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With the industrialization and development of modern science, the application of enzymes as green and environmentally friendly biocatalysts in industry has been increased widely. Among them, lipase (EC. 3.1.1.3) is a very prominent biocatalyst, which has the ability to catalyze the hydrolysis and synthesis of ester compounds. Many lipases have been isolated from various sources, such as animals, plants and microorganisms, among which microbial lipase is the enzyme with the most diverse enzymatic properties and great industrial application potential. It therefore has promising applications in many industries, such as food and beverages, waste treatment, biofuels, leather, textiles, detergent formulations, ester synthesis, pharmaceuticals and medicine. Although many microbial lipases have been isolated and characterized, only some of them have been commercially exploited. In order to cope with the growing industrial demands and overcome these shortcomings to replace traditional chemical catalysts, the preparation of new lipases with thermal/acid-base stability, regioselectivity, organic solvent tolerance, high activity and yield, and reusability through excavation and modification has become a hot research topic. [ABSTRACT FROM AUTHOR]

Cinnamomum camphora seed kernels (CCSKs) are rich in phytochemicals, especially plant extracts. Phytochemicals play a vital role in therapy due to their strong antioxidant and anti-inflammatory activities. Extracts from CCSK can be obtained through multiple steps, including pretreatment, extraction and purification, and the purpose of pretreatment is to separate the oil from other substances in CCSKs. However, C. camphora seed kernel extracts (CKEs) were usually considered as by-products and discarded, and their potential bioactive values were underestimated. Additionally, little has been known about the effect of pretreatment on CKE. This study aimed to investigate the effects of pretreatment methods (including the solvent extraction method, cold pressing method, aqueous extraction method and sub-critical fluid extraction method) on the extraction yields, phytochemical profiles, volatile compounds and antioxidant capacities of different CKE samples. The results showed that the CKE samples were rich in phenolic compounds (15.28–20.29%) and alkaloids (24.44–27.41%). The extraction yield, bioactive substances content and in vitro antioxidant capacity of CKE pretreated by the sub-critical fluid extraction method (CKE-SCFE) were better than CKEs obtained by other methods. CKE pretreated by the solvent extraction method (CKE-SE) showed the best lipid emulsion protective capacity. Moreover, the volatile substances composition of the CKE samples was greatly influenced by the pretreatment method. The results provided a fundamental basis for evaluating the quality and nutritional value of CKE and increasing the economic value of by-products derived from CCSK. [ABSTRACT FROM AUTHOR]

Obesity can be associated with significant metabolic disorders. Our previous study found that medium-chain triglycerides (MCTs) improved lipid metabolism in obese rats. However, scant attention has been given to exploring the impact of MCTs on glucose metabolism in obese rats. This study is designed to examine the effects and mechanisms of three distinct MCTs on glucose metabolism in obese rats. To induce obesity, Sprague–Dawley (SD) rats were fed a high-fat diet, followed by a 12-week treatment with caprylic triglyceride (CYT), capric triglyceride (CT), and lauric triglyceride (LT). The results showed that three types of MCT intervention reduced the levels of lipids (TC, TG, LDL-c, and HDL-c), hyperglycemia, insulin resistance (insulin, OGTT, HOMA-IR, and ISI), and inflammatory markers (IL-4, IL-1β, and TNF-α) in obese rats (p < 0.01), The above parameters have been minimally improved in the high-fat restoring group (HR) group. MCTs can modulate the PI3K/AKT signaling pathways to alleviate insulin resistance and improve glucose metabolism in obese rats. Furthermore, MCTs can activate peroxisome proliferator-activated receptor (PPAR) γ and reduce the phosphorylation of PPARγser237 mediated by CDK5, which can improve insulin sensitivity without lipid deposition in obese rats. Among the MCT group, CT administration performed the best in the above pathways, with the lowest blood glucose level and insulin resistance. These findings contribute to a deeper understanding of the connection between health benefits and the specific type of MCT employed. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of mutating the consensus pentapeptide on the enzymatic properties and structural characteristics of Bacillus licheniformis lipase. Site-directed mutagenesis was used to construct mutants and then expressed in Escherichia coli BL21. After purification and enzyme activity analysis, only A75C and A75G retained activity. Compared to the wild-type lipase and A75G, the A75C showed higher thermostability at 40°C and better alkali resistance in pH 9.0–10.0 after incubation for 1 h. The kinetic parameters, structural characteristics and surface hydrophobicity of the lipases were determined. The results indicated that the secondary structure was hardly changed, while mutants exhibited higher activity, thermostability and hydrophobicity. Finally, the reasons for the increased enzyme activity were conducted through molecular dynamics simulation. The strategy of mutating the first residue of the lipase consensus pentapeptide may provide new insights into the enzyme engineering for industrial applications. [ABSTRACT FROM AUTHOR]

