Mycosubtilin, a multifaceted lipopeptide from Bacillus subtilis for crop protection : an overview of the last decade results obtained from lab to the field
Résumé
Bacterial lipopeptides, and particularly those produced by the Bacillus subtilis group, have been the subject
of a great deal of scientific research over the past few years, as they display interesting biological activities
(biosurfactant, antitumoral, antimicrobial, …). Among these lipopeptides, mycosubtilin belonging to the iturin family,
has been deeply studied as a joint work from our academic and private research teams. This lipopeptide consists of
a heptapeptide linked to a fatty acid chain of variable isomery and length ranging from 15 to 18 carbons. It is a
secondary metabolite produced by a nonribosomal peptide synthetase, a completely original biosynthetic
mechanism.
Through four European projects (INTERREG IV PhytoBio, INTERREG V SmartBioControl – Bioprod and
Bioprotect, BBI BIOSMART, and SME Instrument), we have been able to address various scientific and economic
issues that make this molecule of biological origin a promising candidate to get a place in the agroecological
transition for integrated plant protection without chemical pesticides. In this presentation, we will first discuss the
development of the production of this molecule from the laboratory scale to the semi‐industrial scale. Then, the
multiple activities of mycosubtilin will be presented, by showing the results of antifungal bioactivity found at the
laboratory scale and which demonstrates its exceptional spectrum of activity. Results obtained in greenhouse on the
pathosystems lettuce‐Bremia lactucae, wheat‐Zymoseptoria tritici, and tomato‐Botrytis cinerea will be exposed.
Moreover, the efficacy of a mycosubtilin formulation (alone or in combination with another lipopeptide) will be
demonstrated in field conditions on the pathosystems apple‐Venturia inaequalis, lettuce‐Bremia lactucae, and
tomato‐Botrytis cinerea. Moreover, the biostimulant effect of a formulation containing mycosubtilin will be
presented, particularly on vegetable crops (lettuce and cucumber). Finally, we will discuss the results of cytotoxicity,
toxicity and ecotoxicity in comparison with chemical molecules currently on the market.