Production of prodigiosin and chitinases by tropical Serratia marcescens strains with potential to control plant pathogens

Abstract

The potential of three Serratia marcescens strains (CFFSUR-B2, CFFSUR-B3 and CFFSUR-B4) isolated from tropical regions in Mexico to inhibit the mycelial growth and conidial germination of Colletotrichum gloeosporioides, causal agent of fruit anthracnose, was evaluated. The ability of these strains to produce prodigiosin and chitinases when cultivated in oil seed-based media (peanut, sesame, soybean and castor bean) and in Luria-Bertani medium was determined. All of the strains exhibited similar fungal antagonistic activities and inhibited myceliar growth by more than 40% while inhibiting conidial germination by 81-89% (P = 0.01). The highest level of prodigiosin (40 μg/ml) was produced in the peanut-based medium while growth in soybean-based medium allowed the highest production of chitinases (56 units/ml), independent of the strain used. Strain CFFSUR-B2 grown in peanut medium was used to evaluate the effect of inoculum density and initial pH on metabolite production. The amount of prodigiosin produced increased with greater inoculum densities, with an initial density of 1 × 10(12) resulting in the highest production (60 μg/ml). Prodigiosin production was not affected by pH. The strains studied have the advantage of being adapted to tropical climates and are able to produce chitinases in the absence of chitin induction in vitro. These characteristics suggest their potential as biocontrol agents for fungal pathogens in tropical regions of the world.

Chitinase from a Novel Strain ofSerratia marcescensJPP1 for Biocontrol of Aflatoxin: Molecular Characterization and Production Optimization Using Response Surface Methodology

“…In our study, chitinase production was perhaps related to the high concentrations of peptone. The high peptone content would assure the availability of amino acids required for the synthesis of chitinase in general [18]. Figure 1(c) shows the interactive effect of peptone and (NH 4 ) 2 SO 4 concentrations on chitinase production.…”

“…However, to our knowledge there is no report performed on chitinase produced by endophytic Serratia marcescens isolated from peanut hulls for biocontrol of aflatoxins production. The ability of S. marcescens to produce chitinases is strain dependent and the quantities depended on the nutritional composition of the growth medium and culture condition [18]. Meanwhile the applications of chitinases require large quantities which in turn require optimization of nutritive and physical parameter for the selected isolate.…”

Mechanism of interaction of an endofungal bacterium Serratia marcescens D1 with its host and non-host fungi

“…Although, it may have crucial role in the invasion process through pore formation in the plasma membrane. Involvement of prodigiosin along with chitinases were previously reported during antagonistic activity of Serratia marcescens against fungal pathogens [50]. Chitinase and other chitinolytic enzymes secreted by type II secretion system were reported to be involved in the invasion of fungal hyphae by Burkholderia sp.…”

Mechanism of interaction of an endofungal bacterium Serratia marcescens D1 with its host and non-host fungi

“…Although, it may have crucial role in the invasion process through pore formation in the plasma membrane. Involvement of prodigiosin along with chitinases were previously reported during antagonistic activity of Serratia marcescens against fungal pathogens [52]. Chitinase and other chitinolytic enzymes secreted by type II secretion system were reported to be involved in the invasion of fungal hyphae by Burkholderia sp.…”