16S rRNA-Based Identification of a Glucan-HyperproducingWeissella confusa

Abstract

A gram-positive, nonmotile, irregular, short, rod-shaped new strain of Weissella confusa bacterium was isolated from fermented cabbage. The isolate was physiologically and biochemically characterised. The 16S rDNA was amplified by polymerase chain reaction (PCR). The isolate was identified as Weissella confusa (GenBank accession number: GU138518.1) based on nucleotide homology and phylogenetic analysis. The isolate produces glucansucrase when grown in sucrose-supplemented culture medium which catalyses glucan formation. This novel isolate possesses high capacity of industrial use due to its high productivity of glucan (34 mg/mL) as compared to other strains reported. The optimum temperature for glucansucrase production was 25°C. The shaking condition gave an enzyme activity of 6.1 U/mL which was 1.5 times higher than that given by static condition (4.1 U/mL). The temperature 35°C, pH 5.4, and ionic strength 10–20 mM were optimum for enzyme assay. This investigation unraveled the abundance of industrially valuable microflora of the north east India.

Development of Efficient Fermentation Process at Bioreactor Level by Taguchi's Orthogonal Array Methodology for Enhanced Dextransucrase Production from <i>Weissella confusa</i> Cab3

“…were 25˚C, 7.0 and 180 rpm, respectively for dextransucrase production from Weissella confusa Cab3 as reported earlier [19]. Weissella confusa Cab3 grew well within the range of pH 5.0 to 7.0, and temperature 20˚C to 45˚C however Weissella confusa Cab3 produced maximum dextransucrase (6.0 U/ml) at pH 7.0 and 25˚C in the enzyme production medium [19]. As reported earlier, the effects of several medium components were investigated and sucrose, Tween80, yeast extract and K 2 HPO 4 were effective nutrients which displayed higher dextransucrase production [20].…”

“…Selected factors and their assigned levels for dextransucrase production by Weissella confusa Cab3. were 25˚C, 7.0 and 180 rpm, respectively for dextransucrase production from Weissella confusa Cab3 as reported earlier [19]. Weissella confusa Cab3 grew well within the range of pH 5.0 to 7.0, and temperature 20˚C to 45˚C however Weissella confusa Cab3 produced maximum dextransucrase (6.0 U/ml) at pH 7.0 and 25˚C in the enzyme production medium [19].…”

“…The bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) isolated from fermented cabbage [19] was used for optimization of medium composition for dextransucrase production. The organism was maintained in MRS medium [21] stabs incubated at 25˚C, stored at 4˚C and subcultured every two weeks.…”

“…Fermentation experiments were carried out using Weissella confusa Cab3, subcultured and grown (12 -14 h old) in medium described by Tsuchiya et al, 1952 [22] at optimised culture conditions i.e. 25˚C and 180 rpm [19]. The pH of the medium was adjusted to 7.0 using 2M HCl solution.…”

“…However Weissella confusa is a very potent candidate for dextran production in the sense that it has high dextran yield and the dextran produced by this strain is more linear in nature thus finds its place in food industries. In our earlier reports, the dextransucrase and dextran production capacity by a fermented cabbage isolate Weissella confusa Cab3 were studied [19]. Weissella confusa Cab3 produced dextransucrase (6.0 U/ml) in medium described by Tsuchiya et al, 1952.…”