Amylase Production by Aspergillus niger and Penicillium Species by Solid-State and Submerged Cultivation Using Two Food Industrial Wastes

Amylase enzymes are starch degrading enzymes and have received a great deal of attention due to their perceived technology importance and economic benefit. Amylase enzymes are considered important enzymes used in starch processing industries for the hydrolysis of polysaccharides like starch into simple sugar constituents. This enzyme is also involved in the commercial production of glucose. Solid-state cultivation and submerged cultivation have tremendous potentials for enzyme amylase production by using different solid substrates like rice bran, wheat bran, coconut oil cake, and groundnut oil cake which are rich in starch. These agro-industrial wastes are considered cheap raw materials for the production of amylase. Wastewater from the industry like brewery can also be used as a liquid substrate for submerged cultivation. It may have the possibility of depurination of wastewater. In the present study, Aspergillus niger and Penicillium species were isolated and their amylase activity was determined by the starch hydrolysis method. Enzyme production was done by using coconut oil cake as a substrate for solid-state fermentation and brewery wastewater as a substrate for submerged fermentation. The enzyme produced by the organisms was extracted and enzyme assay was done by the Dinitrisalicilic method (DNS method). The protein estimation was done by Lowry Folin’s method. The qualitative assay was carried out by performing Gas Chromatography-Mass Spectroscopy (GC-MS).

Flow-specific physical properties of coconut flours

Coconut milk residue and virgin coconut oil cake are important co-products of virgin coconut oil that are used in the animal feed industry. Flour from these products has a number of potential human health benefits and can be used in different food formulations. The objective of this study was to find out the flow-specific physical properties of coconut flours at three moisture levels. Coconut milk residue flour with 4.53 to 8.18% moisture content (w.b.) had bulk density and tapped density of 317.37 to 312.65 and 371.44 to 377.23 kg m-3, respectively; the corresponding values for virgin coconut oil cake flour with 3.85 to 7.98% moisture content (wet basis) were 611.22 to 608.68 and 663.55 to 672.93 kg m-3, respectively. The compressibility index and Hausner ratio increased with moisture. The angle of repose increased with moisture and ranged from 34.12 to 36.20 and 21.07 to 23.82° for coconut milk residue flour and virgin coconut oil cake flour, respectively. The coefficient of static and rolling friction increased with moisture for all test surfaces, with the plywood offering more resistance to flow than other test surfaces. The results of this study will be helpful in designing handling, flow, and processing systems for coconut milk residue and virgin coconut oil cake flours.

Optimization of Medium Composition for the Production of Neomycin by Streptomyces fradiae NCIM 2418 in Solid State Fermentation

Neomycin production of Streptomyces fradiae NCIM 2418 was optimized by using response surface methodology (RSM), which is powerful mathematical approach comprehensively applied in the optimization of solid state fermentation processes. In the first step of optimization, with Placket-Burman design, ammonium chloride, sodium nitrate, L-histidine, and ammonium nitrate were established to be the crucial nutritional factors affecting neomycin production significantly. In the second step, a 24 full factorial central composite design and RSM were applied to determine the optimal concentration of significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the important nutrients for the maximum were obtained as follows: ammonium chloride 2.00%, sodium nitrate 1.50%, L-histidine 0.250%, and ammonium nitrate 0.250% with a predicted value of maximum neomycin production of 20,000 g kg−1 dry coconut oil cake. Under the optimal condition, the practical neomycin production was 19,642 g kg−1 dry coconut oil cake. The determination coefficient (R2) was 0.9232, which ensures an acceptable admissibility of the model.