Growth Medium Research Articles

First Report of Bacterial Blight of Pennycress Caused by Xanthomonas campestris in Wisconsin.

In May 2023, pennycress (Thlaspi arvense, L.) lines undergoing seed production in the Walnut Street Greenhouse at the University of Wisconsin-Madison displayed symptoms of chlorosis and black necrotic leaf spots (Fig. S1-A). Lesions eventually enlarged to 1-2 cm in diameter, became necrotic, and coalesced to cover a substantial portion of leaves. Symptoms were observed in ~30% of the pennycress lines adversely affecting overall growth and reproduction. Symptomatic leaves were surface sterilized for 30 seconds in 0.75% sodium hypochlorite, rinsed in sterile deionized water, and bacteria were isolated using three-phase streaking of symptomatic tissue onto KB medium (King et al., 1954). Single colonies of three isolates (creamy white to yellow) from this initial isolation were streaked onto KB medium to obtain pure cultures. Individual colonies were transferred for growth overnight in nutrient broth (Difco) and an equal amount of the broth was added to 30% glycerol in deionized (di) water and stored at -80 °C. To validate Koch's Postulates, bacteria were grown from these stocks on Yeast Dextrose Calcium Carbonate medium (Wilson et al., 1967) and were used to inoculate 5-week-old pennycress plants in the greenhouse. The bacteria were grown for 48 hours at 26°C, suspended in 300 ml of 0.05 M PBS buffer (pH=7.2) for inoculum preparation. Plants were inoculated with three bacterial isolates (approx. 108 CFU/ml) by piercing the mid veins or hydathodes with a sterilized toothpick dipped in the suspension. Inoculated plants were then enclosed in clear plastic bags for 24-48 hours and maintained in the greenhouse at a constant temperature of 26°C with a 16-hour photoperiod. After seven days, water-soaked lesions appeared on the inoculated leaves, eventually developing into the characteristic black spots (Fig. S1-B). DNA from the original isolates was extracted, and 16S PCR and sequencing of the positive bands was done. The negative control only produced brown spots at the site of inoculation (Fig. S1-C). The primer sequences were as follows: 27F: AGAGTTTGATCMTGGCTCAG; 1492R: GGTTACCTTGTTACGACTT (Eden et al., 1991; Weisburg et al., 1991). A BLAST analysis showed that the isolates had an E value of 0.0 to the genus Xanthomonas as well as 100% identity. Amplification and sequencing of the bacterium using gyrB amplicons revealed a 99-100% pairwise match with Xc. To enhance taxonomy resolution and confirm the identity of these isolates, the complete genomes of three samples were sequenced using NextSeq2000 Illumina platform (NCBI bioproject ID PRJNA1040293). Average Nucleotide Identity (ANI) analysis was conducted with representative strains from the Xc species (Dubrow et al., 2022), using PanExplorer (Dereeper et al., 2020) featuring integrated FastANI module (Jain et al., 2018). The isolates genomes exhibited over 98% identity and clustered with that of Xc pv. incanae and Xc pv. barbarae (Fig S2). Further work will be required to identify the pathovar of Xc identified in this study through phenotypic host range assay. This marks the first documented case of Xc in pennycress in the Midwestern US. Given the potential use of pennycress as a cover crop in the region, further investigations are warranted to assess its economic impact on production and develop management strategies.

Using low-shear aerated and agitated bioreactor for producing two specific laccases by trametes versicolor cultures induced by 2,5-xylidine: Process development and economic analysis

Laccase isoforms from basidiomycetes exhibit a superior redox potential compared to commercially available laccases obtained from ascomycete fungi, rendering them more reactive toward mono-substituted phenols and polyphenolic compounds. However, basidiomycetes present limitations for large-scale culture in liquid media, restraining the current availability of laccases from this fungal class. To advance laccase production from basidiomycetes, a newly designed 14-L low-shear aerated and agitated bioreactor provided enzyme titers up to 23.5 IU/mL from Trametes versicolor cultures. Produced enzymes underwent ultrafiltration and LC/MS-MS characterization, revealing the predominant production of only two out of the ten laccases predicted in the T. versicolor genome. Process simulation and economic analysis using SuperPro designer® suggested that T. versicolor laccase could be produced at US$ 3.60/kIU in a 200-L/batch enterprise with attractive economic parameters and a payback period of 1.7 years. The study indicates that new bioreactors with plain design help to produce low-cost enzymes from basidiomycetes.

