Production of gluconic acid by using some irradiated microorganisms

Abstract

a b s t r a c tThe objective of this study was to isolate the potential fungal isolates have the ability for gluconic acid production by using some agro industrial byproducts as sugarcane molasses, banana-must and grape-must. The effect of gamma-irradiation on the most potent isolates and the fermentation conditions as pH, incubation temperature and incubation period was also investigated. Results showed that the most potential fungal isolates were Aspergillus niger, Penicillium puberulum and Penicillium frequentans whereas their gluconic acid production was 62.17, 56.25 and 39.69 g/L, respectively on Czapek's Dox media at 28 ± 1 C, pH 6 for 7 days fermentation period. Irradiation of the three most potential isolates at 0.1, 0.2, 0.3, 0.4 and 0.5 kGy doses of gamma ray showed that 0.1 kGy dose caused an increase in gluconic acid production whereas it was 69.35, 60.17 and 40.31 g/L by the three potential isolates respectively. Data showed that utilization of sugarcane molasses, banana-must and grape-must as a sole carbon source in gluconic acid production by the three potential (0.1 kGy) irradiated isolates at pH 6, 30 C for a 7 days incubation period caused increasing in gluconic acid production whereas the productivity of the three (0.1 kGy) irradiated isolates (A. niger, P. puberulum and P. frequentans) was 69.87, 63.14 and 51.28 g/L by utilizing sugarcane molasses, 61.28, 56.37, 47.15 g/L by utilizing banana-must and 54.25, 52.75 and 44.75 g/L by utilizing grape-must.

The impact of chemical and chemical-physical mutagenisation on phenotypic changes in the bacteria of the species Komagataeibacter xylinus

“…Mutant M34 produced gluconic acid at a concentration of 2.5 g•dm -3 in the medium, at the same time the wild strain produced GA at a concentration of 2.91 g•dm -3 . A similar result after physical mutagenisation was obtained by Ahmed et al [2015] in the case of the Aspergillus terreus strain, where the GA content in the mutant medium was 2.8 g•dm -3 . It was one of the lowest results obtained for a given radiation dose (0.2 kGy).…”

“…It was one of the lowest results obtained for a given radiation dose (0.2 kGy). For comparison, the maximum GA content obtained by the A. terreus wild strain not exposed to a mutagen was 4.21 g•dm -3 [Ahmed et al 2015].…”

Bioleaching of Manganese Oxides at Different Oxidation States by Filamentous Fungus Aspergillus niger

“…It is well known that gluconate is derived from glucose due to glucose oxidase activity [40], and it can serve as an easily utilizable carbon source for A. niger [41]. The gluconate synthesis at a pH lower than 3.5 is significantly inhibited, since the enzyme's activity is dependent on external pH [42] with an optimum at pH 6 [43]. This is in good agreement with our experimental findings (Figure 7), where the accumulation of gluconate was insignificant in the case of manganese-free treatment with the lowest pH level.…”

A Model Procedure for Catalytic Conversion of Waste Cotton into Useful Chemicals

“…A possible solution is to convert cotton textiles by chemical-biological methods into useful energy products, such as biogas or into simple sugars, such as glucose. Via chemical or biological transformations, these products can then be made into valuable chemicals such as gluconic acid [ 10 , 11 , 12 , 13 ] or into other products such as hydrogen, vanillin or monolayer-patched graphene [ 14 , 15 , 16 , 17 ]. The catalytic transformation of glucose into gluconic acid over heterogeneous catalysts is of great interest to the industry [ 18 , 19 , 20 , 21 , 22 , 23 ].…”