Combined Inoculation Research Articles

Effects of combined inoculation of arbuscular mycorrhizal fungi and plant growth-promoting rhizosphere bacteria on seedling growth and rhizosphere microecology.

The effects of rhizosphere microorganisms on plant growth and the associated mechanisms are a focus of current research, but the effects of exogenous combined inoculation with arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on seedling growth and the associated rhizosphere microecological mechanisms have been little reported. In this study, a greenhouse pot experiment was used to study the effects of single or double inoculation with AM fungi (Funneliformis mosseae) and two PGPR (Bacillus sp., Pseudomonas sp.) on the growth of tobacco seedlings, together with high-throughput sequencing technology to reveal associated rhizosphere microecological mechanisms. All inoculation treatments significantly increased the aboveground dry weight; root dry weight; seedling nitrogen, phosphorus, and potassium uptake; plant height; stem thickness; maximum leaf area; chlorophyll content; total root length, surface area, and volume; and average root diameter. The highest values for these indices were observed in the combined treatment of F. mosseae and Pseudomonas sp. SG29 (A_SG29). Furthermore, the A_SG29 treatment yielded the highest diversity indexes and largest percentages of significantly enriched bacterial taxa, and significantly promoted the colonization of AMF in tobacco roots and Pseudomonas in rhizosphere soil. Differential metabolic-pathway predictions using PICRUSt2 showed that the A_SG29 treatment significantly increased the metabolic pathway richness of tobacco rhizosphere microorganisms, and significantly up-regulated some metabolic pathways that may benefit plant growth. Co-inoculation with F. mosseae and Pseudomonas sp. SG29 promoted tobacco-seedling growth by significantly improving rhizosphere microbial communities' structure and function. In summary, the combined inoculation of AMF and SG29 promotes tobacco seedling growth, optimizes the rhizosphere microbial community's structure and function, and serves as a sustainable microbial co-cultivation method for tobacco seedling production.

Combined application of earthworms and plant growth promoting rhizobacteria improve metal uptake, photosynthetic efficiency and modulate secondary metabolites levels under chromium metal toxicity in Brassica juncea L

Chromium (Cr) toxicity impairs essential morphological and metabolic activities in plants. The present investigation was carried out to evaluate the beneficial role of plant growth promoting rhizobacterial strains namely Pseudomonas aeruginosa (M1), Burkholderia gladioli (M2) and earthworms (Eisenia fetida) in alleviating Cr toxicity in 10 days old Brassica juncea L. The findings delineated that addition of earthworms and PGPR restored growth, boosted Cr uptake and showed upregulation of metal transporter genes (SULTR 1-4). Supplementation of rhizospheric amendments reinstated Cr induced impairment in photosynthetic attributes. Gaseous exchange attributes, the efficiency of PS II, the content of total phenols, anthocyanin and flavonoids was enhanced with application of earthworms along with PGPR. Confocal imaging of primary photosynthetic pigment (chlorophyll), accessory photosynthetic pigment (carotenoids) and total phenols showed maximum fluorescence with combined inoculation of earthworms and both microbial strains (M1M2). The gene expression analysis revealed that Phyotene synthase (PSY), Photosystem II core protein psb A, psb B were down regulated in Cr stressed seedlings which upon supplementation with earthworms and PGPR were upregulated. Further, Phenylalanine ammonialyase (PAL), chalcone synthase (CHS) were upregulated with addition of earthworms and PGPR. Increased nitric oxide content, enhanced activity and upregulation of nitrate reductase (NR) gene was observed with addition of PGPR and earthworms

EFFECT OF BIOFERTILIZERS ON SOYBEAN GROWTH AND THEIR KEY PEST DENSITIES AS ALTERNATIVE APPROACH TOWARD SUSTAINABLE AGRICULTURE PRODUCTION

