BMC Biotechnology最新文献

The increasing demand for sustainable alternatives to conventional antifungal agents has prompted extensive research into the antifungal properties of plant essential oils (EOs). This study investigates the use of EOs mixture (Origanum vulgare, Moringa oleifera, and Cinnamomum verum) for controlling fungal deterioration in wall paintings at the archaeological Youssef Kamal Palace in Nag Hammadi, Egypt. Fungal isolates were collected from deteriorated wall paintings and identified using phenotypic and genotypic analyses. Aspergillus sp. was found to be the predominant species (50%), followed by Penicillium sp. (16.7%), Fusarium sp. (16.7%), and others. They were genetically identified to be Aspergillus oryzae, Aspergillus niger, Penicillium chrysogenum, Fusarium solani, Alternaria alternata, Botrytis cinerea, and Trichoderma viride. The antifungal activity of three individual oils (oregano, moringa and cinnamon) was evaluated against the most predominant A. niger strain. Out of the three oils, oregano oil showed the strongest antifungal effect with an inhibition zone diameter (IZD) of 4.5 cm followed by moringa (3.5 cm) and cinnamon (3.2 cm). A mixture design approach optimized the EOs combination, with the most effective composition being (44% oregano, 46% moringa, 10% cinnamon), yielding an IZD of 6.5 cm. The optimized EOs mixture demonstrated complete inhibition against all tested fungal strains. The minimal inhibitory concentration tests showed varying efficacies against different fungal strains, with MIC values ranging from 125 to 500 µg/mL. GC-MS analysis identified the major bioactive compounds: carvacrol (83.25%) in oregano, trans-13-octadecenoic acid (22.62%) in moringa, and cinnamaldehyde (24.42%) in cinnamon. Cytotoxicity testing on human skin fibroblasts (HSF) showed minimal toxicity of EOs mixture with 87.64% cell viability at 100 µg/ml. Colorimetric measurements revealed some colour changes in experimental painting samples, particularly with cinnamon oil on white pigment (ΔE = 9.64) and moringa oil on a yellow pigment (ΔE = 16.31). However, oregano oil consistently showed the least impact across all pigments. These findings demonstrate the potential of the EOs combination as an effective, eco-friendly approach to mitigating fungal deterioration in wall paintings, contributing to sustainable conservation strategies for cultural heritage preservation.

Background: Successful treatment of pathogenic bacteria like Enterobacter Cloacae with bacteriophage (phage) counteract some hindrance such as phage stability and immunological clearance. Our research is focused on the encapsulation of phage HK6 within chitosan nanoparticles.

Result: Encapsulation significantly improves stability, efficacy, and delivery of phages. Chitosan nanoparticles (CS-NPs) achieve a phage entrapment efficiency of 97%. Fourier-transform infrared spectroscopy (FT-IR) reveals shifts towards higher wavenumbers and a new peak, indicating amide bond formation and successful phage encapsulation. The average particle sizes for CS-NP and phage HK6 encapsulated CS-NPs were 180 ± 10 nm and 297 ± 18 nm, respectively. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses reveal that phage HK6 encapsulated CS-NPs are larger on average than CS-NPs, highlighting successful phage encapsulation. Encapsulated bacteriophages maintain its effectiveness at higher pH levels of 11 and 12. Both encapsulated and free bacteriophages are thermostable between 25 and 60 °C; while at higher temperatures (up to 80 °C), the encapsulated phage is thermally stable. Over four days, 70.57% of phages were released from encapsulated CS-NPs. Encapsulation of bacteriophage HK6 in CS-NPs enhances antibacterial activity within the first 2 h, compared to phage or nanoparticles alone.

Conclusion: This suggests that the phage HK6 encapsulated CS-NPs exhibit potentiality as biocontrol agents against resistant microorganisms offering an alternative to phage alone.