Cinnamomum camphora (camphor tree) is an important non-conventional edible plant species found in East Asia. Here, a detailed characterization for the chemical composition and nutritional value of C. camphora seed kernels (CCSKs) collected from different regions in China is provided. The results showed that there were significant differences among the CCSK samples in weights (1000 fruits, 1000 seeds and 1000 kernels), proximate composition, minerals, phenolics, flavonoids and amino acid contents. The highest contents of oil (62.08%) and protein (22.17%) were found in the CCSK samples collected from Chongqing and Shanghai, respectively. The highest content of mineral in the CCSK samples was K (4345.05–7186.89 mg/kg), followed by P (2735.86–5385.36 mg/kg), Ca (1412.27–3327.37 mg/kg) and Mg (2028.65–3147.32 mg/kg). The CCSK sample collected from Guizhou had the highest levels of total phenolic and flavonoid contents (TPC and TFC), while that from Chongqing had the lowest levels. In addition, the most abundant fatty acid in the CCSK samples was capric acid (57.37–60.18%), followed by lauric acid (35.23–38.29%). Similarities in the fatty acid composition among the CCSK samples were found. The CCSK sample collected from Guizhou had the highest percentage (36.20%) of essential amino acids to total amino acids, and Chongqing had the lowest value (28.84%). These results indicated that CCSK may be developed as an excellent source of plant-based medium-chain oil, protein, dietary fiber, minerals, phytochemicals and essential amino acids. [ABSTRACT FROM AUTHOR]

In this paper, magnetorheological (MR) porous fabric composites were prepared by using non-woven fabrics pretreated with lithium stearate. Due to the porous structure of non-woven fabric and the good stability of lithium stearate, the mechanical properties and sedimentation stability of the composite have been improved. The viscosity, shear stress and dynamic viscoelasticity of different samples were analyzed by rheological properties tests. The results indicate that the mechanical properties of the composite samples containing lithium stearate are improved compared with the MRF (magnetorheological fluid) sample, and its sedimentation stability under non-working conditions is also improved. However, with the increase of lithium stearate content, the improving effect of material performance gradually decreased. The experimental results show that when the magnetic flux density is 0.31 T, the shear stress of the MR porous fabric composite with 1 wt% lithium stearate is about 27 kPa, which increases by 51.1% compared with the MRF sample. [ABSTRACT FROM AUTHOR]

The Cinnamomum camphora seed kernel (CCSK), with high contents of medium-chain oil (~59%) and protein (~19%), is an excellent source for a plant-based food ingredient. To broaden the application of the protein isolate (PI) from CCSK in the food industry, the Maillard reaction products (MRPs) were prepared by PI and dextran (DX) under mild wet-heating conditions (60 °C, 5 h), and the structural and functional properties of the PI-DX conjugates were investigated. The covalent bond between PI and DX was confirmed by the degree of grafting and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Compared with the heated PI, the PI-DX conjugates had more ordered structure, with the decreased random coil content. The changes in tertiary structure of PI-DX conjugates were reflected by the results of intrinsic fluorescence and surface hydrophobicity. Moreover, PI-DX conjugates showed better solubility, emulsifying properties, thermal stability and antioxidant activities. These results provided a theoretical basis for the development of PI-based MRPs with desirable characteristics. [ABSTRACT FROM AUTHOR]

