Food and gut originated bacteriocins involved in gut microbe-host interactions.

The gut microbes interact with each other as well as host, influencing human health and some diseases. Many gut commensals and food originated bacteria produce bacteriocins which can inhibit pathogens and modulate gut microbiota. Bacteriocins have comparable narrow antimicrobial spectrum and are attractive potentials for precision therapy of gut disorders. In this review, the bacteriocins from food and gut microbiomes and their involvement in the interaction between producers and gut ecosystem, along with their characteristics, types, biosynthesis, and functions are described and discussed. Bacteriocins are produced by many intestinal commensals and food microbes among which lactic acid bacteria (many are probiotics) has been paid more attention. Bacteriocin production has been generally regarded as a probiotic trait. They give a competitive advantage to bacteria, enabling their colonization in human gut, and mediating the interaction between the producers and host ecosystem. They fight against unwanted bacteria and pathogens without significant impact on the composition of commensal microbiota. Bacteriocins assist the producers to survive and colonize in the gut microbial populations. There is a great need to evaluate and utilize the potential of bacteriocins for improved therapeutic implications for intestinal health.

Nisin Z attenuates lipopolysaccharide-induced mastitis by inhibiting the ERK1/2 and p38 mitogen-activated protein kinase signaling pathways.

Nisin Z is a possible alternative for treating bovine mastitis by inhibiting mastitis-causing pathogens and having anti-inflammatory activity. However, the anti-inflammatory mechanism of nisin Z on mastitis is unknown. Our study aimed to investigate the mechanisms of nisin Z on mastitis. Our results showed that nisin Z inhibited the activation of the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) signaling pathway, decreased the release of pro-inflammatory cytokines (i.e., tumor necrosis factor-α, IL-1ß, and IL-6), and increased the anti-inflammatory cytokine (IL-10) in lipopolysaccharide (LPS)-induced MCF10A cells. After intraperitoneal injection, nisin Z significantly decreased inflammatory cell infiltration in the mammary gland, as well as decreased myeloperoxidase and pro-inflammatory cytokines in serum and mammary gland. Western blot analysis revealed that nisin Z also dramatically suppressed the activation of the ERK1/2 and p38 MAPK signaling pathways in LPS-induced mastitis mice. We also found that nisin Z treatment could enhance the blood-milk barrier. In summary, our study demonstrated that nisin Z exerted an anti-inflammatory effect by inhibiting the ERK1/2 and p38 MAPK signaling pathway and promoting the blood-milk barrier on LPS-induced mastitis.

Cajanusoids A-D, Unusual Atropisomeric Stilbene Dimers with PTP1B Inhibitory Activities from the Leaves of Cajanus cajan.

Four novel stilbene dimers (1-4), together with their biosynthetically related stilbene monomers (5 and 6), were isolated from the leaves of Cajanus cajan. Their structures with absolute configurations were determined by comprehensive analysis of spectroscopic data and electronic circular dichroism calculations. Compounds 1 and 2 are two novel dimeric stilbenes with an unusual coupling pattern that resulted in a rare configurationally stable Csp2-Csp3 chiral axis with both point and axial chirality in their molecules. Due to their unique inherent structural features, both of them naturally occur as equilibrating mixtures of unequally populated atropo-diastereomers and their respective enantiomers. Compounds 3 and 4 are two pairs of novel dimeric stilbene atropisomers featuring a rotationally hindered central biaryl axis. Notably, 3 contains a rare arylbenzoquinone core and 4 is a symmetric dimer with a C2 symmetry axis. The hypothetical biosynthetic pathway of 1-4 was also proposed herein. All the new compounds exhibited significant protein tyrosine phosphatase-1B (PTP1B) inhibition effects. In addition, the preliminary mode of action for the most potent compound 3 was investigated by molecular docking and binding free energy calculation.

Context-aware heatstroke relief station placement and route optimization for large outdoor events.

