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Mercredi 10 décembre
Biopesticides : quand les biotechs se mettent au service d’une agriculture durable Quentin ZUNE, ULg Gembloux Agro-Bio Tech
Marc ONGENA, ULg Gembloux Agro-Bio Tech
Avec le soutien de :
Université de Liège – Gembloux Agro-Bio Tech – Unité de Bioindustries Passage des Déportés, 2 - 5030 Gembloux – Belgique. Tél+32(0)81 62 2305 (Fax 6142) - www.fsagx.ac.be
Biopesticides: quand les biotechs se mettent au service d’une agriculture durable
Quentin Zune & Marc Ongena
Walloon Center for Industrial Biology, Gembloux Agro-Bio Tech/University of Liège
LIEGE CREATIVE, 10th December 2014
Need for phytosanitary products
2
35 % of losses due to pests 70 % if no phytosanitary treatments
Plant diseases caused by: insects, fungi, virus, bacteria, nematodes
Problems of chemicals
Ecotoxicity of the product or residues Pathogen adaptation Lack of specificity Health problems for the users Strong interest from consumers for « safe » food and sustainable agricultural practices Registration/homologation constraints
- «Plan Écophyto 2018» in France, to reduce chemicals by 50%
- «Programme de Réduction des Pesticides et Biocides» to reduce by 25%
- European dir. 128/2009/CE, sustainable use of phytosanitary products
Problems of chemicals
Need for eco-friendly and efficient alternatives
Implementation of Integrated Pest Management (IPM): Disease risk monitoring: Comprehensive information on the life cycles of pests and their interaction with the environment
+ Prevention: soil fumigation/strilization, rotating between different crops, use of pest-resistant varieties, and planting pest-free rootstock
+ Pest control: spraying of pesticides, BIOLOGICAL CONTROL
Adapting agricultural practices to favor antagonists of plant pathogens, reduction of disease vector,… Use of disease resistant genetical-modified crops Introducing antagonists of plant pathogens into the environment or onto the plant
5
Biological control/biopesticides as part of IPM
BIOPESTICIDES
Broad def: any living organism or derived products used on plants for its protective effect against diseases
Biopesticides: nature
Microbes
GMOs
Nematodes, predators
Biochemicals
Insects
Bacteria, fungi, yeast, viruses, protozoa
Insect sex pheromones, Plant extracts, Growth regulators Plant resistance activators
7
Microbial biopesticides
Plant-beneficial (rhizo)bacteria Streptomyces, Arthrobacter, Azotobacter, Burkholderia, Pantoea, Serratia,Collimonas
8
Biopesticides: applications
Insect pests
Nematodes
Soil-born microbial pathogens
Post-harvest diseases
Leaf, flower, fruit diseases
Biopesticides: applications
Organic farming
Conventional agriculture
Industrial greenhouses
Forestry
Biopesticides: market
Global market valued at $1.3 billion in 2011 Expected to reach $4,3 billion by 2019 (rate of 16.0% from 2014 to 2019) Europe expected to be the fastest
growing market (stringent regulation, demand from organic products)
North America dominated the global bio pesticides market (around 40%)
How do they work to protect plants?
