Starch hydrolysis Bacillus subtilis

In 1890, the Japanese chemist Jokichi Takamine had introduced a fermentation process in the United States by which an enzyme blend was produced. This takadias-tase catalyzed starch and protein hydrolysis. Some years later in 1913, Boidin and Effront discovered the bacillus subtilis" that produced an a-amylase stable under heat. This enzyme was used to desize cloth and later in the sugar fermentation process. 

Application and Principle This procedure is used to determine the a-amylase activity, expressed as bacterial amylase units (BAU), of enzyme preparations derived from Bacillus subtilis var., Bacillus licheniformis var., and Bacillus stearoth-ermophilus. It is not applicable to products that contain 13-amylase. The assay is based on the time required to obtain a standard degree of hydrolysis of a starch solution at 30° 0.1°. The degree of hydrolysis is determined by comparing the iodine color of the hydrolysate with that of a standard. 

The commercial production of proteins from micro-organisms began in the United States around 1890 when Takamine introduced a traditional Japanese fermentation process for takadiastase. This product, which was derived from Aspergillus niger (cf. section 6.2.2.2) was a mixture of enzymes which catalysed the hydrolysis of starches and proteins. Some years later, in 1913, Boidin and Effront discovered that Bacillus subtilis produces a heat-stable a-amylase. This enzyme also catalyses the hydrolysis of starches, and was used in the textile industry for desizing cloth. 

Many kinds of microorganisms produce a-amylases. The enzymes are extracellular and are secreted into the environment of the organism for hydrolysis of starch. One of the early microbial a-amylases to be studied in some detail was Bacillus amyloliquefaciens a-amylase (formerly known as Bacillus subtilis liquefying a-... 

B. cereus var. Mycoides could produce two kinds of starch enzymes /3-amylase and pullulanase, where the optimum condition pH is 6-6.5, temperature is 50°C, and the maximum conversion rate (maltose from starch by hydrolysis) is about 95% [18]. In the 1980s, Novo Nordisk Denmark had received Acidophilic Bacillus that hydrolyzed puUulan the pullulanase from it is now the most widely used, and has the largest output [18]. In 1986, Yoshiyuki Takasaki isolated B. subtilis producing heat and acid stable pullulanase, which could produce the mixture of pullulanase and amylase, of which the optimum pH of pullulanase was 7.0-7.5, but also maintained 50% of enzyme activity at pH 5.0 [19]. In 1987, E. Madi and G. Antranikian reported a simultaneous production of u-amylase, pullulanase and glucoamylase bacteria Clostridium thermosulfurgenes. In addition, some actinomycetes such as Streptomyces diastatochromogenes, Beauveria actinomycetes and Micromonosporaceae, Actinomycetes thermomonosporaceae also produce pullulanase. In plants, such as rice, beans, potatoes, sweet corn and malt, pullulanase was observed [20]. 

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