Interruption of Aspergillus niger spore germination by the bacterially produced secondary metabolite collimomycin

Abstract

Collimonas fungivorans Ter331 (CfTer331) is a soil bacterium that produces collimomycin, a secondary metabolite that inhibits the vegetative growth of fungi.Here we show that CfTer331 can also interfere with fungal spore germination and that collimomycin biosynthesis is required for this activity. More specifically, in co-cultures of Aspergillus niger N402 (AnN402) conidiospores with CfTer331, the rate of transition from the isotropic to polarized stage of the germination process was reduced and the relatively few AnN402 conidiospores that completed the germination process were less likely to survive than those that were arrested in the isotropic phase. By contrast, a collimomycindeficient mutant of CfTer331 had no effect on germination: in its presence, as in the absence or delayed presence of CfTer331, unhindered germination of conidiospores allowed rapid establishment of AnN402 mycelium and the subsequent acidification of the culture medium to the detriment of any bacteria present. However, when challenged early enough with CfTer331, the collimomycin-dependent arrest of the AnN402 germination process enabled CfTer331 to prevent AnN402 from forming mycelia and to gain dominance in the culture. We propose that the collimomycin-dependent arrest of spore germination represents an early intervention strategy used by CfTer331 to mitigate niche construction by fungi in nature.

Biomimetic Nanopillar Silicon Surfaces Rupture Fungal Spores

“…To confirm whether the interaction between the A. brasiliensis spores and hydrophilic nSi surface led to membrane rupture, monitoring of propidium iodide (PI) uptake by fluorescence microscopy was used to confirm cell membrane permeabilisation ( Figure 2 B,D). PI can only be taken into cells that have become permeable through physical damage, or otherwise [ 44 ]. Spores were also counterstained with calcofluor white (spore coat) and Syto 9 ® (nucleic acids).…”

Strip intercropping with local crops increased Aconitum carmichaeli yield and soil quality

“…Both maize and rice intercropping could not substantially alter the soil microbial a diversity; however, it strongly influenced the microbial community structure. In the two intercropping systems, the potential functions of 28 potential beneficial genera included the following: the generation of IAA (Bal et al, 2013), nitrogen fixation (Hayat et al, 2010;Shahrajabian et al, 2021), soil mercury content reduction (Ustiatik et al, 2022), the degradation of polycyclic aromatic hydrocarbons (Zhao et al, 2021), antibacterial functions (Mosquera et al, 2020), antimycotic functions (De Brito et al, 2022), aluminum tolerance (Silambarasan et al, 2022), salt and alkali resistance , phosphate solubilization (Chhetri et al, 2021;Saadouli et al, 2021), siderophores (Jamalzadeh et al, 2021;Nie et al, 2022), nitrification (Peng et al, 2021), etc. In the control group, the potential functions of the 15 potentially beneficial genera were as follows: the nitrogen cycle (Zhang et al, 2022), antibiotic functions (Nakkeeran et al, 2021), heavy metal resistance (Zhai et al, 2020;Sharma et al, 2022), phosphate solubilization (Huang et al, 2021;Duan et al, 2022), improved photosynthesis (Katsenios et al, 2021), nitrification (Li et al, 2022), etc.…”

Identification ofCollimonasgene loci involved in the biosynthesis of a diffusible secondary metabolite with broad‐spectrum antifungal activity and plant‐protective properties

“…Bv FZB42 and its mutant AK3 were obtained from the Bacillus Genetic Stock Center (BGSC, Columbus, OH, USA). Aspergillus niger N402 (ATCC 64974; a derivative of CBS120.49, densely sporulating with short conidiophores) (Bos et al ., 1988) has been used previously in confrontation assays with collimonads (Mela et al ., 2011; Fritsche et al ., 2014; Doan et al ., 2020; Mosquera et al ., 2020). Fusarium oxysporum f.sp.…”

“…These compounds feature an ene–triyne moiety that is essential for antifungal activity (Kai et al ., 2018) and is formed through the combined action of the polyketide synthase (PKS) ColA and the desaturases ColB, ColC and ColD (Fritsche et al ., 2014; Kai et al ., 2018). In confrontation with laboratory strains of the fungus Aspergillus niger , collimomycin‐producing CfT er331 induces the stunting, swelling, branching and pigmentation of hyphae (Fritsche et al ., 2014; Kai et al ., 2018) and interrupts the process of spore germination (Mosquera et al ., 2020). Not all Collimonas strains for which fungal suppression has been demonstrated carry the NLP gene or gene cluster K (Mela et al ., 2012; Fritsche et al ., 2014; Song et al ., 2015), suggesting the existence of much unexplored genetic potential for antifungal activity in the Collimonas pangenome.…”