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In order to analyze the factors affecting yolk blackening in salted duck eggs, this study investigated the differences in the color difference, metal ion contents and proteomics in different parts of normal and black-yolked salted duck eggs. The effects of these factors on the degree and rate of yolk blackening were studied by single factor experiments. The results showed that the higher the contents of Fe and Cu, the smaller the color difference value of yolk and the blacker the color. It was speculated that the sulfide formed by the combination of Fe2+ in phosvitin (Pv) and S2- was responsible for the blackening of egg yolk, and the degradation and desulfurization of cysteine was an important contributor to sulfur production in egg yolk. Microbial load, temperature and pH were important factors affecting yolk blackening. With increasing bacterial load and curing temperature of duck eggs, the rate of yolk blackening increased. H2S was produced in the pH range of 7.0–8.0, and the gas production rate was the fastest at pH 7.5. In summary, it can be inferred that yolk blackening in salted duck eggs is caused by the discoloration reaction between sulfur and iron elements in egg yolk. Curing temperature, pH and the bacterial load of duck eggs have a great influence on yolk blackening.

Allantus luctifer is one of the most serious pests of buckwheat, with its larvae mainly damaging leaves during the seedling and flowering stages. Entomogenous fungi play a crucial role as biological regulators of arthropod populations in nature. In this paper, a newly isolated strain 19GZAl-1, was identified as Cordyceps. cateniannulata through the observetions of macroscopic and microscopic morphological features, and the results of rDNA- ITS sequence alignment and phylogenetic analysis. By comparing the efficacy of ten entomopathogenic fungal strains, including six strains of C. cateniannulata and four other Cordyceps species, against A. luctifer larvae, the new strain 19GZAl-1 exhibited the highest mortality rate. Mortality rates of A. luctifer larvae treated by spraying with the strain 19GZAl-1 increased as larval stage decreased, with first instar larvae showing the highest mortality rate of 85%. The appressorium from conidia invaded the larval body through areas with thin cuticle, such as larva pod base and internode folds, after which the hyphae grew rapidly, filling the haemocoel, and finally protruding from the integument upon melanization and decomposition of the intestinal wall cells. The results suggest that the strain 19GZAL-1 of C. cateniannulata has potential against A. luctifer larvae, which is significant for further study on the infection mechanism of C. cateniannulata on insects.

Protein complexes constitute the primary functional modules of cellular activity. To respond to perturbations, complexes undergo changes in their abundance, subunit composition, or state of modification. Understanding the function of biological systems requires global strategies to capture this contextual state information. Methods based on cofractionation paired with mass spectrometry have demonstrated the capability for deep biological insight, but the scope of studies using this approach has been limited by the large measurement time per biological sample and challenges with data analysis. There has been little uptake of this strategy into the broader life science community despite its rich biological information content. We present a rapid integrated experimental and computational workflow to assess the reorganization of protein complexes across multiple cellular states. The workflow combines short gradient chromatography and DIA/SWATH mass spectrometry with a data analysis toolset to quantify changes in a complex organization. We applied the workflow to study the global protein complex rearrangements of THP-1 cells undergoing monocyte to macrophage differentiation and subsequent stimulation of macrophage cells with lipopolysaccharide. We observed substantial proteome reorganization on differentiation and less pronounced changes in macrophage stimulation. We establish our integrated differential pipeline for rapid and state-specific profiling of protein complex organization.