Microbial biopesticides in action
Microbial biopesticides: multiple benefits
Growth promotion, yield increase
via: - help in nutrient acquisition (N, P, Fe) - phytohormone production (cytokinin, gibberelin, IAA, ethylene) - help under abiotic stress
Protection against phytopathogens, disease resistance
via: - competition for space and ressources - antibiosis (antibiotics, lytic enzymes) - host immunization (systemic)
Beneficial)
rhizobacteria)
Formation of microcolonies/biofilms
Root$coloniza+on$and$compe++on$for$niche$and$nutriments$
On)Agar,)4)dpi)
Pathogen)
Anti-fungal, anti-bacterial, anti-viral activities
Botrytis cinerea (grey mould disease)
Pythium ultimum (seedling disease)
Direct$antagonism$of$phytopathogens$$
Secretion of LMW antimibials, Hydrolytic enzymes
Pathogen)
restric9on))
Host plant immunization
Root treatment with: -over producing mutants -enriched LPs extracts -Purified LPs
A"variety"of"biocontrol0related"ac2vi2es"Plant$systemic$resistance$elicita+on$9$ISR$
in Arabidopsis In Solanaceae
Treated Control Treated Control
Elicitor production
16
Must persist in the niche from inoculation to infection > must be perfectly adapted to the environment where it is introduced
Must resist other organisms, be efficient at low doses
> strong producer of active substances Must not induce resistance in the target pathogen
> act via multiple mechanisms
Biopesticides: requirements
View from the industry: The product must work as good as a comparable chemical pesticide
> use/select/optimize the most active agents The product shouldn‘t be more expensive than a chemical pesticide
> cost-effective production at industrial scale The product should be applicable as easily as a chemical pesticide
> optimized formulation
From the strain to a marketable product
Main steps for microbial biopesticide development
18
Main steps for biopesticide development: step 1, strain selection
Highthrouput screening for main biocontrol activities
Suppressive soils Less infected plant tissues
Where to look for?
How to select?
Colonization Antagonism Host immunization
Taxonomy
GRAS
Cultivable
Spore formation
Structure identification
Biosynthesis, genes
- Low molecular weight metabolites:
Antimicrobials, host immunity elicitors, siderophores
- Hydrolytic enzymes
Mode of action, identification of compounds involved in biocontrol activity
Step 2: characterization of biological activity
Physiological factors Environmental parameters
Regulation of genes/products and expression in vivo
Study of factors modulating expression of biocontrol determinants
Step 3: expression of bioactive compounds in vivo
- Developement as root-associated microcolonies/biofilms - Host plant species, cultivar, developmental stage - Nutritional basis imposed by the plant, growth rate - Auxiliary microflora - soil type, pH, T, pO2
Most data on biocontrol metabolites come from in vitro assays
However, in vivo context very different:
2. Fermentation bioprocess
1. Strain selection
3. Downstream process operations and packaging
• Economic
• Efficiency
• Ecofriendly
• Quality product
• Practical application
powder
Vegetative cells
Nutrient excess
Endospore formation
Nutrient limitation Nutrient depletion
spores
Fermentation time
Cell division ! Sporulation
Step 4: Production of the biopesticide
1 – 100 mL
1-100 L
Lab-scale Optimization of medium composition, pH and T° for strain growth
! low transfer capacity, no regulation
Pilot-scale Optimization of transfer operations (homogeneity, cells suspension, oxygen transfer rate)
pH, pO2,T°, substrate regulation
Complex, Expensive and Time consuming
Industrial scale Scale-up conserves critical parameters for fermentation (density power, oxygen transfer rate)
! Heterogeneities!!!
Step 4: Development of the fermentation bioprocess 1 – 100 m³
1. Concentration and purification of the microbial cells
Centrifugation Precipitation
2. Drying of the cream to get a powder
3. Packaging
Atomization (high T°)
Lyophilization (low pressure and T°)
Preserves product quality
Step 4: Downstream process operations and packaging
Biopesticides: market
Global market valued at $1.3 billion in 2011 Expected to reach $4,3 billion by 2019 (rate of 16.0% from 2014 to 2019) Europe expected to be the fastest
growing market (stringent regulation, demand from organic products)
North America dominated the global bio pesticides market (around 40%)
But growth rate of the market lower than expected, could be better!!
Limitations of rhizobacteria as phytosanitary products
Efficacy may be limited or inconsistent !