Акустический пограничный слой твёрдой абсолютно теплопроводной поверхности

The paper presents the analysis results of formation theoretical descriptions of an acoustic boundary layer near solid absolutely thermally conductive surface, obtained by G. Kirchhoff and L.D. Landau. In both cases, the acoustic boundary layer is formed by inhomogeneous viscous and thermal waves in the wall layer of a liquid medium in contact with the surface of a solid body, from which a plane traveling sound wave is reflected. Based on the analysis, conclusions can be drawn: the analyzed problem solutions are physically sound, independent and complementary to each other. During the formation of an acoustic boundary layer, viscous and thermal waves are excited synchronously in pairs. Inside the acoustic boundary layer, each pair of inhomogeneous waves propagates towards each other. Inhomogeneous waves originate on parallel surfaces that limit the volume of the acoustic boundary layer. The analysis of the process of transformation of heat waves into additional one-dimensional inhomogeneous waves, the appearance of which in the boundary layer was predicted by G. Kirchhoff. It is shown that when interacting with the surface of the body of a traveling sound wave in the sound frequency range, these waves do not affect the formation of the boundary layer. The expressions allowing for a numerical estimation of the heat dissipation power density in the boundary layer are refined. A formula has been obtained that allows us to determine the proportion of the energy of the sound wave that is absorbed in the acoustic boundary layer. In practice, the results obtained in the article can be used, for example, in aeroacoustics to assess the dissipative properties of solid surfaces.

The Effect of Banana Stems (Musa Paradisiaca L.) Toward The Growth of Rice Field Eels (Monopterus Albus) in Cultivation Business

Banana plants have not been utilized optimally. Banana stems can be used as a growth medium for eels. Eels are a type of freshwater animal that has quite high economic value. This research aims to determine the effect of banana stems (Musa paradisiaca L.) on the growth of rice field eels (Monopterus albus). This type of research is quantitative research with experimental methods. The research was conducted on Jl. Biduri Senteluk, Senteluk Village, Batulayar District, West Lombok Regency, NTB in the yard of the house for 3 months. The research design used was a Completely Randomized Design (CRD) with 7 treatments and 3 repetitions. Treatment P0 (100% mud) as control, P1 (90% rice field mud + 10% banana stems), P2 (80% rice field mud + 20% banana stems), P3 (70% rice field mud + 30% banana stems), P4 (60% rice field mud + 40% banana stems), P5 (50% rice field mud + 50% banana stems), and P6 (40% rice field mud + 60% banana stems). The parameters observed were absolute weight, absolute length, and survival rate of rice field eels. The research data were analyzed using the ANOVA test and the BNT test (smallest significant difference). The results of the analysis showed that the addition of banana stems had a significant effect on the growth of rice field eels (P>0.05). The best addition of banana stems was in the P3 treatment, which can be seen from the average value of the weight growth of paddy eels which increased by 6,100 grams and the increase in length growth of paddy eels by 7,200 cm, and the survival rate of paddy eels was 100%.

Explainable AI for CHO cell culture media optimization and prediction of critical quality attribute

