Compression Molded Soy Protein Films with Exopolysaccharides Produced by Cider Lactic Acid Bacteria

Genomic and functional evaluation of exopolysaccharide produced by Liquorilactobacillus mali t6-52: technological implications

BACKGROUND

This study explores the biosynthesis, characteristics, and functional properties of exopolysaccharide produced by the strain Liquorilactobacillus mali T6-52. The strain demonstrated significant EPS production with a non-ropy phenotype.

RESULTS

The genomic analysis unveiled genes associated with EPS biosynthesis, shedding light on the mechanism behind EPS production. These genes suggest a robust EPS production mechanism, providing insights into the strain's adaptability and ecological niche. Chemical composition analysis identified the EPS as a homopolysaccharide primarily composed of glucose, confirming its dextran nature. Furthermore, it demonstrated notable functional properties, including antioxidant activity, fat absorption capacity, and emulsifying activity. Moreover, the EPS displayed promising cryoprotective activities, showing notable performance comparable to standard cryoprotective agents. The EPS concentration also demonstrated significant freeze-drying protective effects, presenting it as a potential alternative cryoprotectant for bacterial storage.

CONCLUSIONS

The functional properties of L. mali T6-52 EPS reveal promising opportunities across various industrial domains. The strain's safety profile, antioxidant prowess, and exceptional cryoprotective and freeze-drying characteristics position it as an asset in food processing and pharmaceuticals.

Immunomodulatory activity and protective effect of a capsular polysaccharide in Caenorhabditis elegans, isolated from Lactobacillus fermentum GBJ

A capsular polysaccharide, namely CPS-2, was isolated from Lactobacillus fermentum GBJ, purified using DEAE-52 anion exchange chromatography, and structurally characterized. We found that CPS-2 is homogenous, has an average molecular weight of 377 KDa, and is mainly composed of galactose and glucose at a molar ratio of 1.54:1.00. Its backbone comprises α-D-Galp-(1 → 3), α-D-Galp-(1 → 3,6), β-D-Glcp-(1 → 2), β-D-Galp-(1 → 6), and α-D-Galp-(1 → 4) residues with a side chain of β-D-Glcp-(1→). CPS-2 exerts an immunomodulatory effect by improving the proliferation and phagocytosis of macrophage RAW264.7 and promoting the secretion of NO and cytokines. The maximum secretion levels of IL-1β, IL-6, IL-10, and TNF-α were 1.96-, 0.11-, 0.22-, and 0.46-fold higher than those of the control, respectively. Furthermore, CPS-2 could significantly enhance the antioxidant system, extend lifespan, and improve stress tolerance of Caenorhabditis elegans at both exposure doses of 31.25 and 62.5 μg/mL. The average lifespan of nematodes reached a maximum in the 62.5 μg/mL-treated group after 10.39 days, 6.56 h, and 23.56 h in normal, oxidative stress, and heat shock environment, with extension percentages of 16.61 %, 43.23 %, and 15.77 %, respectively; therefore, CPS-2 displays an anti-aging effect. The significant bioactivity of CPS-2 promotes its application as a promising immunomodulatory and anti-aging ingredient in the food or pharmaceutical field.

Unveiling the microbiome during post-partum uterine infection: a deep shotgun sequencing approach to characterize the dairy cow uterine microbiome

BACKGROUND

The goal of this study was to assess the microbial ecology and diversity present in the uterus of post-partum dairy cows with and without metritis from 24 commercial California dairy farms using shotgun metagenomics. A set subset of 95 intrauterine swab samples, taken from a larger selection of 307 individual cow samples previously collected, were examined for α and β diversity and differential abundance associated with metritis. Cows within 21 days post-partum were categorized into one of three clinical groups during sample collection: control (CT, n = 32), defined as cows with either no vaginal discharge or a clear, non-purulent mucus vaginal discharge; metritis (MET, n = 33), defined as a cow with watery, red or brown colored, and fetid vaginal discharge; and purulent discharge cows (PUS, n = 31), defined as a non-fetid purulent or mucopurulent vaginal discharge.

RESULTS

All three clinical groups (CT, MET, and PUS) were highly diverse, with the top 12 most abundant genera accounting for 10.3%, 8.8%, and 10.1% of mean relative abundance, respectively. The α diversity indices revealed a lower diversity from samples collected from MET and PUS when compared to CT cows. PERMANOVA statistical testing revealed a significant difference (P adjusted < 0.01) in the diversity of genera between CT and MET samples (R2 = 0.112, P = 0.003) and a non-significant difference between MET and PUS samples (R2 = 0.036, P = 0.046). ANCOM-BC analysis revealed that from the top 12 most abundant genera, seven genera were increased in the natural log fold change (LFC) of abundance in MET when compared to CT samples: Bacteroides, Clostridium, Fusobacterium, Phocaeicola, Porphyromonas, Prevotella, and Streptococcus. Two genera, Dietzia and Microbacterium, were decreased in natural LFC of abundance when comparing MET (regardless of treatment) and CT, while no changes in natural LFC of abundance were observed for Escherichia, Histophilus, and Trueperella.

