Method for isolating and purifying electroactive bacteria based on gradient dilution and potentiostatic culture

Abstract

The invention belongs to the technical field of isolation and purification, and particularly relates to a method for isolating and purifying electroactive bacteria based on gradient dilution and potentiostatic culture. The method comprises the following steps: constructing an electroactive bacteria isolation and culture device, diluting a mixed culture in a gradient mode by using sterile water, and inoculating the product in a funnel-shaped carbon paper electrode; externally connecting a potentiostat to constitute an external circuit for potentiostatic culture, and replacing a culture liquid in a carbon paper electrode chamber when a current value is relatively high under the control of a constant potential and an electron donor or electron acceptor has a good removal effect in the carbonpaper electrode chamber, replacing the potentiostat with a fixed value resistance, and culturing an isolate in a microbial fuel cell environment; taking the isolate having a higher dilution factor andbetter metabolic activity and electrical activity and repeating for several times until the purified electroactive bacteria are isolated. The method provided by the invention can be used for isolating anodic electroactive bacteria and cathodic electroactive bacteria.

Description

technical field [0001] The invention belongs to the technical field of separation and purification, and in particular relates to a method for separation and purification of electroactive bacteria based on gradient dilution and constant potential cultivation. Background technique [0002] Microbial fuel cell (MFC) is a new energy technology that can recover electricity while removing pollutants, and it is also a new sewage treatment technology. Electroactive bacteria are functional bacteria for MFC electricity generation and pollutant removal. Separating and purifying high-performance electroactive bacteria and improving their proportion and role in the biological community are the key to enhancing the performance of MFC electricity generation and pollutant removal. The biggest difference between electroactive bacteria and ordinary microorganisms is that electroactive bacteria can transfer electrons with electrodes, and their growth environment is driven by MFC potential. ...

AI Technical Summary

Problems solved by technology

The first two methods have poor selectivity to electroactive bacteria, and not all isolated bacteria are electroactive, and electroactive bacteria are easily missed.

The third method is carried out in the potential-driven environment of MFC, and the isolated bacteria all have electrical activity; but this method cannot provide a suitable growth environment for the isolate when cultivating the isolate, which is not conducive to the growth of the isolate and the separation effect. Poor and easy to miss electroactive bacteria. At present, this method is only used to separate anode electroactive bacteria and not to separate cathodic electroactive bacteria.

However, there is no report on the isolation and purification method of electroactive bacteria based on gradient dilution and constant potential culture, and there is no report on the isolation method of cathode electroactive bacteria.

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