Cell culture media play a critical role in cell growth and propagation by providing a substrate; media components can also modulate the critical quality attributes (CQAs). However, the inherent complexity of the cell culture media makes unraveling the impact of the various media components on cell growth and CQAs non-trivial. In this study, we demonstrate an end-to-end machine learning framework for media component selection and prediction of CQAs. The preliminary dataset for feature selection was generated by performing CHO-GS (-/-) cell culture in media formulations with varying metal ion concentrations. Acidic and basic charge variant composition of the innovator product (24.97 ± 0.54% acidic and 11.41 ± 1.44% basic) was chosen as the target variable to evaluate the media formulations. Pearson’s correlation coefficient and random forest-based techniques were used for feature ranking and feature selection for the prediction of acidic and basic charge variants. Furthermore, a global interpretation analysis using SHapley Additive exPlanations was utilized to select optimal features by evaluating the contributions of each feature in the extracted vectors. Finally, the medium combinations were predicted by employing fifteen different regression models and utilizing a grid search and random search cross-validation for hyperparameter optimization. Experimental results demonstrate that Fe and Zn significantly impact the charge variant profile. This study aims to offer insights that are pertinent to both innovators seeking to establish a complete pipeline for media development and optimization and biosimilar-based manufacturers who strive to demonstrate the analytical and functional biosimilarity of their products to the innovator.Key points• Developed a framework for optimizing media components and prediction of CQA.• SHAP enhances global interpretability, aiding informed decision-making.• Fifteen regression models were employed to predict medium combinations.

A Systematic Genotoxicity Assessment of a Suite of Metal Oxide Nanoparticles Reveals Their DNA Damaging and Clastogenic Potential.

Metal oxide nanoparticles (MONP/s) induce DNA damage, which is influenced by their physicochemical properties. In this study, the high-throughput CometChip and micronucleus (MicroFlow) assays were used to investigate DNA and chromosomal damage in mouse lung epithelial cells induced by nano and bulk sizes of zinc oxide, copper oxide, manganese oxide, nickel oxide, aluminum oxide, cerium oxide, titanium dioxide, and iron oxide. Ionic forms of MONPs were also included. The study evaluated the impact of solubility, surface coating, and particle size on response. Correlation analysis showed that solubility in the cell culture medium was positively associated with response in both assays, with the nano form showing the same or higher response than larger particles. A subtle reduction in DNA damage response was observed post-exposure to some surface-coated MONPs. The observed difference in genotoxicity highlighted the mechanistic differences in the MONP-induced response, possibly influenced by both particle stability and chemical composition. The results highlight that combinations of properties influence response to MONPs and that solubility alone, while playing an important role, is not enough to explain the observed toxicity. The results have implications on the potential application of read-across strategies in support of human health risk assessment of MONPs.

An overview of the two-component system GarR/GarS role on antibiotic production in Streptomyces coelicolor

The Streptomyces genus comprises Gram-positive bacteria known to produce over two-thirds of the antibiotics used in medical practice. The biosynthesis of these secondary metabolites is highly regulated and influenced by a range of nutrients present in the growth medium. In Streptomyces coelicolor, glucose inhibits the production of actinorhodin (ACT) and undecylprodigiosin (RED) by a process known as carbon catabolite repression (CCR). However, the mechanism mediated by this carbon source still needs to be understood. It has been observed that glucose alters the transcriptomic profile of this actinobacteria, modifying different transcriptional regulators, including some of the one- and two-component systems (TCSs). Under glucose repression, the expression of one of these TCSs SCO6162/SCO6163 was negatively affected. We aimed to study the role of this TCS on secondary metabolite formation to define its influence in this general regulatory process and likely establish its relationship with other transcriptional regulators affecting antibiotic biosynthesis in the Streptomyces genus. In this work, in silico predictions suggested that this TCS can regulate the production of the secondary metabolites ACT and RED by transcriptional regulation and protein–protein interactions of the transcriptional factors (TFs) with other TCSs. These predictions were supported by experimental procedures such as deletion and complementation of the TFs and qPCR experiments. Our results suggest that in the presence of glucose, the TCS SCO6162/SCO6163, named GarR/GarS, is an important negative regulator of the ACT and RED production in S. coelicolor.Key points• GarR/GarS is a TCS with domains for signal transduction and response regulation• GarR/GarS is an essential negative regulator of the ACT and RED production• GarR/GarS putatively interacts with and regulates activators of ACT and RED

Examination of the Bactericidal and Fungicidal Activity of Bacillus amyloliquefaciens M Isolated from Spring Waters in Bulgaria

