Objective Chondroitinases are crucial enzymes for the preparation of low-molecular-weight chondroitin sulfate (CS), yet the existing enzymes are insufficient to meet the demands of diverse applications, highlighting the need to discover novel chondroitinases with enhanced properties. Methods A novel chondroitinase belonging to the polysaccharide lyase family 8 (PL8), designated SlChase, was discovered and identified from the model strain Streptomyces lividans TK24. Following heterologous expression in Escherichia coli and the subsequent purification, a soluble and highly active recombinant SlChase was successfully obtained. Results This enzyme exhibited substantial activity within the temperature range of 30-40 ℃ and pH range of 5.5-6.5, and demonstrated excellent long-term stability during storage at 4 ℃. Mg²⁺ and dithiothreitol (DTT) moderately enhanced its catalytic activity, whereas metal ions including Zn²⁺ and Fe³⁺ exerted inhibitory effects on its activity. Notably, SlChase displayed prominent activity towards unsulfated chondroitin (CS-0S), whereas its catalytic activity towards chondroitin sulfate A/C was drastically decreased. Conclusion The discovered SlChase not only expands the diversity of PL8 family enzymes but also affords a novel enzymatic tool for the specific degradation of unsulfated chondroitin, with promising applications in glycoscience research and related biocatalytic processes. Furthermore, this study provides a paradigm for the exploration and utilization of enzymatic resources derived from Streptomyces spp.

Engineered microorganisms, as the core driving force of biomanufacturing and the development of the new bio-economy, demonstrate increasingly prominent strategic values. The newly built Engineered Microorganisms and Genetic Tools Collection Center of China (EMTCC) supported by the Ministry of Education aims to break through the limitations of “microbial culture collection centers” and provide a comprehensive resource innovation service platform supported by information technology and integrating resource acquisition, intelligent creation, data analysis, and open sharing functions. This platform intends to meet the needs of basic research, technology development, and industrial applications. This article elaborates on the building framework of EMTCC, which takes large-scale resource preservation as the basis, intelligent mining and analysis as the core, and digital storage and computing sharing as the link. By carrying out large-scale acquisition and standardized preservation of natural and engineered microorganisms and plasmids and integrating cutting-edge technologies such as high-throughput automation, multi-omics, single-cell analysis, artificial intelligence prediction models, and digital twins, the EMTCC achieves a complete process of “acquisition & preservation, analysis & identification, and data sharing”. On the basis of drawing on the standardization and quality control systems of internationally renowned institutions such as American Type Culture Collection (ATCC), a resource repository model integrating living “organisms, information, and intelligence” will be developed. This innovative practice is expected to provide strong resource guarantee and technical support for research innovation and industrial upgrading in the fields of synthetic biology, metabolic engineering, biomedicine, and environmental remediation.

The dynamic balance between the preservation and distribution of microbial patent strains, the “gene chips” of biotechnology, has become a crucial benchmark for assessing a country’s competitiveness in the bioeconomy. By comparing the global data on the preservation and distribution of patent strains from 2001 to 2023, this paper systematically analyzes the gaps between China, the United States, and other countries in terms of resource reserves and circulation efficiency. The results revealed that while China was a global leader in preservation volume, its strain distribution rate lagged far behind the international level, which restricted technological innovation and industrial transformation. This study proposes comprehensive strategies such as optimizing the preservation systems, enhancing policy coordination, promoting industry-education-research collaborative innovation, strengthening international cooperation, and applying artificial intelligence and blockchain technologies throughout the entire chain. These strategies are designed to enhance the utilization rate of microbial strains, activate the value of China’s patent microbial resources, and position China at the forefront of the global bioeconomy.

Objective To elucidate the diversity and community composition of endophytic and rhizospheric bacteria associated with Apocynum venetum in northern Xinjiang and to screen the strains with efficient and specific degumming potential. Methods Samples of A. venetum were collected from four regions: Karamay, Fukang, Urumqi, and Turpan. The bacterial community structure was analyzed by 16S rRNA gene high-throughput sequencing. Pure-culture techniques were employed for strain isolation, and functional strains exhibiting xylanase and pectinase activities but lacking cellulase activity were screened by Congo red staining and enzyme activity assays. Results High-throughput sequencing identified 872 genera of bacteria belonging to 345 families of 38 phyla, among which Pseudomonadota and Actinomycetota were the dominant phyla. Bacterial abundance and diversity followed the order: rhizospheric soil>root>leaf>stem. Microbial abundance and diversity at the Turpan site were lower than those at the other sampling sites. A total of 361 bacterial strains were isolated in pure culture, belonging to 86 genera, 47 families of 4 phyla. Nine specific degumming strains were screened out, of which seven (77.78%) strains were endophytes derived from stems and leaves. The optimal functional strain, Bacillus rugosus (VFS.M1.04), showed xylanase and pectinase activities of 2 237 U/mL and 1 002 U/mL, respectively. Conclusion The community structures of endophytic and rhizospheric bacteria associated with A. venetum are significantly influenced by habitats and plant parts. Bacillus is the dominant functional genus, and the homologous screening strategy effectively enables the acquisition of elite strains with strong degumming capacity and no cellulose degradation from stem and leaf endophytes. This study provides valuable microbial resources and a theoretical basis for developing a green biological degumming process for A. venetum. These findings support the targeted exploitation of plant-associated microbial strains for sustainable fiber processing.

