Chitosan nanomedicines-engineered bifidobacteria complexes for effective colorectal tumor-targeted delivery of SN-38.

The clinical application of 7-ethyl hydroxy-camptothecin (SN-38) maintains challenges not only due to its poor solubility and stability but also the lack of effective carriers to actively deliver SN-38 to deep tumor sites. Although SN-38-based nanomedicines could improve the solubility and stability from different aspects, the tumor targeting efficiency remains very low. Leveraging the hypoxic taxis of bifidobacteria bifidum (B. bifi) to the deep tumor area, we report SN-38-based nanomedicines-engineered bifidobacterial complexes for effective tumor-targeted delivery. Firstly, SN-38 was covalently coupled with poly-L-glutamic acid (L-PGA) and obtained soluble polymeric prodrug L-PGA-SN38 to improve its solubility and stability. To prolong the drug release, L-PGA-SN38 was mildly complexed with chitosan to form nanomedicines, and nanomedicines engineered B. bifi were further elaborated via electrostatic interaction of the excess of cationic chitosan shell from nanomedicines and anionic teichoic acid from B. bifi. The engineered B. bifi complexes inherited the bioactivity of native B. bifi and exhibited distinctly enhanced accumulation at the tumor site. More importantly, significantly elevated anti-tumor efficacy was achieved after the treatment of CS-L-PGA-SN38 NPs/B. bifi complexes, with favorable tumor suppression up to 80%. Such a B. bifi-mediated delivery system offers a promising platform for effective drug delivery and enhanced drug accumulation in the hypoxia deep tumor with superior anti-tumor efficacy.

Novel microbial fermentation for the preparation of iron-chelating scallop skirts peptides-its profile, identification, and possible binding mode.

Iron chelating peptides have been widely utilized as iron supplements due to their excellent absorption capacity, However, the high cost and cumbersome manufacturing process of these peptides significantly limit their industrial application. In this study, fermentation was used for the first time to prepare iron chelating peptides. Bacillus altitudinis 3*1-3 was selected as the most suitable strain from 50 strains. The hydrolysates of fermented scallop skirts showed excellent iron-chelating capacity (9.39 mg/g). Aspartic acid, glutamic acid, and histidine are crucial for the binding of peptides to ferrous ions. The heptapeptide (FEDPEFE) forms six binding bonds with ferrous irons. Compared with ferrous sulfate, peptide-ferrous chelate showed more stability in salt solution and simulated gastrointestinal juice (p < 0.05). Furthermore, the fermentation method could save >50% of the cost compared with the enzymatic method. The results can provide a theoretical basis for the preparation of ferrous-chelated peptides using the fermentation method.

Lactiplantibacillus plantarum A72, a Strain with Antioxidant Properties, Obtained through ARTP Mutagenesis, Affects Caenorhabditis elegans Anti-Aging.

This research endeavored to elucidate the antioxidant attributes of lactic acid bacteria, specifically their impact on anti-aging and lifespan augmentation in Caenorhabditis elegans. The study focused on Lactiplantibacillus plantarum A72, identified through ARTP mutagenesis for its potent antioxidant properties. In vitro analysis affirmed its free radical neutralizing capacity. In C. elegans, the strain not only extended the lifespan by 25.13% and amplified motility 2.52-fold, but also maintained reproductive capabilities. Remarkably, Lpb. plantarum A72 diminished reactive oxygen species (ROS) and malondialdehyde (MDA) levels in C. elegans by 34.86% and 69.52%, respectively, while concurrently enhancing its antioxidant enzyme activities. The strain also bolstered C. elegans survival rates by 46.33% and 57.78% under high temperature and H2O2 conditions, respectively. Transcriptomic scrutiny revealed that Lpb. plantarum A72 could retard C. elegans aging and extend lifespan by upregulating the sod-5 and hsp-16.1 genes and downregulating the fat-6 and lips-17 genes. These findings propose Lpb. plantarum A72 as a potential antioxidant and anti-aging lactic acid bacteria.

Production optimization of food functional factor ergothioneine in wild-type red yeast Rhodotorula mucilaginosa DL-X01.

