Structural, extraction and safety aspects of novel alternative proteins from different sources

With rapid population growth and continued environmental degradation, it is no longer sustainable to rely on conventional proteins to meet human requirements. This has prompted the search for novel alternative protein sources of greater sustainability. Currently, proteins of non-conventional origin have been developed, with such alternative protein sources including plants, insects, algae, and even bacteria and fungi. Most of these protein sources have a high protein content, along with a balanced amino acid composition, and are regarded as healthy and nutritious sources of protein. While these novel alternative proteins have excellent nutritional, research on their structure are still at a preliminary stage, particularly so for insects, algae, bacteria, and fungi. Therefore, this review provides a comprehensive overview of promising novel alternative proteins developed in recent years with a focus on their nutrition, sustainability, classification, and structure. In addition, methods of extraction and potential safety factors for these proteins are summarized.

Unraveling the carbohydrate metabolic characteristics of Leuconostoc mesenteroides J18 through metabolite and transcriptome analyses

The metabolic characteristics of Leuconostoc mesenteroides subsp. mesenteroides J18, which is mainly responsible for kimchi fermentation, on various carbon sources were investigated through carbon utilization, metabolite, and transcriptome analyses at different culture conditions (10 and 30 °C with/without 2.5% NaCl). The metabolic features of strain J18 were relatively similar across the four culture conditions. However, the metabolic characteristics of strain J18 showed significant variations depending on the carbon source. These distinct metabolic traits of strain J18 on various carbon sources were validated through transcriptomic analyses and the reconstruction of metabolic pathways. The transcriptional expression of the metabolic pathways in response to each carbon source consistently correlated with the production profiles of metabolites, including ethanol, acetoin, diacetyl, and riboflavin, in each carbon source. Our findings suggests that the abundance of Leu. mesenteroides during fermentation and the taste and flavor of fermented food products can be controlled by altering the carbon sources.

Unveiling the performance of a novel alkalizing bacterium Enterobacter sp. LYX-2 in immobilization of available Cd

A novel alkalizing strain Enterobacter sp. LYX-2 that could resist 400 mg/L Cd was isolated from Cd-contaminated soil, which immobilized 96.05% Cd2+ from medium. Cd distribution analysis demonstrated that more than half of the Cd2+ was converted into extracellular precipitated Cd through mobilization of the alkali-producing mechanism by the strain LYX-2, achieving the high immobilization efficiency of Cd2+. Biosorption experiments revealed that strain LYX-2 had superior biosorption capacity of 48.28 mg/g for Cd. Pot experiments with Brassica rapa L. were performed with and without strain LYX-2. Compared to control, 15.92% bioavailable Cd was converted to non-bioavailable Cd and Cd content in aboveground vegetables was decreased by 37.10% with addition of strain LYX-2. Available Cd was mainly immobilized through extracellular precipitation, cell-surface biosorption and intracellular accumulation of strain LYX-2, which was investigated through Cd distribution, Scanning Electron Microscope and Energy-Dispersive X-ray Spectroscopy (SEM-EDS), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) analysis. In addition, the application of strain LYX-2 significantly promoted the growth of vegetables about 2.4-fold. Above results indicated that highly Cd-resistant alkalizing strain LYX-2, as a novel microbial passivator, had excellent ability and reuse value to achieve the remediation of Cd-contaminated soil coupled with safe production of vegetables simultaneously.

Protective mechanism of milk fat globule membrane proteins on Lactobacillus acidophilus CICC 6074 under acid stress based on proteomic analysis

The prerequisite for lactic acid bacteria to perform their probiotic function is that they could survive the acid-stressed environment of production and application. In this experiment, the protective mechanism of milk fat globule membrane (MFGM) proteins on lactic acid bacteria under acid stress was investigated. Scanning electron microscopy and fluorescence probe were used to analyze the condition of the acid-treated bacteria, which showed that MFGM proteins could enhance the survival ability of Lactobacillus acidophilus CICC 6074 under acid stress by maintaining cell morphology, elevating intracellular pH and H+-ATPase activity. Furthermore, Tandem Mass Tags (TMT) proteomic analysis revealed that MFGM protein could exert protective effects on L. acidophilus CICC 6074 by regulating amino acid metabolism, ATPase activity, peptidoglycan synthesis, gene repair and heritage, etc. The results will provide a new approach for the protection and development of functional lactic acid bacteria.

