Biology subjects

Minz, D.

Publications and source records attributed to Minz, D..

4 recordsLinked to original sources

bioRxiv2026

Isolation and characterization of novel banana rhizosphere bacteria for the control of Fusarium oxysporum f. sp. cubense TR4

Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense race TR4 (Foc), is one of the most destructive diseases threatening global banana production, particularly the Cavendish cultivar. Conventional control strategies, including chemical treatments and quarantine, remain largely ineffective and unsustainable, underscoring the urgent need for alternative approaches. Biological control using rhizosphere-associated microorganisms offers a promising and environmentally friendly strategy. In this study, we isolated 436 bacterial strains from the rhizosphere of healthy banana plants and screened them for antifungal activity against Foc. Out of the screened isolates, 93 exhibited significant in-vitro inhibitions, and 64 of these were subsequently evaluated in greenhouse assays. We found that 22 strains reduced Fusarium wilt severity by 45-85% compared to untreated controls. Among them, two isolates, DDC20 and DDC_NEW2, consistently demonstrated strong biocontrol activity. In addition, cell-free culture media (CFCM) and crude extracts inhibited spore germination in fluorescence-based assays, indicating the involvement of secreted antifungal metabolites. Microscopy and confocal observations of GFP-tagged Foc revealed hyphal abnormalities in the presence of bacterial treatments, including swelling, irregular branching, and distortion, accompanied by excessive sporulation characterized by abundant microconidia, macroconidia, and chlamydospores. Whole-genome sequencing and comparative analyses placed both isolates within the genus Bacillus. Genome mining using antiSMASH identified multiple biosynthetic gene clusters encoding known antifungal compounds such as surfactin, fengycin, bacillibactin, and difficidin, as well as putative novel clusters. LC-MS confirmed the presence of surfactin and fengycin in bacterial extracts, supporting the genomic predictions. Collectively, these findings highlight the potential of DDC20 and DDC_NEW2 (related to Bacillus spp.) from the banana rhizosphere as effective biocontrol agents against Foc TR4. This integrated approach, combining phenotypic assays, microscopy, and genome mining, provides a strong foundation for the development of sustainable strategies to manage Fusarium wilt in banana cultivation.

microbiology↗

bioRxiv2025

Dynamics in microbial communities associated with the development of soil fatigue in banana

Soil fatigue, well-documented in various crops, presents a significant challenge to banana production by causing fast and then gradual declines in plant growth and yield over years of cultivation. Despite its impact on profitability, the underlying mechanisms driving soil fatigue remain poorly understood; however, a strong link to shifts in the soil microbiome has been suggested. We investigated the dynamics of microbial communities in relation to soil fatigue, using a novel semi-controlled outdoor experimental system. Soils at different stages of fatigue (0 to 42 months of banana cultivation) were generated in large containers filled with initially healthy soil. Banana plants grown in these soils were replaced with new plants which showed soil age-dependent growth. Three months postplanting, soil and root samples were collected for analyses of soil parameters and microbial community composition using bacterial (16S) and fungal (ITS) amplicon sequencing. We identified minor age-related shifts in mainly pH, potassium, and organic matter in the soil. While alpha diversity remained unchanged, significant shifts in bacterial and fungal community composition were observed in fatigued soils. Notably, the relative abundance of bacterial families such as Flavobacteriaceae, Pseudomonaceae, and Acidibacter increased, as did some fungal taxa (many from groups with known pathogens)-Ceratobasidiaceae (including Rhizoctonia), Dothideomycetes, and Stachybotryaceae. Simultaneously, the relative abundance of bacterial families with known beneficial members, including Gemmatimonadaceae, Moraxellaceae, Sphingomonadaceae, and Azospirillaceae, as well as symbiotic fungal taxa such as Glomeraceae and Lasiosphaeriaceae, declined. Thus, soil fatigue may be correlated to proliferation of pathogenic populations and a loss of beneficial microorganisms.