BACKGROUND: Ergothioneine (EGT) is a high-value food functional factor that cannot be synthesized by humans and other vertebrates, and the low yield limits its application. RESULTS: In this study, the optimal fermentation temperature, fermentation time, initial pH, inoculum age, and inoculation ratio on EGT biosynthesis of Rhodotorula mucilaginosa DL-X01 were optimized. In addition, the effects of three key precursor substances - histidine, methionine, and cysteine - on fungal EGT synthesis were verified. The optimal conditions were further obtained by response surface optimization. The EGT yield of R. mucilaginosa DL-X01 under optimal fermentation conditions reached 64.48 ± 2.30 mg L-1 at shake flask fermentation level. Finally, the yield was increased to 339.08 ± 3.31 mg L-1 (intracellular) by fed-batch fermentation in a 5 L bioreactor. CONCLUSION: To the best of our knowledge, this is the highest EGT yield ever reported in non-recombinant strains. The fermentation strategy described in this study will promote the efficient biosynthesis of EGT in red yeast and its sustainable production in the food industry. © 2024 Society of Chemical Industry.

Mechanism of thermal oxidation into volatile compounds from (E)-4-decenal: A density functional theory study.

Unsaturated aliphatic aldehyde oxidation plays a significant role in the deep oxidation of fatty acids to produce volatile chemicals. Exposing the oxidation process of unsaturated aliphatic aldehydes is crucial to completely comprehend how food flavor forms. In this study, thermal desorption cryo-trapping in conjunction with gas chromatography-mass spectrometry was used to examine the volatile profile of (E)-4-decenal during heating, and 32 volatile compounds in all were detected and identified. Meanwhile, density functional theory (DFT) calculations were used, and 43 reactions were obtained in the 24 pathways, which were summarized into the peroxide reaction mechanism (ROOH), the peroxyl radical reaction mechanism (ROO·) and the alkoxy radical reaction mechanism (RO·). Moreover, the priority of these three oxidative mechanisms was the RO· mechanism > ROOH mechanism > ROO· mechanism. Furthermore, the DFT results and experimental results agreed well, and the oxidative mechanism of (E)-4-decenal was finally illuminated.

Inoculation of Yarrowia lipolytica promotes the growth of lactic acid bacteria, Debaryomyces udenii and the formation of ethyl esters in sour meat.

Yarrowia lipolytica N12 and A13 with high lipase activity obtained by mutagenesis were inoculated into sour meat, and their effects on physicochemical properties, microbial community succession, free amino acids, and volatile compounds of sour meat were investigated. Inoculation fermentation increased the contents of free amino acids observably, rapidly reduced pH, promoted the accumulation of total acids, decreased 2-thiobarbituric acid reactive substances (TBARS) values. In addition, the addition of Y. lipolytica might contribute to the growth of lactic acid bacteria, Candida spp., and Debaryomyces udenii, which play an important role in production of volatile compounds. It was shown that inoculation promoted the production of esters, aldehydes, and alcohols, especially ethyl esters, giving sour meat a better meat flavor. Besides, it was found that Y. lipolytica A13 had better fermenting property. Sample of A13 group had higher contents of ethyl esters, free amino acids and dominant microorganisms. The results may help to provide new strains for sour meat fermentation.

Knockout of Shcbp1 sensitizes immunotherapy by regulating α-SMA positive cancer-associated fibroblasts.