A novel lipase, SCNL, was isolated from Staphylococcus caprae NCU S6 strain in the study. The lipase was purified to homogeneity with a yield of 6.13% and specific activity of 502.76 U/mg, and its molecular weight was determined to be approximately 87 kDa. SCNL maintained above 80% of its initial activity at a wide range of temperatures (20–50 °C) and pH values (6–11), with an optimal temperature at 40 °C and optimal pH at 9.0 with p-nitrophenyl palmitate as a substrate. SCNL exhibited a higher residual activity than the other staphylococcal lipases in the presence of common enzyme inhibitors and commercial detergents. The lipase activity was enhanced by organic solvents (isooctane, glycerol, DMSO and methanol) and metal ions (Na+, Ba2+, Ca2+, and Mn2+). The Km and Vmax values of SCNL were 0.695 mM and 262.66 s−1 mM−1, respectively. The enzyme showed a preference for p-NP stearate, tributyrin and canola oil. These biochemical features of SCNL suggested that it may be an excellent novel lipase candidate for industrial and biotechnological applications. [ABSTRACT FROM AUTHOR]

Based on high-performance liquid chromatography-mass spectrometry (HPLC-MS) and reversed-phase high-performance liquid chromatography-mass spectrometry (RPLC-MS), the changes of drug metabolism and endogenous metabolites in normal rats and tumor model rats were studied by drug metabonomics. The changes of vital signs were used to evaluate the toxicity and pharmacological effects of the new anti-cancer candidate ST on rats, and the differences of endogenous metabolites caused by ST were analyzed by multivariate statistical method. The changes of endogenous metabolites related to ST toxicity and pharmacological effects were analyzed. Studies have shown that the correlation analysis of metabonomics based on metabonomics and changes of animal signs is helpful to screen endogenous metabolites related to drug toxicity and pharmacological effects. [ABSTRACT FROM AUTHOR]

Enzymatic degradation has become the most promising approach to degrading organic ester compounds. In this study, Bacillus licheniformis NCU CS-5 was isolated from the spoilage of Cinnamomum camphora seed kernel, and its extracellular lipase was purified, with a specific activity of 192.98 U/mg. The lipase was found to be a trimeric protein as it showed a single band of 27 kDa in SDS-PAGE and 81 kDa in Native-PAGE. It was active in a wide range of temperatures (5–55 °C) and pH values (6.0–9.0), and the optimal temperature and pH value were 40 °C and 8.0, respectively. The enzyme was active in the presence of various organic solvents, metal ions, inhibitors and surfactants. Both crude and purified lipase retained more than 80% activity after 5 h in the presence of commercial detergents, suggesting its great application potential in detergent industry. The highest activity was found to be towards medium- and long-chain fatty acids (C 6 -C 18). Peptide mass spectrometric analysis of the purified lipase showed similarity to the lipase family of B. licheniformis. Furthermore, it degraded more than 90% 2,4-D butyl ester to its hydrolysate 2,4-D within 24 h, indicating that the novel lipase may be applied to degrade organic ester pesticides. • A lipase-producing strain B. licheniformis NCU CS-5 was firstly isolated. • A novel alkaline, cold adaptive and organic solvent tolerant lipase was purified. • The lipase preferred triacylglycerols with medium- and long-chain fatty acids. • The lipase was stable in commercial detergents at 5 °C and 25 °C. • The lipase efficiently degraded 2,4-D butyl ester. [ABSTRACT FROM AUTHOR]

