Chlorella fusca CHK0059 Keystone-Taxa Antifungal SynCom

In-vitro strawberry rhizosphere microbiome fractions changed composition and diversity during 12- and 36-hour exposure to live or sterilized CHK0059, methanol extract or D-mannitol. Responses differed by substance and time. Only Pseudomonas among the selected network groups was detected in these fractions; this is not demonstrated commensalism, in-plant recruitment or transfer from CHK0059 to the inoculated strains.

Participating Taxa: Chlorella fusca CHK0059, Pseudomonas

Metabolites: D-mannitol (CHEBI:16899 · MediaIngredientMech · CMMMech)

Evidence

• PMID:41937467 - SUPPORT (IN_VITRO)
  "By applying various substances, including Chlorella, Chlorella methanol extract (methanol extract), and D-mannitol, we observed changes in microbial distribution and diversity "

PARTIAL - the four bacterial isolates, alone or in mixtures and sometimes with CHK0059, altered symptom-based Fusarium wilt disease indices in strawberry and tomato. Treat8 contains all four bacteria plus pathogen; Treat9 additionally contains CHK0059. Results depend on arm, host and time; the full mixture does not uniformly outperform each single isolate. Disease reduction is not a fungal-load measurement or demonstrated competition, direct antibiosis, host-defense activation or formal synergy.

Participating Taxa: Pseudomonas, Pseudoduganella rivuli FT92W, Brevibacterium, Fusarium oxysporum, Chlorella fusca CHK0059

Evidence

• PMID:41937467 - PARTIAL (IN_VIVO)
  "a synthetic community (SynCom) of keystone taxa exhibited enhanced antifungal effects against Fusarium oxysporum in both strawberry and tomato, compared to individual strains"

PARTIAL - separate isolate screens found protease activity for 8C3D12; phosphate-solubilization, protease, CAS and Nfb responses for 6C7F4; CAS and Nfb responses for FT92W; and CAS plus Salkowski responses for REN4. Supplementary Table S2 additionally reports a positive FT92W Salkowski/IAA screen. Nfb color change is not measured nitrogen flux, and Salkowski color is not chemically resolved IAA. These screens do not establish colonization facilitation, community complementarity or necessary mediation of plant protection.

Participating Taxa: Pseudomonas, Pseudoduganella rivuli FT92W, Brevibacterium

Evidence

• PMID:41937467 - PARTIAL (IN_VITRO)
  "The FT92W and the 6C7F4 strains showed multiple PGP activities"
• PMID:41937467 - PARTIAL (IN_VITRO)
  "REN4 strain demonstrated siderophore production and indole-3-acetic acid (IAA) production abilities "

Under F. oxysporum f. sp. fragariae F9 challenge, the four-bacterium Treat8 had about 20% strawberry wilt disease index at week 5 versus about 60% for pathogen-only F, consistent with Figure 4. Treat9 adds CHK0059. Table S3 reports Treat8 mean shoot weight 1.47 g versus 0.43 g for F, while the single-isolate Treat3 mean was 2.24 g. These are host symptom and growth endpoints, not proof of direct fungal inhibition or universal mixture superiority.

Participating Taxa: Pseudomonas, Pseudoduganella rivuli FT92W, Brevibacterium, Fusarium oxysporum, strawberry, Chlorella fusca CHK0059

Evidence

• PMID:41937467 - SUPPORT (IN_VIVO)
  "the SynCom treatment group showed a disease index 20% percentage"
• PMID:41937467 - SUPPORT (IN_VIVO)
  "The only SynCom treatment (Treat8) had an average shoot weight of 1.47 g "

Under F. oxysporum f. sp. lycopersici challenge, the Results report week-4 mean tomato wilt disease indices of 25% for four-bacterium Treat8 and 18% for Treat9 with CHK0059, below pathogen-only F (about 68-75%). Single-isolate FT92W Treat2 is reported at 22.2%; Figure 5 shows overlapping post-hoc groups among effective arms. Thus lower disease severity does not establish universal full-mixture superiority, direct antagonism, competition or a specific host-defense mechanism.

Participating Taxa: Pseudomonas, Pseudoduganella rivuli FT92W, Brevibacterium, Fusarium oxysporum, tomato, Chlorella fusca CHK0059

Evidence

• PMID:41937467 - SUPPORT (IN_VIVO)
  "Treat1, Treat2, Treat6, Treat7, Treat8, and Treat9 had lower disease index percentages "

In-vitro rhizosphere microbiome-fraction assays showed higher Pseudomonas relative abundance with exogenous 2% D-mannitol at 36 hours; Figure S4 also shows lower relative abundance in live and sterilized CHK0059 arms. This compositional response is not absolute Pseudomonas growth, recruitment of 8C3D12 or 6C7F4 in plants, demonstrated algal mannitol secretion, or commensalism. A carbon-source mechanism is HYPOTHESIZED, not traced algal-to-bacterial transfer.

Target Taxon: Pseudomonas

Metabolites: D-mannitol (CHEBI:16899 · MediaIngredientMech · CMMMech)

Evidence

• PMID:41937467 - PARTIAL (IN_VITRO)
  "a notable increase in Pseudomonas abundance following 2% D-mannitol treatment"