The crucial role of cancer-associated fibroblasts (CAFs) in promoting T-cell exclusion has a significant impact on tumor immune evasion and resistance to immunotherapy. Therefore, enhancing T-cell infiltration into solid tumors has emerged as a pivotal area of research. We achieved a conventional knockout of Shcbp1 (Shcbp1-/- ) through CRISPR/Cas9 gene editing and crossed these mice with spontaneous breast cancer MMTV-PyMT mice, resulting in PyMT Shcbp1-/- mice. The different CAF subtypes were detected by flow cytometry analysis (FCA). We evaluated collagen and CAFs levels using Sirius red staining, immunohistochemistry (IHC), and immunofluorescence (IF). Primary tumor cells and CAFs were isolated from both PyMT Shcbp1+/+ and PyMT Shcbp1-/- mice. We analyzed CAFs' proliferation, invasion, migration, apoptosis, and cell cycle. Transwell coculture experiments were performed with primary tumor cells and CAFs to evaluate the role of CAFs in increasing the sensitivity of tumor cells to Erdafitinib. Tumors from PyMT Shcbp1+/+ and PyMT Shcbp1-/- mice were orthotopically transplanted to assess the therapeutic effect of the Erdafitinib and PD-1 combination. CAFs and T-cell infiltration in these tumors were assessed using FCA and IF. Knockout of Shcbp1 leads to a significant reduction in tumor burden, promotes longer survival, and decreases CAFs in MMTV-PyMT. Moreover, knockout of Shcbp1 enhances the sensitivity of Erdafitinib, leading to effective inhibition of CAFs' proliferation and invasion, as well as the induction of apoptosis. Additionally, it results in cell cycle arrest at the G2/M phase in vitro. Meanwhile, Shcbp1-/- CAFs change the sensitivity of Shcbp1-/- tumor cells to Erdafitinib compared to Shcbp1+/+ CAFs. Importantly, knockout of Shcbp1 boosts the effectiveness of Erdafitinib in combination with immune checkpoint blockade therapy by augmenting T-cell infiltration through CAFs regulation in vivo. Our findings demonstrate that knockout of Shcbp1 holds significant potential in enhancing the therapeutic response of Erdafitinib combined with PD-1 antibody treatment, offering promising prospects for future breast cancer therapies.

Cost-effective production of ergothioneine using Rhodotorula mucilaginosa DL-X01 from molasses and fish bone meal enzymatic hydrolysate.

Ergothioneine (EGT) is a high-value natural antioxidant that cannot be synthesized by the human body. This study showed that Rhodotorula mucilaginosa DL-X01 can use untreated molasses and fish bone meal enzymatic hydrolysate as the substrates to synthesize EGT. By optimizing the growth conditions, the EGT yield reached 29.39 mg/L when molasses and fish bone meal (FBM) were added at 60 g/L and 400 g/L respectively. Finally, the EGT yield was increased to 216.25 mg/L by fed-batch fermentation in a 5 L bioreactor. Compared with the fermentation by yeast extract peptone dextrose medium, the feedstock cost of EGT production was reduced by 330.91 % by using molasses and FBM as substrates. These results showed that R. mucilaginosa DL-X01 can produce high-value EGT using two cheap processing by-products, molasses and FBM, which is of great significance for environmental protection and sustainable development.

Therapeutic potential of SHCBP1 inhibitor AZD5582 in pancreatic cancer treatment.

Pancreatic cancer (PC) is a highly aggressive and deadly malignancy with limited treatment options and poor prognosis. Identifying new therapeutic targets and developing effective strategies for PC treatment is of utmost importance. Here, we revealed that SHCBP1 is significantly overexpressed in PC and negatively correlated with patient prognosis. Knockout of SHCBP1 inhibits the proliferation and migration of PC cells in vitro, and suppresses the tumor growth in vivo. In addition, we identified AZD5582 as a novel inhibitor of SHCBP1, which efficiently restrains the growth of PC in cell lines, organoids, and patient-derived xenografts. Mechanistically, we found that AZD5582 induced the apoptosis of PC cells by inhibiting the activity of PI3K/AKT signaling and preventing the degradation of TP53. Collectively, our study highlights SHCBP1 as a potential therapeutic target and its inhibitor AZD5582 as a viable agent for PC treatment strategies.

The Screening and Isolation of Ethyl-Carbamate-Degrading Strains from Fermented Grains and Their Application in the Degradation of Ethyl Carbamate in Chinese Baijiu.

Ethyl carbamate (EC), a 2A carcinogen produced during the fermentation of foods and beverages, primarily occurs in distilled spirits. Currently, most studies focus on strategies for EC mitigation. In the present research, we aimed to screen strains that can degrade EC directly. Here, we report two Candida ethanolica strains (J1 and J116), isolated from fermented grains, which can reduce EC concentrations directly. These two yeasts were grown using EC as the sole carbon source, and they grew well on different carbon sources. Notably, after immobilization with chitosan, the two strains degraded EC in Chinese Baijiu by 42.27% and 27.91% in 24 h (from 253.03 ± 9.89 to 146.07 ± 1.67 and 182.42 ± 5.05 µg/L, respectively), which was better than the performance of the non-immobilized strains. Furthermore, the volatile organic compound content, investigated using gas chromatography-mass spectrometry, did not affect the main flavor substances in Chinese Baijiu. Thus, the yeasts J1 and J116 may be potentially used for the treatment and commercialization of Chinese Baijiu.

