The C/N ratio of topsoil (upper layer 15CM) usually varies between 8: 1- 15: 1, and the median is10:1-2:.
The change of carbon-nitrogen ratio is generally related to climatic conditions. For example, the C/N ratio of soil in arid areas is lower than that in humid areas. Under the conditions of roughly the same temperature and annual rainfall, the C/N ratio of soil in warmer areas is lower than that in cold areas, and the C/N ratio of lower soil is generally lower than that of surface soil.
Extended data:
C/N ratio of culture medium in microbial fermentation;
Because carbon and nitrogen sources have a very important influence on the biological growth process, when analyzing the influence of nutrient sources on the growth of recombinant Escherichia coli, people have done a lot of research on the influence of carbon-nitrogen ratio and carbon-nitrogen source concentration on the fermentation process.
It is found that too high or too low C/N ratio is not conducive to cell growth and the expression and accumulation of foreign proteins, and too low C/N ratio leads to early autolysis of bacteria. Too high leads to imbalance of bacterial metabolism, which is not conducive to the accumulation of products.
Even if the ratio of carbon to nitrogen is at an appropriate level, the concentration of carbon and nitrogen sources is too high or too low, which is not conducive to cell growth and the expression and accumulation of foreign proteins. If the concentration is too high, the cells will grow slowly in the later stage of fermentation, resulting in more metabolic wastes, which will eventually cause abnormal cell metabolism and affect the synthesis of foreign proteins. When the concentration is too low, the nutrients provided by the culture medium are limited, which affects cell reproduction.
Baidu encyclopedia-carbon-nitrogen ratio