Biochar and microbial signaling: production conditions determine effects on microbial communication.
Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700 °C (surface area of 301 m(2)/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300 °C (surface area of 3 m(2)/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops.
Department of Earth Science, ‡Department of Biochemistry and Cell Biology, §Department of Bioengineering, and ¶Department of Chemical and Biomolecular Engineering, Rice University , 6100 Main Street, Houston, Texas 77005, United States.
Caroline A
CA
Masiello
Ye
Y
Chen
Xiaodong
X
Gao
Shirley
S
Liu
Hsiao-Ying
HY
Cheng
Matthew R
MR
Bennett
Jennifer A
JA
Rudgers
Daniel S
DS
Wagner
Kyriacos
K
Zygourakis
Jonathan J
JJ
Silberg
D054742:Acyl-Butyrolactones / Q000302:isolation & purification; D000327:Adsorption; D001419:Bacteria / Q000378:metabolism*; D002606:Charcoal / Q000378:metabolism*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature
D054742:Acyl-Butyrolactones; C540010:biochar; D049452:Green Fluorescent Proteins; D002606:Charcoal