Serratia Marcescens ATCC Research Articles

Inducible xylitol dehydrogenases in enteric bacteria.

Morganella morganii ATCC 25829, Providencia stuartii ATCC 25827, Serratia marcescens ATCC 13880, and Erwinia sp. strain 4D2P were found to induce a xylitol dehydrogenase when grown on a xylitol-containing medium. The xylitol dehydrogenases were partially purified from the four strains, and those from M. morganii ATCC 25829, P. stuartii ATCC 25827, and S. marcescens ATCC 13880 were all found to oxidize xylitol to D-xylulose. These three enzymes had KmS for xylitol of 7.1 to 16.4 mM and molecular weights ranging from 130,000 to 155,000. In contrast, the xylitol dehydrogenase from Erwinia sp. strain 4D2P oxidized xylitol at the C-4 position to produce L-xylulose, had a Km for xylitol of 72 mM, and had a molecular weight of 102,000.

Cell-bound and secreted proteases of Serratia marcescens.

Exoprotease of Serratia marcescens ATCC 25419 is exceptional among members of the family Enterobacteriaceae in that it is secreted in large amounts by viable cells into the culture medium. Labeling of cells with radioactive amino acids revealed no intracellular protein that could be precipitated with antibodies raised against purified exoproteases. With substances known to interfere with the excretion of some proteins--tosyl-L-lysine chloromethyl ketone, phenethyl alcohol, procaine, and sodium azide--and with rifampin, an intracellular form (apparent molecular weight, 52,000) larger than the major exoform (molecular weight, 51,000) was identified. Moreover, the 52,000-molecular-weight form was the main protein in immunoprecipitates of a cysteine-auxotrophic mutant starved for cysteine. Beside the major exoform, protease I, two additional exoproteases, termed II and III, appeared in the medium of stationary cultures. They were precipitated by antibodies against protease I, were identical in the Ouchterlony double-diffusion assay, and exhibited only a small difference, if any at all, in the peptide pattern after partial hydrolysis with protease V8 of Staphylococcus aureus. The amino- and carboxy-terminal amino acid sequences of protease I and II were determined and found to be identical, NH2-Ala-Ala-Thr-Gly-Gly-Tyr-Asp-Ala-Val-Asp and Phe-Ile-Val-COOH, respectively. The microheterogeneity of the isolated exoforms revealed by anion-exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was also observed in samples pulse-labeled with radioactive amino acids. It remains to be determined whether the different protease forms are the result of processing (modification) reactions or whether they constitute isoenzymes encoded by very similar genes.

A manganese superoxide dismutase from serratia marcescens.

Superoxide dismutase was easily isolated from Serratia marcescens ATCC 21074 by ammoniumsulfate fractionation and Dyematrex Gel Green A chromatography. The purified enzymewas a manganese-containing protein with a molecular weight of 4.8×104. Combination of gel electrophoresis in dodecylsulfate and gel filtration showed that it was composed of two equal molecular subunits. The dimeric protein contained 1.5 g atoms of manganese and exhibited molecular extinction coefficients of 9.4×104 M-1cm-1 at 280 nmand 8.9×102 M-1cm-1at 470 nm. The enzyme showed similarities with manganese superoxide dismutases from other prokaryotes.

Excretion of a protease by Serratia marcescens.

Excretion of an extracellular protease of Serratia marcescens ATCC 25419 occurred during logarithmic growth and was highest (per cell) when cultures reached the stationary growth phase. Production of the extracellular protease was induced by leucine or casein in minimal medium or by growth in tryptone-yeast medium. In the late stationary phase an intracellular protease activity accumulated which was also observed in mutants with very low extracellular protease activity. The excreted protease was the dominant protein in the growth medium. The protease was purified to homogeneity by column chromatography on Bio-Gel P-100 and on DEAE-cellulose. Quantitative amino acid analysis revealed the absence of sulfur-containing amino acids. The enzyme consists of one polypeptide chain. A molecular weiht of 51,000 and 55,000 was estimated using polyacrylamide gel electrophoresis and chromatography on Bio-Gel P-100 respectively. The enzyme cleaved only N-alpha-benzoyl-DL-lysine-and-arginine-nitroanilides but not the corresponding leucine or tyrosine derivatives nor a set of di- and tripeptides.

Purification and characterization of the extracellular proteinase of Serratia marcescens

The extracellular proteinase produced by a derepressed strain of Serratia marcescens ATCC 25419 was purified and characterized. This strain produces more than 10-times the amount of extracellular proteinase produced by other strains of Serratia tested. The purified enzyme was prepared from the culture supernatant by (NH 4) 2SO 4 fractionation and DEAE-cellulose chromatography. The purified enzyme has an s 20, w 0 of 3.95 and is a monomer of molecular weight 51 900. The proteinase has a broad pH optimum in the alkaline range with a maximum at pH 9.5. The enzyme will utilize a number of proteins as substrate. The products of digestion are primarily in the size range of tripeptides to hexapeptides. Peptides containing a sensitive bond and a minimum size of six amino acids are hydrolyzed. The proteinase is inhibited by chelating agents but unaffected by sulfhydryl or serine reagents and is devoid of esterase activity.