ecology↗

bioRxiv2023

Short- and long-term effects of continuous compost amendment on soil microbiome community

Organic amendment, and especially the use of composts, is a well-accepted sustainable agricultural practice. Compost increases soil carbon and microbial biomass, changes enzymatic activity, and enriches soil carbon and nitrogen stocks. However, relatively little is known about the immediate and long-term temporal dynamics of agricultural soil microbial communities following repeated compost applications. Our study was conducted at two field sites: Newe Yaar (NY, Mediterranean climate) and Gilat (G, semi-arid climate), both managed organically over 4 years under either conventional fertilization (0, zero compost) or three levels of compost amendment (20, 40 and 60 m3/ha or 2, 4, 6 L/m2). Microbial community dynamics in the soils was examined by high-and low-time-resolution analyses. Annual community composition in compost-amended soils was significantly affected by compost amendment levels in G (first, second and third years) and in NY (third year). Repeated sampling at high resolution (9-10 times over 1 year) showed that at both sites, compost application initially induced a strong shift in microbial communities, lasting for up to 1 month, followed by a milder response. Compost application significantly elevated alpha diversity at both sites, but differed in the compost-dose correlation effect. We demonstrate higher abundance of taxa putatively involved in organic decomposition and characterized compost-related indicator taxa and a compost-derived core microbiome at both sites. Overall, this study describes temporal changes in the ecology of soil microbiomes in response to compost vs. conventional fertilization. HighlightsO_LIDose-dependent changes in soil microbiome structure by manure compost application C_LIO_LIDynamic short-and long-term changes in soil microbiomes by compost amendment C_LIO_LIClimate, soil properties and management influence compost-amendment effects C_LIO_LIImmediate and temporal cumulative effects of compost on soil and {beta} diversity C_LI

microbiology↗

bioRxiv2019

The microbiome as a biosensor: functional profiles elucidate hidden stress in hosts

Microbial communities are highly responsive to environmental cues, and both their structure and activity can be altered in response to changing conditions. We hypothesized that host-associated microbial communities, particularly those colonizing host surfaces, can serve as in situ sensors to reveal environmental conditions experienced by both microorganisms and the host. For a proof-of-concept, we studied a model plant-soil system and employed a non-deterministic gene-centric approach. A holistic analysis was performed using plants of two species and irrigation with water of low quality to induce host stress. Our analyses examined the genetic potential (DNA) and gene expression patterns (RNA) of plant-associated microbial communities, as well as transcriptional profiling of host plants. Transcriptional analysis of plants irrigated with treated wastewater revealed significant enrichment of general stress-associated root transcripts relative to plants irrigated with fresh water. Metagenomic analysis of root-associated microbial communities in treated wastewater-irrigated plants, however, revealed enrichment of more specific stress-associated genes relating to high levels of salt, high pH and lower levels of oxygen. Meta-analysis of these differentially abundant genes obtained from other metagenome studies provided evidence of the link between environmental factors such as pH and oxygen and these genes. Analysis of microbial transcriptional response demonstrated that enriched gene content was actively expressed, which implies contemporary response to elevated levels of pH and salt. We demonstrate here that microbial profiling can elucidate stress signals that cannot be observed even through interrogation of host transcriptome, leading to an alternate mechanism for evaluating in situ conditions experienced by host organisms.\n\nSignificance StatementThis study examines the potential for microbial communities to provide insight into stresses experienced by their eukaryotic host organisms, through profiling of metagenomes and metatranscriptomes. Our study uses plant host-associated microorganisms as an in vivo and in situ microsensor to identify environmental stresses experienced by the microbial community and by the plant. Transcriptionally active host-associated microbial communities are responsive in a highly specific manner to environmental conditions. Conversely, host transcriptome sequencing provides only a very general stress response. This study is a proof-of-concept for the use of microbial communities as microsensors, with a great potential for interrogation of a wide range of host systems.

microbiology↗