Need for improving our knowledge
Persistence of populations in the niche and colonization of the host tissue (rhizosphere)
Identification of active ingredients (secondary metabolites) Establishing their functions in multitrophic interactions (molecular cross-talk, antibiosis, stimulation of host immunity) Secretion of biocontrol
metabolites in planta
Exploiting Omics and Bioprocesses
Learning more about microbial biopesticides
Whole genome sequencing Annotation of draft sequence (RAST)
Genome mining -Based on known nucleotide sequences in close relatives (genome alignment software Mauve, NRPSpredictor, BLASTx) -Based on predicted amino acid sequences (Antismash, Norine)
Comparative Genomics: PGPR antibiotic potential
8,5% of CDS devoted to synthesis of NRPS/PKS antibiotics
FZB42, YAU Y2
+ orphan NRPS gene clusters
polyketides
lipopeptides
dipeptides
siderophore
lantibiotics
Linear peptides
Comparative Genomics: PGPR antibiotic potential
LC-ESI-MS analysis of Bacillus antibiotics
Metabolomics: PGPR antibiotic potential
Surfactin Fengycin Iturin
Antiviral +++ - -
Antibacterial ++ (+) (+)
Antifungal (+) +++ +++
Anti-yeast + - ++
Anti-mycoplasma ++ - -
Anti-insect +++ - -
Antiprotozoa +++ - -
ISR in plants +++ +/- -
Different activities of lipopeptides on different targets
rich in PG, CL, low content of PC. No sterols
rich in PE, cholesterol and sphingolipids
high levels of PG, PC, and PE. Cholesterol
PC and PE abundant. Ergosterol
PC and PE abundant, PS, shingolipids. Sitosterol, stigmaterol
=> Selectivity of CLPs to certain membrane compositions
Biophysics: molecular mechanisms of antibiotic activity
Model membranes
Biophysics: molecular mechanisms of antibiotic activity
Experimental, in silico
PM#fraction#only12136%
PM#>#DRMs11233%
DRMs#>#PM8225%
DRMs#fraction#only206%
P-type H+-ATPase Aquaporins Calcium dependent protein kinase Small GTP-binding proteins Leucine rich repeat (LRR)-receptor kinase NADPH oxydase NtrbohD Phospholipase D
Analysis of proteome (2D UPLC-MS/MS, NCBI database) in tobacco plasma membrane raft-like microdomains upon elicitation by surfactin
Confirmation of raft-specific proteome signature
Proteomics: molecular mechanisms of plant immunization
High-affinity receptors for non-self detection
Specific aspects of plant immunization by surfactin
Surfactin preferably interacts with the lipid phase of the plasma membrane, inducing transient disturbance, proteome rearrangement and triggering of defense-related signalling cascade
Micelle&of&surfactin
Cytosol
Cholesterol
Membrane&protein
B
Protein with lipidaddressing motif
x
Production of biocontrol metabolites in planta
Are bioactive metabolites produced by bacteria in sufficient amounts, at the right place, at the right time?
Various approaches are available:
Extraction from soil substrate (difficult!)
Comparative analysis of selected mutants (may be tricky to generate!)