Quorum sensing (QS) is a communication mechanism through which microorganisms secrete and sense signal molecules to regulate mircobial population behaviors. QS plays important roles in biofilm formation and gut colonization of probiotics. In recent years, interfering with the QS of probiotics has become a trending research field of synthetic biology. In this review, we summarize the distribution of QS systems in probiotics and highlights interfering strategies designed to regulate probiotic functions. We summary currently identified QS systems in probiotics and their detection methods, such as photoelectrochemical assays and chromatography-mass spectrometry techniques. Meanwhile, this review outlines the QS interfering approaches for probiotics, including the use of QS agonists and the optimization of related metabolic pathways. Finally, the probiotic intervention strategy targeting QS is proposed in this paper, providing a novel approach for regulating the efficacy of engineered probiotics, which is of great significance for the development and improvement of probiotic functional foods.

Objective To explore the nitrogen and phosphorus removal efficiency of different immobilization strategies and mineralization methods of Bacillus licheniformis ZXT for high nitrogen-phosphorus wastewater, clarify the optimal mineralization conditions and carrier mechanism of action, and provide technical support for the green treatment and recovery of complex high nitrogen-phosphorus wastewater resources such as swine manure wastewater. Methods Four systems—free bacteria, chemical precipitation, activated carbon fiber (ACF) immobilization, and polyvinyl alcohol-sodium alginate-carbon powder (PVA-SA-CP) immobilization—were compared for their mineralization effects under Mg:N:P molar ratios of 0.6:1:1, 1:1:1, and 1.4:1:1. Characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to analyze mineral properties. The application potential of the systems was verified with actual swine manure wastewater. Results The ACF immobilization system exhibited the optimal efficiency. Under the Mg:N:P ratio of 1:1:1, after seven days of cultivation, the final concentration of NH₄⁺ was only 0.59 mg/L (removal rate: 99.81%) and the final concentration of PO₄^3- was as low as 0.03 mg/L (removal rate: 99.99%), both meeting the national discharge standards (GB 8978—1996), with the formation of regular crystalline long plate-like struvite (i.e., magnesium ammonium phosphate, MAP). The PVA-SA-CP immobilization system showed significantly weaker removal effects under the same ratio, with final concentrations of NH₄⁺ and PO₄^3- being 5.07 mg/L and 0.45 mg/L, respectively. The chemical precipitation method failed to meet the standards, as the final concentration of NH₄⁺ ranged from 38.90 to 48.01 mg/L (removal rate: 84.70%-87.61%) within 24 h. Free bacteria achieved the removal rates of 99.97% for NH₄⁺ and 99.92% for PO₄^3- in actual swine manure wastewater after eight days of cultivation, with final NH₄⁺ and PO₄^3- concentrations of 0.15 mg/L and 0.05 mg/L, respectively, which complied with the discharge requirements. Conclusion Due to its developed microporous structure and good biocompatibility, ACF can efficiently enrich bacteria and promote the regular assembly of extracellular polymeric substances. The mineralization with ACF-immobilized B. licheniformis ZXT is the optimal choice, with Mg:N:P=1:1:1 as the best mineralization ratio. This technology can achieve efficient purification of high nitrogen-phosphorus wastewater and recovery of nitrogen and phosphorus resources, thus having important application value in actual wastewater treatment.