BACKGROUND: Heatstroke is becoming an increasingly serious threat to outdoor activities, especially, at the time of large events organized during summer, including the Olympic Games or various types of happenings in amusement parks like Disneyland or other popular venues. The risk of heatstroke is naturally affected by a high temperature, but it is also dependent on various other contextual factors such as the presence of shaded areas along traveling routes or the distribution of relief stations. The purpose of the study is to develop a method to reduce the heatstroke risk of pedestrians for large outdoor events by optimizing relief station placement, volume scheduling and route. RESULTS: Our experiments conducted on the planned site of the Tokyo Olympics and simulated during the two weeks of the Olympics schedule indicate that planning routes and setting relief stations with our proposed optimization model could effectively reduce heatstroke risk. Besides, the results show that supply volume scheduling optimization can further reduce the risk of heatstroke. The route with the shortest length may not be the route with the least risk, relief station and physical environment need to be considered and the proposed method can balance these factors. CONCLUSIONS: This study proposed a novel emergency service problem that can be applied in large outdoor event scenarios with multiple walking flows. To solve the problem, an effective method is developed and evaluates the heatstroke risk in outdoor space by utilizing context-aware indicators which are determined by large and heterogeneous data including facilities, road networks and street view images. We propose a Mixed Integer Nonlinear Programming model for optimizing routes of pedestrians, determining the location of relief stations and the supply volume in each relief station. The proposed method can help organizers better prepare for the event and pedestrians participate in the event more safely.

Identification of Schistosoma japonicum GSK3ß interacting partners by yeast two-hybrid screening and its role in parasite survival.

Schistosoma is the causative agent of schistosomiasis, a common infectious disease distributed worldwide. Our previous phosphoproteomic analysis suggested that glycogen synthase kinase 3 (GSK3), a conserved protein kinase in eukaryotes, is likely involved in protein phosphorylation of Schistosoma japonicum. Here, we aimed to identify the interacting partners of S. japonicum GSK3ß (SjGSK3ß) and to evaluate its role in parasite survival. Toward these ends, we determined the transcription levels of SjGSK3ß at different developmental stages and identified its interacting partners of SjGSK3ß by screening a yeast two-hybrid S. japonicum cDNA library. We further used RNA interference (RNAi) to inhibit the expression of SjGSK3ß in adult worms in vitro and examined the resultant changes in transcription of its putative interacting proteins and in worm viability compared with those of control worms. Reverse transcription-quantitative polymerase chain analysis indicated that SjGSK3ß is expressed throughout the life cycle of S. japonicum, with higher expression levels detected in the eggs and relatively higher expression level found in male worms than in female worms. By screening the yeast two-hybrid library, eight proteins were identified as potentially interacting with SjGSK3ß including cell division cycle 37 homolog (Cdc37), 14-3-3 protein, tegument antigen (I(H)A), V-ATPase proteolipid subunit, myosin alkali light chain 1, and three proteins without recognized functional domains. In addition, SjGSK3ß RNAi reduced the SjGSK3ß gene transcript level, leading to a significant decrease in kinase activity, cell viability, and worm survival. Collectively, these findings suggested that SjGSK3ß may interact with its partner proteins to influence worm survival by regulating kinase activity.

Molecular characterization, expression profile, and preliminary evaluation of diagnostic potential of CD63 in Schistosoma japonicum.

Schistosomes are the causative agents of human schistosomiasis, which is endemic in tropical and subtropical zones. CD63 is a member of the tetraspanin protein family widely expressed among eukaryotes. Previously, we identified a CD63 homolog from extracellular vesicles isolated from Schistosoma japonicum. In this study, we characterized this CD63 homolog using a molecular approach and evaluated the potential of its recombinant protein for the diagnosis of schistosomiasis. A sequence alignment indicated that S. japonicum CD63 (SjCD63) has sequence identities of 76 and 28% with S. mansoni and human CD63, respectively. A phylogenetic analysis displayed that S. japonicum CD63 is related to S. mansoni and Opisthorchis viverrini CD63. The cDNA of SjCD63 was 740 bp long with an expected protein size of 23.58 kDa. A RT-qPCR analysis revealed significantly higher expression of SjCD63 mRNA in adult worms on days 21, 28, and 35 than in 7-day schistosomula, cercariae, and eggs. In addition, recombinant SjCD63 protein detected by ELISA revealed significantly higher optical density values compared to that of the negative control in both S. japonicum-infected mouse and rabbit sera, providing preliminary evidence for its diagnostic potential. Overall, these results provide insight into the molecular properties of SjCD63, its expression profiles, and its preliminary diagnostic potential.

Molecular characterization and expression profile of nanos in Schistosoma japonicum and its influence on the expression several mammalian stem cell factors.

