Isolation and Characterization of Bacterial Strains with Inulinase Activity

Abstract

Thirty-two bacterial strains growing on inulin as the sole carbon and energy source were isolated from soil samples by enrichment culture on a mineral medium. Twenty of the strains were identified as Flavobacterium multivorum. All the bacteria contained a I-fructosidase that was active on both inulin and sucrose. The enzyme activity was cell bound and was produced at the end of the growth phase. These enzymes have potential uses in the preparation of fructose syrups from inulin and invert sugar from sucrose.

Characteristics of an inulinase produced by Bacillus subtilis 430A, a strain isolated from the rhizosphere of Vernonia herbacea (Vell Rusby)

“…Total enzyme activity was inhibited at a fructose concentration of 14 mM, which is Several inulinases have been isolated from yeasts, bacteria and, filamentous fungi (1, 2, 4-8, 10, 11, 14-16, 18). However, there are only a few studies reporting inulinase activity in Bacillus species, and in these studies the enzyme is not characterized (2,15). Thus, there is no information about thermal stability, kinetic parameters, and the degree of purification needed for use in industrial processes.…”

Isolation and Characterization of Thermophilic Bacterial Strains with Inulinase Activity

“…Biomass was determined by dry cell weight, total protein was determined by the method of Lowry et al (5), total sugar was determined by the anthrone method (11), and total reducing sugar was determined by the Nelson method (10) as modified by Somogyi (12). The activity on inulin or sucrose was measured as the rate of liberation of reducing sugars, as previously reported (1). Cells from 5 ml of culture medium were isolated by centrifugation (the supernatant was labeled fraction E), suspended in 10 mM potassium phosphate buffer (pH 7) containing 5 mM cysteine and 10' M phenylmethylsulfonyl fluoride, and homogenized with a French press (4.9 x 108 Pa, four passages).…”

“…The microbial enzymes from yeasts and fungi have been intensively studied (17), while bacterial inulinases are less well known (13,15). In a previous study in our laboratory, a total of 32 mesophilic bacterial strains with inulinase activity were isolated and characterized (1).…”

PRODUCTION AND PROPERTIES OF INULINASE FROM Arthrobacter sp.

“…of Agric., Mansoura Univ., Mansoura, Egypt. Bacterial strain was grown in Allais et al (1986) medium. The medium consists of (g/l): (NH 4 ) 2 SO 4 , 0.5; MgSO 4 7H 2 0, 0.2 ; KH 2 PO 4 , 3.0 ; Inulin, 2.0 ; Mineral salts solution (Atlas, 1995), 2 ml, pH of the medium was adjusted to 7.0.…”