上泽充通大￥ Shanghai Jiao Tong University 4.1 Microbial Nutrition Many prokaryotes require an organic compound as carbon source..Some prokaryotes are autotrophs自养型，use CO2 as C source. Nitrogen氮 A typical bacterial cell is about 12%nitrogen (by dry weight) Nitrogen is an important element in proteins,nucleic acids, and several other constituents in the cell. Shanghai Jiao Tong UniversityShanghai Jiao Tong University 4.1 Microbial Nutrition Carbon碳 • Many prokaryotes require an organic compound as carbon source. Some prokaryotes are autotrophs自养型, use CO2 as C source. Nitrogen氮 • A typical bacterial cell is about 12% nitrogen (by dry weight) • Nitrogen is an important element in proteins, nucleic acids, and several other constituents in the cell