Pluripotent stem cells, called neoblasts, are well known for the regenerative capability and developmental plasticity in flatworms. Impressive advancement has been made in free-living flatworms, while in case of its parasitic counterpart, neoblast-like stem cells have attracted recent attention for its self-renewal and differentiation capacity. Nanos is a key conserved post-transcriptional regulator critical for the formation, development, and/or maintenance of the pluripotent germ line stem cell systems in many metazoans including schistosomes. In the present study, we report the molecular cloning and expression of nanos orthologous genes nanos in Schistosoma japonicum (Sjnanos). The cDNA of Sjnanos is 826 bp long, containing an open reading frame (ORF) for 223 amino acid long protein. qRT-PCR analysis shown that Sjnanos was differently expressed in several stages of schistosomes with relatively high level in schistosomula. Additionally, Sjnanos was expressed highly in adult females compared to adult males. Transfection of recombinant plasmid for expressing Sjnanos resulted in significant proliferation and increased expression of several stem cell factors in mammalian cells. Overall, our preliminary study provides the molecular basis to further functionally characterize Sjnanos in S. japonicum.

Construction and in vitro evaluation of a recombinant live attenuated PRRSV expressing GM-CSF.

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) continues to be an important problem for the swine industry. Inactivated vaccines and modified-live virus vaccines are widely used in the field; however, the efficacy of these PRRSV vaccines is suboptimal due to poor immunogenicity. Granulocyte-macrophage colony stimulating factor (GM-CSF) has been extensively used as an effective genetic and protein adjuvant to enhance the efficiencies vaccines expressing tumor or pathogen antigens. The purpose of this study was to determine if GM-CSF could increase the efficiency of PRRSV vaccine. METHODS: The GM-CSF gene was inserted in the HuN4-F112 vaccine strain by overlap PCR. The expression of GM-CSF by the recombinant virus was confirmed with methods of indirect immunofluorescent assay (IFA) and Western blotting. The stability of recombinant virus was assessed by cDNA sequence and IFA after 20 passages. To detect the biological activity of GM-CSF expressed by the recombinant virus, bone marrow-derived dendritic cells (BMDCs) were isolated and co-cultured with the recombinant virus or parental virus and the surface phenotypes of BMDCs were examined by flow cytometric analysis. The cytokines secreted by BMDCs infected with PRRSV, or treated with LPS, GM-CSF or medium alone were evaluated by ProcartaPlexTM Multiplex Immunoassays and qRT-PCR. RESULTS: A novel modified-live PRRSV vaccine strain expressing GM-CSF (rHuN4-GM-CSF) was successfully constructed and rescued. The GM-CSF protein was stable expressed in recombinant virus-infected cells after 20 passages. Analysis of virus replication kinetics showed that the novel vaccine strain expressing GM-CSF had a similar replication rate as the parental virus. In vitro studies showed that infection of porcine BMDCs with rHuN4-GM-CSF resulted in increased surface expression of MHCI+, MHCII + and CD80/86+ that was dependent on virus expressed GM-CSF. The expression of representative cytokines was significantly up-regulated when BMDCs were incubated with the recombinant GM-CSF expressing virus. CONCLUSIONS: Our results indicated that the expression of GM-CSF during infection with a vaccine strain could enhance the activation of BMDCs and increase cytokine response, which is expected to result in higher immune responses and may improve vaccine efficacy against PRRSV infection.

Dynamic System Stability Modeling Approach with Sparrow-Inspired Meta-Heuristic Optimization Algorithm.

Aiming at the accurate prediction of the inception of instability in a compressor, a dynamic system stability model is proposed based on a sparrow-inspired meta-heuristic optimization algorithm in this article. To achieve this goal, a spatial mode is employed for flow field feature extraction and modeling object acquisition. The nonlinear characteristic presented in the system is addressed using fuzzy entropy as the identification strategy to provide a basis for instability determination. Using Sparrow Search Algorithm (SSA) optimization, a Radial Basis Function Neural Network (RBFNN) is achieved for the performance prediction of system status. A Logistic SSA solution is first established to seek the optimal parameters of the RBFNN to enhance prediction accuracy and stability. On the basis of the RBFNN-LSSA hybrid model, the stall inception is detected about 35.8 revolutions in advance using fuzzy entropy identification. To further improve the multi-step network model, a Tent SSA is introduced to promote the accuracy and robustness of the model. A wider range of potential solutions within the TSSA are explored by incorporating the Tent mapping function. The TSSA-based optimization method proves a suitable adaptation for complex nonlinear dynamic modeling. And this method demonstrates superior performance, achieving 42 revolutions of advance warning with multi-step prediction. This RBFNN-TSSA model represents a novel and promising approach to the application of system modeling. These findings contribute to enhancing the abnormal warning capability of dynamic systems in compressors.

