Production of maltose with amylases produced by streptomyces

Claim 2

A PROCESS FOR THE PREPARATION OF SACCHARIFICATION PRODDUCTS OF STARCH MAINLY COMPOSED OF MALTOSE WHICH IS USEFUL AS A DIET AND NATURAL SWEETENING MATERIAL, WHICH COMPRISES LIQUEFYING AND SACCHARIFYING A STARCH MATERIAL INCLUDING ANY AMULOSE IN AQUEOUS DISPERSION BY REACTING THEREWITH AN AMYLASE PRODUCED BY CULTIVATING A STRAIN OF STREPTOMYCES ALBUS, STREPTOMYCES AUREOFACIENS, STREPTOMYCES HYGROSCOPICUS, STREPTOMYCES HYGROSCOPICUS VAR. AUGUSTOMYCETICUS, STRETOMYCES VIRIDOCHROMOGENES, STREPTOMYCES FLAVUS AND STREPTOMYCES TOSAENSIS UNDER AEROBIC CONDITIONS IN A CULTURE MEDIUM CONTAINING KNOWN CARBON SOURCES AND NITROGEN SOURCES TO PRODUCE AND ACCUMULATE IN THE CULTURE MEDIUM AN AMYLASE HAVING SUCH ENZYMATIC ACTIVITIES AND CHARACTERISTICS THAT THE PH OF THE OPTIMUM ACTIVITY IS IN THE RANGE OF 4.5 - 5.0, THE LIMIT IN THE HYDROLYSIS OF STARCH BY THIS AMYLASE IS NO LESS THAN 75% OF THE THEORETICAL MALTOSE AND THE RATIO OF GLUCOSE TO MALTOSE PRODUCED FROM STARCH BY THE ACTION OF THIS AMYLASE IS NO MORE THAN 0.06:1 BY WEIGHT, UNTIL THERE IS FORMED AN AQUEOUS SOLUTION OF THE SACCHARIFICATION PRODUCTS OF STARCH CONTAINING AT LEAST 70% OF MALTOSE ON THE DRY WEIGHT BASIS.

Claim 3

A process for the preparation of saccharification products of starch mainly composed of maltose which is useful as a dietetic and natural sweetening material, which comprises reacting a known liquefying amylase with a starch material in an aqueous dispersion to liquefy the starch, heating the resultant solution of the liquefied starch to inactivate the liquefying amylase, and then saccharifying the liquefied starch by reacting it in a known manner with an amylase which is produced by cultivating a strain of Streptomyces albus, Streptomyces aureofaciens, Streptomyces hygroscopicus, Streptomyces hygroscopicus var. angustomyceticus, Streptomyces viridochromogenes, Streptomyces flavus and Streptomyces tosaensis under aerobic conditions in a culture medium containing known carbon sources and nitrogen sources to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolysis of starch by this amylase is no less than 75% of the theoretical maltose and the ratio of glucose to maltose produced from starch by the action of this amylase is no more than 0.06:1 by weight, until there is formed an aqueous solution of the saccharification products of starch, that is, the starch hydrolyzate containing at least 70% of maltose on the dry weight basis, heating the last solution to inactivate the Streptomyces amylase, and then, if desired, subjecing said solution of the starch hydrolyzate to filtration, concentration, de-coloration and/or de-salting process.

Claim 4

A process for the preparation of saccharification products of starch mainly composed of maltose which is useful as a dietetic and natural sweetening material, which comprises reacting a known liquefying amylase with a starch material in an aqueous dispersion to liquefy the starch, heating the resultant solution of the liquefied starch to inactivate the liquefying amylase, and then saccharifying the liquefied starch by reacting it in a known manner with an amylase which is produced by cultivating a strain of Streptomyces albus, Streptomyces aureofaciens, Streptomyces hygroscopicus, Streptomyces hygroscopicus var. angustomyceticus, Streptomyces viridochromogenes, Streptomyces flavus and Streptomyces tosaensis under aerobic conditions in a culture medium containing known carbon sources and nitrogen sources to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolysis of starch by this amylase is no less than 75% of the theoretical maltose and the ratio of glucose to maltose produced from starch by the action of this amylase is no more than 0.06:1 by weight, until there is formed an aqueous solution of the saccharification products of starch, that is, the starch hydrolyzate containing at least 70% of maltose on the dry weight basis, heating the last solution to inactivate the Streptomyces amylase, and then, if desired, subjecing said solution of the starch hydrolyzate to filtration, concentration, de-coloration and/or de-salting process.

Claim 5

A process as claimed in claim 1 in which the amylase is produced by cultivating a strain of Streptomyces hydroscopicus identified as ATCC No. 21722 in a culture medium under aerobic conditions to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolysis of starch by this amylase is 82% of the theoretical maltose and the ratio of glucose to maltose produced from starch by the action of this amylase is 0.055:1 by weight and said amylase is reacted with a starch material at about 55* C for about 40 hours.

