Explore the vast range of titles available.

The objective of this study was to evaluate the antagonistic activity of Trichoderma spp. against wild pathogen Fusarium oxysporumF.28.1A, which causes wilt disease on sesame. Twenty-six isolates of Trichodermaspp. isolated from soil samples were tested to control F. oxysporum F.28.1A. Prescreening showed that five isolates were T-02B1, T-18B2, T-20B1, T-28B1, and T-29A1, based on the lowest values of colony radius of F. oxysporum F.28.1A. The selected isolates were identified by their ITS region as T. yunnanenseT-02B1, T. lentiforme T-18B2, T. asperellumT-20B1, T. hamatum T-28B1, and T. hamatum T-29A1, with similarities around 96–100%. The isolates selected were able to produce enzymes including chitinase, exo-β-1,3-glucanase, and endo-β-1,3-glucanase at levels of 0.34–0.44, 0.017–0.034, and 0.032–0.121 UI · ml –1, respectively, which were considered to be a mechanism to prevent the growth of F. oxysporum F.28.1A. The isolates tested were applied in soil pots to prevent damage from F. oxysporumF.28.1A as a following experiment. The greenhouse experiment was arranged in a completely randomized design with 10 treatments, including a negative control, application of only F. oxysporum F.28.1A, application of both F. oxysporum F.28.1A and fungicide chemicals, application of both F. oxysporum F.28.1A and Trichoderma spp. DHCT, application of T. yunnanenseT-02B1, application of T. lentiforme T-18B2, application of T. asperellum T-20B1, application of T. hamatum T-28B1, application of T. hamatum T-29A1 and a mixture of the five selected isolates of Trichoderma spp. with their total population equal to that in individual strain application. The results showed that the five mixed isolates of Trichoderma had a synergistic effect on the reduction of the disease’s prevalence by 35% compared to the negative control treatment.

Soil phosphorus is heavily restricted by soil acidification and salinization. There is a need to determine a biological solution for this issue to replace the overuse of chemical phosphorus fertilizer that aggravates adverse conditions, such as salinity, acidity, and metallic toxicity. Therefore, this study aimed at determining the phosphorus dynamics in terms of the soil, growth, and yield of rice under the supplementation of phosphate (P)-solubilizing purple nonsulfur bacteria (PNSB), Cereibacter sphaeroides ST16 and ST26, in salinized soil collected from An Bien district, Kien Giang province, Vietnam, under greenhouse conditions. The experiment followed a completely randomized block design with two factors and four replications. In particular, the reduced percentages of P fertilizer (A) were 0%, 25%, 50%, 75%, and 100% P. The supplementations of C. sphaeroides strains (B) were the negative control, ST16, ST26, and a mixture of both ST16 and ST26. The results showed that supplying the C. sphaeroides ST16 and ST26 reduced the insoluble P content by 10.1–10.6% Fe-P, 10.3–12.2% Ca-P, and 12.7–43.1% Al-P and increased available P by 8.33–27.8%, leading to total P uptake in plants increasing by 29.4–56.1%. The C. sphaeroides strains also reduced soil Na+. Therefore, supplying the C. sphaeroides strains increased the rice growth and yield components of rice, leading to a greater yield of 26.5–51.0%. Supplying each strain of ST16 and ST26 reduced 50–100% P fertilizer as recommended. Ultimately, inoculation of the bacterial mixture allowed a reduction by 100% P fertilizer percentage as recommended but the yield remained the still.