Abstract Aflatoxin, mainly produced by Aspergillus flavus, is one of the most notorious mycotoxin for its toxicity and carcinogenicity. Despite extensive efforts, effective strategies to control A. flavus and AFB1 contamination remain elusive. Here, we investigate the potential of p‐anisaldehyde (AS), an aldehyde derived from plant essential oils, as a natural antifungal agent against A. flavus and its ability to modulate AFB1 biosynthesis. We found that AS exhibited broad‐spectrum antifungal activities against Aspergillus spp. and effectively inhibited A. flavus asexual development, AFB1 production, and pathogenicity. AS treatment disrupted the cell surface structure and membrane integrity, as observed by scanning electron microscopy and PI staining. RNA‐sequencing analysis revealed that AS significantly altered the expression of genes involved in redox homeostasis, plasma membrane function, and cell cycle progression. Further investigation demonstrated that AS induced a reduction in mitochondrial membrane potential (Δψm) and accumulation of reactive oxygen species (ROS), leading to cell cycle arrest at the G2/M phase. The AS‐induced ROS accumulation was found to be mitigated by the superoxide dismutase‐mediated antioxidant system, which is regulated by transcriptional factor Ap1. Notably, the Ap1‐regulatory ROS detoxification system was also found to be involved in A. flavus pathogenicity and AFB1 production. Overall, these findings provide valuable insights into the inhibitory mechanism of AS against A. flavus, paving the way for its potential application as a natural strategy to mitigate AFB1 contamination in both food and agriculture crops.

ABSTRACT Staphylococcus aureus strains exhibit varying associations with atopic dermatitis (AD), but the genetic determinants underpinning the pathogenicity are yet to be fully characterized. To reveal the genetic differences between S. aureus strains from AD patients and healthy individuals (HE), we developed and employed a random forest classifier to identify potential marker genes responsible for their phenotypic variations. The classifier was able to effectively distinguish strains from AD and HE. We also uncovered strong links between certain marker genes and phage functionalities, with phage holin emerging as the most pivotal differentiating factor. Further examination of S. aureus gene content highlighted the genetic diversity and functional implications of prophages in driving differentiation between strains from AD and HE. The HE group exhibited greater gene content diversity, largely influenced by their prophages. While strains from both AD and HE universally housed prophages, those in the HE group were distinctively higher at the strain level. Moreover, although prophages in the HE group exhibited variously higher enrichment of differential functions, the AD group displayed a notable enrichment of virulence factors within their prophages, underscoring the important contribution of prophages to the pathogenesis of AD-associated strains. Overall, prophages significantly shape the genetic and functional profiles of S. aureus strains, shedding light on their pathogenic potential and elucidating the mechanisms behind the phenotypic variations in AD and HE environments.IMPORTANCEThrough a nuanced exploration of Staphylococcus aureus strains obtained from atopic dermatitis (AD) patients and healthy controls (HE), our research unveils pivotal genetic determinants influencing their pathogenic associations. Utilizing a random forest classifier, we illuminate distinct marker genes, with phage holin emerging as a critical differential factor, revealing the profound impact of prophages on genetic and pathogenic profiles. HE strains exhibited a diverse gene content, notably shaped by unique, heightened prophages. Conversely, AD strains emphasized a pronounced enrichment of virulence factors within prophages, signifying their key role in AD pathogenesis. This work crucially highlights prophages as central architects of the genetic and functional attributes of S. aureus strains, providing vital insights into pathogenic mechanisms and phenotypic variations, thereby paving the way for targeted AD therapeutic approaches and management strategies by demystifying specific genetic and pathogenic mechanisms.

The set packing problem is a core NP-complete combinatorial optimization problem which aims to find the maximum collection of disjoint sets from a given collection of sets, S, over a ground set, U. Evolutionary algorithms (EAs) have been widely used as general-purpose global optimization methods and have shown promising performance for the set packing problem. While most previous studies are mainly based on experimentation, there is little theoretical investigation available in this area. In this study, we analyze the approximation performance of simplified versions of EAs, specifically the (1+1) EA, for the set packing problem from a theoretical perspective. Our analysis demonstrates that the (1+1) EA can provide an approximation guarantee in solving the k-set packing problem. Additionally, we construct a problem instance and prove that the (1+1) EA beats the local search algorithm on this specific instance. This proof reveals that evolutionary algorithms can have theoretical guarantees for solving NP-hard optimization problems.