Effect of Acinetobacter sp on metalaxyl degradation and metabolite profile of potato seedlings (Solanum tuberosum L.) alpha variety

Seed tuber microbiome can predict growth potential of potato varieties

Potato vigour, the growth potential of seed potatoes, is a key agronomic trait that varies significantly across production fields due to factors such as genetic background and environmental conditions. Seed tuber microbiomes are thought to influence plant health and crop performance, yet the precise relationships between microbiome composition and potato vigour remain unclear. Here we conducted microbiome sequencing on seed tuber eyes and heel ends from 6 potato varieties grown in 240 fields. By using time-resolved drone imaging of three trial fields in the next season to track crop development, we were able to link microbiome composition with potato vigour. We used microbiome data at varying taxonomic resolutions to build random forest predictive models and found that amplicon sequence variants provided the highest predictive accuracy for potato vigour. The model revealed variety-specific relationships between the seed tuber microbiome and next season's crop vigour in independent trial fields. With a coefficient of determination value of 0.69 for the best-performing variety, the model accurately predicted vigour in seed tubers from fields not previously included in the analysis. Moreover, the model identified key microbial indicators of vigour from which a Streptomyces, an Acinetobacter and a Cellvibrio amplicon sequence variant stood out as the most important contributors to the model's accuracy. This study shows that seed potato vigour can be reliably predicted based on the microbiota associated with seed tuber eyes, potentially guiding future microbiome-informed breeding strategies.

Enhanced Dissipation of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in Soil by the Bioaugmentation with Newly Isolated Strain Acinetobacter johnsonii MC5

The presented study investigated the possibility of using the Acinetobacter johnsonii MC5 strain, isolated from raw sewage by the enrichment culture method, in the bioremediation of soil contaminated with selected NSAIDs, i.e., ibuprofen (IBF), diclofenac (DCF), and naproxen (NPX), using the bioaugmentation technique. The degradation potential of A. johnsonii MC5 was first evaluated using a mineral salt medium containing drugs as the only sources of carbon and energy. The results show that the strain MC5 was capable of utilizing the tested compounds in medium, indicating that the drugs might be metabolically degraded. IBF and NPX were degraded with a similar rate and DT50 values were determined to be approximately 5 days, while the degradation process for DCF was slower, and the DT50 value was about 5 times higher (22.7 days) compared to those calculated for IBF and NPX. Bioaugmentation of non-sterile soil with A. johnsonii MC5 increased the rate of disappearance of the tested drugs, and DT50 values decreased 5.4-, 3.6-, or 6.5-fold for IBF, DCF, or NPX, respectively, in comparison with the values obtained for the soil with indigenous microorganisms only. The obtained results suggest that A. johnsonii MC5 may have potential for use in bioremediation of NSAID-contaminated soils; however, detailed studies are needed before using this strain in such process on a larger scale.

Rapid MSPD-LC-MS/MS Procedure for Determination of Pesticides in Potato Tubers

The program of potato protection recommended by the producers of agrochemicals requires application: thiamethoxam, lambda-cyhalothrin, deltamethrin, rimsulfuron and metalaxyl. Therefore, there is a risk that these pesticides are present in tubers, thus posing a toxicological risk to the consumer. In this respect, it is necessary to monitor the presence of these compounds in edible plants. Therefore, the aim of this paper was to develop a novel, simple and robust analytical procedure for simultaneous determination of above-mentioned pesticides in potato tubers. To develop an analytical procedure that fulfills SANTE demands, quick, easy, cheap, effective, rugged and safe method and matrix solid phase dispersion technique were investigated. The final determination was conducted by liquid chromatography with tandem mass spectrometry. The obtained experimental data were analyzed by analysis of variance. For the extraction of analytes, matrix solid phase dispersion with octadecyl sorbent and methanol as eluent was chosen, since it provides the validation parameters according to SANTE requirements (recovery: 77-111%, relative standard deviation: 1-10%, limit of quantification: 0.9-5.0 μg/kg). This innovative analytical procedure is a practical analytical tool, which was successfully proven by applying it for target pesticides determination in potato tuber samples of different varieties randomly chosen at local markets.

