Biocontrol of Rhizoctonia solani (Kühn) and Fusarium solani (Marti) causing damping-off disease in tomato with Azotobacter chroococcum and Pseudomonas fluorescens

Abiotic/Biotic Stress and Substrate Dictated Metabolic Diversity of Azotobacter Chroococcum: Synthesis of Alginate, Antifungal n-Alkanes, Lactones, and Indoles

The current paper deals with new metabolites of different groups produced by Azotobacter chroococcum XU1. The strain's metabolic diversity is strongly altered by different factors, and some secondary metabolites are being reported for the first time for this species. As an abiotic/biotic stress response, the strain produced a broad spectrum of indole ring-containing compounds, n-alkanes (eicosane, heneicosane, docosane, tetracosane, and hexacosane), alkanes (7-hexyl eicosane and 2-methyloctacosane), saturated fatty acids (hexanoic and octanoic acids), esters (hexadecanoic acid methyl and pentadecanoic acid-14-methyl-methyl esters), and amides (9-Octadecenamide, (Z)- and 13-Docosenamide, (Z)-). Furthermore, to mitigate the abiotic stress the strain actively produced exopolysaccharide (EPS) to biosorb the Na+ ions. Apart from these metabolites, A. chroococcum XU1 synthesized lactones, namely 1,5-d-gluconolactone and d, l-mevalonic acid lactone in response to carbon source modification.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-024-01212-x.

Biological and chemical control of Ectophoma multirostrata causing root-rot and seedling death of Celosia argentea in Karbala/Iraq

This study was conducted in the College of the Agriculture/University of Karbala to control the fungus Ectophoma multirostrata that causes root rot of Celosia argentea by using Azotobacter chrocooccum, Salicylic acid and the chemical pesticide Beltanol. The pathogenic E. multirostrata was isolated for the first time in Iraq and showed a reduction in seed germination by 16.66% and 16.00%. The results showed that the bio-control bacteria A. chrocooccum, Salicylic acid and Beltanol effectively reduced the infection rate and severity of Celosia argentea root rot disease and increased the growth parameters. Among the treatments, Beltanol was the highest in reducing the infection rate and severity down to 0.00%, followed by the treatment of integration between A. chrocooccum and Salicylic acid to minimize infection and severity to 16.33% and 8.00%, compared to the infected untreated that showed 80%, 62.00% respectively. In addition, the A. chrocooccum and Salicylic acid integration improved plant growth, including shoot length, shoot and root dry weight to be 22.50 cm, 0.423 g and 0.133 g, compared to the untreated infected treatment that resulted in 5.00 cm, 0.090 g, and 0.003g, respectively. Keywords: Celosia argentea, Ectophoma multirostrata, Azotobacter chrocooccum, Root rot

Harnessing microbial multitrophic interactions for rhizosphere microbiome engineering

The rhizosphere is a narrow and dynamic region of plant root-soil interfaces, and it's considered one of the most intricate and functionally active ecosystems on the Earth, which boosts plant health and alleviates the impact of biotic and abiotic stresses. Improving the key functions of the microbiome via engineering the rhizosphere microbiome is an emerging tool for improving plant growth, resilience, and soil-borne diseases. Recently, the advent of omics tools, gene-editing techniques, and sequencing technology has allowed us to unravel the entangled webs of plant-microbes interactions, enhancing plant fitness and tolerance to biotic and abiotic challenges. Plants secrete signaling compounds with low molecular weight into the rhizosphere, that engage various species to generate a massive deep complex array. The underlying principle governing the multitrophic interactions of the rhizosphere microbiome is yet unknown, however, some efforts have been made for disease management and agricultural sustainability. This review discussed the intra- and inter- microbe-microbe and microbe-animal interactions and their multifunctional roles in rhizosphere microbiome engineering for plant health and soil-borne disease management. Simultaneously, it investigates the significant impact of immunity utilizing PGPR and cover crop strategy in increasing rhizosphere microbiome functions for plant development and protection using omics techniques. The ecological engineering of rhizosphere plant interactions could be used as a potential alternative technology for plant growth improvement, sustainable disease control management, and increased production of economically significant crops.

Neocosmospora rubicola, a stem rot disease in potato: Characterization, distribution and management