Soybean (Glycine max L.) is one of the most important crops belong to the leguminous family native to East Asia. Chemical fertilizers are widely used to increase production in quantity and quality. As a result of the harmful effects caused by chemical fertilizers, it become necessary to find alternative solutions as sustainable approach toward supply plant by elements needs such as biofertilizers. In this study, Bradyrhizobium japonicum alone or in combination of microorganism inoculation included (B. japonicum, Bacillus subtilis, Glomus mosseae, and Anabaena azollae) were tested toward soybean growth parameters under open field condition. Results showed that there is a significant differences in terms of plant height, vegetative and dry grain of soybean and other parameters with combined inoculation and B. japonicum alone in compare with control treatments. Moreover, key pest larval density were also affected by treatments such as Popillia japonica, Spodoptera littoralis and Agrotis ipsilon. The results suggest the use of specific combination of microorganism is recommended as alternative approaches toward sustainable agriculture production of soybean crop.

Концентрация на микроелементи в генотипи градински грах под влияние на инокулация с арбускуларни микоризни гъби и полезни ризобактерии

The influence of a microbial inoculant Europlus®, containing AM fungi (Glomus sp.) and beneficial rhizobacteria (Bacillus sp.), on the concentration of micronutrients (Fe, Mn, Zn and Cu) in the aboveground biomass and roots of six garden pea genotypes was studied. The experiment was conducted under field conditions in the Maritsa Vegetable Crop Research Institute on Alluvial-meadow soil. It was found that the microbial inoculant had a weak effect on the agrochemical properties of the soil. The combined inoculation increased the concentration of Fe in the aboveground biomass of most genotypes by 2.4%-22.9%. The increase of iron in the roots was by 4.4%-12.6%. Application of combined inoculant, in some cases, increased the Mn concentration in the aboveground biomass of genotypes - by 9.3%-35.7% compared to the controls. This was associated with an increased in Zn concentrations (+2.1%-64.9%) and Cu concentrations (+5.2%-20.2%) in aboveground biomass of inoculated genotypes. Microbial inoculant application increased root Mn, Zn and Cu concentrations by 4.8%-35.1%, 5.3%-20.8% and 3.3%-24.4%, respectively, compared to non-inoculated controls. The response of the individual pea genotypes to the formation of symbiosis with AM fungi was different. The bioinoculant increased root colonization rates with AM fungi by over 7% on average. A correlation was recorded only with Fe concentrations. The genotype factor had a greater effect on the micronutrient concentrations in pea samples. Inoculation with AM fungi and beneficial rhizobacteria had a weaker effect, but it was also statistically significant in terms of the concentration of Fe, Mn and Zn in aboveground biomass and roots. Hierarchical cluster analysis classified the aboveground samples of pea genotypes from the inoculated and non-inoculated treatments into two main clusters based on the concentration of micronutrients. The 12 root samples were divided into 3 groups.

Yield and Berries Quality of Flame Seedless and Red Globe cvs in Relation to Some Biofertilization Treatments

A field investigation was conducted during 2010 and 2021 seasons on Flame Seedless and Red Globe grapevines cvs., grown in sandy soil located at Malawi district - El-Minia Governorate, Egypt. The examined cvs were irrigated by using drip irrigation system and planted at 2 X 3 meters apart. This investigation was focused on the response of Flame Seedless and Red Globe cvs. to inoculation with Arbuscular Mycrrohiza Fungi (AMF), Azospirillum bacteria and Azotobacter bacteria individually or in combination. The obtained results show that, when using each micro-organism individually, the effect of AMF on yield and its component as well as berries physical and chemical properties was superior to using Azospirillum or Azotobacter each one individually. The combined inoculation shows more effective than the individual inoculations. The vines of both cultivar inoculating with the three micro-organisms in combination (AMF + Azospirillum + Azotobacter) produced the best yield and berry physical and chemical properties

Inclusion of Hybrid Pennisetum and Probiotics Enhanced Anaerobic Fermentation Quality and Bacterial Diversity of Alfalfa Silage

