Improvement in symbiotic efficiency of chickpea (Cicer arietinum) by coinoculation of Bacillus strains with Mesorhizobium sp. Cicer

Rhizobacteria belonging to Bacillus sp. were isolated from the rhizosphere of chickpea (Cicer arietinum). Ten Bacillus strains were studied for their antifungal activity, effect on seedling emergence and plant growth promotion. Two Bacillus strains CBS127 and CBS155 inhibited the growth of all the four pathogenic fungi tested on nutrient agar medium plates in vitro. Seed inoculation with different Bacillus strains showed stimulatory effect on root and shoot growth at 10 d of observation in comparison to control whereas four Bacillus strains CBS24, CBS127, CBS129 and CBS155 caused retardation of shoot growth at 10 d. Maximum nodule-promoting effect was observed with Bacillus strains CBS106, CBS127 and CBS155. The symbiotic effectiveness of Mesorhizobium sp. Cicer strain Ca181 was further improved on coinoculation with six Bacillus strains i.e. CBS9, CBS17, CBS20, CBS106, CBS127 and CBS155 at 80 d of plant growth under sterile conditions and shoot dry weight ratios increased 1.62 to 1.74 times those of Mesorhizobium-inoculated treatments, suggesting the usefulness of introduced rhizobacteria in improving crop productivity.     

Comparing Methods for Identifying Bacillus Strains Capable of Producing the Antifungal Lipopeptide Iturin A

Lipopeptides represent a unique class of bioactive microbial secondary metabolites, and iturin A shows attractive antibiotic properties among them. This study compares three methods, such as yeast/fungal growth inhibition assay, quantitative high-performance liquid chromatography (HPLC) and polymerase chain reaction (PCR) for identifying a number of Bacillus species that produce iturin A. We examined the feasibility of screening iturin A-producing Bacillus strains by PCR using specific primers for ituD and lpa-14 amplification. Twenty standard strains and 120 field-collected Bacillus spp. isolates were tested in this study. Four B. subtilis and one B. circulan strains from ATCC, and B. amyloliquefaciens B128, a known iturin A producer, exhibited positive results. Of the 120 field-collected isolates, 42 strains were positive. The potential of producing iturin A by these PCR-positive strains were then confirmed by conventional methods such as fungal growth inhibition assay and HPLC analysis. The consistency between results of PCR, HPLC, and fungal growth inhibition assay suggests that the PCR method could be used as an alternative tool for fast screening of iturin A-producing Bacillus strains from the environment. This is the first report of detecting iturin A production from B. circulans.     

The plant-associated Bacillus amyloliquefaciens strains MEP2 18 and ARP2 3 capable of producing the cyclic lipopeptides iturin or surfactin and fengycin are effective in biocontrol of sclerotinia stem rot disease

Aims: This work was conducted to identify the antifungal compounds produced by two previously isolated Bacillus sp. strains: ARP₂3 and MEP₂18. Both strains were subjected to further analysis to determine their taxonomic position and to identify the compounds responsible for their antifungal activity as well as to evaluate the efficiency of these strains to control sclerotinia stem rot in soybean. Methods and Results: The antifungal compounds were isolated by acid precipitation of cell‐free supernatants, purified by RP‐HPLC and then tested for antagonistic activity against Sclerotinia sclerotiorum. Mass spectra from RP‐HPLC eluted fractions showed the presence of surfactin C₁₅, fengycins A (C₁₆–C₁₇) and B (C₁₆) isoforms in supernatants from strain ARP₂3 cultures, whereas the major lipopeptide produced by strain MEP₂18 was iturin A C₁₅. Alterations in mycelial morphology and sclerotial germination were observed in the presence of lipopeptides‐containing supernatants from Bacillus strains cultures. Foliar application of Bacillus amyloliquefaciens strains on soybean plants prior to S. sclerotiorum infection resulted in significant protection against sclerotinia stem rot compared with noninoculated plants or plants inoculated with a nonlipopeptide‐producing B. subtilis strain. Conclusions: Both strains, renamed as B. amyloliquefaciens ARP₂3 and MEP₂18, were able to produce antifungal compounds belonging to the cyclic lipopeptide family. Our data suggest that the foliar application of lipopeptide‐producing B. amyloliquefaciens strains could be a promising strategy for the management of sclerotinia stem rot in soybean. Significance and Impact of the Study: Sclerotinia stem rot was ranked as one of the most severe soybean disease in Argentina and worldwide. The results of this study showed the potential of B. amyloliquefaciens strains ARP₂3 and MEP₂18 to control plant diseases caused by S. sclerotiorum.     

