Lunar Regolith Simulant Phosphorus-Solubilizing Bacteria for Nicotiana benthamiana

Community ID CommunityMech:000306

Ecological State ENGINEERED

Environment lunar regolith simulant plant-cultivation laboratory experiment
ENVO:01001405

A defined set of phosphorus-solubilizing bacteria (PSBs) assembled to improve the fertility of lunar regolith simulant for in-situ resource utilization (ISRU) agriculture in bioregenerative life support systems. Five commonly used microbial-fertilizer strains were tested on a CAS-1 lunar soil simulant: Bacillus mucilaginosus (AS1.232), Bacillus megaterium (AS1.217), Bacillus subtilis (CMCC 63501), Bacillus licheniformis (ATCC 11946), and Pseudomonas fluorescens (ATCC 13525). In a 21-day bio-improving experiment followed by a 24-day Nicotiana benthamiana cultivation experiment, three of the strains - Bacillus mucilaginosus, Bacillus megaterium, and Pseudomonas fluorescens - tolerated the lunar regolith simulant conditions and dissociated insoluble inorganic phosphorus from the simulant. The mechanism is chemolithoheterotrophic organic-acid production: the bacteria synthesize organic acids (e.g. oxalic, citric, tartaric acids) from carbon sources in the medium, lowering the pH and chelating metal ions in insoluble phosphates such as Ca3(PO4)2, FePO4, and AlPO4, thereby releasing available phosphate. PSB treatment raised the available phosphorus content of the simulant and promoted Nicotiana benthamiana growth, with the largest improvement when the simulant was pre-cultured with PSBs 18 days before sowing. The work establishes a microbiological route to convert lunar regolith into a plant-cultivation substrate for future lunar bases.

Taxonomy

Taxon	Ontology ID	Abundance
Bacillus mucilaginosus (AS1.232)	NCBITaxon:61624	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "the phosphorus-solublizing bacteria Bacillus mucilaginosus, Bacillus megaterium, and Pseudomonas fluorescens can tolerate the lunar regolith simulant conditions and dissociate the insoluble phosphorus from the regolith simulant" PMID:37945659 - SUPPORT (IN_VITRO) "B. megaterium (AS1.217), B. subtilis (CMCC 63501), P. fluorescens (ATCC 13525), B. licheniformis (ATCC 11946), and B. mucilaginosus (AS1.232)"
Bacillus megaterium (AS1.217)	NCBITaxon:1404	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "the phosphorus-solublizing bacteria Bacillus mucilaginosus, Bacillus megaterium, and Pseudomonas fluorescens can tolerate the lunar regolith simulant conditions and dissociate the insoluble phosphorus from the regolith simulant" PMID:37945659 - SUPPORT (IN_VITRO) "B. megaterium (AS1.217), B. subtilis (CMCC 63501), P. fluorescens (ATCC 13525), B. licheniformis (ATCC 11946), and B. mucilaginosus (AS1.232)"
Pseudomonas fluorescens (ATCC 13525)	NCBITaxon:294	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "the phosphorus-solublizing bacteria Bacillus mucilaginosus, Bacillus megaterium, and Pseudomonas fluorescens can tolerate the lunar regolith simulant conditions and dissociate the insoluble phosphorus from the regolith simulant" PMID:37945659 - SUPPORT (IN_VITRO) "B. megaterium (AS1.217), B. subtilis (CMCC 63501), P. fluorescens (ATCC 13525), B. licheniformis (ATCC 11946), and B. mucilaginosus (AS1.232)"
Bacillus subtilis (CMCC 63501)	NCBITaxon:1423	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "B. megaterium (AS1.217), B. subtilis (CMCC 63501), P. fluorescens (ATCC 13525), B. licheniformis (ATCC 11946), and B. mucilaginosus (AS1.232)"
Bacillus licheniformis (ATCC 11946)	NCBITaxon:1402	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "B. megaterium (AS1.217), B. subtilis (CMCC 63501), P. fluorescens (ATCC 13525), B. licheniformis (ATCC 11946), and B. mucilaginosus (AS1.232)"