This study aims to assess the impact of Bacillus subtilis (BS) and Lactobacillus buchneri (LB) on the fermentation quality, microbial communities, and predicted metabolic pathways in mixed silage made from alfalfa and hybrid Pennisetum. We prepared mixed silage from fresh alfalfa and hybrid Pennisetum in a 1:1 ratio and inoculated it with BS, LB, or a combination of both (BSLB) or left it untreated as a control. The silage was fermented for 30 and 60 days. The results showed that inoculation with BS, LB, or their combination increased the lactic acid and crude-protein content while reducing the fiber content compared to the control. Additionally, BS and LB inoculation raised (p < 0.05) the acetic acid content, and the combination of both strains increased (p < 0.05) the ratio of lactic acid to acetic acid. LB alone and the combined inoculation also increased the relative abundance of Lactobacillus during the pre-silage period. Functional analysis through the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed considerable variations among the different probiotic treatments. The silage process reduced nucleotide metabolism but enhanced carbohydrate, amino acid, energy, cofactor, and vitamin nucleotide metabolism. High-throughput sequencing combined with KEGG functional prediction demonstrated significant differences in community composition and functional changes at 30 and 60 days of fermentation. These findings enhance our understanding of bacterial communities and functional changes in mixed silage of alfalfa and hybrid Pennisetum, offering valuable insights into the fermentation mechanisms of legume and grass silage and informing practices for producing high-quality mixed silage.

Synergistic effects of AMF and PGPR on improving saline-alkaline tolerance of Leymus chinensis by strengthening the link between rhizosphere metabolites and microbiomes

Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) can synergistically enhance their promotional effects on plants. The positive effects are closely related to their modulation on rhizosphere microbiomes. Leymus chinensis is widely used in restoration of saline-alkaline grasslands. However, the information is unavailable on mechanisms of inoculating AMF and PGPR in enhancing saline-alkaline tolerance of L. chinensis. We conducted a pot experiment to examine effects of separate and combined inoculation of AMF and PGPR, with a focus on the pathways of AMF and PGPR effects by regulating complex interactions in plant rhizosphere. The combined inoculation significantly increased plant biomass (by 40.18–193.18 %) and Na+ accumulation, and decreased soil EC and pH to a greater extent than the separate inoculation did, and it was also superior in terms of multiple nutrient accumulation, root ion homeostasis ratios and soil enzyme activities. The combined inoculation significantly enriched beneficial bacterial and symbiotic mycorrhizal taxa, and increased complexity and stability of rhizosphere microbiome. Coexistence of AMF and PGPR activated beneficial secondary metabolic pathways and higher expression of beneficial metabolites, which regulates plant growth and stress response. The inoculation of AMF and PGPR synergically promoted interactions among keystone microbial species from different cluster modules and rhizosphere soil metabolites, and strengthened the roles of core microorganisms and core metabolites, and their interrelations and their relations with host plant. These results implies that the synergistic positive effects of AMF and PGPR on saline-alkaline tolerance of L. chinensis is realized by strengthening the links between rhizosphere metabolites and microbiomes.

Influence of inoculation with different non-Saccharomyces yeasts and Saccharomyces cerevisiae on the aroma chemical composition and sensorial features of red dragon fruit wine

Abstract In this investigation, we focused on elucidating the impact of non-Saccharomyces yeasts on both the aromatic chemical composition and sensory attributes of red dragon fruit wine. This was achieved through the introduction of Hanseniaspora uvarum or Pichia guilliermondii concurrently with Saccharomyces cerevisiae, employing methodologies encompassing co-inoculation or sequential inoculation. The findings suggested that the combined inoculation of non-Saccharomyces yeasts and S. cerevisiae is capable of modulating the sensory properties of wines. Additionally, varying inoculation methods exerted a significant impact on the aromatic qualities of the wine. Co-inoculation and sequential inoculation of H. uvarum or P. guilliermondii with S. cerevisiae demonstrated a remarkable augmentation in the quantity of volatile chemicals while effectively regulating the number of odor activity value (OAV) > 1 in the wine. Therefore, the utilization of mixed fermentation emerges as a viable strategy for regulating the flavor profile of red dragon wine. This methodology stands as a valuable guideline for making various fruit wines, including red dragon fruit wine.