Objective To systematically investigate the diversity of culturable yeasts in extreme environments (glaciers, salt lakes, deserts, etc.) of western China and explore yeast resources with special stress resistance traits. Methods Multiple substrate samples were collected from representative extreme environments. Eight media with different nutrient gradients were employed in combination with direct dilution plating and enrichment culture methods for yeast isolation. Strains were identified by 26S rDNA D1/D2 region sequence analysis. Multivariate statistical analysis was carried out to assess species diversity and community structure differences across habitats and culture methods. Results A total of 904 yeast strains were isolated, representing 77 species, 29 genera, 17 orders, 10 classes, 5 subphyla, and 2 phyla, including 11 potential new species. Basidiomycota was the dominant phylum (90.5%), and Naganishia, Rhodotorula, and Cystobasidium were the dominant genera. Distinct dominant species were observed among different habitats. Naganishia adeliensis and Naganishia albida were widely distributed across all investigated extreme environments, indicating strong broad-spectrum environmental adaptability. Rhodotorula mucilaginosa and Cystobasidium slooffiae were dominant species in glaciers and salt lakes. In addition, enrichment culture and oligotrophic media significantly improved the isolation efficiency of rare species. Conclusion Extreme environments in western China harbor remarkably rich yeast resources. While different extreme environments select for unique dominant groups, certain broadly adaptable polyextremophilic species are shared across environments. Extreme environments serve not only as a reservoir of new species but also potentially as an environmental reservoir for opportunistic pathogenic yeasts.

Objective The saline-alkaline habitats in Xinjiang harbor rich and unique microbial resources. This study employed the culture-dependent way to explore the culturable microbial resources and reveal their diversity and potential functions from seven different saline-alkaline habitats, including Barkol Lake and Aiding Lake in Xinjiang. Methods Soil and sediment samples were collected from the seven saline-alkaline habitats. Thirteen modified media were designed and used for strain isolation via the gradient dilution plating method. The 16S rRNA gene sequencing, phylogenetic analysis, and multi-condition culture were employed to analyze the taxonomic positions, suitable media, and salinity adaptability of the strains. Furthermore, potential novel taxa, anaerobic strains, and exopolysaccharide (EPS)-producing strains were screened. Results A total of 935 bacterial strains were isolated and identified as 310 species belonging to 125 genera, 54 families, 25 orders, 8 classes of 4 phyla, including 20 strains representing 15 potential novel taxa. The dominant culturable taxa were Bacillota, Pseudomonadota, and Actinomycetota. In addition, 52 strains (20 species) of anaerobic bacteria were obtained, with the genus Halomonas being dominant. The microbial resources varied significantly among different media, and R2A was the most effective medium, screening out 108 species. Bacillus was dominant under no salt stress (0 NaCl), and Marinobacter was one of the important genera under moderate salt stress (5% NaCl). However, the genus Halomonas kept being dominant under low-salt (0 NaCl), moderate-salt (5% NaCl), or high-salt (10% NaCl) stress. To obtain the functional strains with extremely strong stress resistance, we screened 15 EPS-producing strains under high-salt and high-alkali conditions. Among them, Marivirga harenae EGI S10258 and Halomonas alkaliantarctica EGI S10283 showed the highest EPS titer, which reached 4.5 g/L. Conclusion The saline-alkaline habitats in Xinjiang were rich with culturable microbial resources. The application of a multi-condition culture approach significantly enhances the depth and breadth of microbial resource exploration. This study provides important microbial resources and data support for subsequent research on systematic taxonomy, ecological adaptation mechanisms, and resource utilization by getting potential novel species and functional strains.

Kitchen waste contains recalcitrant lipids that are prone to rancidification and can cause environmental pollution. Objective To isolate efficient lipase-producing strains from kitchen waste, optimize their enzyme production conditions, and evaluate the lipid-degrading potential of their extracellular products in kitchen waste. Methods Lipase-producing strains were isolated from canteen swill via the neutral red medium and identified based on morphological characteristics and 16S rRNA gene sequences. Lipase production conditions were optimized through single-factor experiments and response surface methodology. The properties of the lipase and the emulsification performance of extracellular polymeric substances (EPS) were analyzed. Results A strain designated C24202, exhibiting strong lipase- and biosurfactant-producing activity, was isolated and identified as Stenotrophomonas maltophilia. The fermentation conditions were optimized as follows: lactose 10.0 g/L, yeast extract 7.5 g/L, emulsified soybean oil 40.0 g/L, FeSO₄ 8.0 g/L, and incubation at 34 ℃ and initial pH 6.5 for 72 h. Under these conditions, the lipase activity reached (229.64±2.17) U/mL, representing a 2.55-fold increase compared with the pre-optimization level. The lipase exhibited an optimal temperature of 60 ℃ and retained 50.70% of its activity after incubation at 50 ℃ for 6 h, demonstrating good thermal stability. The EPS produced by strain C24202 showed strong emulsifying capacity, with an EI₂₄ value of 46.92%. FTIR analysis suggested that the EPS may be polymeric glycolipopeptide-type biosurfactants. Conclusion Strain C24202 possesses dual capabilities of producing thermostable lipase and biosurfactants, demonstrating promising potential for lipid degradation and the treatment of oil-containing wastewater.