Background: With the growing interest in applying fermentation to seaweed biomasses, there is a need for fast and efficient selection of microbial strains that have the ability to 1) acidify quickly, 2) utilize seaweed constituents and c) exhibit some proteolytic activity. The present study aims to provide a fast methodology to screen large bacterial collections for potential applications in optimized seaweed fermentations, as well as investigate and assess the performance of a selected bacterial collection of the National Food Institute Culture Collection (NFICC) in seaweed fermentation. This approach is directed toward high-throughput (HT) methodologies, employing microwell assays for different phenotypical characteristics of lactic acid bacteria isolated from different sources. The overarching aim is the deeper understanding of the selection criteria when designing starter cultures for seaweed fermentation.

Results: By employing high-throughput analytical workflows, the screening processing time is minimized, and among the different strains from a well-characterized strain collection, it was possible to distinguish between strong acidifiers and to replicate similar results when the volumes were scaled from 96-well plates to lab-scale fermentations (40 mL) of whole seaweed. Lactiplantibacillus plantarum, Lacticaseibacillus paracasei and, to a lesser extent, Lacticaseibacillus rhamnosus were among the fastest strains to reach the lowest endpoint pH values (< 4.5) in less than 48 h. Although the results regarding proteolytic capacity were not sufficient to prove that the candidates can also provide some flavor generation by the cleavage of proteins, NFICC1746 and NFICC2041 exhibited potential in releasing free alanine, glutamate and asparate as free amino acids.

Conclusions: With the described methodology, a large number of terrestrial lactic acid bacteria (LAB) isolates were screened for their performance and possible application for fermentation of brown sewaeeds. With a a fast conversion of sugars to organic acids, three potential new plant-isolated strains from NFICC, specifically Lactiplantibacillus plantarum ssp. argentoratensis (NFICC983), Lacticaseibacillus paracasei (NFICC1746) and Lacticaseibacillus rhamnosus (NFICC2041), were identified as promising candidates for future synthetic consortia aimed at application in bioprocessed seaweed. The combination of such strains will be the future focus to further optimize robust seaweed fermentations.

Background: In this study, thermophilic pectinase-producing strains were isolated. Among all the isolates, strain No. 4 was identified as Aspergillus fumigatus BT-4 based on its morphology and 18 S rDNA analysis. This strain was employed to screen various fermentation media to enhance pectinase production. Pectinases are crucial enzymes with significant industrial applications, particularly in the food and textile industries. Identifying efficient pectinase producers and optimizing their production processes are essential for improving industrial applications.

Results: Maximum pectinase production was observed using 1% grapefruit peel in M5 media. Shake flask kinetics demonstrated the highest values of specific rate constant (qp), specific growth rate (µ), product yield coefficient (Y_p/x), volumetric rate of product formation (Q_p), and biomass formation (Q_x) after 72 h of incubation. Furthermore, Optimization of fermentation components via Response Surface Methodology (RSM) improved pectinase production by 50%, showcasing the effectiveness of factorial and central composite designs in fine-tuning parameters. The use of agricultural waste (grapefruit peel) significantly reduced production costs, offering an economically viable substrate alternative. The pectinase enzyme was purified through ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography, resulting in a 2.3-fold purification. The molecular weight of the purified enzyme was determined to be 48 kDa. Enzyme kinetics, determined using a Lineweaver-Burk plot at various pectin concentrations, showed a V_max of 32.7 UmL^- 1 and a K_m of 0.3 mg mL^- 1. Thermodynamic parameters, including activation energy (Ea), enthalpy (ΔH), and entropy (ΔS), were measured at 41.74 kJmol^- 1, 39.53 kJmol^- 1, and 46.9 kJmol^- 1, respectively.

Conclusions: The study successfully isolated and identified Aspergillus fumigatus BT-4 as a potent thermophilic pectinase producer. Optimization of the fermentation process using 1% grapefruit peel in M5 media significantly enhanced pectinase production. Using grapefruit peel as an agricultural waste in pectinase production reduces costs by eliminating the need for expensive raw materials and utilizing a low-cost, sustainable, and locally available substrate. This approach also minimizes waste disposal expenses, making the process more economical. The enzyme was effectively purified, and its kinetic and thermodynamic properties were thoroughly characterized, revealing its potential for industrial applications. The comprehensive analysis of production kinetics and optimization strategies provides a robust foundation for scaling up pectinase production, contributing to more efficient and cost-effective industrial processes.

