Evaluating the effect of exogenous phytohormones on bioremediation efficiency and physiological responses of Chlorella sorokiniana under ciprofloxacin exposure.

Biochemical markers and bioaccumulation capacity of cyanobacteria under fenitrothion stress: implications for aquatic bioremediation

Herbicide Butafenacil and Its Transformation Products Significantly Influence Ecological Dynamics in Marine Environments

Protoporphyrinogen oxidase (PPO) inhibitors have long been considered environmentally friendly herbicides due to their high efficacy and low toxicity. However, we found that a widely used PPO inhibitor butafenacil (BFA) and its transformation products (TPs) possessed exceptionally high toxicity to some marine phytoplankton (96-h EC50 of BFA were 0.71 ± 0.08 μg/L and 1.3 ± 0.06 μg/L for Skeletonema costatum and Chlorella sp., respectively). Bialgal culture experiments revealed that BFA exposure enhanced the competitive advantage of Chlorella sp., triggering a shift in dominance from other microalgae to Chlorella sp., which could alter the community structure and potentially destabilize ecological imbalances in marine environments. The degradation process of BFA in seawater could be accelerated by Phaeodactylum tricornutum, as its half-life decreased from 7.5 to 3.3 days, and 16 (13 new) TPs were identified by solid-phase extraction-liquid chromatography–high-resolution tandem mass spectrometry. Using computational toxicology, TPs with predicted toxicity comparable to parent BFA were isolated by preparative liquid chromatography and subjected to algal toxicity tests. The semiquantitative estimates indicated that the persistent high toxicity to microalgae after BFA degradation was attributable to these toxic TPs on a BFA-equivalent basis, underscoring the necessity to consider the potential environmental risks posed by TPs.

Effect of Methylobacterium on the yield and quality of cauliflower (Brassica oleracea)

Abstract The soil used is sandy in texture, low in nutrients, and low in organic matter, and therefore has low cation exchange capacity. Therefore, the objective was to evaluate the effectiveness of improving their physicochemical and biological properties by inoculating the roots with a solution of Methylobacterium and liquid compost in cauliflower cultivation, as well as integrating a treatment through an automated drip irrigation system. This biostimulant, biofertilizer, and biocontrol agent solution was used, which has applications in agriculture to improve soil health and crop productivity. The experiment was set up under a completely randomized block design with four treatments (T0, T1, T2, and T3), corresponding to doses of 0, 250, 333, and 400 mL per 200 L of water, respectively. The results indicated that treatment T3 significantly optimized the plant's physiological response to salt stress, increasing both its antioxidant capacity and chlorophyll α concentration. Likewise, physical characterization revealed significant differences in the morphological parameters of cauliflower, suggesting greater metabolic resistance and improved nutritional quality. Finally, ultrastructural analysis of the epidermis and stomata using microscopy showed that, while the control treatment (T0) had a collapsed surface, treatment T3 showed a functional and turgid ultrastructure. This demonstrates that the inoculation applied mitigates the phytotoxic impact of the substrate and optimizes the metabolic potential of the crop.

Integrative functional profiling of rhizospheric and endophytic bacteria reveals Lelliottia aquatilis as a multifunctional PGPR in Himalayan ecosystems

This study introduces L. aquatilis strain MC3 as an emerging candidate for bioinoculant development and one of the first reports for identification of L. aquatilis as multifunctional PGPR from Himalayan ecosystems.

Biofertilizer based on mycorrhizal fungi and rhizobacteria in maize cultivation under two water regimes

Biostimulants are able to increase tolerance to water and salt stress and help enhance the absorption of nutrients from the soil, in addition to increasing the extension of roots, they are also effective in the synthesis of plant hormones (such auxins, gibberellins, cytokinins) and in the capacity to make insoluble phosphorus in the soil available to plants, minimizing the effects of biotic and abiotic stresses. The objective of this study was to evaluate the phytotechnical and physiological responses of maize subjected to two water regimes and a biostimulant containing mycorrhizae and rhizobacteria of the genus Bacillus spp., through the characterization of the antioxidant response conditioned by this association. The experiment was set up in a 5x2 factorial scheme, with five treatments related to the doses of biostimulant [negative control; 0.250 kg ha-1; 0.500 kg ha-1; 0.750 kg ha-1 and 1 kg ha-1] and two water availability levels (60% and 100% of field capacity), with four replicates, totaling 40 pots. The following growth parameters were analyzed at 15 and 30 days after planting: plant height, stem diameter, number of leaves, root length and root volume, as well as the following biochemical parameters: lipid peroxidation, total peroxidase and catalase of leaf and root. The biostimulant promoted an increase in the growth of the aerial part and root system of corn plants, in addition to an adjustment of antioxidant enzymes, indicating that, up to 30 days after planting (DAP), corn plants show better adaptability to the water regime with 60% of field capacity.

Synergistic effects of Rhodopseudomonas palustris and Bacillus subtilis on cadmium accumulation in Forsythia suspensa.

Cadmium (Cd(II)) contamination threatens agricultural systems and the safety of traditional Chinese medicinal herbs. While beneficial microbes can alleviate Cd(II) stress in plants, the synergistic mechanisms underlying microbial co-inoculation in medicinal plant species remain unclear. This study investigated the individual and combined effects of Rhodopseudomonas palustris and Bacillus subtilis on Forsythia suspensa under Cd(II) stressed. The results showed that co-inoculation achieved markedly better effects than single-strain inoculation. Specifically, the HRB treatment enhanced plant height, belowground fresh weight, and aboveground fresh weight by 148.87%, 207.91%, and 188.81%, respectively, compared to the Cd(II) group. Furthermore, microbial inoculation enhanced chlorophyll content and strengthened the antioxidant defense system. The activities of SOD, POD, and CAT, as well as GSH content, were greatly improved: SOD activity increased by 3.2-6.3 folds, POD activity by 73.4%-173.9%, CAT activity by 66.2%-156.0%, and GSH content by 131.81% in the HRB group. Meanwhile, oxidative damage was alleviated, with MDA content decreasing by 62.61% in the HRB group. Crucially, co-inoculation modified the rhizosphere microenvironment: it improved bacterial diversity, enhanced soil enzyme activities (S-UE, S-CAT, S-ALP, and S-SC increased by 44.92%, 10.82%, 12.12%, and 10.75%, respectively, in the HRB group), and reduced Cd(II) bioavailability (acid-extractable Cd(II) decreased by 36.77% in the HRB group). Compared to the Cd(II) group, all inoculation treatments significantly increased the relative abundances of beneficial bacterial phyla including Proteobacteria, Actinobacteria, Gemmatimonadetes, and Bacteroidetes, while decreasing the abundances of Chloroflexi and Rokubacteria. These variations ultimately reduced Cd(II) accumulation in plant tissues. Pearson correlation analysis indicated that beneficial bacterial taxa and soil enzyme activities were positively correlated with plant physiological indices, whereas these parameters were negatively correlated with Cd(II) bioavailability and plant Cd(II) accumulation. Collectively, this study demonstrates that R. palustris and B. subtilis work synergistically to mitigate Cd(II) phytotoxicity and reduce Cd(II) accumulation in F. suspensa. The findings provide a promising bioremediation strategy for cultivating safer medicinal plants in Cd(II)-contaminated soils.