Potato (Solanum tuberosum L.) is one of the most important crops in maintaining global food security. Plant stand and yield are affected by production technology, climate, soil type, and biotic factors such as insects and diseases. Numerous fungal diseases including Neocosmospora rubicola, causing stem rot, are known to have negative effects on potato growth and yield quality. The pathogen is known to stunt growth and cause leaf yellowing with grayish-black stems. The infectivity of N. rubicola across a number of crops indicates the need to search for appropriate management approaches. Synthetic pesticides application is a major method to mitigate almost all potato diseases at this time. However, these pesticides significantly contribute to environmental damage and continuous use leads to pesticide resistance by pathogens. Consumers interest in organic products have influenced agronomists to shift toward the use of biologicals in controlling most pathogens, including N. rubicola. This review is an initial effort to carefully examine current and alternative approaches to control N. rubicola that are both environmentally safe and ecologically sound. Therefore, this review aims to draw attention to the N. rubicola distribution and symptomatology, and sustainable management strategies for potato stem rot disease. Applications of plant growth promoting bacteria (PGPB) as bioformulations with synthetic fertilizers have the potential to increase the tuber yield in both healthy and N. rubicola infested soils. Phosphorus and nitrogen applications along with the PGPB can improve plants uptake efficiency and reduce infestation of pathogen leading to increased yield. Therefore, to control N. rubicola infestation, with maximum tuber yield benefits, a pre-application of the biofertilizer is shown as a better option, based on the most recent studies. With the current limited information on the disease, precise screening of the available resistant potato cultivars, developing molecular markers for resistance genes against N. rubicola will assist to reduce spread and virulence of the pathogen.

Laparoscopic and open burch colposuspension for stress urinary incontinence: advantages and disadvantages

OBJECTIVE

Stress urinary incontinence (SUI) causes a significant physical and psychological burden on women. The laparoscopic vaginal suspension (LC), used in the treatment of women with SUI, is known for its advantages such as smaller incisions, short hospital stays, and better aesthetic results. This article throws light upon the advantages and disadvantages of LC and open Burch vaginal (OC) incontinence along with its associated complications.

PATIENTS AND METHODS

Between December 1, 2017 and February 10, 2019, 26 women with SUI with physical, social, and psychological consequences from two hospitals were enrolled in this study. The sample was divided into two equal groups of 13 women each. Data were collected and statistically analyzed. P ≤ 0.05 is statistically significant.

RESULTS

The study showed that the operational time was significantly shorter in the OC method compared to the LC approach (59.2 ± 5.3 min and 91 ± 4.5 min, respectively). Mean blood loss was higher in the OC approach than in the LC approach (152.2 ± 30.3 and 143.3 ± 38.6, respectively). The LC approach has minimal pain and a shorter hospital stay compared to the OC approach. Patients with the LC approach required less analgesia (8.9 ± 1.3 mg vs 2.5 ± 1.8 mg) and less hospital stay (110.3 ± 11.4 h vs 70.2 ± 8.9 h) after surgery. Resumption of normal activity was faster in the LC approach [25.1 ± (12.6) days, 18.9 ± (12.5) days] than in the OC approach. There was no significant difference between the OC and LC approaches in terms of complications.

CONCLUSIONS

Although LC is a superior and less invasive approach than the OC approach in terms of hospital stay, blood loss, pain, and recovery time, the operation time is longer.

Detection of E.coli O157 in water and food using nanosensor

The bacterial pathogens within the water and meat can be recognized utilizing progressed, expensive and time-consuming apparatuses. In addition to these gadgets, nanostructure-based gadgets can be utilized as both are cheap bacterial sensors. This investigation illustrates the creation of a sensor utilizing ZnO-rGO nano composite to distinguish bacterial pathogens. Escherichia Coli O157;h7, a Gram-negative bacterium are displayed in water and nourishment. The sensor was made of an ostensible composition of ZnO-rGO nano composite. Lean film was arranged by a sol - gel strategy utilizing the turn coating onto glass substrates and tests were carried out at room temperature. At that point the sensor was tried with some known concentration of microscopic organisms blended within the water and meat extricate. When a sample of bacteria mixed with water and meat extricate was dropped onto the sensor, the electrical resistance of the sensor varied proportionally with the concentration of bacteria. They proved as reliable and sensitive sensors for detecting bacteria in water.

Physico-Chemical Characterization and Biological Activities of a Digestate and a More Stabilized Digestate-Derived Compost from Agro-Waste

The excessive use of agricultural soils and the reduction in their organic matter, following circular economy and environmental sustainability concepts, determined a strong attention in considering composting as a preferred method for municipalities and industries to recycle organic by-products. Microorganisms degrade organic matter for producing CO₂, water and energy, originating stable humus named compost. The current study analyzed the chemical composition of a cow slurry on-farm digestate and a more stabilized digestate-derived compost (DdC), along with their phytotoxic, genotoxic and antifungal activities. The chemical analysis showed that digestate cannot be an ideal amendment due to some non-acceptable characteristics. Biological assays showed that the digestate had phytotoxicity on the tested plants, whereas DdC did not induce a phytotoxic effect in both plants at the lowest dilution; hence, the latter was considered in subsequent analyses. The digestate and DdC induced significant antifungal activity against some tested fungi. DdC did not show genotoxic effect on Vicia faba using a micronuclei test. Soil treated with DdC (5 and 10%) induced damping-off suppression caused by Fusarium solani in tomato plants. The eco-physiological data indicated that DdC at 5–10% could increase the growth of tomato plants. In conclusion, DdC is eligible as a soil amendment and to strengthen the natural soil suppressiveness against F. solani.