Researchers investigated the production of beta-amylase by different strains of Bacillus bacteria. They found that Bacillus polymyxa strains produced the highest amounts of beta-amylase, with one strain (NCIB 8524) being the most efficient. Bacillus cereus and some Bacillus megaterium strains needed nutrient broth for good beta-amylase production, but the enzyme was unstable in protein-rich media. Bacillus polymyxa strains could produce beta-amylase on a cheaper, semi-synthetic medium. The temperature at which the bacteria were cultivated also affected beta-amylase yield, with 30 and 37 degrees Celsius being optimal for different strains.