In vitro inhibition of plant pathogens by Bacillus subtilis and Enterobacter aerogenes and in vivo control of two postharvest cherry diseases

Abstract

Twenty-one isolates of the bacterium Bacillus subtilis and one of Enterobacter aerogenes were tested on agar for antagonism to Alternaria alternata, Armillariella mellea, Botrytis allii, Botrytis cinerea, Colletotrichum lindemuthianum, Monilinia fructicola, Penicillium expansum, Phytophthora cactorum, Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium cepivorum, Verticillium dahliae, and Venturia inequalis, causal organisms of many plant diseases. Enterobacter aerogenes was antagonisic to all of the pathogenic fungi tested except Verticillium dahliae and Armillariella mellea. Similarly, Bacillus subtilis was antagonistic to all of the pathogenic fungi tested except Pythium ultimum. When Enterobacter aerogenes and Bacillus subtilis were tested in vivo on cherry fruit for control of postharvest brown rot and alternaria rot, Enterobacter aerogenes was ineffective. Eleven isolates of Bacillus subtilis provided effective alternaria rot control and 15 isolates provided brown rot control which ranked with the best fungicide control.

Suppression ofBotrytis cinereasporulation on irradiated grape leaf tissue by the antagonistic bacteriumSerratia liquefaciens

“…The inhibition zones produced by the most promising bacterial isolates in this study were comparable in size to those previously reported for Bacillus subtilis and Enterobacter aerogenes in dual culture against B. cinerea (Utkhede & Sholberg 1986;Ferreira 1990). However, results from the dual inoculation should be interpreted with care.…”

“…Dual culture assays can identify the production of compounds by one organism which are inhibitory towards the growth of another organism but this does not necessarily imply good biocontrol activity. Microorganisms which are successful in vitro often fail in vivo and the reverse has also been found to be true (Utkhede & Sholberg 1986;Sobiczewski et al 1996)). The influence of pH and nutritional status of the assay medium is often identified as a reason for the lack of correlation between in vitro and in vivo results.…”

Bio-suppression of Sclerotinia Stem Rot of Tomato and Biostimulation of Plant Growth Using Tomato-associated Rhizobacteria

“…Reduced Sclerotinia Stem Rot incidence and severity have been demonstrated in numerous studies and successful disease control was achieved using fungi [10][11][12][13][14], bacteria [7,12,[15][16][17] or biofungicides [18][19][20] in many cropping systems. The most efficient bacteria used for Sclerotinia Stem Rot management belonged mainly to the genera Bacillus [1,9,[12][13]21], Pseudomonas [7,22], Enterobacter [23,24], Serratia [22,[25][26][27], and at a lesser extent Streptomyces, Burkholderia, Pantoea, and Paenibacillus [22,25].…”

The production of antifungal volatiles by Bacillus subtilis

“…All the work presented so far points to the principal mode of action of this antagonist as the production of antibiotics (Loeffler et al 1986;McKeen et al 1986). Although these antibiotics typically have a broad spectrum of activity against many genera of fungi (Utkhede and Scholberg 1986), little is known about other possible antagonistic modes of action which are available to B . subtilis.…”