Screening Of The Strain Degrading Caffeine And Its Fermentation

Caffeine also knows as caffeine,a purine alkaloid,is a central nervous system stimulant which can temporarily drive away the drowsiness and restore energy,so coffee,tea,soft drinks and energy drinks are very popular.Coffee skin and tea residue,which are byproduct of a variety of coffee and tea drinks are produced every year,these substances are usually treated as waste and cause environmental pollution.Some tea residue can be used as fertilizer,but can change the soil characteristics,cause the land salinization.Tea residue are rich in sugar and protein.They can be made into feed instead of grain and the traditional animal feed,but this use is restricted because of the existence of caffeine.This research took soil samples from tea garden to screen a strain CF-1 degrading caffeine by using the medium with caffeine as the sole carbon source and the nitrogen source.Ten strains grew better from the fifty strains.Then screened strain through the liquid medium for caffeine degrading test.A strain called CF-1 was screened to degrade caffeine almost entirely in 72 hours by using ultraviolet spectrophotometry.It provided references on microbe degrading caffeine.The strain degrading caffeine was identified based on the strain of cell morphology and Gram observation.Ten higher homology strains were found by 16S rDNA amplification and sequencing.The strain CF-1 was indentified as Burkholderia sacchari by constructing system development tree and physiological and biochemical tests.Based on strain of Burkholderia sacchari CF-1,the culture conditions were optimized.At result the bacteria grew better when pH was 5.5,temperature was 35?and time was 3 days.Inoculated the optimized strain at a certain amount into wet tea residue to ferment.It showed the fermentation conditions were optimized as follows:time 6 days?temperature 40??H 4.5?the water content 88.51%.It had the highest degradation rate of the caffeine in the tea residue.The highest caffeine degradation rate can reach 78.6%by optimizing.It provided references on the problem that the tea residue contained too much caffeine.Microbial degradation caffeine can make up for insufficiency of physical and chemical methods.It had very important economic and social benefits.