Need for accurate spatio-temporal monitoring of antibiotic production in situ
Pump)
Drying)under)
vaccuum)during)
1h30B2h)
Automated)
9AA)matrix)
deposi9on)
MALDIBTOF/TOF)analysis)in)
nega9ve)ion)mode)
Sample):))
colonized)root)on)an)
ITO)coated)glass)slide)
covered)by)agar)
Imaging Mass Spectrometry for antibiotic signature in planta
control$
inoculated$
Imaging Mass Spectrometry for antibiotic signature in planta
Surfactins much more abundant but iturins and fengycins detected in low amounts
MALDI-TOF MS imaging of CLPS Surfactins
Iturins
Fengycins
Imaging Mass Spectrometry for antibiotic signature in planta
Transcriptomics: antibiotic gene expression in planta
qRTPCR RNAseq
Reporter systems (yellow fluorescent protein, YFP)
In vitro experiment
• Petri dish, microtiter plates and flask cultures
(+) Easiness of implementation, cheap
(+) Fast and high throughput screening
But…
(-) Not representative of real conditions at several levels
Bioprocess technologies to mimic natural systems
• Omics technology characterize cell physiology at the cell level (in vivo)
! bioprocess study mecanisms at the population level
Planktonic)state)=)free)cells)
suspended)in)the)liquid)medium)Biofilm)=)bacterial)community)growing)
on)solid)surface)
≠Physiology$
Cells
EPS Matrix
• )Gene)expression)
• )Metabolism)(I))
• )Growth)rate)
• )Secre9on)profiles)
Bioprocess technologies to mimic natural systems
Batch)condi9on)=)cell)growth)stops)
when)nutrients)are)depleted)
No)control)of)the)growth)rate)
Chemostat)condi9on)=)con9nuous)
feeding)of)root)exsudate))
Effect)of)growth)rate)on)biofilm)
metabolism))
Kine+c$
≠Substrate)
Batch)(flask))
Root)system)
Need$:)experimental)device)close)to)natural)condi9ons)(biofilm),)
con9nuous)feeding)rate)and)taking)into)account)cell)history)
Biomass)
Bioprocess technologies to mimic natural systems
Flow cell to study biofilm growth
• Flow rate modulation ! growth rate control of the biofilm
• Steady-state of biofilm (Chemostat)
• Coupled with microscopy
• Pulse adds and on line sampling
• Design of a bioreactor with a support to immobilize biomass on a biofilm
• pH, T°, pO2 regulation
Fresh medium
Waste
Fresh medium
Waste
Biofilm colonization of the support
Biofilm reactor to study biofilm growth
Bioprocess technologies to mimic natural systems
! cellular steady state increases relative surfactin gene expression
Steady-state
High expression
Modulation of pump flow rate
! Low growth rate increases surfactin production
Note : time of experiment ! 72 hours
Root system
In vivo
In vitro
Bioprocess technologies to mimic natural systems
Biofilm : great heterogeneity, complex behavior!
Flow cell technology & biofilm reactor ! response at the biofilm level
• Isogenic population ! phenotypic diversity
secretor non-secretor dormant cell (spore) motile cell EPS producer
Combined with :
• Confocal microspoy
• Fluorescent reporter system
• Flow cytometry
Structure & composition
Response mechanism at the
biofilm scale
Nutritional context of in planta conditions
Confocal microscopy
3D visualization
! biofilm structure (roughness, smoothness, mushroom-like structure)
Specific staining
! characterize and locate phenotypes (secretor, spores, ect.)
Biofilm : great heterogeneity, complex behavior!
Transcriptional reporter system Expression of a fluorescent protein when a specific gene is activated!
! easy detection and quantification
Screening of genes involved in regulation mechanisms
On-line measurement of gene activation under specific conditions
On-line localization of cells expressing the gene
Pstress
GFP coding sequence
Environmental cue
Signal transduction
GFP synthesis
Sectional view
Biofilm : great heterogeneity, complex behavior!
Laser 520nm
Side scatter canal (FSC)
Side scatter (SSC)
Green fluorescence (FL1)
Yellow fluorescence (FL2)
Red fluorescence(FL3) Cells sample
Analysis of 30000 cells / sample (time 30-60s)
Distinction of subpopulations
Biofilm : great heterogeneity, complex behavior!
• Useful tool to characterize and select phenotypes inside a biofilm
Product( Bioagent/(mode(of(action(
Crop( Company(
Avogreen®) B.#subtilis/#antibiosis) Avocado) Ocean)Agriculture))
Bacillus)SPP®) Bacillus)spp./)antibiosis# Several)crops) Bio)Insumos)Nativa)Ltda,)Chile.))
Ballad®) B.#pumilus#/)antibiosis,)compettition,)growth)promotion)and)resistance)induced#
Cereals,)oil)plant,)corn,)sugar)beet)) AgraQuest)Inc,)USA.))
Bio)safe®) B.#subtilis/#antibiosis) Soybean,)bean,)cotton) Lab.)Biocontrole)Farroupilha,)Brazil)
Biosubtilin))
B.#subtilis/#antibiosis,)competition# Cotton,)cereals,)ornamental)and)vegetable)crops)
Biotech)International)Ltd.))