Ecological Interactions

Taxon

Cross-feeding

Mutualism

Syntrophy

Competition

Commensalism

Niche partitioning

Colonization facilitation

Strain competition

Predation

Phosphorus solubilization from lunar regolith simulant via organic-acid secretion

CROSS_FEEDING

Metabolites: phosphate (CHEBI:18367), oxalic acid (CHEBI:16995), citrate (CHEBI:16947)

Biological Processes:

organic acid biosynthetic process (GO:0016053)

Evidence

PMID:37945659 - SUPPORT (IN_VITRO)

"PSBs to synthesize organic acids by using carbon sources in the medium to reduce regolith pH, thus activating insoluble inorganic phosphorus in lunar regolith simulant"
PMID:37945659 - SUPPORT (IN_VITRO)

"organic acid ions also facilitate the dissolution of phosphate minerals through chelating with the metal ions in Ca 3 (PO 4 ) 2 , FePO 4 , AlPO 4"

Phosphorus-enabled promotion of Nicotiana benthamiana growth

COLONIZATION_FACILITATION

Target Taxon: Nicotiana benthamiana

Metabolites: phosphate (CHEBI:18367)

Evidence

PMID:37945659 - SUPPORT (IN_VITRO)

"The phosphorus-solubilizing bacteria treatment improves the available phosphorus content of the regolith simulant, promoting the growth of Nicotiana benthamiana"
PMID:37945659 - SUPPORT (IN_VITRO)

"the growth of Nicotiana benthamiana could be most improved by treating the regolith simulant with PSBs 18 days before sowing"

External Resources

Name	Repository	Resource ID
Primary publication - phosphorus-solubilizing bacteria improve Nicotiana benthamiana on lunar regolith simulant Xia et al., Communications Biology (2023). Primary source describing the five tested PSB strains, phosphorus solubilization from CAS-1 lunar regolith simulant, and improved Nicotiana benthamiana growth.	OTHER	doi:10.1038/s42003-023-05391-z
PMID:37945659 - SUPPORT (IN_VITRO) "five species of phosphorus-solubilizing bacteria are used as test strains"
NCBI Taxonomy - Paenibacillus mucilaginosus NCBI Taxonomy record for Paenibacillus mucilaginosus (reported as Bacillus mucilaginosus).	OTHER	NCBITaxon:61624
NCBI Taxonomy - Priestia megaterium NCBI Taxonomy record for Priestia megaterium (reported as Bacillus megaterium).	OTHER	NCBITaxon:1404
NCBI Taxonomy - Pseudomonas fluorescens NCBI Taxonomy record for Pseudomonas fluorescens.	OTHER	NCBITaxon:294

Environmental Factors

Factor	Value	Unit
Lunar regolith simulant substrate	CAS-1 lunar soil simulant	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "The simulant used in our study is a copy of the CAS-1 lunar soil simulant"
Available phosphorus increase in liquid medium	soluble inorganic phosphorus increased by 212 percent	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "soluble inorganic phosphorus in the liquid medium was significantly increased by 212"
Acidification as the phosphorus-dissolving factor	bacterial acidic substances lower pH	N/A
PMID:37945659 - SUPPORT (IN_VITRO) "the acidic substances were the key factor in dissolving inorganic phosphorus from the simulant"

Growth Media

PSB phosphorus-solubilization liquid medium (shaking-flask assay)

pH 7.0

Temperature 30 °C

Atmosphere AEROBIC

Composition

Component	Concentration	Unit	CHEBI
glucose	10	g/L	N/A
Ca3(PO4)2 (insoluble inorganic phosphorus source)	5	g/L	CHEBI:18367

Preparation notes: Strains were cultured overnight in a shaking flask at 180 rpm and 30 C. The phosphorus-solubilization assay used a liquid medium containing glucose 10 g/L, (NH4)2SO4 0.5 g/L, Ca3(PO4)2 5 g/L (insoluble inorganic phosphorus source), NaCl 0.3 g/L, FeSO4 0.03 g/L, KCl 0.3 g/L, MgSO4 0.3 g/L, MnSO4 0.03 g/L, at pH 7.0.

Evidence

PMID:37945659

"cultured overnight in a shaking flask at 180 rpm and 30 °C"

PMID:37945659

"glucose 10 g/L"