New insights into searching patulin degrading enzymes in Saccharomyces cerevisiae through proteomic and molecular docking analysis

Global warming has increased the contamination of mycotoxins. Patulin (PAT) is a harmful contaminant that poses a serious threat to food safety and human health. Saccharomyces cerevisiae biodegrades PAT by its enzymes during fermentation, which is a safe and efficient method of detoxification. However, the key degradation enzymes remain unclear. In this study, the proteomic differences of Saccharomyces cerevisiae under PAT stress were investigated. The results showed that the proteins involved in redox reactions and defense mechanisms were significantly up-regulated to resist PAT stress. Subsequently, molecular docking was used to virtual screen for degrading enzymes. Among 18 proteins, YKL069W showed the highest binding affinity to PAT and was then expressed in Escherichia coli, where the purified YKL069W completely degraded 10 μg/mL PAT at 48 h. YKL069W was demonstrated to be able to degrade PAT into E-ascladiol. Molecular dynamics simulations confirmed that YKL069W was stable in catalyzing PAT degradation with a binding free energy of - 7.5 kcal/mol. Furthermore, it was hypothesized that CYS125 and CYS101 were the key amino acid residues for degradation. This study offers new insights for the rapid screening and development of PAT degrading enzymes and provides a theoretical basis for the detoxification of mycotoxins.

Combined effects of cold and acid on dual-species biofilms of Pseudomonas fluorescens and Listeria monocytogenes under simulated chilled beef processing conditions

Interactions across bacterial species boundaries are usually influenced by environmental stresses, yet little has been evaluated regarding multifactorial stresses on the fate of dual-species biofilm formation in food industry. In this study, the processing conditions of chilled beef were established as a combination of cold and acid stresses (4 °C and pH 5.4), with pH 7.0 or 25 °C serving as the controls, to investigate the interaction of dual-species biofilm between Pseudomonas fluorescens and Listeria monocytogenes. Dual-species biofilms significantly increased biofilm formation at 72 h under the condition of 25°C-pH7.0 and 25°C-pH5.4 (P < 0.05). Compared with mono-species biofilms, the cell numbers of L. monocytogenes in dual-species biofilms were lower at 25 °C (P < 0.05), however, the adherent cells of L. monocytogenes was higher in dual-species biofilms at 4 °C (P < 0.05). Furthermore, the amount of extracellular polysaccharides and proteins secreted by single P. fluorescens biofilms at 4 °C was more than three times than those at 25 °C. The surface-enhanced Raman spectroscopy further profiled the variability of extracellular polymeric substances (EPS) composition. Additionally, RT-qPCR results revealed an upregulation of biofilm-related and genes in co-culture species. It provides valuable insights into the strategies for removing mixed biofilms under diverse stressful conditions in practical food processing.

Dellaglioa spp. an underestimated genus isolated from high-oxygen modified-atmosphere packaged meat

The genus Dellaglioa (D.) actually comprises two species, i.e., D. algida and the recently described species D. carnosa. Both species are adapted to cold and have been typically recovered from meat products. However, their importance has thus far been underestimated, since routine culture-based analysis failed to support their growth. Furthermore, their occurrence on meat packed under high-oxygen MA conditions (HiOx-MAP) is controversial because they have been described as being oxygen-sensitive. In this study, we focused on the targeted isolation of Dellaglioa spp. from HiOx-MAP meat samples and the characterization of our isolates regarding their adaption to HiOx-MAP conditions, their spoilage potential, as well as food safety aspects. We used a medium recently developed specifically for strains of this genus and investigated ten meat batches from seven different suppliers. Our study confirms that the occurrence of Dellaglioa spp. on HiOx-MAP meat is non-sporadic, reaching cell counts ranging from log10 5.8-7.1 CFU/cm2 at a late stage of chilled storage. Autochthonous Dellaglioa spp. and Leuconostoc (L.) gasicomitatum dominated the microbiota of the beef steaks with similar growth behavior. Our results suggest that Dellaglioa spp. benefits from the heme-dependent respiration of oxygen by L. gasicomitatum. Furthermore, whole genome analysis revealed the presence of genes predictively involved in oxidative stress defense, survival, and adaptation in meat environments. Moreover, we predict a weak aminogenic potential of D. algida strains. Tyramine production from tyrosine seems to be a species-specific characteristic of D. carnosa. The extent to which D. algida and D. carnosa occurrence is influenced by or even dependent on the composition of the entire microbiota remains to be investigated.

Chemical characterization, anti-struvite crystal, anti-inflammatory, analgesic, and antidepressant activities of Papaver rhoeas L. root and leaf extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Papaver rhoeas L. (P. rhoeas) is used to treat a wide range of pathologies. But there is no data on the anti-struvite, anti-inflammatory, analgesic, and anti-depressant effects of root and leaf extracts from this medicinal plant.