Botrybell)
)B.velezensis# tomato,)lettuce,)pepper,)grape,)strawberry,)
and)vegetable#)Agricaldes,)Spain))
Cease®) B.subtilis# Several(crops# BioWorks)Inc.,)USA)
Companion®)) B.#subtilis/)antibiosis,)growth)promotion,)resistance)induction,)competition#
Cotton,)bean,)pea,)soybean,)peanut,)corn,)and)others)
Growth)Products)Ltd.,)USA))
EcoGuard)TM)Biofungicide)
B.#licheniformis#/antibiosis)and)enzymes#
golf)courses,)sports)turf,)lawns,)turf)farms)and)arboretums)
Novozymes)A/S,)Denmark.)Novozymes)Biologicals,)USA)
Ecoshot) B.#subtilis# Grape,)citrus,)vegetable,)legumes,)and)others)
Kumiai)Chemical)Industry)Co,)Japan)
FZB24®WG,)li)and)TB)
B.#subtilis# Several)crops) ABiTEP)GmbH,)Germany.))
HiStick'N/T®'/'Subtilex®'/'Pro4Mix®'
B.#subtilis# Soybean,'ornamental'plants'and'other'crops'
4Becker'Underwood,'USA''Premier'Horticulture'Inc.,'Canada''
Kodiak' B.#subtilis/'antibiosis,'growth'promotion,'resistance'induction,'competition#
Cotton' Gustafson'Inc,'USA'
Rhapsody®' B.#subtilis'# Turf,'forest,'ornamen4tals' AgraQuest'Inc,'USA''
Rhizo'Plus®' B.#subtilis#FZB24# Gardening'(Several'crops)' ABiTEP'GmbH,'Germany'
RhizoVital®42'li'' B.#amylolique0faciens# Potato,'corn,'strawberry,'tomatoes,'cucumber,'ornamentals'
ABiTEP'GmbH,'Germany'
Serenade®' B.#subtilis/'antibiosis' Grapes,'Apple,'pears,'bananas,'cherries,'Walnuts,'Peanuts,'Hops,'Leafy'vegetables,''tomatoes,'peppers,'cucurbits,'mango,'bean,'onion,'garlic,'potatoes,'Broccoli,'Carrots.'
AgraQuest'Inc,'USA'
Sonata®' B.#pumilus#' Tomatoes,'peppers,''Potato,'grapes,'strawberry,'cucurbit,'apple,'pear'
AgraQuest'Inc,'USA'
Sublic®' Bacillus#spp.# Several'crops' ELEP'Biotechnologies4,'Itália.''
Yield'Shield®' B.#pumilus'# Soybean' Bayer'CropScience,'USA''
Some success stories for microbial biopesticides
B. subtilis, B. amyloliquefaciens, B. licheniformis, B. pumilus...
However still far from optimal exploitation…
Biotechs may be used in situ but also ex vivo to better understand how microbes function to protect plants
Should help to better appreciate:
why some microbial strains are more efficient than others why a given strain is efficient on some crops and not on others why a given strain is efficient in certain soil conditions and not in others
Should benefit industrial producers (production, formulation) and farmers (application)
There is a future, big players are getting involved…
Global theme: “From Omics to the Field”
Sponsoring still welcomed!
Co-organizers: Monica Höfte and Marc Ongena
!!