Interaction of cruciferous phytoanticipins with plant fungal pathogens: indole glucosinolates are not metabolized but the corresponding desulfo-derivatives and nitriles are

Glucosinolates represent a large group of plant natural products long known for diverse and fascinating physiological functions and activities. Despite the relevance and huge interest on the roles of indole glucosinolates in plant defense, little is known about their direct interaction with microbial plant pathogens. Toward this end, the metabolism of indolyl glucosinolates, their corresponding desulfo-derivatives, and derived metabolites, by three fungal species pathogenic on crucifers was investigated. While glucobrassicin, 1-methoxyglucobrassicin, 4-methoxyglucobrassicin were not metabolized by the pathogenic fungi Alternaria brassicicola, Rhizoctonia solani and Sclerotinia sclerotiorum, the corresponding desulfo-derivatives were metabolized to indolyl-3-acetonitrile, caulilexin C (1-methoxyindolyl-3-acetonitrile) and arvelexin (4-methoxyindolyl-3-acetonitrile) by R. solani and S. sclerotiorum, but not by A. brassicicola. That is, desulfo-glucosinolates were metabolized by two non-host-selective pathogens, but not by a host-selective. Indolyl-3-acetonitrile, caulilexin C and arvelexin were metabolized to the corresponding indole-3-carboxylic acids. Indolyl-3-acetonitriles displayed higher inhibitory activity than indole desulfo-glucosinolates. Indolyl-3-methanol displayed antifungal activity and was metabolized by A. brassicicola and R. solani to the less antifungal compounds indole-3-carboxaldehyde and indole-3-carboxylic acid. Diindolyl-3-methane was strongly antifungal and stable in fungal cultures, but ascorbigen was not stable in solution and displayed low antifungal activity; neither compound appeared to be metabolized by any of the three fungal species. The cell-free extracts of mycelia of A. brassicicola displayed low myrosinase activity using glucobrassicin as substrate, but myrosinase activity was not detectable in mycelia of either R. solani or S. sclerotiorum.     

Antifungal substances produced by Penicillium oxalicum strain PY-1—potential antibiotics against plant pathogenic fungi

This paper reports the isolation from soil of Penicillium strain PY-1 with strong antagonistic activity against plant pathogenic fungi. On the basis of its morphological characteristics and the sequence of the ITS region, strain PY-1 was identified as P. oxalicum. Strain PY-1 produces antifungal substances that suppress the mycelial growth of Sclerotinia sclerotiorum and many other plant pathogenic fungi tested; the highest antagonistic activity was detected at 72 h when cultured in a 250-ml flask containing 80 ml potato dextrose broth. Compared with carbendazim, the relative activity of the antifungal substances produced by strain PY-1 was approximately 4 μg active ingredient (a.i.) per milliliter. The antifungal substances were extracted with ethyl acetate and further separated by high-performance liquid chromatography (HPLC); at least two active components were discovered. The ability to control plant disease with strain PY-1 was confirmed with S. sclerotiorum, a widespread pathogenic fungus that attacks rapeseed (Brassica napus) and other plants. Spores (10⁶ or 10⁷ ml⁻¹) and filtrate (tenfold diluted or undiluted) of strain PY-1 could significantly suppress infection and/or the extent of infection by S. sclerotiorum of plants at seven-true-leaves stage. The potential of strain PY-1 for identifying new antibiotics to control fungal disease and for biological control of plant disease, for example oilseed rape stem rot, is discussed.     

