Effect of chitosan and a biocontrol streptomycete on field and potato tuber bacterial communities

Abstract

Four treatments applied on potato seed tubers i.e. talc only, chitosan only, Streptomyces melanosporofaciens strain EF-76 in talc and S. melanosporofaciens strain EF-76 in chitosan were compared for their efficiency to reduce common scab incidence. As previously reported the joint application of the geldanamycin-producing S. melanosporofaciens strain EF-76 and chitosan was effective to control common scab of potato. Nevertheless, field application of S. melanosporofaciens EF-76 did not allow the selection of geldanamycin-resistant actinomycetes (GRA) in the bulk soil during the potato growing season. The number of GRA on harvested potato tubers was, however, significantly higher in treatments that contained chitosan than in other treatments suggesting that chitosan might promote the establishment of the antagonistic actinomycete on progeny tubers. Biolog EcoPlates were used to determine the metabolic profiles of the bacterial soil communities. A permutation MANOVA analysis detected significant differences within the metabolic profiles of the bacterial communities at the potato flowering period but not at the beginning of the season or a week before harvest. A combination of S. melanosporofaciens EF-76 and chitosan thus represents a promising tool against common scab, with low short-term impact on soil bacterial communities.

Interaction between the Microbial Community and Invading Escherichia coli O157:H7 in Soils from Vegetable Fields

“…Following inoculation, microorganisms undergo a variety of processes, including growth, death, physiological adaption, gene transfer, and interactions with the indigenous microbial community (20,40). Irrespective of plastic-greenhouse cultivation periods, changes in the soil microbial community caused by the invading E. coli O157:H7 were detected in this study (Fig.…”

Carbon utilization profiles of bacteria colonizing the headbox water of two paper machines in a Canadian mill

“…It is a valuable and rapid tool for microbial community analysis, but it has some limitations [29,38]. For example, some of the bacteria that were isolated from the headbox machine did not show any metabolic activity on substrates contained in the Biolog EcoPlate.…”

“…For example, some of the bacteria that were isolated from the headbox machine did not show any metabolic activity on substrates contained in the Biolog EcoPlate. Prévost et al [29] have also reported that Biolog EcoPlate could not be used to determine the metabolic proWle of bacterial species such as Streptomyces spp. In this study, strains belonging to a same taxonomic genus showed the same metabolic proWle, but some genera could not be distinguished from each other by their metabolic patterns.…”

“…Principle component analysis (PCA) was used to evaluate the diVerences in the carbon source utilization patterns of the bacterial communities between paper machines and among sampling dates [29]. PCA was done using SAS System Windows (version 6.12) statistical package.…”

Dehydrated pork manure by-product: effect of a chitosan amendment on bacterial community and common scab incidence

“…Microbial cells were extracted from 3 g of biosolid as previously described (Prévost et al 2006). Briefly, a biosolid sample was added to 100 mL of sterile sodium pyrophosphate 0.1% (w:v) for 30 min at room temperature.…”