Optimization of gluco-amylase production from Aspergillus spp. for its use in saccharification of liquefied corn starch

Abstract

Fungal gluco-amylase is required for the production of sugars from starchy substrates. Commercially available fungal gluco-amylase is quite costly which makes the process uneconomical. This study was undertaken to standardize physico-chemical parameters for optimum production of gluco-amylases from spp. Two fungal cultures, i.e., and , were compared for gluco-amylase activity both under stationary and shake flask conditions. Among two fungal cultures, maximum gluco-amylase activity was shown by (243.09 U/ml) under stationary conditions as compared to (126.34 U/ml). Gluco-amylase activity of increases by 42.48% from 243.09 to 346.35 U/ml after optimization using response surface methodology, whereby a substrate concentration of 7%, yeast extract 0.25%, temperature 32.5 °C and pH 5.5 were found to be optimum for gluco-amylase production. Crude enzyme was compared with commercial enzyme and it was found that when 500 U of Glucoamylase ex. were inoculated into starch-supplemented minimal media (SSMM) liquefied using 2 g of fungal diastase, it increases the reducing sugar concentration from 2.19 to 21.15 mg/ml and a saccharification efficiency of 77.7% was achieved, whereas 1.5 ml of crude enzyme (extracted from) was able to produce 14.46 mg/ml of reducing sugars with a saccharification efficiency of 53.2%.

Optimization of α‐amylase and Glucoamylase Production Using Cull Potatoes as Substrate

“…Starch agar slants were used for the growth of selected amylolytic bacterial isolates and incubated at 37°C for 48 h. For amylase production study, a loopful of culture was inoculated in starch supplemented minimal media (SSMM) broth as suggested by Jain and Katyal [12] and incubated at 37°C. Fungal culture (Aspergillus niger) was grown on PDA medium at 28°C for 4 days.…”

“…Earlier studies have also reported that amylase activity declined significantly after 24 h of incubation that can be due to poor availability of nutrients, accumulation of toxic metabolites and fast metabolism. [12,21]…”

“…Out of four different nitrogen sources yeast extract showed maximum amylase production 198.20 U mL −1 after 24 h of incubation at 37°C followed by (NH 4 ) 2 SO 4 (117.93) whereas -amylase production was 60.81 U mL −1 with soybean meal and 9.70 U mL −1 with urea. Alariya et al [24] and Jain & Katyal [12] have also reported that supplementation of yeast extract resulted in highest enzyme production as compared to other nitrogen sources (ammonium sulphate, peptone and urea) at 24 h of incubation. This is mainly due to the presence of trace elements (Mn, Mg, Fe, Mo, and Zn) and growth factors (vitamins B1, B2, B6, niacin, folic acid, pantothenic acid and biotin) present in the yeast extract.…”

“…After optimization using RSM, the glucoamylase activity of fungal culture (Aspergillus niger) increased from 228.72 to 317.44 U mL −1 which represents an increment of 38.78% at 5.0% substrate concentration, 30°C temperature, 4 days of incubation and pH 5. Similarly, Jain and Katyal [12] optimized various conditions such as yeast extract, temperature, pH and substrate concentration for glucoamylase production from Aspergillus niger by RSM. After optimization of pH (5.5), substrate concentration (7%), yeast extract (0.25%) and temperature 32.5°C maximum activity was reported.…”

Transcriptomic and Metabolic Profiling of High-Temperature Treated Storage Roots Reveals the Mechanism of Saccharification in Sweetpotato (Ipomoea batatas (L.) Lam.)

“…Saccharification refers to the process in which tissues rich in starch or cellulose undergo acidolysis or hydrolysis to produce sweet substances in the presence of water [10]. Saccharification of sweetpotato storage roots is a process in which the starch is converted into soluble sugar during cooking.…”