Nitrogen defect control method for production of ethanol through fermentation of synthesis gas with mixed bacteria

Abstract

The invention belongs to the field of biological energy sources and particularly relates to a nitrogen defect control method for production of ethanol through fermentation of synthesis gas with mixed bacteria. The method comprises steps as follows: a first stage: mixed bacteria are cultured to grow in a fermentation medium to reach a stable state, that is, the yield of fermentation products is stable and unchanged; a second stage: the mixed bacteria growing to reach the stable state are cultured at the second stage, the nitrogen concentration of the fermentation medium at the stage is controlled to be lower than that at the first stage, the mixed bacteria are the same type of acetogenic bacteria which come from cow dung, urban excess sludge and enriched products thereof, as ethanol is a non-growth coupling type product of the acetogenic bacteria, insufficient nitrogen nutrients possibly cause abnormal cell metabolism, cells enter a non-growth state or dormant state, the condition not beneficial to growth of the acetogenic bacteria is created through nitrogen nutrient defects, so that the metabolism pathway is changed from the acid producing phase to the solvent producing phase, and ethanol production is controlled.

Description

technical field

[0001] The invention belongs to the field of biological energy, and in particular relates to a nitrogen deficiency control method for producing ethanol by fermenting synthetic gas with mixed bacteria. Background technique

[0002] Syngas fermentation to produce ethanol is a new technology to produce ethanol from biomass, that is, complete gasification of biomass to obtain CO, H 2 , CO 2 Syngas as the main component, and then use microorganisms to convert the syngas into ethanol. This technology does not require expensive enzymes and reagents such as acids and alkalis, which reduces production costs, and in theory microorganisms can completely utilize gases, which is an environmentally friendly technology.

[0003] Mixed culture biotechnology is a very promising technology in recent years. Its concept is to combine traditional elements of environmental biotechnology from the perspective of bioengineering, to maximize products like industrial biotechnology wh...

Images