We recently performed a targeted metagenomic analysis of leaf and spike samples of Piper longum plant, and found that the number of bacterial OTUs were >200 times higher than that of fungal OTUs, though the no. of sequencing reads in both the cases were similar.
Could it be due to less robust fungal databases or do endophytic bacterial communities actually outnumber those of fungal communities under normal natural conditions.
Thanks in advance
Sushma
I think that the number of bacterial Operational taxonomic units (OTUs) is larger comparing to fungi due to different taxonomic criteria for species identification. If you use 16S/18S rRNA, many bacteria are well-differentiated on the species level, when fungi are not . Estimated from 16S variablility total number of bacterial species is huge ( I have met different numbers in the range from 3 million to 1 billion species).
Agree totally with Alex. Also worth remembering the difference in size. Bacterial numbers can mask the fact that fungal biomass can hugely outnumber bacterial biomass.
Thank you Dr. Ignatov and Dr. Philp.
Alex Ignatov So, if I have understood correctly, this discrepancy in the no. of OTUs is due to the algorithms used, and might not represent the actual abundance of bacterial and fungal communities.
Jim C Philp If we consider the cellular size of bacteria and fungi, there would be potentially higher number of bacteria residing in the plant tissues?
Sushma Mishra You are right! Estimations of Paul et al, (work done at 1990s) made at poplar plantation , gave in 20 cm top soil a total biotic carbon about 300 kg/ha, bacterial part among it - only 75 kg. In deeper soil fungal part was larger.
Horwath WR, Paul EA. Microbial biomass. Methods of Soil Analysis: Part 2 Microbiological and Biochemical Properties. 1994 Jan 1;5:753-73.
Harris (ser.org)
http://chapter.ser.org/europe/files/2012/08/Harris.pdf
- Badges
- Science topic
- Similar topics
- Mathematics
- Statistics
- Sampling Design
- Sample Size