Co-inoculation of cyanobacteria, rhizobia, and azospirilla associated with fertilizer N increases the common bean grain yield

A large number of beneficial microorganisms have been used as inoculants in agriculture to increase grain yield. The objective of the study was to evaluate the response of common bean (Phaseolus vulgaris) to inoculation and co-inoculation with rhizobia, azospirilla and cyanobacteria combined with doses of N-fertilizer. A field experiment was carried out in two growing seasons to assess twelve treatments using single and combined inoculation of rhizobia (Rhizobium tropici + R. freirei), Azospirillum brasilense, Anabaena cylindrica, and Calothrix brevissima, and application of 30 and 60 kg N kg ha−1 as topdressing in a factorial design. A control without N-mineral and inoculation was included. Co-inoculation of common bean (cv. IPR Curió) using A. cylindrica, C. brevissima with rhizobia, and A. brasilense, with the application of 30 kg N ha−1 in topdressing increases grain yields. Regardless of the growing season and the N dose, the dual inoculation of rhizobia and C. brevissima stood out in the increase of grain yield concerning the control without inoculation, showing that it is an efficient agronomic practice for common bean under tropical conditions.

Microbiomes-Plant Interactions and K-Humate Application for Salinity Stress Mitigation and Yield Enhancement in Wheat and Faba Bean in Egypt’s Northeastern Delta

Salinity, resulting from climate change and excessive mineral fertilization, burdens farmers and negatively impacts soil and water ecosystems in the Northeastern Nile Delta. Organic and biological approaches are crucial for addressing these issues. This study examined the effects of individual and combined inoculations with cyanobacteria, yeast, and Arbuscular Mycorrhizal Fungi (AMF), with or without K-Humate and reducing Nitrogen, phosphorus and potassium (NPK) mineral fertilizers application rates to crop quality of wheat and faba bean. In preliminary laboratory experiments, the interactive effects of these microbiomes on plant antioxidant and soil enzyme production were examined under salinity stress. Results showed that co-inoculation, especially with K-Humate, yielded superior outcomes compared to individual inoculations. These findings were validated by a field trial conducted in saline-alkaline soil in the Northeastern Nile Delta region. All biological treatments 25% of recommended doses, and enhancing salinity tolerance, increasing yield, and improving enhanced rhizosphere microbial activity, including soil enzyme activity, AMF colonization, spore density, and the total numbers of bacteria, cyanobacteria, and yeast. These effects were further amplified by K-Humate and were more pronounced with combined inoculations than with individual ones, leading to improved soil fertility and significant increases in both crop quantity and quality compared to control treatments. The triple treatment, combining cyanobacteria, yeast, and mycorrhizae in the presence of K-Humate while reducing the mineral NPK rate by 75%, achieved superior increases in the productivity of wheat grains and faba bean seeds, reaching 54.72% and 128.92%, respectively, compared to the 100% NPK mineral control. This treatment also significantly improved crop quality, with notable increases in nitrogen, potassium, phosphorus, and protein percentages in wheat grains and faba bean seeds. Microbiomes-interaction increased potassium uptake over sodium, enhancing the plant’s potassium/sodium ratio and improving salt stress tolerance. This approach reduces reliance on costly mineral fertilizers, enabling bio-organic farming in marginal lands, optimizing resource utilization, and preserving natural resources.

Enhancing the flavor quality of Chinese rice wine (Huangjiu) through inoculation with Lactobacillus plantarum and Leuconostoc mesenteroides

This study investigates the modulation of flavor in Chinese rice wine (Huangjiu) by inoculating with Lactobacillus plantarum (L. plantarum) and Leuconostoc mesenteroides (L. mesenteroides). Firmicutes and lactic acid bacteria (LAB) were predominant in both inoculated and spontaneously fermented samples. We observed an enhanced bacterial diversity in treatments involving single and combined inoculations, which corresponded with increases in volatile components, organic acids, and amino acids compared to spontaneously fermented controls. Sensory evaluations, assessing alcohol aroma, sourness, and full-bodiedness, identified the co-inoculated samples as superior, outperforming those from single inoculations and spontaneous fermentations. These results elucidate the impact of starter cultures on the fermentation process and flavor profile of Huangjiu, providing insights for selecting optimal starters to engineer desired flavor characteristics.

