Microbial control agents project

Project description
The Bacillus thuringiensis toxin specificity database
Toxin specificity database categories
How to use the database
Publications
Toxin specificity data summaries

Toxin specificity database categories

References

1. Journal Reference and/or unpublished work

Gene designation

2. New: designation according to Crickmore's list

3. Old: designation as per Hofte & Whiteley

4. Accession No: Gene bank accession number

Parental strain

5. Serovar, isolate: B. thuringiensis (B.t.) serovar designation if known and isolate number or designation

6. Culture collection: collection where isolate was obtained from OR where it was deposited

Toxin preparation

7. Expression host: organism in which single genes were expressed as recombinant proteins. If assays were performed on purified toxins from single gene strains, the expression host is the same as the parental strain and is flagged with a *.

Some common expression hosts:

E. coli
P. fluorescens
B. subtilis
B. megaterium
B. cereus
B.t. kurstaki HD-1 cry-
B.t. kurstaki HD-73 cry-

8. Inclusion Body Extraction: method used for breaking open cells to harvest inclusion body protein.

Categories:

cell-free extract (excreted toxins)
autolysis (Bacillus expressed proteins)
sonication
lysozyme
whole cell (no extraction)
French press
freeze/thaw + sonication
freeze/thaw + lysozyme
sonication + lysozyme
French press + lysozyme
other combinations (please specify)

9. Inclusion body purification: method used to purify IB preparation beyond the usual steps of centrifugation and repeated washing.

Categories:

density gradient (centrifugation on any gradient incl. renografin, sucrose, NaBr, CsCl to separate IB from spores)
recrystallization (denaturation followed by dialysis to permit recrystallization)

10. Solubilization: specifies buffer type, pH, and reducing agents used for solubilization of IB protein

11. Activation: specifies enzyme system used for conversion of protoxins into activated toxins. If activation was done by incubation of intact IB in high pH buffer, specify the buffer.

Some common activation systems:

trypsin
chymotrypsin
gut juice from various insect species

12. Toxin purification: method used for purification of either soluilized protoxins or activated toxins.

Target insect

15. Pest species:

Taxonomy: Order, family, genus, species, common name
Strain: Selected vs non-Selected; if Resistant, specify against which product or toxin resistance was selected. Example: Plutella xyostella (Dipel-Resistant) Spodoptera exigua (cry1C-Resistant)

16. Stage:

adult
neonate
L1 (first larval instar)
L2 (second larval instar), etc
age in days

Bioassay

17. Type:

diet incorporation (toxin mixed in)
diet surface (surface contamination)
leaf surface (toxin applied to leaf)
leaf dip (leaf dipped in suspension)
force feed (forced ingestion)
free ingestion (aquatic, adult Diptera)
others (please specify)

Length: duration of the assay (in days)

Temperature: temperature during assay

Parameters: parameter used to assess effect of toxin

mortality
weight
frass
pupation

Toxicity

21. Slope: slope of the dose-response regression

22. ED₅₀: 50% effective concentration or dose reported as:

ED₅₀ (LL-UL) (95% CL in brackets)
ED₅₀ ± SD (mean and standard deviation of repeated assays)
x1-x2 (values bracketing expected ED₅₀)
>x1 (ED₅₀ exceeding this value)

23. ED₉₀ or 95: 90 or 95% lethal dose

24. Units: units in which ED values are expressed.

cells/cm² (whole cell cultures)
ng cells/cm² (whole cell cultures)
ng/cm² (leaf surface or diet surface)
ng/ml (diet incorp, leaf dip, aquatic,diet surface)
ng/larva (forced ingestion,leaf or diet surface)
others (please specify)

25. Qualitative:

not active
active
low activity
intermediate activity
high activity

Toxin specificity database categories

How to use the database

Project status

On-going