Isolation of Bacterial Antagonists of Aspergillus flavus from Almonds

Bacteria were isolated from California almond orchard samples to evaluate their potential antifungal activity against aflatoxin-producing Aspergillus flavus. Fungal populations from the same samples were examined to determine the incidence of aflatoxigenic Aspergillus species. Antagonistic activities of the isolated bacterial strains were screened against a nonaflatoxigenic nor mutant of A. flavus, which accumulates the pigmented aflatoxin precursor norsolorinic acid (NOR) under conditions conducive to aflatoxin production. Using solid and liquid media in coculture assays, 171 bacteria isolated from almond flowers, immature nut fruits, and mature nut fruits showed inhibition of A. flavus growth and/or inhibition of NOR accumulation. Bacterial isolates were further characterized for production of extracellular enzymes capable of hydrolyzing chitin or yeast cell walls. Molecular and physiological identification of the bacterial strains indicated that the predominant genera isolated were Bacillus, Pseudomonas, Ralstonia, and Burkholderia, as well as several plant-associated enteric and nonenteric bacteria. A set of 20 isolates was selected for further study based on their species identification, antifungal phenotypes, and extracellular enzyme production. Quantitative assays using these isolates in liquid coculture with a wild-type, aflatoxin-producing A. flavus strain showed that a number of strains completely inhibited fungal growth in three different media. These results indicate the potential for development of bacterial antagonists as biological control agents against aflatoxigenic aspergilli on almonds.     

Potential for improving pea production by co-inoculation with fluorescent Pseudomonas and Rhizobium

Seed bacterization with five plant growth promoting fluorescent Pseudomonas strains isolated from Indian and Swedish soils and three Rhizobium leguminosarumbiovar viceae strains isolated from Swedish soils were shown to promote plant growth in Pisum sativum L. cv. Capella. Co-inoculation of the fluorescent pseudomonads and Rhizobium improved plant growth in terms of shoot height, root length and dry weight. Both the fluorescent pseudomonads and Rhizobium were shown to exhibit a wide range of antifungal activity against pathogens specific to pea. Seed bacterization with plant growth promoting strains alone and together with a rhizobial isolate, R 361-27 reduced the number of infected peas grown in Fusarium oxysporum infested soils. We found that the introduced organisms were able to colonize the roots, which was confirmed using immunofluorescence staining and drug resistant mutant strains. In a synthetic culture medium, all the plant growth promoting fluorescent pseudomonads strains produced siderophores, which shown to express antifungal and antibacterial activity. Our results suggest the potential use of these bacteria to induce plant growth and disease suppression in sustainable agriculture production systems.     

Enhancement of Green Gram Nodulation and Growth by Bacillus Species

Rhizobacteria belonging to Bacillus sp. were isolated from the rhizosphere of green gram (Vigna radiata). Seed inoculation with the rhizobacteria showed stunting effect on root growth whereas four Bacillus strains caused stimulation of shoot growth at both 4 and 7 d of observations. Coinoculation of some Bacillus strains with effective Bradyrhizobium strain S24 resulted in enhanced nodulation and plant growth of green gram. The shoot dry mass (ratio to uninoculated control) varied from 1.32 to 6.33 at day 30 and from 1.28 to 3.55 at day 40 of plant growth. Nodule promoting effect after 40 d of plant growth was observed with majority of Bacillus strains except for MRS9 and MRS26. Maximum gains in nodulation, nitrogenase activity and plant growth were observed with Bacillus strains MRS12, MRS18, MRS22 and MRS27 after 40 d of plant growth, suggesting the usefulness of introduced rhizobacteria in improving crop productivity.     

Phenotypic and biological properties of two antagonist <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strains

Bacillus subtilis KB-1111 and KB-1122 were studied to illustrate their phenotypic and biological properties. Comparison of KB-1111 with KB-1122 in morphology was carried out by microscopy and agar plate assays. Biological assay of the test strains showed that they may possess different physiological pathways from those of reference strain ATCC6501. The assessment of antagonism against the indicator fungi showed that both test strains had broad antifungal characteristics against eight phytopathogenic fungi. Of those fungal species, Magnaporthe grisea P131, Sclerotinia sclerotiorum, and F. oxysporium exhibited high sensitivity to the test strains.     

Isolation of micropropagated strawberry endophytic bacteria and assessment of their potential for plant growth promotion

Twenty endophytic bacteria were isolated from the meristematic tissues of three varieties of strawberry cultivated in vitro, and further identified, by FAME profile, into the genera Bacillus and Sphingopyxis. The strains were also characterized according to indole acetic acid production, phosphate solubilization and potential for plant growth promotion. Results showed that 15 strains produced high levels of IAA and all 20 showed potential for solubilizing inorganic phosphate. Plant growth promotion evaluated under greenhouse conditions revealed the ability of the strains to enhance the root number, length and dry weight and also the leaf number, petiole length and dry weight of the aerial portion. Seven Bacillus spp. strains promoted root development and one strain of Sphingopyxis sp. promoted the development of plant shoots. The plant growth promotion showed to be correlated to IAA production and phosphate solubilization. The data also suggested that bacterial effects could potentially be harnessed to promote plant growth during seedling acclimatization in strawberry.     

