Serratia

Abstract

Ser.ra' ti.a . M.L. fem. n. Serratia named after Serafino Serrati, an Italian physicist. Proteobacteria / Gammaproteobacteria / Enterobacteriales / Enterobacteriaceae / Serratia Straight rods , 0.5–0.8 × 0.9–2.0 µm in length, with rounded ends. Conform to the general definition of the family Enterobacteriaceae . Gram negative, generally motile , by means of peritrichous flagella. Facultatively anaerobic. Nitrate and chlorate are reduced anaerobically. Growth factors are generally not required . Colonies on nutrient agar are most often opaque, somewhat iridescent, and either white, pink, or red in color . Almost all strains can grow at temperatures between 10 and 36°C, at pH 5–9, and in the presence of 0–4% (w/v) NaCl. The catalase reaction is strongly positive. d ‐ Glucose is fermented through the Embden–Meyerhof pathway. The major glucose entry route involves a phosphoenolpyruvate‐dependent phosphotransferase system with both enzyme II Glc (glucose permease) and enzyme II Man (mannose permease). Glucose is also oxidized to gluconate in the presence of pyrroloquinoline quinone. Gluconate is oxidized to 2‐ketogluconate. Acetoin is produced from pyruvate by all species except S. fonticola . Fructose, D ‐galactose, maltose, D ‐mannitol, D ‐mannose, ribose, and trehalose are fermented and utilized as sole carbon sources. L ‐fucose is fermented and utilized as sole carbon source by all species except S. fonticola . L ‐sorbose is not fermented or utilized as sole carbon source. All species but S. fonticola fail to ferment or utilize dulcitol and tagatose. N ‐acetylglucosamine, D ‐alanine, L ‐alanine, citrate, D ‐galacturonate, D ‐glucosamine, D ‐glucuronate, 2‐ketogluconate, L ‐proline, putrescine, L ‐serine are utilized as sole carbon sources by most strains. Caprate, caproate, caprylate , and tyrosine are utilized as sole carbon sources by all species except S. fonticola . 5‐Aminovalerate, butyrate, m ‐coumarate, ethanolamine and tryptamine are not utilized as sole carbon sources. All species except S. fonticola fail to utilize 3‐phenylpropionate. All species except S. entomophila fail to utilize itaconate. Phenylalanine, histidine, and tryptophan deaminases and thiosulfate reductase (H 2 S from thiosulfate) are not produced. o ‐ Nitrophenyl ‐β‐ d ‐ galactopyranoside (ONPG) is hydrolyzed by most strains . Esculin is hydrolyzed by most strains except S. proteamaculans subsp. quinovora . Extracellular enzymes of all species except S. fonticola hydrolyze DNA, lipids (tributyrin, corn oil) and proteins (gelatin, casein), but not starch (in four days), polygalacturonic acid, or pectin. Tween‐80 is hydrolyzed by all species except S. odorifera . The organisms occur in the natural environment (soil, water, plant surfaces) or as opportunistic human pathogens . The mol % G + C of the DNA is : 52–60. Type species : Serratia marcescens Bizio 1823, 288.

A collection ofSerratia marcescensdiffering in their insect pathogenicity towardsManduca sextalarvae

“…For the 12 strains which grew well on mannitol-salt agar at 25°C, only two still grew at 37°C, and those two grew poorly ( Table 2). These results are consistent with those expected for a population of S. marcescens [32] because all strains of S. marcescens ferment mannitol as the sole carbon and energy source and, even though 0.5% NaCl is the optimal salt concentration for growth, > 90% of strains grew in 7% NaCl, 11-89% grew in 8.5% NaCl, and none grew in 10% NaCl [32]. Interestingly, the three red pigmented strains (KWN, Nima, and D1) were colorless when growing on the high salt mannitol plates at 25°C ( Table 2).…”

“…This conclusion agrees with the observations of Zhou et al [31] who found that 8 pigmented and non-pigmented strains of S. marcescens had equivalent LD 50 values towards larvae of the silkworm Bombyx mori. In agreement with the findings of Grimont and Grimont [24,32], the red pigmentation by prodigiosin was only observed for biotypes A1 and A2 (Table 1). All strains produced large capsules when grown on the defined, high C/N Gauger's medium [16].…”

“…Interestingly, the three red pigmented strains (KWN, Nima, and D1) were colorless when growing on the high salt mannitol plates at 25°C ( Table 2). It is well known that pigmentation is determined in part by cultural conditions, including amino acids, carbohydrates, pH, temperatue, and inorganic ions, and that prodigiosin is not made anaerobically [32]. Now we know that prodigiosin is not made on mannitol-salt agar plates.…”

“…One strain (5384) caused the bile salts in the SMAC plates to precipitate. The uniform ability to metabolize sorbitol was expected because S. marcescens is characterized by the ability to ferment sorbitol but not arabinose, rhamnose, or xylose [32,35]. Additionally, the ability to metabolize other more unusual carbon sources helps define an organism's biotype.…”

Effect of Certain Compounds on the Pigmentation Characteristis of Some Bacterial Isolates

“…The best known prodigiosin is a linear tripyrrole attach to the cytoplasmic membrane (Vinas et al, 1983;Parachuri and Harshey, 1987). Some strains of S. marcescens belonging to the biotype A 40 synthesise a rose coloured diffusible pigment pyrimine (Grimont and Grimont, 1984) Tyrosinase is a copper containing enzyme which catalyzes the first reaction of the melanogenesis pathway.…”