The Influence of Maternal Folate Status on Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Maternal folate has been shown to relate to the risk of gestational diabetes mellitus (GDM). However, the existing studies have yielded inconsistent conclusions. The purpose of this study was to systematically review the association between maternal folate status and the risk of GDM. Observational studies up to 31 October 2022 were included. Study characteristics, the means and standard deviations (SDs) of folate levels (serum/red blood cell (RBC)), the odds ratios (ORs) with 95% confidence intervals (CIs) and the time for folate measurement were extracted. Compared with the non-GDM group, serum and RBC folate levels in women with GDM were significantly higher. Our subgroup analysis demonstrated that serum folate levels in the GDM group were significantly higher than in the non-GDM group only in the second trimester. RBC folate levels in the GDM group were significantly higher than in the non-GDM group in the first and second trimesters. Taking serum/RBC folate levels as continuous variables, the adjusted odds ratios of GDM risk showed that increased serum folate concentration rather than RBC folate elevated the risk of GDM. In the descriptive analysis, five studies reported high serum folate levels increased GDM risk, whereas the other five showed no association between serum folate levels and GDM risk. Moreover, the rest three studies pointed out high RBC folate levels increased GDM risk. Altogether we found that the risk of GDM is associated with high serum/plasma and RBC folate levels. Future studies should determine the recommended folic acid cutoff balancing the risk for GDM and fetal malformations.

A Novel Two-Component Bacteriocin, Acidicin P, and Its Key Residues for Inhibiting Listeria monocytogenes by Targeting the Cell Membrane.

Listeria monocytogenes is an important pathogen which easily contaminates food and causes fatal systemic infections in human. Bacteriocins have received much attention regarding their natural methods of controlling health-related pathogens. Here, we investigated and characterized a novel two-component bacteriocin named acidicin P from Pediococcus acidilactici LAC5-17. Acidicin P showed obvious antimicrobial activity to L. monocytogenes. Through a sequence similarity network analysis for two-component bacteriocin precursors mined in the RefSeq database, acidicin P was observed to belong to an unusual group of two-component bacteriocins. Acidicin P contains two peptides designated Adpα and Adpß which are assessed to interact with each other and form a helical dimer structure which can be inserted into the lipid bilayer of target cell membrane. We demonstrate that A5, N7, and G9 in the A5xxxG9 motif of Adpα and S16, R19, and G20 in the S16xxxG20 motif of Adpß played crucial roles in stabilizing the helix-helix interaction of Adpα and Adpß and were essential for the antilisterial activity of acidicin P by site-directed mutagenesis. A positive residue, R14, in Adpα and a negative residue, D12, in Adpß are also important for acidicin P to fight against L. monocytogenes. These key residues are supposed to form hydrogen bonding, which is crucial for the interaction of Adpα and Adpß. Furthermore, acidicin P induces severe permeabilization and depolarization of the cytoplasmic membrane and causes dramatic changes in L. monocytogenes cell morphology and ultrastructure. Acidicin P has the potential to be applied to inhibit L. monocytogenes efficiently both in the food industry and medical treatments. IMPORTANCE L. monocytogenes can cause widespread food contamination and severe human listeriosis, which amount to a large proportion of the public health and economic burdens. Today, L. monocytogenes is usually treated with chemical compounds in the food industry or antibiotics for human listeriosis. Natural and safe antilisterial agents are urgently required. Bacteriocins are natural antimicrobial peptides that have comparable narrow antimicrobial spectra and are attractive potentials for precision therapy for pathogen infection. In this work, we discover a novel two-component bacteriocin designated acidicin P, which shows obvious antilisterial activity. We also identify the key residues in both peptides of acidicin P and demonstrate that acidicin P is inserted into the target cell membrane and disrupts the cell envelop to inhibit the growth of L. monocytogenes. We believe that acidicin P is a promising lead for further development as an antilisterial drug.

Analysis of sheep peripheral blood mononuclear cells in response to Echinococcus granulosus microRNA-71 overexpression.