In order for a strain to be considered a probiotic or suitable plant bioprotective agent, it must have proven antimicrobial activity against pathogenic bacteria and phytopathogenic fungi. Bacillus amyloliquefaciens M exhibited significantly high antifungal activity against pathogenic fungi of the genera Aspergillus, Penicillium, Fusarium, and Sclerotinia; yeasts of the genera Candida and Saccharomyces; as well as high antibacterial activity against pathogens of the genera Escherichia, Salmonella, Staphylococcus, Listeria, Pseudomonas, and Bacillus. The manifested antimicrobial activity was influenced by the composition of the growth medium. The antifungal activity of the strain was investigated at growth temperatures of 30 °C and 37 °C, and at different pH values in aerobic and anaerobic cultivation, under static and dynamic culturing conditions. High antifungal activity was observed at the 24th h on both growth media (LBG broth and MPB broth) at pH = 6 and pH = 7 in aerobic and anaerobic cultivation. Bacillus amyloliquefaciens M produced antibiotic substances at pH > 5.0, and the antibiotic substances were either secreted into the medium or associated with the cell surface. Four compounds with different antifungal activity and different Rf values were registered through thin-layer chromatography (Rf1 = 0.47; Rf2 = 0.55; Rf3 = 0.67; and Rf4 = 0.75), two of the compounds were ninhydrin-positive. Bacillus amyloliquefaciens M was cultured in a bioreactor with stirring, and the parameters of the growth kinetics and the sporulation kinetics have been modeled. A spore concentrate of Bacillus amyloliquefaciens M has been obtained. In further research, the efficiency of the concentrate as a plant bioactive agent will be tested.

Effect of Quorum Sensing Molecules on the Quality of Bacterial Nanocellulose Materials.

Bacterial nanocellulose (BNC) biofilms, produced by various bacterial species, such as Gluconacetobacter xylinus, represent a highly promising multifunctional material characterized by distinctive physiochemical properties. These biofilms have demonstrated remarkable versatility as nano biomaterials, finding extensive applications across medical, defense, electronics, optics, and food industries. In contrast to plant cellulose, BNC biofilms exhibit numerous advantages, including elevated purity and crystallinity, expansive surface area, robustness, and excellent biocompatibility, making them exceptional multifunctional materials. However, their production with consistent morphological properties and their transformation into practical forms present challenges. This difficulty often arises from the heterogeneity in cell density, which is influenced by the presence of N-acyl-homoserine lactones (AHLs) serving as quorum sensing signaling molecules during the biosynthesis of BNC biofilms. In this study, we employed surface characterization methodologies including scanning electron microscopy, energy-dispersive spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, and atomic force microscopy to characterize BNC biofilms derived from growth media supplemented with varying concentrations of distinct N-acyl-homoserine lactone signaling molecules. The data obtained through these analytical techniques elucidated that the morphological properties of the BNC biofilms were influenced by the specific AHLs, signaling molecules, introduced into the growth media. These findings lay the groundwork for future exploration of leveraging synthetic biology and biomimetic methods for tailoring BNC with predetermined morphological properties.

Deciphering the importance of culture pH on CD22 CAR T-cells characteristics

BackgroundChimeric antigen receptor (CAR) T-cells have demonstrated significant efficacy in targeting hematological malignancies, and their use continues to expand. Despite substantial efforts spent on the optimization of protocols for CAR T-cell manufacturing, critical parameters of cell culture such as pH or oxygenation are rarely actively monitored during cGMP CAR T-cell generation. A comprehensive understanding of the role that these factors play in manufacturing may help in optimizing patient-specific CAR T-cell therapy with maximum benefits and minimal toxicity.MethodsThis retrospective study examined cell culture supernatants from the manufacture of CAR T-cells for 20 patients with B-cell malignancies enrolled in a phase 1/2 clinical trial of anti-CD22 CAR T-cells. MetaFLEX was used to measure supernatant pH, oxygenation, and metabolites, and a Bio-Plex assay was used to assess protein levels. Correlations were assessed between the pH of cell culture media throughout manufacturing and cell proliferation as well as clinical outcomes. Next-generation sequencing was conducted to examine gene expression profiles of the final CAR T-cell products.ResultsA pH level at the lower range of normal at the beginning of the manufacturing process significantly correlated with measures of T-cell expansion and metabolism. Stable or rising pH during the manufacturing process was associated with clinical response, whereas a drop in pH was associated with non-response.ConclusionspH has potential to serve as an informative factor in predicting CAR T-cell quality and clinical outcomes. Thus, its active monitoring during manufacturing may ensure a more effective CAR T-cell product.