Aims Purple nonsulfur bacteria (PNSB), Rhodopseudomonas palustris strains (TLS06, VNW02, VNW64 and VNS89), were investigated to increase rice growth and grain yield in acid sulfate soils (ASS) with low available phosphorus (Pavail). Methods P-solubilizers were tested in vitro. A 4 × 3 factorial design consisted of PNSB at 5.4 × 104 cells g−1 dry soil weight (mixture of 4 strains, VNW64 singly, or no-PNSB) and P fertilizer levels (0, 30, 45 and 60 kg P2O5 ha−1) that were used with the rice variety OM5451 in pots with two types of ASS (Hon Dat and Phung Hiep). Results The four PNSB mixture had the ability to dissolve insoluble P from variscite and strengite. The combination of mixed culture with 45 P was the most effective, increasing grain yield by 34%. Enhancement of rice growth and yield in both soils corresponded to the maximal levels of Pavail, total P and NH4+, and the lowest levels of Alexch and Fe2+. Soil health with this treatment was significantly improved, with a strong positive correlation between PNSB population and phosphatase activity in both soil types. Conclusions The combination of PNSB mixture with P fertilizer reduced the amount of chemical fertilizer needed for maximal grain yield, provided safe rice, and maintained soil health.

This study evaluated the effects of a mixture of four N 2 -fixing strains of Rhodopseudomonas palustris -VNW64, VNS89, TLS06, and VNS02-(PNSB) on soil properties, nitrogen (N) uptake, plant growth, and yield of canary melon cultivated in alluvial soil. A greenhouse experiment was conducted using a completely randomized block design with eight treatments: (i) 100% N of recommended fertilizer formula (RFF), (ii) 85% N of RFF, (iii) 70% N of RFF, (iv) 100% N of RFF + PNSB, (v) 85% N of RFF + PNSB, (vi) 70% N of RFF + PNSB, (vii) PNSB only, and (viii) no fertilization. The application of PNSB improved soil pH and available N concentrations. The highest N uptake (33.9 kg N ha ⁻ ¹) was recorded in the 100% RFF + PNSB treatment. Notably, the 70% RFF + PNSB treatment achieved comparable N uptake (27.7 kg N ha ⁻ ¹) to the 100% RFF treatment (28.6 kg N ha ⁻ ¹). The 85% RFF + PNSB treatment maintained plant height and yield equivalent to the 100% RFF treatment. These results suggest that supplementing with PNSB can reduce N fertilizer application by up to 15% without compromising crop performance. The PNSB mixture should be further tested under a field trial.

The overuse of chemical fertilizers under adverse conditions endangers the sustainability of agriculture. A biological approach should be investigated to address this issue. Therefore, this study aimed to detect the potency of purple non-sulfur bacteria that can fix nitrogen (N) (PNSB-fN) Rhodobacter sphaeroides in soil N fertility, plant N uptake, growth, and rice yield. In brief, an experiment was conducted to check whether the biofertilizer containing PNSB-fN strains can improve rice yield and soil fertility under a highly saline acidic condition. A randomized complete block design was used with four replicates on saline soil in An Bien-Kien Giang, Vietnam. The first factor was the N fertilizer level, i.e., (i) 100%, (ii) 75%, (iii) 50%, and (iv) 0%; the second factor was the PNSB-fN (R. sphaeroides), i.e., (i) the control, (ii) S01, (iii) S06, and (iv) combined S01–S06. In the results, supplying PNSB-fN increased NH4+ compared with the control, i.e., 104.7–112.0 mg NH4+ kg−1 compared with 94.0 mg NH4+ kg−1 in season 1 and 35.9–38.0 mg NH4+ kg−1 compared with 34.2 mg NH4+ kg−1 in season 2. Additionally, by supplying each PNSB-fN strain, the soil Na+ and plant Na in culm leaf and grain were decreased in comparison with those in treatments without PNSB-fN. The total N uptake was also enhanced by the PNSB-fN compared with the control. Moreover, supplying PNSB-fN improved the crop height, panicle length, panicle quantity pot−1, grain quantity panicle−1, filled spikelet rate, and grain yield compared with the control. Ultimately, in extremely saline soil, the mixture of PNSB-fN not only improved soil fertility and reduced soil salinity but also replaced 25% of chemical N fertilizer to ensure sustainable agriculture. This newly developed biofertilizer was potent in not only improving the rice and soil health in the locality but also performing the same under similar conditions around the globe.