Escherichia coli O157:H7 and Salmonella Typhimurium are both foodborne pathogens commonly found in contaminated chicken meat. In this study, the combined effects of monocaprin and thymol, carvacrol, citral, and cinnamaldehyde against both pathogens were investigated to evaluate their effects in chicken meat preservation. Among the combinations, only the combination of monocaprin and carvacrol exhibited distinct synergistic effects on both pathogens in vitro. This combination showed a stronger synergistic biofilm inhibition and bactericidal effect than monocaprin or carvacrol alone. SEM and TEM microscopy showed that the combined treatment synergistically damaged the morphology of E. coli O157:H7 and S. Typhimurium. DAPI/SYTOX Green double-staining, outer and inner membrane permeability, membrane potential, and reactive oxygen species (ROS) generation experiments were performed to further assess the synergistic action. Results indicated that carvacrol rapidly increased the outer membrane permeability, allowing monocaprin to enter the cell of both pathogens, and damage the plasma membrane, and monocaprin increased the ROS accumulation effect of carvacrol, resulting in cell death. Monocaprin and carvacrol also showed synergistic effect on retarding the growth of E. coli O157:H7 and S. Typhimurium in chicken breast meat during storage at 4 °C. Besides, the results of sensory evaluation, including appearance, odor, firmness and overall acceptance, showed that the combined treatment reduced deterioration of the sensory properties of chicken breast meat. These findings suggest that this combination may be used as a novel approach to the preservation of chicken meat. • Monocaprin and carvacrol exhibited synergistic effect on E. coli O157:H7 and S. typhimurium. • This combination inhibited biofilm formation and rapidly inactivated cell counts. • Carvacrol induces monoocaprin entry into cells by increasing OM permeability. • Monocaprin intensified the ROS accumulation effect of carvacrol. • This combination can be used as a natural alternative for the preservation of chicken meat. [ABSTRACT FROM AUTHOR]

In this study, the antibacterial activity of monocaprin against Gram-negative foodborne pathogens and its underlying mechanism against E. coli were investigated. It was found that monocaprin exerted excellent antibacterial effects on E. coli , Vibrio parahaemolyticus and Shigella dysenteriae with the minimum inhibitory concentration/minimum bactericidal concentration values of 1.25 mM, 0.625 mM and 0.625 mM, respectively. The results of growth curve and time-kill assay showed that monocaprin could not only delay the growth of E. coli , but quickly inactivate the cells within 15 min. The effects of monocaprin on membrane integrity, inner and outer membrane permeability, proton motive force, and its interaction with model membranes and cell morphology were investigated to explore the antibacterial mechanism of monocaprin. The results indicated that monocaprin rapidly inactivated E. coli by penetrating its outer membrane, then destroying the phospholipid bilayer structure of the inner membrane, as well as dissipating the proton motive force, resulting in increases of the permeability of the outer and inner membranes and leakage of intracellular substances. Besides, monocaprin significantly reduced the viability of E. coli in apple and carrot juices at 4 °C and 25 °C without changing their sensory properties. • Monocaprin effectively inhibited E. coli , V. parahaemolyticus and S. dysenteriae. • Monocaprin rapidly inactivated of E. coli within 15 min by targeting cell membrane. • Monocaprin destroyed cytoplasmic membrane and dissipated the proton motive force. • Monocaprin increased the inner and outer membrane permeability of E. coli. • Monocaprin may be useful as a potent preservative for preventing E. coli in apple and carrot juices. [ABSTRACT FROM AUTHOR]

