Medium modification for the growth of Rhizopus oligosporus and Acetobacter xylinum as starter cultures in the production of biofoam, environmentally friendly packaging

Abstract

Acetobacter xylinum was injected to reduce the porosity value and water absorption of biofoam which was made using bagasse and Rhizopus oligosporus. However, data interpretation of the total counts of both microbes could be misleading. Therefore, the aim of this research was to create a specific medium for the growth of both microbes. The research was conducted in three stages. In the first stage, soybean flour was added into bagasse to produce depithed bagasse at different ratios (1:1 and 1:1.5) for use in the growth of Rhizopus oligosporus. In the second stage, urea and bean sprouts extract were used to grow Acetobacter xylinum. Finally, modified media was used to grow both starters. The results showed that the total plate counts of Rhizopus oligosporus on bagasse medium was quite similar with the depithed bagasse ranging from 4.58 to 4.87 log cfu/gram. The addition of bean sprouts extract had an absorbance yield of 0.162 while the addition of urea had an absorbance value of 0.085. Therefore, bagasse and soybean flour (in the ratio of 1:1.5) and bean sprouts extract are recommended to grow both starters because of the efficiency process and the highest absorbance yield.