Use of Plackett–Burman design for enhanced phytase production by Williopsis saturnus NCIM 3298 for applications in animal feed and ethanol production

Abstract

Distiller-dried grain solid (DDGS), a co-product of alcohol production, contains cereal grain residues, proteins, and yeast metabolites, which make it suitable in poultry feeding. However, high phytate content of DDGS limits its applicability in poultry feed. In this study, Plackett-Burman design was used to improve cell-bound phytase production by Williopsis saturnus NCIM 3298, and we achieved an enzyme activity of 269 IU/g of dry-wet biomass. The effect of this enhanced phytase-displaying yeast strain on hydrolysis of corn phytate and subsequently on ethanol production and DDGS quality was then investigated. Results of saccharification in the presence of phytase showed that reducing sugar content of liquefied mash increased by 11%, which subsequently improved the ethanol production by 18% (w/v) (p < 0.01) compared with the control. Notably, phytase treatment decreased the phytate content of corn by 70% (p < 0.01) compared with the control, thereby improving the availability of free phosphate in fermentation broth and DDGS. Thus, the results obtained suggest that the addition of W. saturnus NCIM 3298 strain has the potential of providing a new source of phytase that would be useful in the feed and ethanol industries.

Utilizing Plackett–Burman design and response surface analysis to optimize ultrasonic cleaning of pesticide residues from rape

“…As shown in Fig. 1(a), the actual results were scattered uniformly around the straight line in the form of points and were infinitely close to the straight line, which indicated the model of triadimefon explained the experimental results 23 . For triadimefon, the correlation coefficient ( R 2 ) between the experimental (actual) and predicted responses was 0.9657 as established by the model.…”

“…PBD is a kind of design of experiments (DOE), which is a systematic approach using mathematical tools to define the importance of specific processing variables and studying how to control them to optimize system performance 21 . PBD has been widely used on studying physicochemical properties of materials, animal feed and ethanol production, etc 22,23 . Test results obtained via PBD were analyzed by response surface methodology (RSM).…”