Nondestructive Chemical Sensing within Bulk Soil Using 1000 Biosensors per Gram of Matrix

TY - JOUR

T1 - Nondestructive Chemical Sensing within Bulk Soil Using 1000 Biosensors per Gram of Matrix

AU - Fulk, Emily M.

AU - Gao, Xiaodong

AU - Lu, Li Chieh

AU - Redeker, Kelly R.

AU - Masiello, Caroline A.

AU - Silberg, Jonathan J.

PY - 2022/7/15

Y1 - 2022/7/15

N2 - Gene expression can be monitored in hard-To-image environmental materials using gas-reporting biosensors, but these outputs have only been applied in autoclaved matrices that are hydrated with rich medium. To better understand the compatibility of indicator gas reporting with environmental samples, we evaluated how matrix hydration affects the gas signal of an engineered microbe added to a sieved soil. A gas-reporting microbe presented a gas signal in a forest soil (Alfisol) when hydrated to an environmentally relevant osmotic pressure. When the gas signal was concentrated prior to analysis, a biosensor titer of 103cells/gram of soil produced a significant signal when soil was supplemented with halides. A signal was also observed without halide amendment, but a higher cell titer (106cells/gram of soil) was required. A sugar-regulated gas biosensor was able to report with a similar level of sensitivity when added to an unsterilized soil matrix, illustrating how gas concentration enables biosensing within a soil containing environmental microbes. These results establish conditions where engineered microbes can report on gene expression in living environmental matrices with decreased perturbation of the soil environment compared to previously reported approaches, using biosensor titers that are orders of magnitude lower than the number of cells typically observed in a gram of soil.

AB - Gene expression can be monitored in hard-To-image environmental materials using gas-reporting biosensors, but these outputs have only been applied in autoclaved matrices that are hydrated with rich medium. To better understand the compatibility of indicator gas reporting with environmental samples, we evaluated how matrix hydration affects the gas signal of an engineered microbe added to a sieved soil. A gas-reporting microbe presented a gas signal in a forest soil (Alfisol) when hydrated to an environmentally relevant osmotic pressure. When the gas signal was concentrated prior to analysis, a biosensor titer of 103cells/gram of soil produced a significant signal when soil was supplemented with halides. A signal was also observed without halide amendment, but a higher cell titer (106cells/gram of soil) was required. A sugar-regulated gas biosensor was able to report with a similar level of sensitivity when added to an unsterilized soil matrix, illustrating how gas concentration enables biosensing within a soil containing environmental microbes. These results establish conditions where engineered microbes can report on gene expression in living environmental matrices with decreased perturbation of the soil environment compared to previously reported approaches, using biosensor titers that are orders of magnitude lower than the number of cells typically observed in a gram of soil.

KW - biosensor

KW - gas reporter

KW - material

KW - microbe

KW - sediment

KW - soil

KW - synthetic biology

UR - http://www.scopus.com/inward/record.url?scp=85133978469&partnerID=8YFLogxK

U2 - 10.1021/acssynbio.2c00083

DO - 10.1021/acssynbio.2c00083

M3 - Article

C2 - 35715210

AN - SCOPUS:85133978469

SN - 2161-5063

VL - 11

SP - 2372

EP - 2383

JO - ACS Synthetic Biology

JF - ACS Synthetic Biology

IS - 7

ER -