Cyst echinococcosis, caused by Echinococcus granulosus, remains a zoonotic disease posing a great threat to public health and meat production industry. Sheep infected with E. granulosus show relatively high abundance of egr-miR-71 in the sera, but its role is unknown. Using bioinformatics and cell migration and Transwell assays, we comparatively analyzed the proteomes and cell invasion of sheep PBMCs in response to egr-miR-71 overexpression. The results showed that the egr-miR-71 induced a total of 157 proteins being differentially expressed and mainly involved in immune responses. In sheep PBMCs, egr-miRNA-71 overexpression induced significant downregulation of macrophage migration inhibitory factor (MIF) and accordingly promoted cell migration and invasion compared with the control. The results will provide a clue for further investigation of a role of circulating egr-miR-71 in immune responses during E. granulosus infection.

Metagenomic sequencing for identifying pathogen-specific circulating DNAs and development of diagnostic methods for schistosomiasis.

Timely diagnosis of Schistosoma infection, particularly in the early stage is crucial for identifying infected hosts and then taking effective control strategies. Here, metagenomic next-generation sequencing was used to identify pathogen-specific circulating DNAs (cDNAs) in the sera/plasma of New Zealand rabbits infected with S. japonicum, and the identified cDNAs were validated by PCR and qPCR. Loop-mediated isothermal amplification (LAMP)-based CRISPR-Cas12a and recombinase polymerase amplification-based lateral flow strip (RPA-LF) methods combined with the newly identified cDNA were developed to evaluate the potentials for diagnosing murine and human schistosomiasis. The results indicated that twenty-two cDNAs were identified. The developed LAMP-based CRISPR/Cas12a and RPA-LF methods showed a good potential for diagnosing murine or human schistosomiasis as early as 5 days of post-infection with 5 cercariae infection. In a word, S. japonicum specific cDNAs in circulation of infected hosts could be effective biomarkers for detecting Schistosoma infection particularly for early stages.

Exploring the bacterial community succession and metabolic profiles of Lonicera japonica Thunb. residues during anaerobic fermentation.

Discarding Lonicera japonica Thunb. (LJT) residues containing many active metabolites create tremendous waste. This study aimed to effectively use LJT residues by anaerobic fermentation. Fermentation significantly decreased the pH values and reduced the abundance of undesirable bacteria (potential pathogenic and biofilm-forming) while increasing Lactobacillus abundance. Compound additive use further improved fermentation quality (significantly increased the lactic acid (LA) content and decreased the pH values and ammonia nitrogen (a-N) content) and nutrient quality (significantly decreased the acid detergent fiber (ADF) content and increased the water-soluble carbohydrate (WSC) content) and optimized the microbial community (increased the Lactobacillus abundance). Fermentation also altered the flavonoids, alkaloids and phenols contents in the residues with minor effects on the functional metabolites amounts. The LJT residues metabolic profile was mainly attributed to its epiphytic bacteria, with a small contribution from the compound additive. Thus, compound additives may improve anaerobic LJT residue fermentation without functionally impairing the metabolites.

An urban-level prediction of lockdown measures impact on the prevalence of the COVID-19 pandemic.

The world still suffers from the COVID-19 pandemic, which was identified in late 2019. The number of COVID-19 confirmed cases are increasing every day, and many governments are taking various measures and policies, such as city lockdown. It seriously treats people's lives and health conditions, and it is highly required to immediately take appropriate actions to minimise the virus spread and manage the COVID-19 outbreak. This paper aims to study the impact of the lockdown schedule on pandemic prevention and control in Ningbo, China. For this, machine learning techniques such as the K-nearest neighbours and Random Forest are used to predict the number of COVID-19 confirmed cases according to five scenarios, including no lockdown and 2 weeks, 1, 3, and 6 months postponed lockdown. According to the results, the random forest machine learning technique outperforms the K-nearest neighbours model in terms of mean squared error and R-square. The results support that taking an early lockdown measure minimises the number of COVID-19 confirmed cases in a city and addresses that late actions lead to a sharp COVID-19 outbreak.

Modulation of Fermentation Quality and Metabolome in Co-ensiling of Sesbania cannabina and Sweet Sorghum by Lactic Acid Bacterial Inoculants.