Introduction: Breast cancer, a formidable global health challenge for women, necessitates innovative therapeutic strategies with enhanced efficacy and minimal side effects. Aripiprazole (ARI), a widely used schizophrenia medication, exhibits promising potential in the treatment of breast cancer. As cancer therapy evolves towards a combination approach, multimodal nano-based delivery systems, such as ARI-loaded niosomes (NIOs) combined with Chitosan-Au nanoparticles for chemo-photothermal therapy, show promise over traditional chemotherapy alone by enhancing targeted efficacy and minimizing side effects.

Methods: In this study, a niosomal formulation was designed, incorporating ARI and chitosan-coated AuNPs (i.e. NIOs/AuNPs-CS/ARI), to study the synergistic effect of photothermal/chemotherapy in breast cancer cells.

Results: The nanosystems were characterized using UV-Vis spectroscopy and Fourier-transform infrared spectroscopy (FT-IR), confirming the successful synthesis steps. The hydrodynamic diameter of NIOs/AuNPs-CS was determined to be 44.62 nm with a zeta potential of -0.836. Also, Transmission Electron Microscopy (TEM) and Field-Emission Scanning Electron Microscopical (FE-SEM) analysis were performed to assess the size and morphology of NPs. The loading efficiency of ARI in NIOs and NIOs/AuNPs-CS was 75% and 88%, respectively. Furthermore, the release rate of the drug from NIOs/AuNPs-CS is higher than blank NIOs at two pH values (5.8 and 7.4). The cellular uptake of AuNPs-CS-encapsulated NIOs was considerably higher than that of blank NIOs. The Annexin V/PI staining assay showed that the apoptosis/necrosis rate was high in NIOs/AuNPs-CS/ARI (46%) and NIOs/ARI (36%) in 48 h. The results of MTT assessments demonstrated higher cytotoxicity by ARI-loaded NPs. The viability of MCF-7 cells treated with NIOs/AuNPs-CS/ARI was reduced from 60% and 50% to 40% and 20%, respectively, after 24 and 48 h upon laser irradiation.

Conclusion: The results of this experiment demonstrated the remarkable effectiveness of NIOs/AuNPs-CS/ARI in cancer treatment, owing to their unique properties, including the PTT capability and pH sensitivity.

Bacteria communicate through the accumulation of autoinducer (AI) molecules that regulate gene expression at critical densities in a process called quorum sensing (QS). Extensive work using simple systems and single strains of bacteria have revealed a role for QS in the regulation of virulence factors and biofilm formation; however, less is known about QS dynamics among communities, especially in vivo. In this review, we summarize the diversity of QS signals as well as their ability to influence "non-target" behaviors among species that have receptors but not synthases for those signals. We highlight host-microbe interactions facilitated by QS and describe cross-talk between QS and the mammalian endocrine and immune systems, as well as host surveillance of QS. Further, we describe emerging evidence for the role of QS in non-infectious, chronic, microbially associated diseases including inflammatory bowel diseases and cancers. Finally, we describe potential therapeutic approaches that involve leveraging QS signals as well as quorum quenching approaches to block signaling in vivo to mitigate deleterious consequences to the host. Ultimately, QS offers a previously underexplored target that may be leveraged for precision modification of the microbiota without deleterious bactericidal consequences.

This study investigated the ability of Phyllanthus emblica encapsulated within chitosan-coated casein (CS-casein-Amla) nanoparticles to inhibit the growth of multi-drug-resistant Pseudomonas aeruginosa (P. aeruginosa) bacteria and prevent the formation of biofilms. The MDR strains underwent screening, and the morphological characteristics of the resulting nanoparticles were assessed using SEM, DLS, and FTIR. In addition, the efficacy of encapsulation, stability, and drug release were evaluated. The PpgL, BdlA, and GacA biofilm gene transcription quantities were quantified by quantitative real-time PCR. Simultaneously, the nanoparticles were assessed for their antibacterial and cytotoxic effects using the well diffusion and MTT procedures. CS-casein-Amla nanoparticles with a size of 500.73 ± 13 nm, encapsulation efficiency of 76.33 ± 0.81%, and stability for 60 days at 4 °C (Humidity 30%) were created. The biological analysis revealed that CS-casein-Amla nanoparticles exhibited strong antibacterial properties. This was shown by their capacity to markedly reduce the transcription of PpgL, BdlA, and GacA biofilm genes at a statistically significant value of p ≤ 0.01. The nanoparticles demonstrated decreased antibiotic resistance compared to unbound Amla and CS-casein. Compared to Amla, CS-casein-Amla nanoparticles showed very little toxicity against HDF cells at dosages ranging from 1.56 to 100 µg/mL (p ≤ 0.01). The results highlight the potential of CS-casein-Amla nanoparticles as a significant advancement in combating highly resistant P. aeruginosa. The powerful antibacterial properties of CS-casein-Amla nanoparticles against P. aeruginosa MDR strains, which are highly resistant pathogens of great concern, may catalyze the development of novel antibacterial research approaches.