The aim of the current research was to evaluate the effects of members of purple nonsulfur bacteria (PNSB), Rhodopseudomonas palustris strains of VNW02, TLS06, VNW64, and VNS89, mixed with spent rice straw (SRS) from mushroom cultivation as a carrier on promoting sesame growth and yield, and ameliorating the alluvial soil (AS) fertility in dykes. A 4 × 3 factorial experiment consisting of different levels of the solid PNSB biofertilizer mixture at 0, 3, 4, and 5 t·ha−1 (0, 1.81 × 108, 2.24 × 108, and 2.68 × 108 cells pot−1, respectively), and nitrogen (N) and phosphorus (P) inorganic fertilizer rates (100, 75, and 50 kg·N·ha−1; 60, 45, and 30 kg P2O5·ha−1, respectively) was performed in pots with the sesame variety of ADB1 in the dyked AS. The solid PNSB biofertilizer mixture at at least 3 t·ha−1 significantly enhanced the sesame seed yield by providing higher macronutrients for plants by increasing available N and soluble P concentrations in the soil. The solid PNSB biofertilizer mixture in addition to 75% of the recommended N and P fertilizers produced an equivalent yield in comparison to the utilized 100% of N and P inorganic fertilizers. The solid PNSB biofertilizer mixture in the SRS from the mushroom production reduced at least 25% of N and P chemical fertilizers for gaining the maximal seed yield and enriched soil characteristics for the sustainable black sesame cultivation in the dyked AS.

This study was conducted to evaluate the effectiveness of phosphorus P-solubilizing purple nonsulfur bacteria, Cereibacter sphaeroides ST16 and ST26, on improving soil quality, nutrient uptake, growth, and yield of rice farmed in salinized soil in the rice-shrimp system. A two-factor experiment was arranged in completely randomized blocks with four replications. Factor (A) represented P fertilizing rates, including 0%, 25%, 50%, 75%, and 100% P as the recommendation. Factor (B) consisted of the negative control (NC), a strain of C. sphaeroides ST16, C. sphaeroides ST26, and the mixture of ST16 and ST26. The results indicated that using the ST16-ST26 mixture decreased Na+ concentration by 15.2–21.1%, improved soluble P content by 11.5–21.0%, and reduced contents of Fe-P by 14.8–15.1%, Ca-P by 6.18–22.5%, and Al-P by 4.55–8.58%. Additionally, a single or the mixture application increased the total P uptake by 16.7–37.0% and decreased the total Na uptake by 6.12–17.2%, as compared with NC. In addition, fertilizing 100% P developed rice grain yield by 26.1–34.7% as compared with the 0% P applied. Simultaneously, using the ST16-ST26 mixture elevated the rice grain yield by 10.7–25.0%, chlorophyll content, and lowered proline content as compared with NC.

Resistance mechanisms of acid Mn 2+ -resistant purple nonsulfur bacteria (PNSB) were investigated to determine their ability to alleviate adverse effects of excess manganese on plant growth and productivity in acid sulfate soils (ASS). PNSB were isolated and selected based on their resistance to acid and manganese. Their resistance mechanisms were assessed on the basis of biosorption, bioaccumulation, and plant growth promoting properties. Six PNSB were selected for their resistance to Mn 2+ in acidic conditions (pH 3.5–5.5). They were identified as Rhodopseudomonas palustris strains TLS12, VNS19, VNS32, VNS62, and VNW95, and Rhodopseudomonas harwoodiae strain TLW42. Under aerobic dark and microaerobic light incubating conditions in aqueous solution at pH 4.25 for 30 min, these strains adsorbed Mn 2+ (1500 mg L −1 ) more effectively with released exopolymeric substances (EPS) than with their biomass. Under both incubating conditions, bioaccumulation of Mn 2+ diminished in the following order: cell wall, cytoplasm, plasma membrane. Scanning electron microscope-energy dispersive X-ray spectrometry (SEM-EDS) found accumulated manganese (0.30–0.67% of total elements) in bacterial cells caused morphological change in the form of wrinkles and bleb-like features on exterior surfaces. All selected strains under both incubating conditions released NH 4 + by N 2 fixing and PO 4 3− by solubilizing phosphate from various P-sources. Siderophores, 5-aminolevulinic acid (ALA), and indole-3-acetic acid (IAA) were also released and pH increased. The studied strains showed potential as bioremediators that could reduce Mn 2+ toxicity using EPS and effectively release nutrients and plant growth promoting substances to improve cultivation and fertility in acidic conditions.