AIM OF THE STUDY

This study aimed to chemically characterize and determine the antidepressant, analgesic, anti-inflammatory, and anti-struvite activities of the root extract (RE) and leaf extract (LE) of P. rhoeas, a wild plant.

MATERIALS AND METHODS

The extraction of secondary metabolites and phytochemical screening were carried out using standard methods. The anti-struvite effect of our samples was assessed by Fourier transform infrared spectroscopy (FT-IR) and microscopic observation. For the anti-inflammatory impact, we used the carrageenan-induced paw edema technique in rats. To assess the analgesic effect of the extracts, we recorded the resulting abdominal contraction after intraperitoneal (IP) acetic acid injection. Finally, we assessed the antidepressant effect by conducting the Forced Swimming Test (FST).

RESULTS

Phytochemical screening results revealed the presence of phenols, flavonoids, saponins, tannins, coumarins, terpenoids, and alkaloids. Extraction results confirmed that our extracts were rich in secondary metabolites. Both P. rhoeas extracts limited struvite crystal development by reducing the size and number of crystals, as indicated by FT-IR analysis and microscopic observation. Additionally, the anti-struvite effects of the LE sample were greater than those of the RE sample. The results of the anti-inflammatory capacity of our extracts demonstrate the maximum inhibition of carrageenan-induced edema following 6 h (T6) of injection, ranging from 72.73 ± 7.7% for LE (400 mg/kg) to 95.45 ± 6.42% for the RE sample (400 mg/kg). On the other hand, the results for analgesic activity showed that the number of abdominal contractions in rats treated with RE and LE ranged from 11 ± 1.73 for RE (400 mg/kg) to 18 ± 1.50 for LE (200 mg/kg), while that of aspirin was 10.33 ± 0.57. Furthermore, the FST results show that the immobility time in rats treated with RE and LE varied from 91.98 ± 4.24 s for LE-treated rats (300 mg/kg) to 123.54 ± 7.83 s for RE-treated rats (150 mg/kg).

CONCLUSION

Based on these results, the roots and leaves of the studied plant can be considered a significant source of biologically active molecules for use in the pharmaceutical industry.

Buyang Huanwu Decoction alleviates blood stasis, platelet activation, and inflammation and regulates the HMGB1/NF-κB pathway in rats with pulmonary fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Qi deficiency and blood stasis are identified to be pathological factors of pulmonary fibrosis (PF) in traditional Chinese medicine (TCM) theory. Buyang Huanwu Decoction (BYHWD) is a traditional Chinese prescription ameliorating Qi deficiency and blood stasis.

AIM OF THE STUDY

The objective of this study was to investigate the anti-fibrosis effect of BYHWD and the potential molecular mechanism in rats.

MATERIALS AND METHODS

Bleomycin was used to construct PF rat models. 27 PF rats were randomly divided into three groups based on treatments: model group (saline solution, n = 9), low-dose BYHWD group (3.5 g/kg, n = 9), and high-dose BYHWD group (14.0 g/kg, n = 9). Moreover, 9 normal rats were used as the blank group. The blood viscosity, coagulation indexes (APTT, TT, PT, and FIB), platelet-related parameters (PLT, PDW, MPV, PCT, and PLCR), platelet microparticles (PMPs), and inflammatory factors (IL-2, IL-10, IL-1β, IL-6, IL-8, IL-17, IFN-γ, TNF-α, PAC-1, HMGB1, NF-κB, and TF) were determined. The lung tissue samples of rats were observed after hematoxylin-eosin (HE) staining. The full component analysis of the BYHWD extract was performed using the ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. The signaling pathway included into the study was selected on the basis of bioinformatics analysis and the results of the phytochemical analysis. The expression levels of genes and proteins involved in the selected signaling pathway were detected.

RESULTS

Compared to the blank group, the whole blood viscosity, PLR, PDW, MPV, PCT, PLCR, PMPs, and the levels of IL-1β, IL-6, IL-8, IL-17, TNF-α, PAC-1, HMGB1, NF-κB, and TF were increased, while the levels of IL-2 and IL-10 were decreased in the model group. Both low-dose BYHWD and high-dose BYHWD reversed these PF-induced effects in spite of the fact that low-dose BYHWD had no significant effect on the level of NF-κB. In addition, BYHWD ameliorated PF-induced inflammation in the rat lung tissue. The phytochemical analysis of the BYHWD extract combined with the bioinformatics analysis suggested that the therapeutical effect of BYHWD on PF was related to the HMGB1/NF-κB pathway, which consisted of NF-κB, IKBKB, ICAM1, VCAM1, HMGB1, and TLR4. Both RT-qPCR and western blot analyses showed that PF induced increases in the expression levels of NF-κB, ICAM1, VCAM1, HMGB1, and TLR4, but a decrease in the expression level of IKBKB. Moreover, both low-dose BYHWD and high-dose BYHWD exerted the opposite effects, and recovered the expression levels of NF-κB, ICAM1, VCAM1, HMGB1, TLR4, and IKBKB, despite the fact that low-dose BYHWD had no effects on the mRNA expression levels of NF-κB or TLR4.