E-mail for contact: [email protected] let us know your interest in attending the meeting! Website for info: http://www.events.gembloux.ulg.ac.be/pgpr2015/
The rhizosphere zoo:
The rhizosphere microbiome:
Mendes et al, 2013
Metagenomics: for antibiotic effect on auxiliary microflora
heatmap indicates differences in the relative abundances of OTUs
Sampling and DNA extraction
DGGE analysis of 16S rRNA gene fragments amplified from TotalCommunity-DNA
Pyrosequencing and statistical analysis
Schreiter et al, 2014
Metagenomics: for antibiotic effect on auxiliary microflora
Co9culture$characteriza+on$!$microbial$consor+um$management))• 2 strains
• Complementary behaviors (cross-feeding)
• Promote biobased compounds synthesis
• Mutual protection
Combined confocal microscopy and flow cytometry to manage microbial consortia
0$
1$
2$
3$
4$
5$
6$
7$
8$
0$
5$
10$
15$
20$
25$
0$ 5$ 10$ 15$ 20$ 25$ 30$
β9gal$U/10
5$cells)$Ce
lls$x$106$/g$of$roo
t$
Days$post9inocula+on$
coloniza+on$BGS3$rela+ve$srfA$gene$expression$
Expression of srfA genes in the rhizosphere using lacZ reporter system
Higher)surfac9n)gene)expression)when)popula9on)established)
Approx. 1.8 µM in the plant growth medium
Transcriptomics: Bacillus antibiotic production in planta
PGPR: A myriad of chemically divers antibiotics
Lipopeptides formed by Non Ribosomal Synthetases (NRPS)
Surfac9n)assembly)line)
Strieker)et)al.)Cur)Opin)Struct)Biol)2010)
NRPS synthesis serves structural diversity of LPs
Genus)level:)families/groups) Strain)level:)variants/homologues)
Variants:$Pep+de$sequence$
Homologues$:$FA$lenght,$isomery$
Pseudomonas Bacillus
Most)are)cyclic,)some)are)linear)
CLP FaXy$acid Pep+de$sequence Iturin'family'(Bacillus)
Iturin)A C14BC17 Asn Tyr Asn Gln Pro Asn Ser
iturin)C C14BC17 Asp Tyr Asn Gln Pro Asn Ser
mycosub9lin C14BC17 Asn Tyr Asn Gln Pro Ser Asn
Bacillomycin)D C14BC16 Asn Tyr Asn Pro Glu Ser Thr
Bacillomycin)F C14BC17 Asn Tyr Asn Gln Pro Asn Thr
Bacillomycin)L C14BC16 Asp Tyr Asn Ser Glu Ser Thr
Bacillomycin)Lc C14BC16 Asn Tyr Asn Ser Glu Ser Thr
Subtulene)A C15* Asn Tyr Asn Gln Pro Asn Ser
VariantsBhomologues)