Synergistic interactions of biocontrol agents and chemical fungicides enhance the disease resistance in Vigna radiata (L.) against Macrophomina phaseolina-associated with dry root rot

Macrophomina phaseolina, a necrotrophic fungus responsible for dry root rot disease in Vigna radiata L. (greengram) causes extensive yield losses. Biocontrol agents are reported to suppress phytopathogens, mitigate biotic stress, and improve growth and yield of plants. Here, Bacillus subtilis PSB-5 and Trichoderma sp. TD-6 along with chemical fungicides; mancozeb (MZB) and carbendazim (CBZM) were evaluated alone/or in combination for their effectiveness against M. phaseolina-induced root rot disease in greengram. B. subtilis and Trichoderma sp. suppressed phyto-fungal growth by 72 and 78 %, respectively. Both bioagents synthesized indole-3-acetic acid, ammonia, and solubilized insoluble phosphate, released antimicrobial substances including siderophore, hydrogen cyanide, and various extracellular lytic enzymes. Further, efficacy of bioagents and fungicides (at 50 and 100 ppm) were tested (single and combined) against M. phaseolina-infected greengram cultivated in pot soils. While evaluating, bioagents and fungicides increased plant height, biomass, and vigor indices of infected greengram in order: PSB-5 + TD-6 > PSB-5 > TD-6 > MZB + CBZM (100 ppm) > CBZM (100 ppm) > MZB (100 ppm). Further, among treatment, dual inoculation of bioagents (B. subtilis + Trichoderma), maximally increased total chlorophyll (59.4 %), carotenoid (68 %), root phosphorous (69.6 %), root nitrogen (65.7 %), total soluble protein (80 %), soluble sugar (76 %), pod yield (82.3 %) and seed protein (68 %) over infected plants. Moreover, biotic stress-induced oxidative stress biomarkers (proline, malondialdehyde, electrolyte leakage) and reactive oxygen species were significantly (p ≤ 0.05) lowered in fungal-infected greengram following fungicides and bioagents application. Furthermore, combined inoculation of bioagents significantly (p ≤ 0.05) reduced percent disease index (PDI) and increased % protection in biotic-stressed greengram. Besides, bioagents potentially increased disease resistance in M. phaseolina-infected greengram plants by modulating defense responses such as activities of β-1, 3 glucanase, catalase, phenylalanine ammonia lyase, polyphenol oxidase, peroxidase, and superoxide dismutase which significantly protected plants from fungal pathogen. Soil populations of pathogen and bioagents declined and considerably increased, respectively, at harvest. Application of antagonistic bacterial and fungal strains enhances greengram resistance to M. phaseolina while concurrently offering agriculture an environmentally friendly choice. Also, these strains can be applied as biocontrol agents in disease suppression over chemical fungicides.

Synergistic effect of Pseudomonas putida and endomycorrhizal inoculation on the physiological response of onion (Allium cepa L.) to saline conditions

Salinity stress negatively affects the growth and yield of crops worldwide. Onion (Allium cepa L.) is moderately sensitive to salinity. Beneficial microorganisms can potentially confer salinity tolerance. This study investigated the effects of endomycorrhizal fungi (M), Pseudomonas putida (Ps) and their combination (MPs) on onion growth under control (0 ppm), moderate (2000 ppm) and high (4000 ppm) NaCl salinity levels. A pot experiment was conducted with sandy loam soil and onion cultivar Giza 20. Results showed that salinity reduced growth attributes, leaf pigments, biomass and bulb yield while increasing oxidative stress markers. However, individual or combined inoculations significantly increased plant height, bulb diameter and biomass production compared to uninoculated plants under saline conditions. MPs treatment provided the highest stimulation, followed by Pseudomonas and mycorrhizae alone. Overall, dual microbial inoculation showed synergistic interaction, conferring maximum benefits for onion growth, bulbing through integrated physiological and biochemical processes under salinity. Bulb yield showed 3.5, 36 and 83% increase over control at 0, 2000 and 4000 ppm salinity, respectively. In conclusion, combined application of mycorrhizal-Pseudomonas inoculations (MPs) effectively mitigate salinity stress. This approach serves as a promising biotechnology for ensuring sustainable onion productivity under saline conditions.