Background: False flax, or gold-of-pleasure (Camelina sativa) is an oilseed that has received renewed research interest as a promising vegetable oil feedstock for liquid biofuel production and other non-food uses. This species has also emerged as a model for oilseed biotechnology research that aims to enhance seed oil content and fatty acid quality. To date, a number of genetic engineering and gene editing studies on C. sativa have been reported. Among the most common targets for this research are genes, encoding fatty acid desaturases, elongases, and diacylglycerol acyltransferases. However, the majority of these genes in C. sativa are present in multiple copies due to the allohexaploid nature of the species. Therefore, genetic manipulations require a comprehensive understanding of the diversity of such gene targets.

Results: Here we report the detailed analysis of FAD2, FAD3 and FAE1 gene diversity in five Camelina species, including hexaploid C. sativa and four diploids, namely C. neglecta, C. laxa, C. hispida var. hispida and var. grandiflora. It was established that FAD2, FAD3 and FAE1 homeologs in C. sativa retain very high conservancy, despite their allohexaploid inheritance. High sequence conservancy of the identified genes along with their different expression patterns in C. sativa suggest that subfunctionalization of these homeologs is mainly grounded on the transcriptional balancing between subgenomes. Finally, fatty acid composition of seed lipids in different Camelina species was characterized, suggesting potential variability in the activity of fatty acid elongation/desaturation pathways may vary among these taxa.

Conclusion: It was shown that the FAD2, FAD3 and FAE1 genes retain high conservation, even in allohexaploid C. sativa after polyploidzation, in which the subfunctionalization of the described homeologs is mainly grounded on the expressional differences. The major differences in FA accumulation patterns within the seeds of different species were identified as well. These results provide a foundation for future precise gene editing, which would be based on targeting of particular FAD2, FAD3 and FAE1 gene copies in C. sativa that allow regulating the dosage of the mentioned genes, thus shaping the desired FA composition in cultivated false flax.

Background: Aiming at the problem that traditional transfer methods are prone to lose data information in the overall domain-level transfer, and it is difficult to achieve the perfect match between source and target domains, thus reducing the accuracy of the soft sensor model.

Methods: This paper proposes a soft sensor modeling method based on the transfer modeling framework of substructure domain. Firstly, the Gaussian mixture model clustering algorithm is used to extract local information, cluster the source and target domains into multiple substructure domains, and adaptively weight the substructure domains according to the distances between the sub-source domains and sub-target domains. Secondly, the optimal subspace domain adaptation method integrating multiple metrics is used to obtain the optimal projection matrices $W_s$ and $W_t$ that are coupled with each other, and the data of source and target domains are projected to the corresponding subspace to perform spatial alignment, so as to reduce the discrepancy between the sample data of different working conditions. Finally, based on the source and target domain data after substructure domain adaptation, the least squares support vector machine algorithm is used to establish the prediction model.

Results: Taking Pichia pastoris fermentation to produce inulinase as an example, the simulation results verify that the root mean square error of the proposed soft sensor model in predicting Pichia pastoris concentration and inulinase concentration is reduced by 48.7% and 54.9%, respectively.

Conclusion: The proposed soft sensor modeling method can accurately predict Pichia pastoris concentration and inulinase concentration online under different working conditions, and has higher prediction accuracy than the traditional soft sensor modeling method.