Antifungal Effects of Bacilysin and Fengymycin from Bacillus subtilis F-29-3 A Comparison with Activities of Other Bacillus Antibiotics

Of the two antifungal antibiotics produced by Bacillus subtilis F-29-3, the dipeptide compound bacilysin inhibits yeasts (and bacteria), whereas the formerly unknown fengymycin, a complex of closely related lipopeptide components, shows antibiotic activity against filamentous fungi. Bacilysin production, formerly known for a few strains only, could be demonstrated for all 12 wild-type cultures of Bacillus subtilis tested during this study. The antibiotic also occurs in some strains of three other Bacillus species considered as closely realted to B. subtilis. Members of the lipopeptide class of antifungal Bacillus metabolites were formed by 8 of 12 Bacillus subtilis-isolates and several other Bacillus strains. The antibiotics of F-29-3 were compared with antifungal metabolites of other Bacillus isolates using TLC, agar-diffusion techniques and tests demonstrating the capacity of six lipopeptide and peptide preparations to protect rice seedlings from phytomycosis due to Rhizoctonia solani. Fengymycin proved to be different from the other compounds tested. It was less toxic to the test plants and protected them better from Rhizoctonia disease than the other antibiotics of the study did.     

Production of lipopeptides among <Emphasis Type="Italic">Bacillus</Emphasis> strains showing growth inhibition of phytopathogenic fungi

The biological activity and the presence of genes sfp and ituD (surfactin and iturin A) among Bacillus strains isolated from the Amazon basin were determined. Bacillus spp. were tested for hemolytic activity and inhibition of fungal growth by agar plate assays in parallel with PCR for identification of sfp and ituD genes. All strains tested produced surface-active compounds, giving evidence by lysis of erythrocytes and emulsifying activity on mineral oil and soybean oil. These strains of Bacillus caused growth inhibition of several phytopathogenic fungi, including Fusarium spp., Aspergillus spp., and Bipolaris sorokiniana. The presence of genes ituD and sfp was confirmed by PCR and sequence analysis. The only exception was Bacillus sp. P34 that lacks sfp gene. Lipopeptides were isolated from culture supernatants and analyzed by mass spectrometry. Characteristic m/z peaks for surfactin and iturin were observed, and some strains also produced fengycin and bacillomycin. The remarkable antifungal activity showed by the strains could be associated with the co-production of three or more lipopeptide antibiotics. Screening for novel bacteria producing useful biosurfactants or biocontrol agents for agriculture is a topic of greatest importance to eliminate chemical pollutants.     

Mass spectrometry identification of antifungal lipopeptides from Bacillus sp. BCLRB2 against Rhizoctonia solani and Sclerotinia sclerotiorum

This work aims to characterize the bioactive molecules produced by an antagonistic Bacillus sp. strain BCLRB2 isolated from healthy leaves of olive tree against Rhizoctonia solani and Sclerotinia sclerotiorum. The bacterial strain isolated showed a high and persistent antifungal activity against the two pathogens. The free-cell supernatant showed also a high antifungal activity against R. solani and at a lower extent against S. sclerotiorum. The partial purification of the antifungal substances with methanol gradient applied to C18 column binding the Bacillus BCLRB2 culture supernatant showed that the 20% and 60% methanol fractions had a high and specific activity against S. sclerotiorum and R. solani, respectively. The mass spectrometry identification of the compounds in the fraction specifically active against S. sclerotiorum revealed the presence of bacillomycin D C16 as a major lipopeptide. The fraction specifically active against R. solani contained bacillomycin D C15 and 2 unknown lipopeptides. The 80% methanol fraction had a moderate and a broad spectrum activity against the two pathogens and consisted from two iturin D (C13 and C14) as a major lipopeptides.     