Unravelling the Complexity of Ginger Rhizome Rot Disease: A Focus on Pathogen Interactions

ABSTRACTRhizome rot poses a significant threat to ginger cultivation, caused by a complex interaction of pathogens such as Pythium aphanidermatum, Fusarium oxysporum, Ralstonia solanacearum, Sclerotium rolfsii and Meloidogyne incognita. The pathogens were individually inoculated at 75, 105 and 135 days after planting (DAP), as well as in various combinations, to evaluate disease severity and symptom development. Results revealed that R. solanacearum exhibited the highest disease severity and fastest symptom development across all stages of inoculation, followed by P. aphanidermatum, F. oxysporum, S. rolfsii and M. incognita. The combined inoculation of pathogens significantly increased disease incidence and rhizome rot compared to individual inoculations, indicating synergistic interactions among the pathogens. Sequential inoculation experiments demonstrated that pre‐infection by M. incognita exacerbated disease severity, highlighting the role of nematodes in predisposing plants to secondary infections.

Combined inoculation of arbuscular mycorrhiza fungi with Meso‐rhizobium improves nutrient uptake, growth performance, and moisture stress tolerance of chickpea (Cicer arietinum L.)

AbstractBiofertilizers can be better alternatives to chemical fertilizers to enhance plant nutrition and productivity as they improve the soil fertility and crop productivity in an eco‐friendly and cost‐effective manner. A pot experiment was conducted between December 2018 and March 2019 in southern Ethiopia to evaluate the combined inoculation of arbuscular mycorrhizal fungi (AMF) and Meso‐rhizobium (MR) on biomass yield, nutrient uptake, and moisture stress tolerance of chickpea (Cicer arietinum L.) (variety: Habru). The experiment was executed as a factorial arrangement using a completely randomized design with three replications. The treatments were control (non‐fertilized), sole AM fungi inoculation, AM fungi inoculation with phosphorus fertilizer (20 kg P ha−1) and MR, and sole inorganic fertilizers (20 kg P;10 kg N ha−1) at four different moisture levels (optimum throughout the growing season, stressed at vegetative, flowering, and seed filling stages). The results demonstrated that biomass yields were limited by moisture stress, especially at vegetative and flowering stages of chickpea. Sole and co‐application of AMF with MR and inorganic P increased biomass yields on average by 19%, 39%, and 33% under water stress conditions, respectively, compared to the non‐inoculated control. The application of AMF with MR and inorganic P also significantly increased nodulation, AMF colonization, and nutrient uptake, but these effects were dependent on soil moisture status. In conclusion, there are potential advantages to be gained from sole and combined AMF application with rhizobium to improve growth and productivity of chickpea through enhanced nutrient and water uptake, though the results of this pot experiment should be validated through field trials.

The potential of soil endemic microorganisms in ameliorating the physicochemical properties of soil subjected to a freeze-thaw cycle

Establishing soil biological crusts will result in the long-term restoration of ecosystems. Nonetheless, little research has been conducted to demonstrate the influence of soil endemic microorganisms on suppressing the adverse effects of freezing-thawing on soil properties. This current study evaluated the formation of biological crusts, the enhancement of physical and chemical characteristics of soil, and surface soil stability by inoculating native bacteria and cyanobacteria into the soil during a freezing-thawing cycle. The soil was collected from the Badranlou Region in North Khorasan Province, Northern Iran, and native bacteria and cyanobacteria were isolated, identified, chosen, and cultured. The native treatments of bacteria and cyanobacteria were then inoculated in individual bacteria, cyanobacteria, and combined inoculation of cyanobacteria and bacteria onto an experimental soil in six replications. After 60 days, they were subjected to freezing-thawing conditions to have maximum effect on the soil environment, and finally, the soil surface properties were statistically compared. The results of the significant effect (p<0.001) of inoculation treatments on the physical and chemical properties of the study soil revealed that the carbon, nitrogen, organic matter, phosphorus, potassium, and surface soil stability in bacterial treatment compared to the control treatment increased by 68, 39, 68, 17, 25, 99 %, respectively. While under cyanobacterial treatment, they rose by 83, 61, 83, 18, 73, and 172 %, respectively. The combination inoculation treatment of bacteria and cyanobacteria enhanced the study variables by 73, 66, 73, 25, 58, and 189 %, respectively. Compared to control plots, the soil bulk density in bacterial, cyanobacterial, and compound inoculation treatments was substantially reduced (p<0.001) by 9, 15, and 12 %, respectively. The soil stability, carbon, and organic matter were among the most essential properties of the soil, and they best showed the difference between the various treatments applied. It confirmed the region's potential restoration by inoculating native soil microorganisms.