The application of dodecyl gallate (DG) is limited due to its poor stability and water-solubility. A new compound of DG microencapsulated with methyl-β-cyclodextrin (MβCD), MβCD-DG was produced, and the inhibition effects of MβCD-DG against three common foodborne pathogens (Staphylococcus aureus , Bacillus cereus and Bacillus subtilis) were investigated in the study. The antioxidant activity of MβCD-DG was determined by the DPPH method (EC 50 = 4.515 ± 0.5 μg/mL). The minimum inhibitory concentration (MIC) of MβCD-DG against these bacteria were 0.11, 0.06 and 0.06 mg/mL, and minimum bactericidal concentration (MBC) were 0.22, 0.11 and 0.11 mg/mL, respectively. The MICs remained steady under different pH values (3.0–9.0) and temperatures (4 and 25 °C), indicating that the anti-bacterial effect of MβCD-DG was independent of pH and temperature. Measurements of permeability of cell wall and membrane, membrane potential, release of cellular contents and observation of cell morphology were carried out to explore the antibacterial mechanism of MβCD-DG. The results indicated that MβCD-DG inhibited S. aureus by increasing the permeability of cell membrane and leakage of cellular contents without obvious cell morphological changes. MβCD-DG may kill B. cereus and B. subtilis by damaging the cell wall and cytoplasmic membrane to make the release of cellular contents. As a novel preservative, MβCD-DG is more efficient than DG and common chemical additives, and is thus worthy of further exploitation in food industry. • The MICs of dodecyl gallate microcapsule against S. aureus , B. cereus and B. subtilis remained constant from pH 4.0 to 9.0. • Dodecyl gallate microcapsule may be used as a novel preservative to daily foods at different temperatures. • Dodecyl gallate microcapsule killed B. cereus and B. subtilis by diffusion across the cell wall and plasma membrane. • Dodecyl gallate microcapsule inhibited S. aureus by increasing the permeability of the cell membrane. [ABSTRACT FROM AUTHOR]

In this study, protein isolate (PI) and protein-phenolic complex (PPC) were prepared from Cinnamomum camphora seed kernel (CCSK). The effects of naturally present phenolic compounds on the structural characteristics, functional properties and antioxidant activities of CCSK protein before and after hydrolysis by Alcalase were evaluated. The formation of PPC was confirmed by the ultraviolet–visible and intrinsic fluorescence spectra. The resultant PPC hydrolysates (PPHs) had higher degree of hydrolysis values than PI hydrolysates (PHs). Fourier transform infrared spectroscopy analysis showed that PHs and PPHs had more disordered structure, with the increase of random coil content. PI and PPC had similar solubility curves in the pH range of 2.0–9.0. However, hydrolysis led to a decrease in the solubility of PHs and PPHs at pH 2.0 and 3.0, and the solubility of PPHs was higher than that of PHs at pH 6.0 and 7.0. In addition, PPC exhibited better emulsifying properties and stronger antioxidant activities than those of PI before and after hydrolysis. These results indicated that PPC and PPHs obtained from CCSK may have great application potential in food industry as functional ingredients. • Protein products PI and PPC were prepared from Cinnamomum camphora seed kernel. • Protein hydrolysates PHs and PPHs were obtained by hydrolysis with Alcalase. • PPHs had higher degree of hydrolysis values than PHs. • Hydrolysis increased the random coil contents of PHs and PPHs. • PPHs showed better emulsifying properties and antioxidant activities than PHs. [ABSTRACT FROM AUTHOR]

Phytate, an anti-nutritional factor in Cinnamomum camphora seed kernel protein isolate (CPI), chelated with minerals and proteins to form complexes that reduced their bioavailability. The study aimed to evaluate the effects of phytase treatment on the structural and functional properties and in vitro digestibility of CPI. The results showed that the degree of phytate degradation was improved with the increase in phytase treatment time. Most of the original secondary structures were retained in the treated CPI samples. The removal of phytate increased the Zeta potential of CPI, and the protein isoelectric point was increased. Low phytate CPI samples showed higher thermal stability and higher Ca2+ content. In terms of functional properties, foaming capacity was positively correlated with phytate content, whereas foam stability, emulsifying activity index and emulsion stability index were negatively correlated with phytate content. The reduction of phytate content had a positive effect on in vitro gastrointestinal digestion, and the bioavailability of CPI was significantly improved. These results have demonstrated that phytase treatment retained most of the original structure, and improved functional properties and digestibility of the protein isolate from Cinnamomum camphora seed kernel. • The decrease in phytate content changed the ζ-potential of CPI samples. • Most of the secondary structure of the protein was retained after phytase treatment. • Phytase treatment improved functional properties of CPI samples. • The decrease in phytate content improved in vitro digestibility and the availability of protein. [ABSTRACT FROM AUTHOR]

