A new strain of Rhodococcus indonesiensis T22.7.1T and its functional potential for deacetylation of chitin and chitooligsaccharides.

Introduction: Chitin, abundant in marine environments, presents significant challenges in terms of transformation and utilization. A strain, T22.7.1T, with notable chitin deacetylation capabilities, was isolated from the rhizosphere of Acanthus ebracteatus in the North Sea of China. Comparative 16S rDNA sequence analysis showed that the new isolate had the highest sequence similarity (99.79%) with Rhodococcus indonesiensis CSLK01-03T, followed by R. ruber DSM 43338T, R. electrodiphilus JC435T, and R. aetherivorans 10bc312T (98.97%, 98.81%, and 98.83%, respectively). Subsequent genome sequencing and phylogenetic analysis confirmed that strain T22.7.1T belongs to the R. indonesiensis species. However, additional taxonomic characterization identified strain T22.7.1T as a novel type strain of R. indonesiensis distinct from CSLK01-03T. Methods: This study refines the taxonomic description of R. indonesiensis and investigates its application in converting chitin into chitosan. The chitin deacetylase (RiCDA) activity of strain T22.7.1T was optimized, and the enzyme was isolated and purified from the fermentation products. Results: Through optimization, the RiCDA activity of strain T22.7.1T reached 287.02 U/mL, which is 34.88 times greater than the original enzyme's activity (8.0 U/mL). The natural CDA enzyme was purified with a purification factor of 31.83, and the specific activity of the enzyme solution reached 1200.33 U/mg. RiCDA exhibited good pH and temperature adaptability and stability, along with a wide range of substrate adaptabilities, effectively deacetylating chitin, chitooligosaccharides, N-acetylglucosamine, and other substrates. Discussion: Product analysis revealed that RiCDA treatment increased the deacetylation degree (DD) of natural chitin to 83%, surpassing that of commercial chitosan. Therefore, RiCDA demonstrates significant potential as an efficient deacetylation tool for natural chitin and chitooligosaccharides, highlighting its applicability in the biorefining of natural polysaccharides.

A Comparative Transcriptome Analysis Unveils the Mechanisms of Response in Feather Degradation by Pseudomonas aeruginosa Gxun-7.

Microbial degradation of feathers offers potential for bioremediation, yet the microbial response mechanisms warrant additional investigation. In prior work, Pseudomonas aeruginosa Gxun-7, which demonstrated robust degradation of feathers at elevated concentrations, was isolated. However, the molecular mechanism of this degradation remains only partially understood. To investigate this, we used RNA sequencing (RNA-seq) to examine the genes that were expressed differentially in P. aeruginosa Gxun-7 when exposed to 25 g/L of feather substrate. The RNA-seq analysis identified 5571 differentially expressed genes; of these, 795 were upregulated and 603 were downregulated. Upregulated genes primarily participated in proteolysis, amino acid, and pyruvate metabolism. Genes encoding proteases, as well as those involved in sulfur metabolism, phenazine synthesis, and type VI secretion systems, were notably elevated, highlighting their crucial function in feather decomposition. Integration of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) taxonomies, combined with a review of the literature, led us to propose that metabolic feather degradation involves environmental activation, reducing agent secretion, protease release, peptide/amino acid uptake, and metabolic processes. Sulfite has emerged as a critical activator of keratinase catalysis, while cysteine serves as a regulatory mediator. qRT-PCR assay results for 11 selected gene subset corroborated the RNA-seq findings. This study enhances our understanding of the transcriptomic responses of P. aeruginosa Gxun-7 to feather degradation and offers insights into potential degradation mechanisms, thereby aiding in the formulation of effective feather waste management strategies in poultry farming.

Innovation of Network Political and Ideological Education in Colleges Based on Service Concept in Network Environment.

With the ongoing advancement of information technology, we must adopt the proper mindset when addressing the opportunities and difficulties that political thought education in institutions of higher learning face in the current network environment, take full advantage of the network's benefits, and take proactive steps to address the innovation of political thought education in institutions of higher education under the network environment. Based on the field of political thought education itself, this article studies the new characteristics of political thought education communication in institutions of higher learning under the network environment, analyses the problems and causes in the process of political thought education innovation in institutions of higher learning under the network environment, and explores a number of measures to improve the innovation level of political thought education under the network environment. This article describes the significance, traits, and internal connections between network media and the innovative development of political thought education in higher education institutions and proposes a cutting-edge course for the advancement of political thought education in higher education in the network era. In parallel, a system for early detection and evaluation of political thought education in higher education institutions is being built. The accuracy of this algorithm, according to experiments, can reach a high level of 95.31%, which is impressive. This study has served as a guide and a source of encouragement for institutions of higher learning to use network carriers to deliver political thought education.

A Net Meta-Analysis of the Effectiveness of Different Types of Dressings in the Treatment of Diabetic Foot.

Objective: This is an analysis of the impact of a new dressing commonly used to treat diabetic foot (DFU). Methods: Chinese and English databases were searched to collect clinical randomized controlled studies (RCTs) of various types of dressings for the treatment of DFU, and the healing rates of the different dressings were combined by reticulation meta-analysis. Results: The aggregate of the 36 RCTs included in this study analysed the healing rates of nine dressings: conventional dressing, alginate dressing, chitosan dressing, hyaluronic acid dressing, platelet-rich plasma dressing, amniotic membrane dressing, honey dressing, human recombinant growth factor dressing, and silver ionomer dressing. Conclusion: Hyaluronic acid dressing, amniotic membrane dressing, honey dressing, and platelet-rich plasma dressing are the ideal materials for topical treatment of DFU.

The Protective Effect of Caring for Grandchildren on the Mental Health of the Elderly: A Structural Equation Modeling Analysis.

Population aging has become a common problem all over the world, and the process of China's population aging is developing rapidly. China has made active aging a national development strategy, giving full attention to the physical and mental health of the elderly. Bloodline and family continuity make the Chinese elderly attach great importance to the responsibility of caring for grandchildren. This study takes the elderly as the research center, and aims to investigate the relationship between caring for grandchildren and the mental health of the elderly in China, and whether participation in social activities mediates such an association. Adopting the data from the 2018 China Health and Retirement Longitudinal Study (CHARLS), a Chi-squared test and multiple regression results showed that caring for grandchildren significantly improved the mental health level of the elderly in China, and the results were still valid after the use of the Propensity Score Matching (PSM) to solve the endogenous problems. Analysis of the mediating effects using the Structural Equation Model (SEM) showed that caring for grandchildren indirectly contributed to the reduction of depression by increasing the diversity and frequency of participation in social activities. The constant adjustment of China's fertility policy increases the possibility of the elderly caring for multiple grandchildren, and prolongs their time of caring for grandchildren. The elderly caring for grandchildren is a proactive choice, which continuously relieves the child-rearing stress, and highlights the family value and social value of the elderly. At the same time, raising and accompanying grandchildren makes the elderly's lives more fulfilling and positive, which in turn promotes participation in social activities, and the mental health of the elderly.