Anthocyanin-Colored Microencapsulation Effects on Survival Rate of Lactobacillus rhamnosus GG, Color Stability, and Sensory Parameters in Strawberry Nectar Model

Probiotic microencapsulation is a promising way to produce functional food, while their stability and sensory acceptability still a challenge. This study aims to enhance the functional properties of strawberry (Fragaria × ananassa, cultivar Camarosa) nectar and sensory acceptance using novel anthocyanin-colored microencapsulation of Lactobacillus rhamnosus. Four formulations (F1–F4) of coated materials (alginate, whey protein, and pullulan) integrated with anthocyanin pigment were used for encapsulation. The physical properties of microencapsulated probiotics (size, color, efficiency, stability, and survival rate) and quality parameters of nectar (pH, anthocyanin, and sensory acceptability) during 4 weeks of storage at 4 and 25 °C were evaluated. All formulations exhibited high encapsulation efficiency (> 89%), medium bead size (406–504 μm), and proper color (red color). The microencapsulated cells were stable in simulated gastrointestinal and processing conditions (up 7 log10 CFU mL−1) compared to free cells. F4 (alginate 2% + anthocyanin 0.1% + whey protein 2% + pullulan 2% + cocoa butter 1% + L. rhamnosus GG) showed the greatest viability in nectar during storage (6.72 log10 CFU mL−1/4 °C/4 weeks), while a significant decrease in pH (< 2) and anthocyanin (< 60 mg 100 g−1) was observed in nectar-containing free cells. The sensory scores with a difference-preference test as exploratory and preliminary responses revealed that colored probiotic microcapsules enhanced the sensory characters (up to 4 weeks) and commercially accepted (> 80% agreed) of strawberry nectar. Results demonstrated that anthocyanin-colored alginate-whey protein-pullulan matrix had the potential to enhance probiotic viability in functional nectar without negative impact.

Stain-free nucleus identification in holographic learning flow cyto-tomography

Quantitative Phase Imaging (QPI) has gained popularity because it can avoid the staining step, which in some cases is difficult or impossible. However, QPI does not provide the well-known specificity to various parts of the cell (e.g., organelles, membrane). Here we show a novel computational segmentation method based on statistical inference that bridges the gap between the specificity of Fluorescence Microscopy (FM) and the label-free property of QPI techniques to identify the cell nucleus. We demonstrate application to stain-free cells reconstructed through the holographic learning and in flow cyto-tomography modality. In particular, by means of numerical simulations and two cancer cell lines, we demonstrate that the nucleus-like regions can be accurately distinguished within the stain-free tomograms. We show that our experimental results are consistent with confocal FM data and microfluidic cytofluorimeter outputs. This is a significant step towards extracting the three-dimensional (3D) intracellular specificity directly from the phase-contrast data in a typical flow cytometry configuration.

Harmful behaviour through plasmid transfer: a successful evolutionary strategy of bacteria harbouring conjugative plasmids

Conjugative plasmids are extrachromosomal mobile genetic elements pervasive among bacteria. Plasmids' acquisition often lowers cells' growth rate, so their ubiquity has been a matter of debate. Chromosomes occasionally mutate, rendering plasmids cost-free. However, these compensatory mutations typically take hundreds of generations to appear after plasmid arrival. By then, it could be too late to compete with fast-growing plasmid-free cells successfully. Moreover, arriving plasmids would have to wait hundreds of generations for compensatory mutations to appear in the chromosome of their new host. We hypothesize that plasmid-donor cells may use the plasmid as a ‘weapon’ to compete with plasmid-free cells, particularly in structured environments. Cells already adapted to plasmids may increase their inclusive fitness through plasmid transfer to impose a cost to nearby plasmid-free cells and increase the replication opportunities of nearby relatives. A mathematical model suggests conditions under which the proposed hypothesis works, and computer simulations tested the long-term plasmid maintenance. Our hypothesis explains the maintenance of conjugative plasmids not coding for beneficial genes. This article is part of the theme issue ‘The secret lives of microbial mobile genetic elements’.