Claim 6

A process for the production of a mixture of sugar alcohols mainly composed of maltitol which is useful as a dietetic sweetening material, which comprises saccharifying a starch material, an at least partially hydrolyzed starch material and an amylose by reacting therewith in an aqueous dispersion thereof an amylase produced by cultivating a strain of Streptomyces albus, Streptomyces aureofaciens, Streptomyces hygroscopicus, Streptomyces hygroscopicus var. angustomyceticus, Streptomyces viridochromogenes, Streptomyces flavus and Streptomyces tosaensis under aerobic conditions in a culture medium containing known carbon sources and nitrogen sources to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolyiis of starch by this amylase is no less than 75% of the theoretical maltose and the ratio of glucose to maltose produced from starch is no more than 0.06:1 by weight, until there is formed a starch hydrolyzate solution containing at least 70% of maltose and up to 4% of glucose on the dry weight basis, then catalytically hydrogenating the starch hydrolyzate solution with hydrogen in the presence of a nickel catalyst, and separating the nickel catalyst from the hydrogenated starch hydrolyzate solution to recover the nickel catalyst and to give an aqueous Solution of a mixture of sugar alcohols containing at least 70% of maltitol and up to 5% of sorbitol on the dry weight basis, and then, if desired, concentrating the solution of a mixture of sugar alcohols to a syrup or to dryness.

Claim 7

A process for the production of a mixture of sugar alcohols mainly composed of maltitol which is useful as a dietetic sweetening material, which comprises saccharifying a starch material, an at least partially hydrolyzed starch material and an amylose by reacting therewith in an aqueous dispersion thereof an amylase produced by cultivating a strain of Streptomyces albus, Streptomyces aureofaciens, Streptomyces hygroscopicus, Streptomyces hygroscopicus var. angustomyceticus, Streptomyces viridochromogenes, Streptomyces flavus and Streptomyces tosaensis under aerobic conditions in a culture medium containing known carbon sources and nitrogen sources to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolyiis of starch by this amylase is no less than 75% of the theoretical maltose and the ratio of glucose to maltose produced from starch is no more than 0.06:1 by weight, until there is formed a starch hydrolyzate solution containing at least 70% of maltose and up to 4% of glucose on the dry weight basis, then catalytically hydrogenating the starch hydrolyzate solution with hydrogen in the presence of a nickel catalyst, and separating the nickel catalyst from the hydrogenated starch hydrolyzate solution to recover the nickel catalyst and to give an aqueous Solution of a mixture of sugar alcohols containing at least 70% of maltitol and up to 5% of sorbitol on the dry weight basis, and then, if desired, concentrating the solution of a mixture of sugar alcohols to a syrup or to dryness.

Claim 8

A process as claimed in claim 4 in which the starch hydrolyzate solution from the saccharification step is processed by loading initially therein a nickel catalyst in a proportion of about 5% by weight based on the amount of reducing sugars present in said starch hydrolyzate solution to be hydrogenated in the first run of the catalytic hydrogenation, catalytically hydrogenating the first batch of the starch hydrolyzate solution in the first run in the presence of the loaded nickel catalyst, separating the nickel catalyst from the hydrogenated, starch hydrolyzate solution to recover the nickel catalyst and to give an aqueous solution of a mixture of sugar alcohols containing at least 70% of maltitol and up to 5% of sorbitol on the dry weight basis, re-using the recovered catalyst to load in a second batch of the starch hydrolyzate solution to be hydrogenated in the second run of the hydrogenation; effecting the second run of the hydrogenation in the same manner as in the first run; effecting successively several further runs of the catalytic hydrogenation with further batches of the starch hydrolyzate solution while repeating the recovery and re-use of the nickel catalyst in each of the second run and these further runs; when a recovered catalyst separated from the last run of these further runs has been exhausted to such an extent that the residual amount of the reducing sugars in the hydrogenated starch hydrolyzate solution approaches about 1% as determined at the completion of the hydrogenation of this last run, supplementing to this exhausted, recovered catalyst an amount of a fresh nickel catalyst in a proportion of 1 - 3% by weight based on the amount of reducing sugars present in the starch hydrolyzate solution to be hydrogenated; loading the recovered catalyst which has exhausted and re-activated by the supplement of the fresh catalyst, into another batch of the starch hydrolyzate solution to be hydrogenated in a run next to the above-mentioned last run; effecting this next run of the catalytic hydrogenation; and subsequently performing more further runs of the hydrogenation successively for more further batches of the starch hydrolyzate solution while repeating the recovery and re-use of the catalyst in the more further runs of the catalytic hydrogenation and with occasionally conducting the supplement of a fresh nickel catalyst to the recovered catalyst at each time when the recovered catalyst as separated from one run has been exhausted to such an extent that the residual amount of the reducing sugars in the hydrogenated starch hydrolyzate solution approaches 1% as determined at the completion of the hydrogenation in that one run.

Claim 9

A process as claimed in claim 4 in which the amylase is produced by cultivating a strain of Streptomyces hydroscopicus identified as ATCC No. 21722 in a culture medium under aerobic conditions to produce and accumulate in the culture medium an amylase having such enzymatic activities and characteristics that the pH of the optimum activity is in the range of 4.5 - 5.0, the limit in the hydrolysis of starch by this amylase is 82% of the theoretical maltose and the ratio of glucose to maltose produced from starch by the action of this amylase is 0.055:1 by weight and said amylase is reacted with the starch material.