Research Article
Use of Nonspecific, Glutamic Acid-Free, Media and High Glycerol or High Amylase as Inducing Parameters for Screening Bacillus Isolates Having High Yield of Polyglutamic Acid
Table 2
Extracellular amylase: protease activity and PGA production by Bacillus strains.
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Amylase/ bProtease assay: Bacillus subtilis (nonmucoid strain) and Bacillus T. and F. were inoculated in 1% starch broth or 1% skimmed milk broth and incubated at 37°C and amylase/protease activity was assayed. cProduction medium (pH = 7): all substrates were added to Bushnell and Hass synthetic medium base (composition g/L: MgSO4 0.2, CaCl2 0.02, FeCl3 0.05, K2HPO4 1, KH2PO4 1, NH4NO3 1, and agar 25. +/(+) = PGA present/variable. Values in parentheses are the standard deviation. − = PGA absent. dA = amylase activity using starch agar (white/brown zone of hydrolysed starch visible after addition of Lugol’s iodine solution). eP = protease activity (clear zone against turbid background of skimmed milk agar). |