Carrier-free immobilized culture method of microbial flocculating agent

Abstract

The invention discloses a carrier-free immobilized culture method of a microbial flocculating agent. The method is characterized by comprising the following steps of: adding self-flocculating bacteria spore suspension in a volume which is 0.1 to 1 percent of the volume of a culture medium into the culture medium, wherein each millimeter of suspension contains 106 self-flocculating bacteria spores; putting the culture medium into a shaking bed, and performing culture and fermentation, wherein the culture conditions comprise that the revolution speed is 150 to 180 revolutions per minute, the temperature is 20 to 30 DEG C and the pH is 3.5 to 10.5; and standing after the suspension is cultured for 24 to 120 hours, and separating mycelium pellets generated by the self-flocculating bacteria and the fermentation solution, wherein the solid part is the mycelium pellets, and the liquid part is the microbial flocculating agent. Sucrose is used as a carbon source, sodium nitrate is used as a nitrogen source, the self-flocculating bacteria generate stress reaction by using the characteristic that the self-flocculating bacteria can form the mycelium pellets and improving the salt concentration of the culture medium, and the purpose of generating the microbial flocculating agent by the self-flocculating bacteria is fulfilled. The microbial flocculating agent prepared by the method has the advantages of low cost, extensive production conditions and high flocculating activity, and can be used for treating multiple kinds of printing and dyeing wastewater.

Description

technical field [0001] The invention relates to the technical field of microorganisms and cell engineering, in particular to a method for carrying out carrier-free immobilized culture using self-flocculation bacteria in a shaker without carrier medium, and simultaneously producing a microbial flocculant with a better flocculation rate. Background technique [0002] Microbial flocculant is a metabolite of microorganisms, not necessary for the survival of microorganisms, but its response to environmental stress. It is obtained by the fermentation of bacteria, fungi and other microorganisms by using microbial technology. It is a kind of water treatment agent with flocculation effect, high efficiency, non-toxic, and no secondary pollution. Compared with inorganic polymers and synthetic organic polymer flocculants, microbial flocculants have the characteristics of convenient use, wide flocculation range, high activity, safety, non-toxicity, and no pollution to the environment. G...

AI Technical Summary

Problems solved by technology

In addition, the traditional carrier-immobilized cell technology still has the following problems: 1. Physiological aspects: carrier materials sometimes have relatively large physiological toxicity to cells, affecting the biosynthesis of target metabolites; 2. Ecological aspects: carrier materials make cells and Small cell groups are separated from each other, which is easy to form an environment that is not conducive to the coordination between cells and affects the biosynthesis of metabolites; 3. In terms of technology: the large-scale preparation process of carrier-immobilized cells is complicated, and it is easy to cause bacterial infection; 4. Engineering aspects: On the one hand, the mass transfer performance of the carrier-immobilized cells is poor, and the concentration gradient of the external nutrient matrix and internal metabolites is large, making the overall activity low; The expansion and cracking of the produced gas will also cause the rupture of the solidified cells of the carrier, which will affect the life of its continuous use; 5. Economic aspects: the use and continuous consumption of carrier materials bring additional costs

Disadvantages: Requires use of chemicals other than nutrients required for cell growth and metabolite biosynthesis