Neuroprotective Effects of Microfluidic Encapsulated Induced Conjunctival Mesenchymal Stem Cells Through Autophagy Modulation in a Parkinsonian Model

Background and Aim: Parkinson's disease (PD) is a progressive neurodegenerative disorder in which cause is attributed to the alpha-synuclein (α-Syn) accumulation due to the decreases rated of autophagy. According to recent studies, cell therapy has been attracted much attention for PD treatment. Due to the many advantages mesenchymal stem cells (MSCs) have proposed, they have been considered a valuable resource for PD cell therapy. The present study aimed to investigate the therapeutic effect of Conjunctival MSCs (CJ-MSCs) on the autophagy manner and the expression of Mammalian target of rapamycin (mTOR), TH, and α-Syn in the parkinsonian rat model.Materials and Methods: our investigation has been performed using the Parkinson's model of rats. Stereotaxic 6-hydroxy dopamine (6-OHDA) was injected directly into the medial forebrain bundle (MFB) to induce Parkinson's disease. An apomorphine-induced rotation test was used to confirm the model establishment. CJ-MSCs were encapsulated in alginate microgel using a microfluidic system. The green fluorescent protein (GFP) labeled CJ-MSCs both encapsulated and free cells were transplanted into the rats' right striatum. Behavioral and molecular analyses have been carried out to evaluate the potency of CJ-MSCs (both encapsulated and free cells) on PD rats. The Rotation, Rotarod Open field test was recruited as the behavioral tests. Immunohistochemistry was used to determine the tyrosine hydroxylase (TH), and Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) has been performed for investigating the α-Syn and mTOR gene expression.Results: Our obtained results indicated that transplantation of CJ-MSCs leads to a decrease in the number of rotations while raising the balance and motor abilities. Immunohistochemistry analysis revealed an increase in the number of TH+ cells compared to the control group. The gene expression evaluation showed a significant reduction in mTOR and α-Syn mRNA levels than the control group. Our results also represented a significant difference between rats receiving encapsulated CJ-MSCs compared to the group received free CJ-MSCs.Conclusion: It seems that CJ-MSCs can promote the degradation of intracellular α-Syn by reducing mTOR and thus increase TH expression that led improve the motor functions of rats. Our results indicated the CJ-MSCs as a suitable source of MSCs to reduce PD complications.

Microencapsulation of Lactobacillus rhamnosus GG with Resistant Starch and Xanthan Gum

Microencapsulation is the most common method in improving probiotic survivability against adverse conditions. In this research, resistant starch was incorporated as prebiotic coating material during the microencapsulation of Lactobacillus rhamnosus GG (LGG) in calcium alginate beads coated with xanthan gum. Three types of microcapsules were produced: LGG only, LGG with resistant starch, and LGG with resistant starch and xanthan gum coating. The size and morphology of microcapsules were measured. Furthermore, the viability for free cells and microencapsulated LGG was tested in the simulated gastric juice (SGJ) (pH 2.0, 2 h) and simulated intestinal juice (SIJ) (pH 7.5, 4 h). The results indicated that 2.0 %(w/v) resistant starch and 0.3 %(w/v) xanthan gum had the highest microencapsulation efficiency (MEE). The morphology for microencapsulated LGG was spherical and white. The mean diameter for all 3 types of microcapsules was in between the range of 562.67 to 614.33 μm and xanthan gum-coated microcapsules had the highest MEE of 84.67 %. The addition of resistant starch and xanthan gum had increased the MEE for encapsulated probiotics. Both encapsulated LGG with and without xanthan gum coating had higher survivability than free cells, which indicated the positive role of resistant starch and xanthan gum in promoting the viability of probiotics during gastrointestinal transit. In general, co-extrusion encapsulation and the addition of resistant starch and xanthan gum coating could protect the viable LGG against the harsh human gastrointestinal condition. HIGHLIGHTS Microencapsulation of Lactobacillus rhamnosus GG using co-extrusion technique LGG encapsulated with resistant starch as wall material and xanthan gum coating Xanthan gum coated-LGG microbead displays highest microencapsulation efficiency Xanthan gum coated-LGG microbeads survives simulated gastrointestinal transit Co-extrusion technique had a positive impact on the viability of LGG GRAPHICAL ABSTRACT

Free Cells in Hyperspaces of Graphs

Often for understanding a structure, other closely related structures with the former are associated. An example of this is the study of hyperspaces. In this paper, we give necessary and sufficient conditions for the existence of finitely-dimensional maximal free cells in the hyperspace C(G) of a dendrite G; then, we give necessary and sufficient conditions so that the aforementioned result can be applied when G is a dendroid. Furthermore, we prove that the arc is the unique arcwise connected, compact, and metric space X for which the anchored hyperspace Cp(X) is an arc for some p∈X.