Association between Systemic Immune Inflammation Index and Cognitive Impairment after Acute Ischemic Stroke.

BACKGROUND AND AIMS: Post-stroke cognitive impairment (PSCI) is one of the major complications after ischemic stroke. PSCI has been shown to be associated with low-grade systemic inflammation. As a novel inflammatory marker, the systemic immune-inflammation (SII) index could reflect clinical outcomes in severe cardiovascular diseases. We therefore performed a prospective study to investigate the correlation between the SII index and the risk of PSCI in patients with ischemic stroke. METHODS: We prospectively enrolled 254 patients with ischemic stroke with symptoms onset <72 h. The SII index was detected within 24 h after admission. The Montreal Cognitive Scale (MoCA) was utilized to evaluate cognitive function, and PSCI was defined as a MoCA score of <25 points. RESULTS: During the 3-month follow-up, 70 participants (27.6%) had mild cognitive impairment and 60 (23.6%) had severe cognitive impairment. In binary logistic regression analysis, each one-standard deviation increase in the SII index was significantly associated with the prevalence of PSCI after adjusting for age, sex, and other confounders (odds ratio 2.341; 95% confidence interval, 1.439-3.809, p = 0.001). Similar significant findings were observed when SII was defined as a categorical variable. In addition, the multiple-adjusted spline regression model showed a linear association between the SII index and cognitive impairment (p = 0.003 for linearity). CONCLUSIONS: Our study indicated that an increased SII index was closely related to PSCI at 3 months in patients with ischemic stroke. Further research is required to evaluate the efficacy of inflammation management in these patients.

Ergothioneine: new functional factor in fermented foods.

Ergothioneine (EGT) is a high-value natural sulfur-containing amino acid and has been shown to possess extremely potent antioxidant and cytoprotective activities. At present, EGT has been widely used in food, functional food, cosmetics, medicine, and other industries, but its low yield is still an urgent problem to overcome. This review briefly introduced the biological activities and functions of EGT, and expounded its specific applications in food, functional food, cosmetic, and medical industries, introduced and compared the main production methods of EGT and respective biosynthetic pathways in different microorganisms. Furthermore, the use of genetic and metabolic engineering methods to improve EGT production was discussed. In addition, the incorporation of some food-derived EGT-producing strains into fermentation process will allow the EGT to act as a new functional factor in the fermented foods.

Malnutrition and the Risk of Early Neurological Deterioration in Elderly Patients with Acute Ischemic Stroke.

Background and Purpose: This study aimed to investigate the relationship between malnutrition and early neurological deterioration (END) in elderly patients with acute ischemic stroke in China. Methods: We used the registry data in the Third Affiliated Hospital of Nantong University and Nanjing Brain Hospital from June 2019 to January 2021. Malnutrition risk was evaluated by controlling nutritional status score (CONUT), geriatric nutritional risk index (GNRI) and prognostic nutritional index (PNI) score, respectively. END was defined as an increment of at least two points in the total NIHSS score within three days after admission. We evaluated the relationship between malnutrition and END with multivariable logistic regression models and reclassification indexes. Results: A total of 732 elderly patients with first-ever acute ischemic stroke were included in the study. 243 patients developed END. 5.7%, 21.4%, 4.6% patients were classified as moderate to severe malnutrition by CONUT, GNRI and PNI, respectively. Malnutrition was associated with the risk of END for CONUT (odds ratio [OR], 1.210; 95% confidence interval [CI] 1.092-1.341; P < 0.001), for GNRI (OR, 0.943; 95% CI, 0.919-0.967; P < 0.001), and for PNI (OR, 0.936; 95% CI, 0.908-0.965; P < 0.001) in multivariable logistic regression models using the back-ward selection method. The discriminative ability was 0.763 (95% CI, 0.727-0.798) for CONUT, 0.769 (95% CI, 0.733-0.805) for GNRI and 0.769 (95% CI, 0.733-0.805) for PNI after adjusting for confounders. Besides, adding malnutrition indexes into models made the prediction of END more accurate. Conclusion: Malnutrition was associated with END in elderly Chinese patients with acute ischemic stroke.

