Solid-State Fermentation of Carrot Pomace for the Production of Inulinase by Penicillium oxalicum BGPUP-4

Abstract

SUMMARYInulinases are an important class of industrial enzymes which are used for the production of high-fructose syrup and fructooligosaccharides. Inulin, a polyfructan, is generally employed for the production of inulinase, which is a very expensive substrate. A number of agroindustrial residues have been used for cost-effective production of inulinases. In the present study, carrot pomace was selected as a substrate for the production of inulinase by Penicillium oxalicum BGPUP-4 in solid-state fermentation. Carrot pomace is one of the good substrates for bioprocesses, because it is rich in soluble and insoluble carbohydrates. A central composite rotatable design (CCRD) used in response surface methodology was employed for the optimal production of inulinase from carrot pomace. Using CCRD, 15 runs were practiced to optimize the range of three independent variables: moisture content (70-90 %), incubation time (4-6 days) and pH (5.0-7.0) for inulinase production. Carrot pomace supplemented with 0.5 % inulin as an inducer, 0.2 % NH 4 H 2 PO 4 , 0.2 % NaNO 3 , 0.2 % KH 2 PO 4 , 0.05 % MgSO 4 ·7H 2 O and 0.001 % FeSO 4 ·7H 2 O was used for the production of inulinase in solid-state fermentation at 30 °C. Inulinase production (322.10 IU per g of dry substrate) was obtained under the optimized conditions, i.e. moisture content of 90 %, incubation time 4 days and pH=7.0. The corresponding inulinase/invertase (I/S) ratio (3.38) was also high, which indicates the inulolytic nature of the enzyme. Multiple correlation coefficients R for inulinase production and I/S ratio were 0.9995 and 0.9947, respectively. The R value very close to one indicates an excellent correlation between experimental and predicted results.

Strategies to Increase the Value of Pomaces with Fermentation

“…It is also relevant to comment that a recent experiment indicated that the use of sugarcane bagasse is a relevant strategy to reduce moisture loss during fermentation and improve the production yield of pectinase from orange pomace [64]. In a similar way, carrot pomace was indicated as an interesting substrate for fermentation, which can be utilized in the production of inulinase [65]. The production of inulinase was affected by moisture content, fermentation period, and pH.…”

Response surface methodology to optimize inulinase production by a newly isolated Penicillium amphipolaria strain by solid-state fermentation of Saccharum arundinaceum

“…Proper mixing of the solid substrate, fermentation media and the spore suspension was done to ensure the availability of nutrients uniformly. The asks were incubated at 30℃ for ve days [42]. During the process of preliminary screening, it was found that the maximum production of inulinase occurred at 96 th h. All the subsequent experiments were thus carried out for 96 h.…”

Inulinase production in shake-flask fermentations from Mucor circinelloides BGPUP-9

“…Higher concentration of both the medium supplements was inhibitory for inulinase production. Potassium dihydrogen orthophosphate and potassium chloride are basic components of the medium used for both microbial growth and inulinase production from various microorganisms [6,16,44]. The presence of these components in the medium has been reported to have a synergistic effect with other components for inulinase production.…”

“…Various low-cost substrates like root tubers of Asparagus sp. [2][3][4], raw dahlia inulin [5], carrot pomace [6] have been used for inulinase production. The production of high fructose syrup [7][8][9][10][11][12] and fructooligosaccharides [13,14] are the two major applications of inulinases.…”