CONCLUSIONS

In summary, BYHWD alleviated PF-induced blood stasis, platelet activation, and inflammation in the rats. Our study suggested BYHWD had a therapeutic effect on PF and was a good alternative for the complementary therapy of PF, and the potential molecular mechanism was modulation of HMGB1/NF-κB signaling pathway, and it needs further study.

Comparing the decay of human wastewater-associated markers and enteric viruses in laboratory microcosms simulating estuarine waters in a temperate climatic zone using qPCR/RT-qPCR assays

This study investigated the decay rates of wastewater-associated markers and enteric viruses in laboratory microcosms mimicking estuarine water environments in temperate Sydney, NSW, Australia using qPCR and RT-qPCR assays. The results demonstrated the reduction in concentrations of Bacteroides HF183, Lachnospiraceae Lachno3, cross-assembly phage (crAssphage), pepper mild mottle virus (PMMoV), human adenovirus (HAdV 40/41), and enterovirus (EV) over a span of 42 days under spring/summer temperatures, presence/absence of microbiota, and different light conditions. The study found that HF183, Lachno3, crAssphage, PMMoV, HAdV 40/41, and EV exhibited varying decay rates depending on the experimental conditions. The average T90 values ranged from a few days to several months, indicating the rapid decay or prolonged persistence of these markers and enteric viruses in the estuarine environment. Furthermore, the study examined the effects of indigenous microbiota and spring/summer temperatures on wastewater-associated markers and enteric viruses decay rates. It was found that the presence of microbiota and temperature significantly influenced the decay rates of HF183 and PMMoV. Additionally, the study compared the effects of artificial sunlight and spring/summer temperatures on marker decay rates. Bacterial markers decayed faster than viral markers, although among viral markers crAssphage decay rates were relatively faster when compared to PMMoV. The exposure to artificial sunlight significantly accelerated the decay rates of bacterial markers, viral markers, and enteric viruses. Temperature also had an impact on the decay rates of Lachno3, crAssphage, and HAdV 40/41. In conclusion, this study provides valuable insights into the decay rates of wastewater-associated markers and enteric viruses under different experimental conditions that mimicked temperate environmental conditions. The findings contribute to our understanding of the fate and persistence of these markers in the environment which is crucial for assessing and managing risks from contamination by untreated human wastewater.

Deciphering the complexes of zinc ions and hen egg white lysozyme: Instrumental analysis, molecular docking, and antimicrobial assessment

In the research presented in this manuscript, an intricate study has been carried out on the interaction of zinc ions with the hen egg white lysozyme (HEWL) protein. Utilizing a spectroscopic technique, the alterations that arise due to the binding of Zn2+ to the HEWL were scrutinized, underscoring the paramount significance of deprotonated carboxyl and thiol groups in the process of binding. The binding phenomena were substantiated using capillary electrophoresis integrated with inductively coupled plasma mass spectrometry (CE-ICP-MS). Further spectrometric assessments (MALDI-TOF MS and FT-ICR-MS) shed light on the direct interaction of zinc ions with the functional groups of the protein. Importantly, high-resolution FT-ICR-MS techniques elucidated the capability of a single protein molecule to bind to multiple zinc ions. The empirically derived spectroscopic data received additional confirmation via a molecular docking study of the Zn2+ binding process, which highlighted a substantial affinity between the predicted 3D model of zinc-lysozyme complexes. Predominantly, the interaction between the bound entities was observed at the cysteine residues. Lastly, the conducted antimicrobial tests revealed that the zinc-lysozyme complexes manifest an inhibitory effect against bacterial (E. coli and S. aureus) and yeast (C. albicans) strains.

