Potential of waste starch substrate as a bioplastics production substrate by microbes.

Bioplastics are plastics that microorganisms can degrade from compounds in plants such as starch, cellulose, and lignin. The study determines "Potential of Starch Substrate from Waste as a substrate for Bioplastic Production by Microbe". Qualitative determination of bioplastic accumulation was carried out by Sudan black painting. Painting was carried out on bacterial colonies in minimally solid media at a temperature 30°C in 48 hours. Colonies bacterial that grew then dissolved in ethanol and grown in media liquid minimally, a source of starch carbon from the waste. Use a shaker speed in 125 rpm and temperature of 30 °C for 72 hours. Cells bacterial were extracted by centrifugation for 20 minutes at 3000 rpm. Determined content of the bioplastic was using a UV-Vis spectrophotometer at wavelength of 235 nm with concentrated H2SO4 as solvent. The research conducted by screening indigenous bacteria for bioplastic production showed that from 24 bacterial isolates, 13 isolates produced bioplastic using peel starch cassava, 5 isolates produced bioplastic using cassava rice-washed, and there were no bacterial isolates using peel starch banana. The results of the screening of 13 isolates showed that the bacterial isolate with code S110-5A1 had an absorbance value of 3.6989, and the results of the screening of 5 isolates showed that the bacterial isolate with the code S110-3A2 had an absorbance value of 1.5654, indicated which the potential producer of bioplastics good. [ABSTRACT FROM AUTHOR]