Co-application of biochars and Piriformospora indica improved the quality of coastal saline soil and promoted the growth of forage.

Soil quality is defined as the ability of soil to maintain the soil environment and the biosphere. Due to the limitation of salt and alkali stress, soil quality can be reduced, which in turn affects agricultural production. Biochar is widely used in saline-alkali land improvement because of its special pore structure and strong ion exchange ability, while Piriformospora indica is widely used in saline-alkali land improvement because it can symbiose with plants and improve plant stress resistance. However, the synergistic effect of combined biochar application and inoculation of P. indica on the quality of saline-alkali soil and plant development is uncertain. Hence, we investigated the combined influences of biochar and P. indica on the soil physicochemical characteristics, as well as the growth and chlorophyll florescence of sorghum-sudangrass hybrids (Sorghum bicolor × Sorghum sudane) in our study. The results indicated that after applying biochar and P. indica together, there was a considerable drop in soil pH, conductivity, Na+, and Cl- concentrations. Meanwhile, the soil organic matter (SOM), available phosphorus (AP), and alkaline hydrolyzable nitrogen (AN) increased by 151.81%, 50.84%, and 103.50%, respectively, when the Bamboo biochar was combined with 120 ml/pot of P. indica. Eventually, sorghum-sudangrass hybrid biomass, transpiration rate, and chlorophyll content increased by 111.69%, 204.98%, and 118.54%, respectively. According to our findings, using P. indica and biochar together can enhance soil quality and plant growth. The results also provide insights to enhance the quality of saline-alkali soils and the role of microorganisms in nutrient cycling.

Impact of inoculating Staphylococcus xylosus CICC21445 and Staphylococcus vitulinus CICC10850 on lipid metabolism and flavor development in dry-cured duck

The metabolic activity of microorganisms can influence the characteristics of dry-cured meat. This study aimed to investigate the impact of single or combined inoculation of Staphylococcus vitulinus CICC10850 and Staphylococcus xylosus CICC21445 on the quality of dry-cured duck. The results showed that co-inoculation significantly inhibited the lipid oxidation of dry-cured duck compared to single inoculation S. vitulinus CICC10850 or S. xylosus CICC21445, and the viable cell counts of Staphylococcus were higher (8.3 ± 0.04 log CFU/g, on the 7th day). Co-inoculation significantly increased the activities of neutral lipase (1.68 ± 0.12 U/g) and phospholipase (1.78 ± 0.10 U/g) on the 7th day. The contents of 12 free fatty acids in the dry-cured duck were significantly altered, with notable changes in the levels of C16:0, C18:0, and C18:6n9c. 43 flavor compounds were detected, and the aldehydic flavor compounds were significantly influenced by Staphylococcus inoculation. Compared to the control, co-inoculation led to significant changes in the contents of 333 non-volatile metabolites, 150 of which were lipid-related. KEGG analysis identified 11 differented metabolic pathways, primarily involving amino acid and lipid metabolism. Furthermore, the human-machine interaction evaluation demonstrated that the co-inoculation of S. xylosus CICC21445 and S. vitulinus CICC10850 significantly enhanced the sensory attributes of dry-cured ducks.

