Preliminary study for optimization of enzymatic hydrolysis of waste cellulosic materials

Lignocellulose is a generic term describing the main constituents in most plants, namely cellulose, hemicelluloses, and lignin. Cellulose is a glucose polysaccharide, hemicelluloses are polysaccharides with a backbone of different hexoses (glucose, mannose, galactose) and pentoses (xylan, arabinose), and lignin is a complex network of different phenyl propane units. The cellulosic materials are potential sources of ethanol. Steps of this process are saccharification of cellulose to reduce sugars, under enzymes action and to reduce sugars fermentation by yeast to obtain ethanol.The aim of this study is to examine the influence of substrateconcentration, temperature and pH upon enzymatic saccharification ofwaste cellulosic materials, based on office paper, newspaper andcardboard, in ratio of 1:1:1 (w/w) and reducing sugar accumulationdynamics in optimised conditions. The study has established optimalparameters: the ratio of enzyme:substrate as 0.5 EU/g substrate,temperature 48°C, pH 4.8 and addition of surfactant Tween 80 inproportion of 0.3 %, reported to the total volume of liquid. The reducing sugar yield was 35 mg reducing sugars/ g dry weight cellulosic waste

Optimization of protein production by Geotrichum candidum MIUG 2.15 by cultivation on paper residues, using response surface methodology

Response surface methodology (RSM) based on the 23 factorial central composite design (CCD) was used to optimize the biotechnological conditions for growth and protein production by a selected fungal strain Geotrichum candidum MIUG 2.15, by solid-state cultivation on a semisolid medium based on a mixture of paper residues, i.e. office paper, newspaper, and cardboard, mixed in a ratio of 1:1:1(w/w), supplemented with cheese whey waste and complex manure. Three independent variables, the solid:liquid ratio, the concentration of complex manure, and cultivation time, were evaluated to determine their correlative effect on biomass production and protein biosynthesis. The optimal conditions for obtaining a maximum protein yield of 9.53% w/w dry mass were the following: the complex manure concentration of 0.5%, the solid:liquid ratio of 1:5, and the growth time of 10 days