Complete the sentence about microbial interactions:
In the nitrogen cycle, microorganisms such as __________ and __________ convert atmospheric nitrogen into __________, which plants can use directly.
1
Nitrosomonas, Nitrobacter, nitrites
2
Rhizobium, Azotobacter, ammonia
3
Lactobacillus, Streptococcus, lactic acid
4
Bacillus, Clostridium, methane