group concentrations. The coupled extraction/ 31 P-NMR method was applied to three sediment cores from the Santa Barbara Basin, and the first-ever high-resolution depth profiles of molecular-level Po,g distribution during diagenesis were generated.These depth profiles were used to consider regulation of Pm, distribution by biomass abundance, chemical structure, and physical protection mechanisms. Biomass cannot account for more than a few percent of sedimentary Po,g. No evidence for direct structural control on remineralization of Po,g was found. Instead, sorptive protection appears to be an important mechanism for Po,g preservation, and structure may act as a secondary control due to preferential sorption of specific Pm, compound classes.

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Section: Polyphosphates: Indicators Of Luxury P Consumptionmentioning

confidence: 99%

Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation

Laarkamp¹

2000

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“…Stationary-phase Escherichia coli cells are resistant to high temperature, high concentrations of H202 (12), and very high medium osmolarity (11). During entry into stationary phase, glycogen is synthesized as a storage compound (23). Although overall protein synthesis is reduced, expression of at least 30 to 50 proteins is stimulated (10).…”

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confidence: 99%

Growth phase-regulated expression of bolA and morphology of stationary-phase Escherichia coli cells are controlled by the novel sigma factor sigma S

1991

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The novel sigma factor (as) encoded by rpoS (katF) is required for induction of many growth phase-regulated genes and expression of a variety of stationary-phase phenotypes in Escherichia coli. Here we demonstrate that wild-type cells exhibit spherical morphology in stationary phase, whereas rpoS mutant cells remain rod shaped and are generally larger. Size reduction of E. coli cells along the growth curve is a continuous and at least biphasic process, the second phase of which is absent in rpoS-deficient cells and correlates with induction of the morphogene bol in wild-type cells. Stationary-phase induction of boUl is dependent on as. The "gearbox," a characteristic sequence motif present in the cS-dependent growth phase-and growth rate-regulated bolAp1 promoter, is not recognized by cs, since stationary-phase induction of the mcbA promoter, which also contains a gearbox, does not require rs, and other crs-controlled promoters do not contain gearboxes. However, good homology to the potential -35 and -10 consensus sequences for crs regulation is found in the bolAp, promoter.

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“…When limited for N, some pure cultures of microbes respond to excess carbohydrate by accumulating reserve carbohydrate (35), whereas others spill energy (3). This study determined whether mixed cultures of rumen microbes would respond by accumulat- ing reserve carbohydrate, spilling, or both.…”

Section: Discussionmentioning

confidence: 99%

Quantifying the Responses of Mixed Rumen Microbes to Excess Carbohydrate

Hackmann

Diese

Firkins

2013

Appl Environ Microbiol

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The aim of this study was to determine if a mixed microbial community from the bovine rumen would respond to excess carbohydrate by accumulating reserve carbohydrate, energy spilling (dissipating excess ATP energy as heat), or both. Mixed microbes from the rumen were washed with N-free buffer and dosed with glucose. Total heat production was measured by calorimetry. Energy spilling was calculated as heat production not accounted by (i) endogenous metabolism (heat production before dosing glucose) and (ii) synthesis of reserve carbohydrate (heat from synthesis itself and reactions yielding ATP for it). For cells dosed with 5 mM glucose, synthesis of reserve carbohydrate and endogenous metabolism accounted for nearly all heat production (93.7%); no spilling was detected (P ‫؍‬ 0.226). For cells dosed with 20 mM glucose, energy spilling was not detected immediately after dosing, but it became significant (P < 0.05) by approximately 30 min after dosing with glucose. Energy spilling accounted for as much as 38.7% of heat production in one incubation. Nearly all energy (97.9%) and carbon (99.9%) in glucose were recovered in reserve carbohydrate, fermentation acids, CO 2 , CH 4 , and heat. This full recovery indicates that products were measured completely and that spilling was not a methodological artifact. These results should aid future research aiming to mechanistically account for variation in energetic efficiency of mixed microbial communities.

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Chemistry and Metabolism of Intracellular Reserves

Cited by 34 publications

References 303 publications

Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation

Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation

Growth phase-regulated expression of bolA and morphology of stationary-phase Escherichia coli cells are controlled by the novel sigma factor sigma S

Quantifying the Responses of Mixed Rumen Microbes to Excess Carbohydrate

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