CONCLUSIONS

The results presented here, are the current deepest shotgun metagenomic analyses conducted on the bovine uterine microbiome to date (mean of 256,425 genus-level reads per sample). Our findings support that uterine samples from cows without metritis (CT) had increased α-diversity but decreased β-diversity when compared to metritis or PUS cows, characteristic of dysbiosis. In summary, our findings highlight that MET cows have an increased abundance of Bacteroides, Porphyromonas, and Fusobacterium when compared to CT and PUS, and support the need for further studies to better understand their potential causal role in metritis pathogenesis.

Biopolymers Produced by Lactic Acid Bacteria: Characterization and Food Application

Plants, animals, bacteria, and food waste are subjects of intensive research, as they are biological sources for the production of biopolymers. The topic links to global challenges related to the extended life cycle of products, and circular economy objectives. A severe and well-known threat to the environment, the non-biodegradability of plastics obliges different stakeholders to find legislative and technical solutions for producing valuable polymers which are biodegradable and also exhibit better characteristics for packaging products. Microorganisms are recognized nowadays as exciting sources for the production of biopolymers with applications in the food industry, package production, and several other fields. Ubiquitous organisms, lactic acid bacteria (LAB) are well studied for the production of exopolysaccharides (EPS), but much less as producers of polylactic acid (PLA) and polyhydroxyalkanoates (PHAs). Based on their good biodegradability feature, as well as the possibility to be obtained from cheap biomass, PLA and PHAs polymers currently receive increased attention from both research and industry. The present review aims to provide an overview of LAB strains' characteristics that render them candidates for the biosynthesis of EPS, PLA, and PHAs, respectively. Further, the biopolymers' features are described in correlation with their application in different food industry fields and for food packaging. Having in view that the production costs of the polymers constitute their major drawback, alternative solutions of biosynthesis in economic terms are discussed.

Bionanocomposite Active Packaging Material Based on Soy Protein Isolate/Persian Gum/Silver Nanoparticles; Fabrication and Characteristics

In this study, nanocomposite active films were fabricated containing silver nanoparticles (SNPs) embedded within soy protein isolate (SPI)/Persian gum (PG) matrices. The physical, mechanical, and antibacterial properties of these composite films were then characterized. In addition, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were used to provide information about the microstructure, interactions, and crystallinity of the films. Pure SPI films had poor physicochemical attributes but the addition of PG (0.25, 0.5, or 1 wt%) improved their water vapor permeability, mechanical properties, and water solubility (WS). The moisture content (MC) of the films decreased after the introduction of PG, which was attributed to fewer free hydroxyl groups to bind to the water molecules. Our results suggest there was a strong interaction between the SPI and the PG and SNPs in the films, suggesting these additives behaved like active fillers. Optimum film properties were obtained at 0.25% PG in the SPI films. The addition of PG (0.25%) and SNPs (1%) led to a considerable increase in tensile strength (TS) and a decrease in elongation at break (EB). Furthermore, the incorporation of the SNPs into the SPI/PG composite films increased their antibacterial activity against pathogenic bacteria (Escherichia coli and Staphylococcus aureus), with the effects being more prominent for S. aureus. Spectroscopy analyses provided insights into the nature of the molecular interactions between the different components in the films. Overall, the biodegradable active films developed in this study may be suitable for utilization as eco-friendly packaging materials in the food industry.

A Brief Overview of Polymers Science and Technology, in Spain

This Special Issue State-of-the-Art on Polymer Science and Technology in Spain is comprised of a collection of 42 publications/contributions related to very different topics undertaken by the numerous research groups working in Spain in Polymer Science and Technology. This monograph collects the contributions of more than 200 different authors from 24 different national Institutions (>30 different centers/departments) from Universities and CSIC centers distributed throughout the whole of Spain. Two-thirds of the contributions to this Special Issue arise from Institutional collaborations, half of which are international collaborations with European research groups and the other half with other international research groups outside Europe including China, Australia or United States of America among others. This brief overview communication provides a general overview of the research lines in Polymer Science and Technology covered in Spain and show most of the representative polymer groups and their distribution throughout Spain. Most of Spanish polymer groups belong to the Grupo Especializado de Polímeros (GEP) being part of the European Polymer Federation (EPF). It also shows how Spanish science about polymers is positioned at European level.