Analysis of exopolysaccharide production by Lactobacillus casei CG11, isolated from cheese

Abstract

Exopolysaccharide-producing Lactobacilus casei CGll was isolated from soft, white, homemade cheese. In basal minimal medium, it produces a neutral heteropolysaccharide consisting predominantly of glucose (about 75%) and rhamnose (about 15%). Plasmid curing experiments revealed that exopolysaccharide production by strain CGll is linked to a plasmid approximately 30 kb in size.

Production by and isolation of exopolysaccharides from Streptococcus thermophilus grown in a milk medium and evidence for their growth-associated biosynthesis

“…No slime production could take place in media such as MRS and M17, classical culture media for lactic acid bacteria. However, Petit et al (1991), and Kojic et al (1992) and Mozzi et al (1995), found exopolysaccharide biosynthesis in MRS (pH-controlled) and M17 (free pH) medium, respectively. They quantified the exopolysaccharide yield colorimetrically.…”

“…thermophilus OR 901, consisting of L-rhamnose and Dgalactose in a 1·00 : 1·47 ratio; Lact. casei CG11 produces a heteropolysaccharide mainly composed of glucose (approximately 75%) and rhamnose (approximately 15%) (Kojic et al 1992) and small amounts of galactose and mannose (Cerning et al 1994). It still has to be determined whether the monomer composition can influence the rheology of solutions and fermented milk drinks prepared with these exopolysaccharides.…”

“…delbrueckii subsp. bulgaricus strains (Kojic et al 1992;Gancel and Novel 1994a;Mozzi et al 1995). On the other hand, some authors clearly showed enhanced exopolymer levels with increased temperatures (Garcia-Garibay and Marshall 1991;Grobben et al 1995).…”

“…and Escherichia coli. However, secondary metabolite kinetics have also been proposed for lactic acid bacteria (Manca de Nadra et al 1985;Kojic et al 1992;Gancel and Novel 1994a). On the other hand, growthassociated exopolymer production (primary metabolite kinetics) has been observed for several lactic acid bacterial strains (Petit et al 1991;Dueñas et al 1995;Grobben et al 1995;van den Berg et al 1995).…”

Construction of a food-grade cell surface display system for Lactobacillus casei

“…Two methods were employed for plasmid elimination in L. casei ATCC 334. The strain was cultured and passaged in MRS broth either for eight subcultures at 42 • C or for eight subcultures at 37 • C in the presence of novobiocin (10 g/mL) (Kojic et al 1992). The remaining cultures were plated on MRS solid medium, and single colonies were selected.…”