Culture medium and method for producing phytase by using vinegar residue as raw material through solid fermentation

Abstract

The invention provides a culture medium and a method for producing phytase by using vinegar residues as raw materials through solid fermentation. The adopted culture medium of the method comprises vinegar residues, glucose and bean slag, wherein according to the total weight of a solid culture medium, the content of the glucose is 7.2 percent by weight, and the content of the bean slag is 5.1 percent by weight. By a PB test, three factors of the glucose, the bean slag and fermentation time which have obvious influence for a fermentation result are obtained and a method of steepest ascent is adopted to select factor levels of a maximum response value for the selected important factors, then, a central composite test is adopted to be combined with response surface analysis (RSM) to obtain arelational expression between the response value and the important factors, and the important factor level of the maximum response value is calculated, thereby an optimal fermentation condition for producing the phytase through the solid fermentation is ensured, namely, the content of the glucose is 7.2 percent by weight, the content of the bean slag is 5.1 percent by weight, and the fermentationtime is 271 hours. By a verifying test, the activity even value of the phytase is 98.37U / g DMR under the condition.

Description

technical field [0001] The invention relates to a culture medium and a method for producing phytase by fermentation, in particular to a culture medium and a method for producing phytase by solid fermentation using vinegar grains as a raw material. Background technique [0002] Phytic acid, phytic acid, is the main storage form of phosphorus in plant seeds, and 60% to 70% of phosphorus exists in the form of phytate. Due to the lack of phytate-decomposing enzymes in the digestive tract of monogastric animals, expensive inorganic phosphate must be added to the feed, which not only increases the feed cost, but also excretes the inorganic phosphorus that cannot be digested and absorbed with the feces, causing environmental pollution; in addition, phytic acid Salt can chelate nutritional factors such as protein and minerals, which reduces the utilization rate of nutritional factors and is considered as an anti-nutritional factor. Phytase can decompose phytic acid and its salts in...

AI Technical Summary

Problems solved by technology

[0004] When optimizing the fermentation medium, one-factor-at-one-time (one-factor-at-one-time) method (Chu Yiwen, 1999) is usually used, or an orthogonal test is used to supplement the interaction between factors on the basis of a single factor These methods only compare the pros and cons of the selected levels of each factor when investigating factors, and cannot provide information on uninspected areas, cannot perform forecasting and control, and require more trials and longer trial periods. Especially for strains with a long growth cycle, a longer test period is required

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