The survival of airborne Serratia marcescens in urban concentrations of sulfur dioxide.

Aerosols of Serratia marcescens ATCC 274 were suspended in a 709L rotating drum at 20 ± 1 °C and high to mid-range relative humidities. At specified times after bacterial aerosolization, sulfur dioxide was added to concentrations of 2.5, or 5 mg/m3. Viable cell decay rate constants, in control aerosols without added sulfur dioxide, increased rapidly from near 100% to 60% RH in the first hour (termed: young aerosol) of suspension, and from a minimum rate constant at 80% in the succeeding four hours (termed: old aerosol).Upon addition of sulfur dioxide to a cloud of S. marcescens, generally, viable cell decay rate constants increased further. One exception was at 80% relative humidity where maximum resistance to SO2 accelerated death was observed for old aerosols. Cells in young aerosols were particularly sensitive to SO2 addition at mid-range humidities, while in older aerosols the cells were insensitive to up to 5 mg SO2/m3 introduced at high RH; but were up to 10 times more sensitive than cells in young aerosols to a given increase (from 2.5 to 5 mg/m3) in SO2 concentration at mid-range humidities.

Production of N-Succinyl-L-diaminopimelic Acid by Auxotrophic Mutants of Aerobacter aerogenes and Serratia marcescens

α,e-Diaminopimelic acid (DAP)-requiring mutants isolated from Aerobacter aerogenes ATCC 8308 and Serratia marcescens ATCC 19180 were found to accumulate N-succinyl-l-diaminopimelic acid (SDAP) which was an intermediate in the biosynthesis of lysine in Escherichia coli. SDAP was isolated from the culture broth and identified by the behavior in paper chromatography, melting point, elementary analysis, infrared spectrum, and optical rotation.The culture conditions for SDAP production by A. aerogenes KY 7049 (DAP−) and S. marcescens KY 8921 (DAP−/Lys−) were investigated. A. aerogenes KY 7049 has an absolute requirement for DAP together with a relative requirement for l-lysine. High levels of DAP (2000~4000 μg/ml) were proved to be favorable for SDAP accumulation, while if lysine along with DAP was added to the fermentation medium, optimal level of DAP for SDAP production was relatively low (about 200 μg/ml at 200 μg/ml of lysine). A variety of compounds which may conceivably affect the course of a fermentatio...

Production of Tumor-Inhibitory L-Asparaginase by Submerged Growth of Serratia marcescens1

Production of a tumor-inhibitory asparaginase by submerged fermentation with Serratia marcescens ATCC 60 was studied to ascertain optimal nutritional conditions for large-scale production leading to enzyme purification studies. Five strains of S. marcescens were screened in shake-flask studies and were found to produce 0.8 to 3.7 IU/ml 48 hr after inoculation. The requirements for asparaginase production with S. marcescens ATCC 60, the high producing strain, included the following: 4% autolyzed yeast extract medium (initial pH 5.0), an incubation temperature of 26 C, and limited aeration for a zero level of dissolved oxygen during the fermentation. Addition of various carbohydrates to the fermentation medium did not enhance yields. The peak cell population in the fermentation medium and the maximal asparaginase yields occurred simultaneously. Highest enzyme yields were found when the pH of the fermentation cycle rose to approximately 8.5. Yields of 4 IU of asparaginase/ml of cell suspension have been obtained consistently in 40 to 42 hr from 10-liter volumes (500 ml/4-liter bottle) produced on a reciprocating shaker. Scale-up to a 60-liter fermentor yielded 3.1 IU/ml in 35 hr.

BACTERIA CAN PENETRATE ROCK

A method is described for studying the penetration of bacteria in intact rock cores. The test microorganism (Serratia marcescens ATCC No. 274) was labelled with radioactive phosphorus (32P) and suspended in sterile demineralized water. The cell suspension was allowed to enter the epoxy-coated rock core under atmospheric pressure. Penetration and migration of the labelled microorganisms were followed by measuring the radiation emitted at ports drilled through the epoxy coating, at various locations throughout the length of the core, and at various intervals of time after the beginning of the experiment. When migration was considered to be complete the core was aseptically split longitudinally and the results of the radiation studies confirmed by autoradiogram and culture. S. marcescens passed through 14.25 in. of Berea sandstone (the longest core available), and through 3-in. cores (longest available) of Mississippian limestone, Early Devonian limestone, and Late Mesozoic sandstone. The significance of these findings is discussed with respect to presence of so-called prehistoric microorganisms in geological specimens.