Sesbania cannabina (SC) is a protein-rich roughage that thrives under moderate-severe saline-alkali (MSSA) soils with the potential to relieve the shortage of high nutritive forage. Sweet sorghum (SS) also tolerates MSSA soils and contains rich fermentable carbohydrates which could improve the fermentation quality in mixed silage. The present study investigated the silage quality, bacterial community, and metabolome in the mixed silage of SC and SS (SC-SS) with or without lactic acid bacterial (LAB) inoculants. Four ratios (10:0, 7:3, 5:5, and 3:7) of SC and SS were treated with sterile water or LAB inoculants (homofermentative Companilactobacillus farciminis and Lactiplantibacillus plantarum, and heterofermentative Lentilactobacillus buchneri and Lentilactobacillus hilgardii), which were analyzed after 60 days of ensiling. Results revealed that LAB inoculation improved the fermentation quality by increasing the lactic acid content and decreasing the ammonia nitrogen and butyric acid contents compared with the untreated group. LAB inoculation also raised the relative feed value by reducing indigestible fibers [e.g., neutral detergent fiber (NDF), acid detergent fiber, and hemicellulose]. Microbial and metabolomic analysis indicated that LAB inoculants could modify the bacterial community and metabolome of SC-SS silage. In co-ensiling samples except for SC alone silage, L. buchneri and L. hilgardii were the dominant species. Metabolites with bioactivities like anti-inflammatory, antioxidant, antimicrobial, and anti-tumor were upregulated with LAB inoculation. Furthermore, correlation analysis demonstrated that active metabolites (e.g., glycitin, glabrene, alnustone, etc.) were positively correlated with L. buchneri, while tripeptides (e.g., SPK, LLK, LPH, etc.) were positively correlated with L. hilgardii. Adequately describing the SC-SS silage by multi-omics approach might deepen our understanding of complicated biological processes underlying feature silages fermentation. Moreover, it may also contribute to screening of targeted functional strains for MSSA-tolerating forage to improve silage quality and promote livestock production.

Rhodium(III)-Catalyzed Asymmetric 1,2-Carboamidation of Alkenes Enables Access to Chiral 2,3-Dihydro-3-benzofuranmethanamides.

Through the initial screening and further rational design of chiral cyclopentadienyl ligands, a chiral rhodium-catalyzed enantioselective 1,2-carboamidation of aromatic tethered alkenes was developed, enabling the asymmetric preparation of various chiral 2,3-dihydro-3-benzofuranmethanamides with an enantioenriched all-carbon quaternary center at the ß position of amide. This robust transformation has a broad functional group tolerance, excellent enantioselectivities (up to 98.5:1.5 er), and a mild reaction conditions, releasing CO2 as the single byproduct.

High-throughput discovery of novel lanthipeptides and producers by metagenomic mining of isolates population (MMIP) from Chinese spicy cabbage.

Lanthipeptides are known antimicrobial agents having great potential for application in food preservation. Many lanthipeptide biosynthetic gene clusters (BGCs) were mined in fermented food microbiota, however, it is difficult to obtain the bioactive lanthipeptides and their producing strains. Here, we established a high-throughput strategy designated Metagenomic Mining of Isolates Population (MMIP) to efficiently excavate and obtain novel lanthipeptides, especially their potential producing strains. MMIP procedure involves gathering bacteria isolates using culturable strategy, metagenomic mining for lanthipeptides and screening their producers, and characterization of specific lanthipeptides. 928 biosynthetic gene clusters including 139 ribosomally synthesized and post-translationally modified peptides (RiPPs) gene clusters were discovered in the metagenomic data of the isolates by antiSMASH. Entianin, lactocin S, lichenicidin, and 17 novel lanthipeptides gene clusters corresponding to 29 possible producers were further found from the harvested isolates population. Entianin and a novel two-component lanthipeptide paralicin were purified from Bacillus subtilis C5B1 and Bacillus paralicheniformis BaC1-8, respectively. They showed strong inhibitory activity to food spoilage bacteria Bacillus cereus and Listeria monocytogenes, and have great potential for application in food preservation. A novel lanthipeptide polysacin was also obtained using semi-in vitro biosynthesis. MMIP affords a novel strategy for effectively excavating lanthipeptides, especially their producers from diverse environmental niches.

Dynamic Changes in Fermentation Quality and Structure and Function of the Microbiome during Mixed Silage of Sesbania cannabina and Sweet Sorghum Grown on Saline-Alkaline Land.

