Isolation and selection of amylase-producing microbes isolated from ragi tape and cassava tape available on the markets

Abstract

Amylase has an important role in biotechnology development and occupies an important position in the world enzyme market, as a biocatalyst in various industrial fields. This study has the goal to find microbial isolates that have the ability to produce amylase enzymes. The study was conducted in two stages, namely: 1) Isolation and selection of microbes that can produce amylase enzymes using starch as substrate, was incubated for 4-7 days at 30°C. Microbial isolates that can produce amylase enzymes are characterized by the presence of clear zones around the colony after the addition of an iodine solution of 1% in the overgrown media of microbes, 2) Test the activity of amylase enzymes using a dinitrosalicylic acid reagent test. The activity of the amylase enzyme is determined by measurement using a spectrophotometer at a wavelength of 540 nm. The sample used comprised of 7 types of ragi tape and 2 samples from cassava tape that has been fermented for 5-7 days. The results obtained in the first stage were 65 microbial isolates, 16 of which had clear zones, consisting of 7 isolates from ragi tape samples and 9 isolates from cassava tape samples. In the enzyme activity test, there are several isolates that have the potential to produce amylase enzymes, these include R5I4 (0.897 ± 0.018 U/mL), R2I5.1 (0.814 ± 0.011 U/mL), R5I3 (0.727 ± 0,042 U/mL) (derived from cassava ragi tape samples) and T2I2.2 (0.812 ± 0.013 U/mL), T2I6.1 (0.817 ± 0.010 U/mL), T2I2.1 (0.735 ± 0.023 U/mL), T1I4 (0.755 ± 0.020 U/mL) (derived from cassava tape samples). The isolate with the highest enzyme activity is the R5I4 which has the value enzyme activity of 0.897 ± 0.018 U/mL and with a fairly high or moderate category, while the lowest enzyme activity is the T1I1.1 isolate of 0.284 ± 0.020 U/mL.