The effect of continuous long-term illumination with visible light in different spectral ranges on mammalian cells

One of the biggest challenges in tissue engineering and regenerative medicine is to ensure oxygen supply of cells in the (temporary) absence of vasculature. With the vision to exploit photosynthetic oxygen production by microalgae, co-cultivated in close vicinity to oxygen-consuming mammalian cells, we are searching for culture conditions that are compatible for both sides. Herein, we investigated the impact of long-term illumination on mammalian cells which is essential to enable photosynthesis by microalgae: four different cell types—primary human fibroblasts, dental pulp stem cells, and osteoblasts as well as the murine beta-cell line INS-1—were continuously exposed to warm white light, red or blue light over seven days. We observed that illumination with red light has no adverse effects on viability, metabolic activity and growth of the cells whereas exposure to white light has deleterious effects that can be attributed to its blue light portion. Quantification of intracellular glutathione did not reveal a clear correlation of this effect with an enhanced production of reactive oxygen species. Finally, our data indicate that the cytotoxic effect of short-wavelength light is predominantly a direct effect of cell illumination; photo-induced changes in the cell culture media play only a minor role.

Research on the sealing performance of micro-nano composite magnetic powder to liquid media with different viscosities

This paper mainly focuses on the research on micro-nano composite magnetic powder (MNC-MP) sealing liquid medium. Micro-nano composite magnetic powder and temperature-resistant magnetic powder (TR-MP) were prepared, and their magnetization curves were measured. The influence of temperature on the saturation magnetization of the TR-MP was analyzed. The results show that after heat treatment at 100 °C for 10 min, the specific saturation magnetization remains unchanged at 102.55A·m2/kg. The pressure resistance performance of the MNC-MP sealing liquids of different viscosities and the pressure change of the TR-MP sealing silicone oil were studied in the static sealing test. The results show that the higher the viscosity of the MNC-MP sealing liquid, the better the sealing performance, and pressure remains stable at 120 kPa when sealing dimethyl silicone oil. The dynamic sealing test analyzed the relationship between the pressure and rotation speed of the MNC-MP sealing silicone oil. We concluded that when MNC-MP seals dimethyl silicone oil, the effective time of the seal decreases with the increase of rotational speed, and the leakage rate after failure increases as the rotational speed increases. The changes in temperature and torque of MNC-MP and TR-MP sealing silicone oil with time at different rotational speeds were compared. Compared with MNC-MP, the temperature of the TR-MP seal can be reduced by 23.74 %, and the friction torque can be reduced by 17.58 %.

The influence of exogenous phytohormones and zinc sulfate on the morphophysiological characteristics of Salvinia natans (Salviniaceae)

Hydrophytic ferns of the family Salviniaceae, such as those of the genus Salvinia, hold promise for application in water purification and bioassessment. The Salvinia species are known for their rapid growth, adaptability, resistance to adverse environmental conditions, and also their ability to adsorb pollutants. The manipulation of plant growth and development through the application of exogenous phytohormones is an effective technique. In laboratory settings, we investigated the impact of exogenous phytohormones and zinc sulfate on the morphophysiological characteristics of young sporophytes of Salvinia natans. During the phase of intensive growth, the addition of exogenous abscisic acid (ABA) at a concentration of 10−5 M to the growth medium inhibited the accumulation of biomass in S. natans sporophytes. However, gibberellic acid (GA3) and cytokinins (kinetin or zeatin) at a concentration of 10−6 M, along with indole-3-acetic acid (IAA) at a concentration of 10−5 M, induced a slight increase in biomass. In sporophytes of S. natans grown in a medium containing varying concentration of zinc sulfate (228, 114, 57, 28.5, and 14.25 mg of zinc per liter of water), sings of chlorosis in floating fronds were observed as early as the second day of cultivation, followed by symptoms of necrosis. There was a decrease in the content of photosynthetic pigments. Sporophyte biomass decreased, as zinc concentration increased, ranging from 9.6% to 51%. Simultaneous application of phytohormones with the highest concentration of zinc sulfate partially mitigated the adverse effects of the metal, reducing biomass degradation and sustaining sporophyte viability. Qualitative alterations in the fern phenotype were observed, highlighting the phytotoxicity of excessive zinc concentrations. This underscores the potential use of S. natans as a bioindicator for water pollution.