Protein-rich Sesbania cannabina and sugar-rich sweet sorghum [Sorghum dochna (Forssk.) Snowden] are characterized by their higher tolerance to saline-alkaline stresses and simultaneous harvests. They could be utilized for coensiling because of their nutritional advantages, which are crucial to compensate protein-rich forage in saline-alkaline regions. The current study investigated the fermentation quality, microbial community succession, and predicted microbial functions of Sesbania cannabina and sweet sorghum in mixed silage during the fermentation process. Before ensiling, the mixtures were treated with compound lactic acid bacteria (LAB) inoculants followed by 3, 7, 14, 30, and 60 days of fermentation. The results revealed that the inoculated homofermentative species Lactobacillus plantarum and Lactobacillus farciminis dominated the early phase of fermentation, and these shifted to the heterofermentative species Lactobacillus buchneri and Lactobacillus hilgardii in the later phase of fermentation. As a result, the pH of the mixed silages decreased significantly, accompanied by the growth of acid-producing microorganisms, especially L. buchneri and L. hilgardii, which actively influenced the bacterial community structure and metabolic pathways. Moreover, the contents of lactic acid, acetic acid, 1,2-propanediol, and water-soluble carbohydrates increased, while the contents of ammonia-N and fiber were decreased, with increasing ratios of sweet sorghum in the mixed silage. Overall, coensiling Sesbania cannabina with >30% sweet sorghum is feasible to attain high-quality silage, and the relay action between homofermentative and heterofermentative LAB species could enhance fermentation quality and conserve the nutrients of the mixed silage. IMPORTANCE The coensiling of Sesbania cannabina and sweet sorghum is of great practical importance in order to alleviate the protein-rich forage deficiency in saline-alkaline regions. Furthermore, understanding the microbial community's dynamic changes, interactions, and metabolic pathways during ensiling will provide the theoretical basis to effectively regulate silage fermentation. Here, we established that coensiling Sesbania cannabina with >30% sweet sorghum was effective at ensuring better fermentation quality and preservation of nutrients. Moreover, the different fermentation types of LAB strains played a relay role during the fermentation process. The homofermentative species L. plantarum and L. farciminis dominated in the early phase of fermentation, while the heterofermentative species L. buchneri and L. hilgardii dominated in the later phase of fermentation. Their relay action in Sesbania cannabina-sweet sorghum mixed silage may help to improve fermentation quality and nutrient preservation.

Influence of Lactobacillus plantarum inoculation on the silage quality of intercropped Lablab purpureus and sweet sorghum grown in saline-alkaline region.

Ensiling legume with cereal is an effective method to ensure the energy rich-feed, but no information is available on the microbial fermentation mechanism of intercropped Lablab purpureus (Lablab) and sweet sorghum in the saline-alkaline region. Therefore, the present study investigated the silage quality and microbial community of intercropped Lablab and sweet sorghum silages grown in the saline-alkaline region with or without inoculation of Lactobacillus plantarum (LP). The experimental treatments were prepared according to the Lablab and sweet sorghum planting patterns: Lablab and sweet sorghum sowing seed ratios were 1:1 (L), 5:1 (M), and 9:1 (H). After harvesting, each mixture was treated with LP or sterilized water (CK), followed by 60 days of fermentation. Results showed that both LP inoculation and intercropping significantly raised the lactic acid (LA) content and decreased the pH value, acetic acid (AA), and ammonia-N in intercropped silages. The LP addition and intercropping also improved the relative feed value by reducing structural carbohydrates. Moreover, LP silages had a greater relative abundance of Lactobacillus than CK silages, and its relative abundance increased with an increased seed-sowing ratio of Lablab in intercropping. LP was the prevalent species in LP silages compared to CK silages, and its relative abundance also increased with an increased seed-sowing ratio of Lablab in intercropping. The genus Lactobacillus was negatively correlated with ammonia-N (R = -0.6, p = 0.02) and AA (R = -0.7, p < 0.01) and positively correlated with LA (R = 0.7, p < 0.01) and crude protein (R = 0.6, p = 0.04). Overall, the intercropped seeding ratios of Lablab and sweet sorghum of ≥ 5:1 with LP inoculation resulted in better fermentation quality and preservation of nutritional components providing theoretical support and guidance for future intercropped protein-rich silage production in the saline-alkaline region.