Abstract: The cyclic tetrasaccharide, cyclo{-6)-&agr;-D-Glcp-(1,3)-&agr;-D-Glcp-(1,6)-&agr;-D-Glcp-(1,3)-&agr;-D-Glcp-(1-}, may be produced by alternanase hydrolysis of complex carbohydrates other than alternan. Panose, pullulan, &agr;-D-Glcp-(1,6)-&agr;-D-Glcp-(1,3)-D-Glc, and D-glucans having alternating &agr;-(1,6) and &agr;-(1,4) linkages, are all hydrolyzed by alternanase to produce this cyclic tetrasaccharide. In this process, the cyclic tetrasaccharide is produced by contacting a solution of one or more of the above-mentioned complex carbohydrates with an amount of alternanase under conditions effective for activity of the enzyme. The substrate panose used in the reaction may be produced from a variety of polysaccharides or oligosaccharides, including starch, maltose, maltodextrins, pullulan, and mixtures thereof.

Abstract: Four new Penicillium spp. isolates (NRRL 21966, NRRL 21967, NRRL 21968, and NRRL 21969) are capable of essentially quantitative conversion of native alternan to a polymeric modified form having a lower apparent molecular weight than native alternan. A fifth isolate (NRRL 30489) obtained from a survey of deposited organisms and classified as a Penicillium subgenus Biverticillium has the same ability. The modified alternan has rheological properties similar to ultrasonicated alternan and is produced without the expense of ultrasonication. It would have utility as a substitute for gum arabic for uses such as bulking agents and extenders in foods and cosmetics.

Abstract: Four new Penicillium spp. isolates (NRRL 21966, NRRL 21967, NRRL 21968, and NRRL 21969) are capable of essentially quantitative conversion of native alternan to a polymeric modified form having a lower apparent molecular weight than native alternan. A fifth isolate (NRRL 30489) obtained from a survey of deposited organisms and classified as a Penicillium subgenus Biverticillium has the same ability. The modified alternan has rheological properties similar to ultrasonicated alternan and is produced without the expense of ultrasonication. It would have utility as a substitute for gum arabic for uses such as bulking agents and extenders in foods and cosmetics.

Abstract: A new enzyme, alternanase, which is effective for the endo-hydrolytic cleavage of alternan, producing a thinned composition of low molecular weight fractions which exhibit reduced viscosity and increased solubility relative to native alternan, is described. The enzyme is produced and secreted extracellularly by a plurality of novel bacteria isolated from soil. One of the fractions present in the thinned alternan resulting from hydrolysis with alternanase is a the cyclic tetrasaccharide, cyclo{-6)-.alpha.-D-Glcp-(1,3)-.alpha.-D-Glcp-(1,6)-.alpha.-D-Glcp-(1,3)-. alpha.-D-Glcp-(1-}. A novel method for isolating strains of microorganisms which produce endo-.alpha.-D-glucanases such as alternanase effective for the endo-hydrolytic cleavage or thinning of alternan is also described. Cultures of the subject strains are contacted with a test substrate of alternan coupled to a detectable indicator. Detection of released indicator provides an indication of endo-.alpha.-D-glucanase activity.

Abstract: A new enzyme, alternanase, which is effective for the endo-hydrolytic cleavage of alternan, producing a thinned composition of low molecular weight fractions which exhibit reduced viscosity and increased solubility relative to native alternan, is described. The enzyme is produced and secreted extracellularly by a plurality of novel bacteria isolated from soil. One of the fractions present in the thinned alternan resulting from hydrolysis with alternanase is a the cyclic tetrasaccharide, cyclo{-6)-.alpha.-D-Glcp-(1,3)-.alpha.-D-Glcp-(1,6)-.alpha.-D-Glcp-(1,3)-. alpha.-D-Glcp-(1-}. A novel method for isolating strains of microorganisms which produce endo-.alpha.-D-glucanases such as alternanase effective for the endo-hydrolytic cleavage or thinning of alternan is also described. Cultures of the subject strains are contacted with a test substrate of alternan coupled to a detectable indicator. Detection of released indicator provides an indication of endo-.alpha.-D-glucanase activity.

Abstract: A rapid screening procedure to select microorganism strains that produce a high proportion of alternan to dextan and a high proportion of alternansucrase to dextransucrase is described. Strains selected by the method are useful to produce a high proportion of alternansucrase to dextransucrase and to produce a high proportion of alternan to dextran, either fermentatively by cultivation of the strains on sucrose, or enzymatically by using alternansucrase produced by the strains of the invention. The selected strains can also be used to obtain microorganism strains having further improvements.

Abstract: A new enzyme, alternanase, which is effective for the endo-hydrolytic cleavage of alternan, producing a thinned composition of low molecular weight fractions which exhibit reduced viscosity and increased solubility relative to native alternan, is described. The enzyme is produced and secreted extracellularly by a plurality of novel bacteria isolated from soil. One of the fractions present in the thinned alternan resulting from hydrolysis with alternanase is a the cyclic tetrasaccharide, cyclo{-6)-.alpha.-D-Glcp-(1,3)-.alpha.-D-Glcp-(1,6)-.alpha.-D-Glcp-(1,3)-. alpha.-D-Glcp-(1-}. A novel method for isolating strains of microorganisms which produce endo-.alpha.-D-glucanases such as alternanase effective for the endo-hydrolytic cleavage or thinning of alternan is also described. Cultures of the subject strains are contacted with a test substrate of alternan coupled to a detectable indicator. Detection of released indicator provides an indication of endo-.alpha.-D-glucanase activity.

Abstract: A rapid screening procedure to select microorganism strains that produce a high proportion of alternan to dextran and a high proportion of alternansucrase to dextransucrase is described. Strains selected by the method are useful to produce a high proportion of alternansucrase to dextransucrase and to produce a high proportion of alternan to dextran, either fermentatively by cultivation of the strains on sucrose, or enzymatically by using alternansucrase produced by the strains of the invention. The selected strains can also be used to obtain microorganism strains having further improvements.