Permeabilized whole-cell biocatalyst containing co-expressed two enzymes facilitates the synthesis of maltoheptaose (G7) from starch.

Maltoheptaose (G7) is one of the mixtures of maltodextrin widely used in the food, pharmaceutical, and cosmetics industries. A genetically engineered strain, which simultaneously expressed cyclodextrin glucanotransferase (CGTase) from Gracilibacillus alcaliphilus SK51.001 and cyclomaltodextrinase (CDase) from Bacillus sphaericus E-244, two enzymes, was constructed by cloning the above two genes into a plasmid and transformed into the host Escherichia coli BL21(DE3) (E. coli) strain, resulted in recombinant cells harboring the vector pETDuet-GaCGT/BsCD (pGaBs). These cells were used as whole-cell catalysts for the biotransformation of G7 from the inexpensive substrate (starch). Due to the high molecular weight of starch, the cell membrane prevents the entry of starch into the cellular system. Therefore, the pGaBs cell wall was permeabilized by lysozyme, EDTA, and heat treatment. After reaching the optimized conditions of permeabilized pGaBs cell amount, lysozyme amount, reaction temperature, and metal ion concentration, approximately 4.1 g/L of G7 was produced from 30 g/L starch in 1 h with the addition of Ca2+. This co-expression system offers a one-pot synthesis approach to the production of G7 using an inexpensive substrate, avoiding enzyme purification steps.

Dictyoglomus turgidum DSM 6724 α-Glucan Phosphorylase: Characterization and Its Application in Multi-enzyme Cascade Reaction for D-Tagatose Production.

Phosphorylase is a type of enzyme-producing sugar phosphates through the reversible phosphorolysis reactions of glycosides, which makes it an important starting enzyme in multi-enzyme systems for rare sugar biomanufacturing. To investigate its application in D-tagatose biosynthesis from maltodextrin using in vitro multi-enzyme cascade biosystem, the α-glucan phosphorylase (αGP; EC 2.4.1.1) from the thermophile D. turgidum DSM 6724 was prepared and characterized. It exhibited the specific activity of 30.28 U/mg at its optimal temperature of 70 °C. Thermostability results revealed that DituαGP could maintain more than 25% of initial activity for 4 h, even at 90 °C. The highest activity was observed at pH 5.5, and most divalent metal ions deactivated the enzyme. DituαGP exhibited great application potential in the multi-enzyme system that about 3.919 g/L of D-tagatose was produced from 150 g/L of maltodextrin within 36 h. DituαGP has played an important role in this biosystem and will also be applied in the synthesis of other rare sugars from maltodextrin.

General Purpose Low-Level Reinforcement Learning Control for Multi-Axis Rotor Aerial Vehicles.

This paper proposes a multipurpose reinforcement learning based low-level multirotor unmanned aerial vehicles control structure constructed using neural networks with model-free training. Other low-level reinforcement learning controllers developed in studies have only been applicable to a model-specific and physical-parameter-specific multirotor, and time-consuming training is required when switching to a different vehicle. We use a 6-degree-of-freedom dynamic model combining acceleration-based control from the policy neural network to overcome these problems. The UAV automatically learns the maneuver by an end-to-end neural network from fusion states to acceleration command. The state estimation is performed using the data from on-board sensors and motion capture. The motion capture system provides spatial position information and a multisensory fusion framework fuses the measurement from the onboard inertia measurement units for compensating the time delay and low update frequency of the capture system. Without requiring expert demonstration, the trained control policy implemented using an improved algorithm can be applied to various multirotors with the output directly mapped to actuators. The algorithm's ability to control multirotors in the hovering and the tracking task is evaluated. Through simulation and actual experiments, we demonstrate the flight control with a quadrotor and hexrotor by using the trained policy. With the same policy, we verify that we can stabilize the quadrotor and hexrotor in the air under random initial states.

Characterization of Feruloyl Esterase from Bacillus pumilus SK52.001 and Its Application in Ferulic Acid Production from De-Starched Wheat Bran.