An overview of the potential application of chitosan in meat and meat products

Chitosan is considered the second most ubiquitous polysaccharide next to cellulose. It has gained prominence in various industries including biomedicine, textile, pharmaceutical, cosmetic, and notably, the food industry over the last few decades. The polymer's continual attention within the food industry can be attributed to the increasing popularity of greener means of packaging and demand for foods incorporated with natural alternatives instead of synthetic additives. Its antioxidant, antimicrobial, and film-forming abilities reinforced by the polymer's biocompatible, biodegradable, and nontoxic nature have fostered its usage in food packaging and preservation. Microbial activity and lipid oxidation significantly influence the shelf-life of meat, resulting in unfavorable changes in nutritional and sensory properties during storage. In this review, the scientific studies published in recent years regarding potential applications of chitosan in meat products; and their effects on shelf-life extension and sensory properties are discussed. The utilization of chitosan in the form of films, coatings, and additives in meat products has supported the extension of shelf-life while inducing a positive impact on their organoleptic properties. The nature of chitosan and its compatibility with various materials make it an ideal biopolymer to be used in novel arenas of food technology.

Amino sugars influence Aspergillus fumigatus cell wall polysaccharide biosynthesis, and biofilm formation through interfering galactosaminogalactan deacetylation

Aspergillus fumigatus is a ubiquitous fungal pathogen responsible for a significant number of deaths annually due to invasive aspergillosis infection. While the utilization of diverse carbon sources, including amino sugars, has been explored in other fungi, its impact on A. fumigatus remains uncharted territory. In this study, we investigated A. fumigatus responses to glucose (Glc), glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) as carbon sources. GlcN inhibited growth, reduced sporulation and delayed germination, while GlcNAc had no such effects. Both amino sugars induced alterations in cell wall composition, leading to a reduction in glucan and galactomannan levels while increasing chitin and mannan content, rendering A. fumigatus susceptible to cell wall stress and osmotic stress. GlcN repressed biofilm formation via downregulation of galactosaminogalactan (GAG) cluster genes, notably agd3, which encodes a GAG-specific deacetylase. Moreover, GlcN increased biofilm susceptibility to echinocandins, suggesting its potential for enhancing the effectiveness of antifungal treatments. This study sheds light on the multifaceted effects of amino sugars on A. fumigatus, encompassing growth, cell wall biosynthesis, and biofilm formation, offering promising avenues for innovative aspergillosis treatment strategies.

Changes in arsenic mobility and speciation across a 2000-year-old paddy soil chronosequence

Rice accumulates arsenic (As) when cultivated under flooded conditions in paddy soils threatening rice yield or its safety for human consumption, depending on As speciation. During long-term paddy use, repeated redox cycles systematically alter soil biogeochemistry and microbiology. In the present study, incubation experiments from a 2000-year-old paddy soil chronosequence revealed that As mobilization and speciation also change with paddy soil age. Younger paddies (≤100 years) showed the highest total As mobilization, with speciation dominated by carcinogenic inorganic oxyarsenic species and highly mobile inorganic thioarsenates. Inorganic thioarsenates formed by a high availability of reduced sulfur (S) due to low concentrations of reducible iron (Fe) and soil organic carbon (SOC). Long-term paddy use (>100 years) resulted in higher microbial activity and SOC, increasing the share of phytotoxic methylated As. Methylated oxyarsenic species are precursors for cytotoxic methylated thioarsenates. Methylated thioarsenates formed in soils of all ages being limited either by the availability of methylated As in young soils or that of reduced-S in older ones. The present study shows that via a linkage of As to the biogeochemistry of Fe, S, and C, paddy soil age can influence the kind and the extent of threat that As poses for rice cultivation.

Smartphone-assisted fluorescence-based detection of sunrise-type smart amplification process and a 3D-printed ultraviolet light-emitting diode device for the diagnosis of tuberculosis

Accurate and rapid diagnosis of infectious diseases plays a key role in clinical practice, especially in resource-limited countries. In this study, we integrated sunrise-type smart amplification process (s-SmartAmp), a convenient and sensitive isothermal amplification method for nucleic acid, into a portable 3D-printed device equipped with smartphone-assisted image analysis capabilities to develop a novel fluorescence-based sensing system for the on-site diagnosis of tuberculosis (TB). To increase the efficiency of fluorescence (or Förster) resonance energy transfer, two types of sunrise probe systems were compared to detect the IS6110 DNA sequence of TB. Subsequently, linear regression was conducted to compare the performance of s-SmartAmp and loop-mediated isothermal amplification (LAMP). The results indicated that, compared with LAMP, s-SmartAmp yielded more stable and precise results with lower background interference and high linear correlation coefficients (R2 = 0.9994 and 1, respectively) for the FAM-TAMRA and FITC-BHQ-1 probe system. The detection time was 45 min with a detection limit of 10 fg/μL. To evaluate the performance of our proposed on-site sensing system, we used s-SmartAmp 3D-printed ultraviolet light-emitting diode device to test multiple clinical samples of TB. Our findings suggest that the proposed system has the potential to achieve accurate and rapid on-site diagnosis of TB.