Degradation of chlorpyrifos by an endophytic bacterium of the Sphingomonas genus (strain HJY) isolated from Chinese chives (Allium tuberosum)

The degradation of chlorpyrifos (CP) by an endophytic bacterial strain (HJY) isolated from Chinese chives (Allium tuberosum Rottl. ex Spreng) was investigated. Strain HJY was identified as Sphingomonas sp. based on morphological, physiological, and biochemical tests and a 16S rDNA sequence analysis. Approximately 96% of 20 mg L^-1 CP was degraded by strain HJY over 15 days in liquid minimal salts medium (MSM). The CP degradation rate could also be increased by glucose supplementation. The optimal conditions for the removal of 20 mg L^-1 CP by strain HJY in MSM were 2% inoculum density, pH 6.0, and 30-35°C. The CP degradation rate constant and half-life were 0.2136 ± 0.0063 d^-1 and 3.2451 ± 0.0975 d, respectively, under these conditions, but were raised to 0.7961 ± 0.1925 d^-1 and 0.8707 ± 0.3079 d with 1% glucose supplementation. The detection of metabolic products and screening for degrading genes indicated that O,O-diethyl O-3,5,6-trichloropyridinol was the major degradation product from CP, while it was likely that some functional genes were undetected and the mechanism responsible for CP degradation by strain HJY remained unknown. Strain HJY is potentially useful for the reduction of CP residues in Chinese chives and may be used for the in situ phytoremediation of CP.

Degradation Processes of Pesticides Used in Potato Cultivations

Potato is one of the most important crops, after maize, rice and wheat. Its global production is about 300 million tons per year and is constantly increasing. It grows in temperate climate and is used as a source of starch, food, and in breeding industry.Potato cultivation requires application of numerous agro-technical products, including pesticides, since it can be affected by insects, weeds, fungi, and viruses. In the European Union the most frequently used pesticides in potato cultivations check are: thiamethoxam, lambda-cyhalothrin and deltamethrin (insecticides), rimsulfuron (herbicide) and metalaxyl (fungicide).Application of pesticides improves crop efficiency, however, as pesticides are not totally selective, it affects also non-target organisms. Moreover, the agrochemicals may accumulate in crops and, as a consequence, negatively influence the quality of food products and consumer health. Additional risks of plant protection products are related to their derivatives, that are created both in the environment (soil, water) and in plant organisms, since many of these compounds may exhibit toxic effects.This article is devoted to the degradation processes of pesticides used in potato crop protection. Attention is also paid to the toxicity of both parent compounds and their degradation products for living organisms, including humans. Information about the level of pesticide contamination in the environment (water, soil) and accumulation level in edible plants complement the current knowledge about the risks associated with widespread use of thiamethoxam, lambda-cyhalothrin and deltamethrin, rimsulfuron and metalaxyl in potato cultivation.

Identification and functional characteristics of chlorpyrifos-degrading and plant growth promoting bacterium Acinetobacter calcoaceticus

A bacterial strain D10 with strong ability of degrading chlorpyrifos was isolated from rhizosphere of chives contaminated with pesticide. It was found that it's capable of utilizing chlorpyrifos as the sole source of carbon for growth, and within the first 4 days the extent of degradation at initial concentration of 100 mg L(-1) was 60.0%. It also showed a high ability of degrading chlorpyrifos in sterilized soil, and the degradation reached up to 60.2% after 18 days. In addition, the strain D10 also showed multiple plant growth-promoting traits of phosphate solubilization, indole-3-acetic acid and siderophore production. The results indicate that the strain D10 has potential in the application of pesticide-degrading and plant growth promotion. Strain D10 was identified as Acinetobacter calcoaceticus based on its morphological, physiological-biochemical properties and the 16S rRNA sequence analysis.