Table 1 Phenotypic and molecular characteristics of Chromobacterium vialoceum strain TRFM-24

Colony feature after 24-h growth

Growth on TSA, BHI, MacConkey agar, NA: Light purple, circular, smooth, entire, convex, size 0.5 mm and non-flourescent

KB agar: pin point colony with no pigmentation; LB agar: dark purple, circular, smooth, entire, convex, size 1.0 mm and non-flourescent

Cell shape

rod

Gram reaction

-ve

Catalase test

+ve

Oxidase test

+ve

Arginine dihydrolysis

+ve

Urease hydrolysis

-ve

Citrate utilization

+ve

Indole production

-ve

Triple sugar agar

+ve for glucose fermentation

H₂S production

-ve

Nitrate reduction

-ve

Methyl red

+ve

Voges–Proskauer

-ve

Starch hydrolysis

+ve

Gelatin hydrolysis

+ve

Cellulose hydrolysis

+ve

Lipase production

-ve

Anaerobic growth

Poor growth with no pigment production

Haemolysis test on blood agar

+ve

DNAse test

+ve

Growth at different pH & temperatures

Optimum growth: pH 6 to 9

No growth: below 5 and above 12 pH

Optimum growth: 30 °C

No growth: at 10 °C & 45 °C

Acid formation: sugar utilization

Fully utilized: fructose and mannose

Poorly utilized: dextrose, inulin, cellobiose and xylose

Amino acid utilization

Arginine, ornathine and lysine

Chemotaxonomy

  Fatty acid profiling (Sim: 0.6)

C_16:1ω7c (32.7%), C_16:0 (26.3%), C_18:1ω7c (16.9%), C_12:0 (6.2%), C_10:0 (4.8%) and C_{12:0–3 OH} (4.1%)

Molecular analysis

  16S rRNA gene sequence analysis & identity

GenBank Accession MK 841034 with similarity to C. violaceum ATCC 12472