Antifungal effects of volatile organic compounds from the endophytic fungus Cryptosporiopsis ericae Cc-HG-7 isolated from Coptis chinensis Franch

In this study, 136 strains of endophytic fungi were isolated from the Chinese traditional medicinal plant Coptis chinensis Franch. Of these, 129 strains were classified into 12 different genera according to morphological traits and internal transcribed spacer (ITS) gene sequence analyses. Their antifungal activities were assessed against the following fungi: Magnaporthe oryzae, Pythium graminicola, Cylindrocarpon destructans, Fusarium oxysporum, Cercospora zeae-maydis, Sclerotinia sclerotiorum, Setosphaeria turcica and Botrytis cinerea. Fourteen endophytic strains were active against at least one of the selected fungi. The most active strain Cc-HG-7 identified as Cryptosporiopsis ericae displayed inhibition rates of 81.42% and 72.00%, respectively, against S. sclerotiorum and S. turcica in dual culture technique. The volatile antifungal compounds were identified using headspace solid-phase microextraction, followed by gas chromatography mass spectrometry to investigate the potential biocontrol mechanisms of strain Cc-HG-7. The results suggested that the strain Cc-HG-7 could be a potential agent for the biological control of S. sclerotiorum and S. turcica.     

Evaluation of indigenous bacterial strains for biocontrol of the frogeye leaf spot of soya bean caused by Cercospora sojina

Aims: Assessment of biological control of Cercospora sojina, causal agent of frogeye leaf spot (FLS) of soya bean, using three indigenous bacterial strains, BNM297 (Pseudomonas fluorescens), BNM340 and BNM122 (Bacillus amyloliquefaciens). Methods and Results: From cultures of each bacterial strain, cell suspensions and cell‐free supernatants were obtained and assayed to determine their antifungal activity against C. sojina. Both mycelial growth and spore germination in vitro were more strongly inhibited by bacterial cell suspensions than by cell‐free supernatants. The Bacillus strains BNM122 and BNM340 inhibited the fungal growth to a similar degree (I～52–53%), while cells from P. fluorescens BNM297 caused a lesser reduction (I～32–34%) in the fungus colony diameter. The foliar application of the two Bacillus strains on soya bean seedlings, under greenhouse conditions, significantly reduced the disease severity with respect to control soya bean seedlings and those sprayed with BNM297. This last bacterial strain was not effective in controlling FLS in vivo. Conclusions: Our data demonstrate that the application of antagonistic bacteria may be a promising and environmentally friendly alternative to control the FLS of soya bean. Significance and Impact of the Study: To our knowledge, this is the first report of biological control of C. sojina by using native Bacillus strains.     

Identification of two Bacillus amyloliquefaciens strains with high suppression to the key fruit pathogens of Chinese jujube

Two bacterial strains (ZJ01 and ZJ02) isolated from the phyllosphere of Chinese jujube were tested for antifungal activities and morphological mechanisms against Phoma destructiva, Alternaria alternata and Fusicoccum spp., three key pathogens of jujube fruits. Based on their physiological characteristics and 16S rDNA gene sequences, both strains were identified as Bacillus amyloliquefaciens. The disease incidence of jujube fruits sprayed with the fermentation liquor of ZJ01 and ZJ02 on the puncture wounds before inoculation with the spores of those three key pathogenic fungi was 10% or 66.7%, significantly lower than that of Nutrient Broth medium treatment (100%). These results suggest that strains ZJ01 may be a potential biological control agent for Chinese jujube fruit diseases. The antagonistic bacteria could cause five kinds of hyphal alterations of the causal agents, the maximum number ever observed. Of them, hyphal swelling and excessive branching were the dominant phenomenon, the other three varied with the pathogens. The diverse morphological malformation might be helpful to understand the broad antifungal activity of Bacillus spp..     

Microbial conversion and in vitro and in vivo antifungal assessment of bioconverted docosahexaenoic acid (bDHA) used against agricultural plant pathogenic fungi

Microbial modification of polyunsaturated fatty acids can often lead to special changes in their structure and in biological potential. Therefore, the aim of this study was to develop potential antifungal agents through the microbial conversion of docosahexaenoic acid (DHA). Bioconverted oil extract of docosahexaenoic acid (bDHA), obtained from the microbial conversion of docosahexaenoic acid (DHA) by Pseudomonas aeruginosa PR3, was assessed for its in vitro and in vivo antifungal potential. Mycelial growth inhibition of test plant pathogens, such as Botrytis cinerea, Colletotrichum capsici, Fusarium oxysporum, Fusarium solani, Phytophthora capsici, Rhizoctonia solani and Sclerotinia sclerotiorum, was measured in vitro. bDHA (5 μl disc⁻¹) inhibited 55.30–65.90% fungal mycelium radial growth of all the tested plant pathogens. Minimum inhibitory concentrations (MICs) of bDHA against the tested plant pathogens were found in the range of 125–500 μg ml⁻¹. Also, bDHA had a strong detrimental effect on spore germination for all the tested plant pathogens. Further, three plant pathogenic fungi, namely C. capsici, F. oxysporum and P. capsici, were subjected to an in vivo antifungal screening. bDHA at higher concentrations revealed a promising antifungal effect in vivo as compared to the positive control oligochitosan. Furthermore, elaborative study of GC-MS analysis was conducted on bioconverted oil extract of DHA to identify the transformation products present in bDHA. The results of this study indicate that the oil extract of bDHA has potential value of industrial significance to control plant pathogenic fungi.     