First Report of Root Rot Caused by Fusarium incarnatum on Mongolian Snake gourd in China.

First Report of Root Rot Caused by Fusarium incarnatum on Mongolian Snake gourd in China.

Cactus pear (Opuntia ficus-indica) cladode extracts as a growth medium for Lactobacillus species: the case of Lactobacillus reuteri and Lactobacillus mali

Cactus pear (Opuntia ficus-indica) cladode extracts as a growth medium for Lactobacillus species: the case of Lactobacillus reuteri and Lactobacillus mali

Production of Ochratoxin A and Citrinin and the Expression of Their Biosynthetic Genes from Penicillium verrucosum in Liquid Culture.

Penicillium verrucosum is a fungal pathogen capable of producing two mycotoxins of concern, ochratoxin A (OTA) and citrinin (CIT). The production profile of these two mycotoxins is not well understood but could help mitigate co-contamination in the food supply. As such, the production of OTA and CIT from P. verrucosum DAOMC 242724 was investigated under different growing conditions in liquid culture. We found that among the different liquid media chosen, liquid YES (yeast extract sucrose) medium induced the highest production of both OTA and CIT, when P. verrucosum DAOMC 242724 was cultured in stationary mode. Shake culture significantly reduced the amounts of OTA and CIT produced. Among all culture conditions tested, far greater amounts of CIT were produced compared to OTA. Consequently, upon transcriptomic data analysis, a statistically significant increase in the expression of CIT biosynthetic genes was easier to detect than the expression of OTA biosynthetic genes. Our study also revealed that the putative biosynthetic gene clusters of OTA and CIT in P. verrusocum DAOMC 242724 are likely distinct from each other. It appears that despite sharing a highly similar structure, the isocoumarin rings of OTA and CIT are each assembled by a specialized polyketide synthase enzyme. Our data identified a putative nonreducing polyketide synthase responsible for assembling the carbo-skeleton of CIT. In contrast, a highly reducing polyketide synthase appears to be involved in the biosynthesis of OTA.

Correlation between electrical conductivity and antibacterial activity of chitosan-stabilized copper and silver nanoparticles

In this study chemical reduction method is used to synthesize the copper and silver nanoparticles. Chitosan was utilized as a stabilizing agent, a suitable medium for nanoparticle growth, and to stop the oxidation and aggregation of the particles. Various characterization such as FTIR Spectra, UV spectra, PL spectra, XRD, EDAX, TEM and Zeta potential approaches were used to examine the copper and silver nanoparticles. The antibacterial activity was assessed through the disc diffusion method. The antibacterial activity to the selected human pathogens, which included two bacterial pathogens such as S. pyogenes and K. pneumoniae as well as one fungal pathogen, Candida albicans . The size and shape of the synthesized CuNPs and AgNPs were evaluated using TEM. The average size distribution is 23.65 nm for CuNPs and 21.76 nm for AgNPs. Copper and AgNPs show antibacterial efficacy against two bacterial strains and a fungi strain. The AgNPs show significant antibacterial activity in comparison with the Chitosan and CuNPs.

Comparative analysis of cosmetic ingredient degradation: Fungal vs. bacterial activity in diverse media as potential replacements