Feruloyl esterase (FAE; EC 3.1.1.73) catalyzes the hydrolysis of the 4-hydroxy-3-methoxycinnamoyl group in an esterified sugar to assist in waste biomass degradation or to release ferulic acid (FA). An FAE-producing strain was isolated from humus soil samples and identified as Bacillus pumilus SK52.001. The BpFAE gene from B. pumilus SK52.001 was speculated and heterogeneously expressed in Bacillus subtilis WB800 for the first time. The enzyme exists as a monomer with 303 amino acids and a molecular mass of 33.6 kDa. Its specific activity was 377.9 ± 10.3 U/ (mg protein), using methyl ferulate as a substrate. It displays an optimal alkaline pH of 9.0, an optimal temperature of 50 °C, and half-lives of 1434, 327, 235, and 68 min at 50, 55, 60, and 65 °C, respectively. Moreover, the purified BpFAE released 4.98% FA of the alkali-acidic extractable FA from de-starched wheat bran (DSWB). When the DSWB was enzymatically degraded by the synergistic effect of the BpFAE and commercial xylanase, the FA amount reached 49.47%. It suggested that the alkaline BpFAE from B. pumilus SK52.001, which was heterologously expressed in B. subtilis WB800, possesses great potential for biomass degradation and achieving high-added value FA production from food by-products.

Whole-cell biosynthesis of d-tagatose from maltodextrin by engineered Escherichia coli with multi-enzyme co-expression system.

d-tagatose is a functional sweetener that occurs in small quantity in nature. It is mainly produced through the isomerization of d-galactose by l-arabinose isomerase (l-AI; EC 5.3.1.4). However, the cost of d-galactose is much higher than those commonly used for the production of functional sweeteners such as glucose, maltodextrin, or starch. Here, a multi-enzyme catalytic system consists of five enzymes that utilizes maltodextrin as substrate to synthesize d-tagatose were co-expressed in E. coli, resulting in recombinant cells harboring the plasmids pETDuet-αgp-pgm and pCDFDuet-pgi-gatz-pgp. The activity of this whole-cell catalyst was optimal at 60 °C and pH 7.5, and 1 mM Mg2+ and 50 mM phosphate were the optimal cofactors for activity. Under the optimal reaction conditions, 2.08 and 3.2 g L-1d-tagatose were produced by using 10 and 20 g L-1 maltodextrin as substrates with recombinant cells for 24 h. This co-expression system provides a one-pot synthesis approach for the production of d-tagatose using inexpensive substrate, avoiding enzymes purification steps and supplementation of expensive cofactors.

Dual-site catalysis for sustainable polymers to replace current commodity polymers - carbonylative copolymerization of ethylene, ethylene oxide, and tetrahydrofuran.

Zwitterionic Ni(ii)-catalyzed carbonylative copolymerization of ethylene and cyclic ethers for the synthesis of photolytically and hydrolytically degradable polymers is reported. The segmented tetrapolymer products are composed of polyketone segments from alternating enchainments of CO and ethylene and poly(ether-co-ester) segments from non-alternating enchainments of CO, ethylene oxide, and tetrahydrofuran. Plastic and elastic products can be obtained via the general synthetic platform with the appropriate choice of catalyst and polymerization conditions.

Characteristics of a fructose 6-phosphate 4-epimerase from Caldilinea aerophila DSM 14535 and its application for biosynthesis of tagatose.

Tagatose is a rare hexoketose with potential health benefits. Here, an enzyme, GatZ subunit ofd-tagatose-1,6-bisphosphate aldolase, was characterized. GatZ is involved in a multi-enzyme cascade reaction system that can produce tagatose from maltodextrin. It showed maximum activity at 70 °C and a pH 8.0, and required supplementation with 5 mM Mg2+ to achieve the highest catalytic activity. The Km and Vmax values of GatZ using fructose 6-phosphate as substrate were 5.66 mM and 0.0329 mmol/L min, respectively. An in vitro multi-enzyme system containing GatZ was constructed, and 1.75 g/L tagatose was produced from 5 g/L maltodextrin after 10 h. This biosystem could potentially enrich the application of C4 epimerases in rare sugar bioproduction.