Cinnamomum camphora seed kernel protein isolate (CPI) has attracted increasing attention due to its sustainability and potential applications. This study aimed to investigate the effects of freeze-drying (FD), vacuum-drying (VD), and spray-drying (SD) on the physicochemical and functional properties of CPI. The morphology observation results showed that the SD-CPI, SD-CPI, and VD-CPI were spherical, lamellar, and massive, respectively. Compared to FD and SD, VD had more impact on the color, surface hydrophobicity, intermolecular disulfide bonds, intrinsic fluorescence, and thermal stability of CPI. Fourier transform infrared spectroscopy (FTIR) analyses showed that among three CPI samples, VD-CPI had the highest content of β-sheet but the lowest contents of α-helix and β-turn. At different pH values, the solubility, emulsification, and foaming properties of VD-CPI were inferior to those of FD-CPI and SD-CPI. These results provide useful information on the changes in the physicochemical and functional properties of CPI subjected to different drying methods, and offer theoretical guidance for the production and use of CPI in the food industry.

Aims: Isolation and characterization of Enterococcus phages and application of phage cocktail to control E. faecalis in milk., Methods and Results: For phage isolations, double layer agar method was used. Host range of the phages were determined by the spot test. Twelve phages with varying host ranges were isolated. Phages PEF1, PEF7b, and PEF9 with different host ranges and lytic activities were selected for phage cocktails. Compared to two-phages cocktails tested, the cocktail containing all the three phages displayed stronger antibacterial and biofilm removal activities. The cocktail treatment reduced viable E. faecalis in biofilm by 6 log within 6 h at both 30°C and 4°C. In milk, the cocktail gradually reduced the viable count of E. faecalis and the count reached below the lower limit of detection at 48 h at 4°C., Conclusion: The strong bactericidal and biofilm removal activities of the phage cocktail suggest the potential of this cocktail as a natural biocontrol agent for combating E. faecalis in milk., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)

Cucurbitales are an important order of flowering plants known for encompassing edible plants of economic and medicinal value and numerous ornamental plants of horticultural value. By reanalyzing the genomes of two representative families (Cucurbitaceae and Begoniaceae) in Cucurbitales, we found that the previously identified Cucurbitaceae common paleotetraploidization that occurred shortly after the core-eudicot-common hexaploidization event is shared by Cucurbitales, including Begoniaceae. We built a multigenome alignment framework for Cucurbitales by identifying orthologs and paralogs and systematically redating key evolutionary events in Cucurbitales. Notably, characterizing the gene retention levels and genomic fractionation patterns between subgenomes generated from different polyploidizations in Cucurbitales suggested the autopolyploid nature of the Begoniaceae common tetraploidization and the allopolyploid nature of the Cucurbitales common tetraploidization and the Cucurbita-specific tetraploidization. Moreover, we constructed the ancestral Cucurbitales karyotype comprising 17 proto-chromosomes, confirming that the most recent common ancestor of Cucurbitaceae contained 15 proto-chromosomes and rejecting the previous hypothesis for an ancestral Cucurbitaceae karyotype with 12 proto-chromosomes. In addition, we found that the polyploidization and tandem duplication events promoted the expansion of gene families involved in the cucurbitacin biosynthesis pathway; however, gene loss and chromosomal rearrangements likely limited the expansion of these gene families., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Society of Plant Biologists.)