The aim of this study was to determine the proper combination of nitrogen (N) fertilizer level and nitrogen fixing endophytic bacteria (NFEB) supplementation for the maximum grain yield of sesame cultivated in alluvial soil in dykes. The experiment followed a completely randomized block design with two factors. The first one was the levels of N fertilizer used, including 0, 50, 75, and 100% N of recommended fertilizer formula (RFF), and the other consisted of no bacteria applied, an individual strain of Enterobacter cloacae ASD-48 or E. cloacae ASD-21 applied, and their mixture, with 5 replicates. The results revealed that fertilizing with 100% N of RFF led to an enhancement of the plant height (16.8 cm), the chlorophyll a and b and their total content (6.45, 1.86, and 8.30 μg mL−1), the number of capsules per plant (7.22 capsules plant−1), the total N uptake (126.5 mg N pot−1), and the grain yield (9.08 g pot−1), in comparison to no N fertilizer applied. Supplementation of two NFRB strains enhanced the soilconcentrations of NH4+ and NO3−, the total N uptake, and the grain yield. The treatment fertilized with 75% N of RFF plus an individual NFEB strain or their bacterial mixture had equivalent total N uptake to that the treatment fertilized with 100% N of RFF had, 120.8–125.5 mg N pot−1 compared to 124.4 mg N pot−1. Regarding the sesame yield, with a reduction by 25–50% N of RFF plus ASD-48 and ASD-21, either individually or in mixture, it increased by 2.39–8.56%, compared to that in the treatment fertilized with 100% N of RFF.

Potassium (K) is immobilized within the clay minerals, making it unavailable for plant use. Therefore, the current study aimed to (i) select isolates of purple nonsulfur bacteria that can dissolve K (K-PNSB) and (ii) evaluate the production of plant-growth-promoting substances by the K-PNSB isolates. The results revealed that from in-dyked alluvial soils in hybrid maize fields, 61 K-PNSB isolates were obtained under the pH 5.50 conditions. The total dissolved K content (Kdis) by the 61 K-PNSB isolates fluctuated from 56.2 to 98.6 mg L−1. Therein, three isolates, including M-Sl-09, M-So-11, and M-So-14 had Kdis of 48.1–48.8 mg L−1 under aerobic dark condition (ADC) and 47.6–49.7 mg L−1 under microaerobic light condition (MLC). Moreover, these three isolates can also fix nitrogen (19.1–21.5 mg L−1 and 2.64–7.24 mg L−1), solubilize Ca-P (44.3–46.8 mg L−1 and 0.737–6.965 mg L−1), produce indole-3-acetic acid (5.34–7.13 and 2.40–3.23 mg L−1), 5-aminolevulinic acid (1.85–2.39 and 1.53–2.47 mg L−1), siderophores (1.06–1.52 and 0.92–1.26 mg L−1), and exopolymeric substances (18.1–18.8 and 52.0–56.0%), respectively, under ADC and MLC. The bacteria were identified according to their 16S rDNA as Cereibacter sphaeroides M-Sl-09, Rhodopseudomonas thermotolerans M-So-11, and Rhodospeudomonas palustris M-So-14. These potential bacteria should be further investigated as a plant-growth-promoting biofertilizer.