Quantification of<Emphasis Type="Italic">Bacillus</Emphasis> species in a wastewater treatment system by the molecular analyses

Bacillus species were observed and quantified by molecular approaches, using the 165 rDNA primers/probes, in a wastewater treatment plant designed for the purpose of stimulating the growth ofBacillus species. The plant has been operating as a test plant since 1997 in the city of Ina, Japan, with excellent treatment performance. Observations byin situ hybridization, usingBacillus-specific probes, indicated thatBacillus strains were inhabited in the plant and their numbers decreased during the treatment process. Similar results were obtained from a quantitative PCR analysis using aBacillus-specific primer set, and the amount of DNA originating from variousBacillus species was maximally 1.91% of the total DNA in the wastewater treatment tank. Clone library analysis using theBacillus-specific primers suggested that, while the population was noticeably increased, the phylogenetic diversity of the increasingBacillus species was very low.     

Determination of Toxigenic Potentials of <Emphasis Type="Italic">Bacillus</Emphasis> Strains Isolated from <Emphasis Type="Italic">Okpehe</Emphasis>, a Nigerian Fermented Condiment

The toxigenic potential of Bacillus species isolated from the traditional fermented condiment okpehe was determined; this is aimed at selection of non-toxigenic bacilli as starter cultures to bring about production of safe product. B. subtilis and B. cereus strains isolated from okpehe were evaluated for their possible possession of virulence characteristics. Fifty isolates were screened for their ability to produce diarrhoea enterotoxin by reversed passive latex agglutination (BCET-RPLA) test kit; the result showed that 40% of the B. cereus strains were toxigenic. The ability of the selected isolates to compete in situ and in vitro toxin production during the fermentation was also determined. The enterotoxin was not detected using BCET-RPLA kit in the spontaneously fermented samples of okpehe, but the toxin was detected in the okpehe samples fermented using B. cereus enterotoxin producer in mixed starter culture fermentation. The PCR amplification of virulence genes revealed that Bacillus cereus and B. licheniformis, a strain from the B. subtilis group, contained DNA sequences encoding the haemolysin BL (hblD) enterotoxin complex. The growth ability of B. cereus strains to high population during the fermentation and the presence of detectable diarroheagenic genes in B. cereus and B. licheniformis showed that strains carrying virulence characteristics cannot be totally ruled out in traditionally fermented okpehe.     

Inhibition of Rhizoctonia by endospore forming bacteria indigenous to landscape planting beds

Endospore forming bacteria were collected from root samples of 35 genera of bedding plants growing in established commercial landscape beds in Central Florida. One hundred and twenty-nine bacterial strains associated with 14 species were identified using fatty acid analysis (Microbial Identification System, MIDI). All strains were evaluated for in vitro inhibition of damping off disease caused by the fungus Rhizoctonia solani. The strongest inhibition of Rhizoctonia by soluble exudates in cocultivation was observed with strains belonging to six species: B. cereus, B. pumilus, B. thuringiensis, L. sphaericus, B. amyloliquefaciens, and B. subtilis. Most strains that inhibited Rhizoctonia growth in cocultivation also inhibited growth via volatile compounds. All 129 strains were evaluated for ability to protect impatiens plants from subsequent challenge infection by Rhizoctonia solani. Certain strains of endospore forming bacteria also enhanced plant growth. It is apparent from this study that the Bacillus community associated with bedding plants in established planting beds produce soluble antifungal compounds, volatile antifungal compounds, and enhance plant growth. In developing biological control, it may be a more practical approach to promote or enhance a natural, multifaceted community of Bacillus strains within our planting beds.