The study explores the resilience of fungi and bacteria in degrading three selected cosmetic ingredients, butylated hydroxy anisole (BHA), benzophenone 3 (BZ3), and decamethylcyclopentasiloxane (D4), across different pH levels and temperatures. Understanding microbial adaptability and optimizing degradation conditions are crucial for effective biodegradation processes, given the influence of pH and temperature on microbial activity. Trametes versicolor and Pseudomonas aeruginosa were chosen as representative fungal and bacterial species for degradation studies, with synthetic wastewater utilized alongside traditional growth media. Our research pioneers the utilization of synthetic wastewater alongside traditional growth media, recognizing its untapped potential in enhancing degradation efficiency. By subjecting fungi to environmental stressors, we illuminate the adaptive strategies employed by these organisms, crucial for optimizing biodegradation processes. The hypothesis posited that synthetic wastewater would enhance degradation efficiency, while subjecting fungi to environmental stressors would elucidate their adaptability. Two temperatures (25 °C & 37 °C) and two pH levels (2.5 & 6.89) were examined to mimic real-world conditions, employing advanced techniques like Nuclear Magnetic Resonance (NMR) to assess degradation efficiency. Results revealed successful fungal degradation, particularly with complete D4 degradation in synthetic wastewater and partial degradation in PDB media at 25 °C. At 37 °C, complete BHA and BZ3 degradation occurred in PDB media, with higher rates in synthetic wastewater. However, bacterial degradation was incomplete, especially in synthetic wastewater. Leveraging synthetic wastewater as a medium for targeted degradation of multiple pollutants by specific microbial species represents an innovative advancement in biodegradation methodologies, highlighting the importance of microbial adaptability in biodegradation processes.

Antimicrobial activity of rambutan peel colouring agent containing cardamom oil in shrimp paste and its potential mode of action

SummaryRambutan peel (RP), an agricultural by‐product from rambutan trading, contains the red pigment anthocyanin. This research explores developing a colouring agent from RP, utilising cardamom oil (CM) to enhance colour stability, improve antimicrobial functionality, and create a new high‐value red colouring agent from fruit waste. A colouring agent was produced by placing 50 g of RP inside a 1 L glass box, and varying amounts of CM (5 μL, 25 μL, 50 μL, and 100 μL) on filter paper were placed inside the box lid. The box was sealed and left closed for 8 h to allow CM vapour to release onto the surface of RP before being dried at 30 °C and ground into powder. The antibacterial impact of CM‐treated RP on Staphylococcus aureus was assessed using the nutrient broth. The CM‐treated RP powder was used as a food colouring agent in shrimp paste to evaluate the shelf life of shrimp paste during storage at 30 °C. Results revealed that treated RP with 25 μL of CM showed the best red colour appearance in the dried powder. RP with 25 μL of CM exhibited time killing against S. aureus (approximately 4 log10cfu g−1) after being added to the medium for 6 h, disrupting the cell membrane integrity of S. aureus and leading to cell lysis. RP treated with 25 μL of CM also prevented darkening in shrimp paste, maintaining higher values for L* and a*, resulting in increased lightness and a more red appearance. It also inhibited pathogenic bacteria, extending shelf life, and preserving colour stability for 14 days, compared to the control's 7 days. These insights provide valuable guidance for the sustainable utilisation of agricultural waste in the food colouring industry.

Root uptake of umbelliferone enhances pea's resistance against root-knot nematodes

Coumarins are secondary plant metabolites which play a key role in plant–plant and plant–microbe interactions. In particular, they are highly involved in environmental stress responses. Coumarins can transfer from plants producing coumarins to non-coumarin-producing neighbouring plants. As in vitro studies have shown that coumarins are nematicidal, we hypothesized that this transfer may also result in enhanced resistance against plant parasitic nematodes in coumarin-receiving plants. To test if the uptake of coumarins in a non-coumarin- producing plant protects the plant against nematode attack, we incubated non-coumarin- producing pea seedlings in growth media with the coumarin umbelliferone for three weeks, after which the plants were transplanted into soil and inoculated with root-knot nematodes (Meloidogyne incognita). We quantified the coumarin content in pea organs and nematode root invasion 2, 4, and 6 weeks after transplantation. Umbelliferone was taken up by the pea roots and translocated to the shoots. As a result of metabolization, umbelliferone and its derived metabolites coumarin, scopoletin, and scopolin were detected in the plants. The root uptake of umbelliferone reduced root-knot nematode invasion significantly up to 4 weeks after the root exposure. Our results suggest that the root uptake and the transfer of bioactive compounds between plants can expand the understanding of plant–plant interactions.