Formation of Se (0) Nanoparticles by Duganella sp. and Agrobacterium sp. isolated from Se-laden soil of North-East Punjab, India

Table 1 Phenotypic characteristics of four strains isolated after enrichment from Se-containing soils in north-east Punjab, India

Parameters (Growth in)	C1	C4	C6	C7
Liquid medium after 7 d	Single suspended cells		Clump formation
Nutrient agar	very good: white-yellow, flat colonies, 2–4 mm Ø	very good: white-yellow, flat colonies with dark raised center, 2–4 mm Ø	very good: white-yellow, flat colonies up to 3 mm Ø
Tryptic-Soy agar	very weak: orange-yellow, round colonies upto 1.5 mm Ø	no growth	very good: orange-yellow, round, little slimy colonies with raised yellow center and colorless edge upto 4 mm Ø	very good: orange-yellow, round, little slimy colonies with raised yellow center and colorless edge upto 2.5 mm Ø
Yeast-Malt agar	very good: white colonies with flattened center upto 2 mm Ø	very good: white colonies with flattened center upto 3 mm Ø	very good: yellowish-white, very slimy colonies with a dark center upto 4 mm Ø
Yeast-Mannitol agar with 0.025% Congo red			very good: slimy colonies, pink color > confirm Agrobacterium sp. as according to Bergey’s manual Rhizobium sp. forms white colonies on this medium
1/10 Tryptic-Soy broth + 100 μg/ml Cycloheximide (OD 578 nm)	0.477	0.467	0.716	0.618
Spore forming agar	very good: no spores observed under microscope
Growth on SP medium	−	+/−	+	+
Enzyme activity
α-Galactosidase	−	−	+	+
β-Glucuronidase	−	−	+/−	+
β-Galactosidase	−	+	+	+
β-Fucosidase	−	+	+	+
β-Glucosidase	−	−	+	+
Chitinase	+/−	+	+	+
Oxidase	+	+	+	+
Catalase	+	+	+	+
Gram-staining	−	−	−	−

All four strains did not form acids from L(+)-Arabinose, D(−)-Fructose, D(+)-Galactose, D(+)-Glucosamin, D(+)-Glucose, D-Glucuron acid, Glycerin, D(+)-Glycogen, meso-Inositol, Lactulose, D(+)-Maltose, Melibiose, L(+)-Rhamnose, D(−)-Ribose, D(−)-Salicin, L(−)-Sorbose, D(+)-Xylose. Only strain C 4 formed acids from D-arabinose.

ISSN: 1475-2859