Plant growth promotion activities of Bacillus spp. isolated from Jakrem hot water spring of Meghalaya, North East India

The study aims to investigate plant growth promotion (PGP) activities of thermophilic bacteria isolated from the Jakrem hot spring in Meghalaya, North-East India, and determine their effect on Brassica juncea's growth. The bacteria were isolated by a culture-dependent approach following a serial dilution method in a nutrient agar medium. All the isolates were determined for PGP attributes such as indole acetic acid, phosphate solubilization, hydrolytic enzymes, and siderophore production. The potent bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis. Altogether, 53 bacterial isolates were obtained, most belonging to the genus Bacillus. Of the total isolates, 37.7% exhibited both PGP and hydrolytic enzyme activities. Three isolates, namely JAB1, JAB8, and JAB100, showed promising PGP and were identified as Bacillus velezensis, B. proteolyticus, and Bacillus sp., respectively. The PGP attributes of these isolates were determined in vivo on B. juncea, and their effects were measured in terms of shoot and root length biomass and biochemical contents. It was observed that combined inoculation of all three isolates significantly enhanced the growth and development of B. juncea, evident by increased shoot and root length, fresh and dry weight, and higher levels of protein, phenol, flavonoid, and chlorophyll content compared to the control. In conclusion, the study highlights the potential application of thermophilic Bacillus spp. from hot springs as bioinoculants to enhance crop productivity in sustainable agricultural practices.

Malaria prevalence and transmission in the Zakpota sub-district of central Benin: baseline characteristics for a community randomised trial of a new insecticide for indoor residual spraying

BackgroundMalaria transmission is known to be perennial and heterogeneous in Benin. Studies assessing local malaria prevalence, transmission levels and vector characteristics are critical for designing, monitoring and evaluating new vector control interventions in community trials. We conducted a study in the Zakpota sub-district of central Benin to collect baseline data on household characteristics, malaria prevalence, vector characteristics and transmission dynamics in preparation for a randomised controlled trial to evaluate the community impact of VECTRON™ T500, a new broflanilide indoor residual spraying (IRS) product.MethodsA total of 480 children under 5 years of age from the 15 villages of the sub-district were tested for malaria by rapid diagnostic tests (RDTs). Mosquitoes were collected by human landing catches (HLCs), pyrethrum spray catches (PSCs) and Centers for Disease Control and Prevention miniature light traps (CDC-LTs) in selected houses in each village to assess vector density, composition, vector infectivity and prevalence of insecticide resistance markers. Bioassays were performed to detect vector susceptibility to pyrethroids, broflanilide (6 µg/bottle) and clothianidin (90 µg/bottle).ResultsA total of 9080 households were enumerated in the 15 study villages. Insecticide-treated net (ITN) usage was > 90%, with 1–2 ITNs owned per household. Houses were constructed mainly with cement (44%) and mud (38%) substrates or a mixture of cement and mud (18%), and 60% of them had open eaves. The overall prevalence of P. falciparum infection was 19% among surveyed children: 20% among females and 18% among males. The haemoglobin rate showed an anaemia (< 11 g/dl) prevalence of 66%. Anopheles coluzzii and An. gambiae sensu stricto (s.s.) were the two vector species present at an overall proportion of 46% versus 54%, respectively. The human biting rate was 2.3 bites per person per night (b/p/n) and biting occurred mostly indoors compared with outdoors (IRR = 0.776; P = 0.001). The overall proportion of outdoor biting was 44% and exceeded indoor biting in three villages. The sporozoite rate was 2% with a combined yearly entomological inoculation rate (EIR) of 16.1 infected bites per person per year (ib/p/y). There was great variability in malaria transmission risk across the villages, with EIR ranging from 0 to 29.3 ib/p/y. The vector population showed a high intensity of resistance to pyrethroids across the study villages but was largely susceptible to broflanilide and clothianidin.ConclusionsThis study found high levels of malaria prevalence, vector density and transmission in the Zakpota sub-district despite the wide use of insecticide-treated nets. The vector population was mostly indoor resting and showed a high intensity of pyrethroid resistance but was generally fully susceptible to broflanilide. These findings demonstrated the suitability of the study area for the assessment of VECTRON™ T500 in a community randomised trial.Graphical