Nitrogen source, medium and culture method for producing riboflavin

Abstract

The invention relates to a method for obtaining a nitrogen source for producing riboflavin. The method comprises the following steps: performing desalination treatment on wastewater of a riboflavin fermentation broth after extraction, wherein the total salt content of the wastewater is controlled to be less than 5g / l after desalination; adding 2-5% of polymerized ferrous sulfate for flocculating for 1-2 hours, centrifuging for filtering by using a double-conical decanter centrifuge so as to obtain a solid substance, and drying the solid substance so as to obtain bacterial protein. By adopting the method, the problem that the riboflavin bacterial protein is hard to utilize because of high salt content is solved, the bacterial protein which can be alternatively used as a fermentation nitrogen source is obtained, the application of the expensive organic nitrogen source is greatly reduced, and recycling and utilization of resource are achieved. Besides, on the basis of the bacterial protein, the invention further discloses a corresponding seed culture medium formula and a fermentation culture medium formula, and the process control conditions are optimized starting from factors including temperature, pH values, residual sugar content, dissolved oxygen content, ammonia feeding amount, material supplement mode and the like which can affect the stability of fermentation.

Description

technical field [0001] The invention relates to the production of riboflavin by a biological method. Background technique [0002] The main carbon source used in the microbial fermentation of riboflavin is vegetable oil, glucose, molasses or rice sugar, etc.; the organic nitrogen source is mainly peptone, bone glue, fish meal, corn steep liquor and well-proportioned biological nitrogen; the inorganic salts include NaCl, K2HPO4, MgSO4, etc. The prices of the raw materials used are constantly rising, leading to high costs in industrial applications. At the same time, the production wastewater in the riboflavin fermentation industry is high-concentration organic wastewater, which has the characteristics of high chroma, high salinity, high COD, high BOD, and high bacterial content, and the treatment is difficult. Wastewater contains a large amount of sugar, protein, SS and ammonia nitrogen. These substances are not toxic and harmful substances, and can be used by some microorg...

AI Technical Summary

Problems solved by technology

Although this method provides a way to use waste cells as a nitrogen source, it does not use the bacterial protein with high salinity, nor does it combine the characteristics of riboflavin fermentation to solve the problem caused by the high salt content of bacterial protein. The problem of low added value