Variants:$Pep+de$sequence$
Homologues$:$FA$lenght,$isomery$
O H N H
N H N H
O H
N H
N H 2
O N H
N N H
N H O
N H 2
O O
N H 2
O
O
O
O
O
O O N H
2
O
NRPS synthesis serves structural diversity of CLPs
60
Essais au champs ou en serres industrielles
Activité protectrice des lipopeptides sur diverses cultures d’intérêt
I. Lipopeptides as weapons to survive/compete: primary role (?)
- +
- +
By$inhibi+ng$growth$of$microbial$compe+tors$
An3viral''
An3protozoal'
An3bacterial''
An3oomycete' An3fungal''
Membrane)permeabiliza9on,)cell)lysis)
Biophysic)on)model)membranes)
3DBconforma9onal)studies)
Mechanisms)of)pore)forma9on)and)target)specificity)
An3;nematode'
By$repelling$predators$
Serraween)ac9ng)as)avoidance)cues)
Pradel)et)al.)PNAS)2007)
Physico-chemical interactions between co-produced LPs
In)Bacillus)S499) In)Pseudomonas)CMR12a)
Sessilin)and)orfamide)physically)interact)
and)form)a)white)line))
a
b
c
a
b
c
I F
S
Fengycin)and)surfac9n)coBprecipitate)
Different activities for structural variants on a specific target
Bacterial colony Fungal mycelium
2
1
Fusaricidins)from)P."polymyxa"
MS)Imaging)
II. Role of LPs in motility, dispersal
Surfac9n)for)B."amyloliquefaciens" Orfamide)for)Pseudomonas)CMR12a)
Effect)of)interac9on)on)swarming)poten9al)
D’aes)et)al.)Environ)Microbiol)2014)
III. Role of LPs in biofilm formation
Surfac9n)for)B."amyloliquefaciens" Sessilin)for)Pseudomonas)CMR12a)
Surfac9n)as)signal)driving)cell)
differen9a9on)and)biofilm)forma9on))
Romero,)Res)Microbiol.)2013)
IV. Role of LPs in root colonization
Several)strains)tested)In)different)growing)systems:)
)efficient)surfac9n)producers)are)beher)colonizers)
On)Agar,)4)dpi)
In)perlite,)14)dpi))
In)peat)soil,)5)weeks)pi)
V. Role of LPs in plant immunization
C$$$$$$$$$$$$$$ $$$LP$
● Disease)reduc9on)on)leaves)upon)root)treatment)with)purified)LPs)))
)
● Disease)reduc9on)on)leaves)upon)root)treatment)with)mutants))
) ) ) ) ))
● No)migra9on)of)inducing)agent)from)roots)to)the)infected)leaves)
)
● Efficient)produc9on)of)the)inducing)agent)in)the)rhizosphere)
)
● Protec9on)associated)with)defence)responses)at)the)molecular)level))
Fast production upon contact with washed roots of tomato and AT:
Stimulation of surfactin upon root perception by Bacillus
S C15
S C15
i, control cells ii, cells in contact with root
UPLC-ESI-MS i ii
3h30
4h30
5h30
6h30
In the presence of purified cell wall polymers:
2h30
$Shared$benefits$for$both$the$bacterium$and$the$plant:$$$faster$establishement$in$the$rhizosphere $immuniza+on$without$
$ $ $ $ $ $growth$cost $ $$
VI. Role of LPs in pathogen virulence
From)Pseudomonas"syringae" From)Pseudomonas"cichorii"
Syringomycin/syringopep9n)as)necrosis)inducers)
)Cichopep9n)contributes)to)virulence)
))
Pauwelijn et al. MPMI 2013
Scholz-Schroeder et al. MPMI 2001
Colonization, biofilm
Antiviral
Antiprotozoal
Antibacterial
Antioomycete Antifungal
Chelation, solubilization
Motility Virulence, Immunization
In conclusion
Much more than just molecular pneumatic drills!
CLPs thus also favor the ecological fitness/rhizosphere competence of the producing strains and act as signals or impact various developemental processes in cohabiting organisms without causing any detrimental leakage in membrane, lower [ ] involved.
High cytotoxicity favoring direct antagonism of pathogens > CLPs considered as molecular pneumatic drills, high [ ] required.
In conclusion
Are antibiotics produced in sufficient amounts, at the right place, at the right time? Need for more accurate spatiotemporal monitoring of antibiotic production in situ
Other functions to be discovered at sub-inhibitory concentrations?
The Bacillus CLP pattern may be influenced by:
- nutritional basis imposed by the plant - host plant species - biofilm formation - growth rate (not shown) - temperature - pH (not shown) - oxygen availability (not shown)
Summary
May explain why some Bacillus strains are efficient but not others May explain why a given strain is efficient on some crops and not on others May explain why a given strain is efficient in certain soil conditions and not in others
73
Conclusions The demand for organic produce is growing in the main markets (EU, USA, asia) Organic agriculture is in line with mainstream trends (low/no residue, low input, eco-system services) The production is often limited to the most suitable pedoclimatic conditions (least disease and pest pressure) If biocontrol agents can adequately control key pests/diseases, production areas will grow rapidly und thus also extend the demand for existing biocontrol PPPs
Thanks
Supported by:
For your attention…
Phytopathology Lab Ghent University Jolien D’aes Ellen Pauwelijn
)
Gembloux Agro-Bio Tech Laurent Franzil Hélène Cawoy Guillaume Henry Emmanuel Jourdan
Lab Mass Spec at ULg Delphine Debois Edwin De Pauw