This study aimed to prepare monoclonal antibodies against human β2-MG and to establish rapid and accurate quantitative and qualitative immunoassay methods for β2-MG detection. Recombinant β2-MG was produced through prokaryotic expression and purification, and subsequently used for immunizing BALB/c mice. Monoclonal antibodies against human β2-MG were generated using hybridoma technology and screened via double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), which facilitated the development of a chemiluminescence enzyme immunoassay (CLEIA). Clinical serum β2-MG levels were measured to evaluate and analyze the detection performance of the proposed CLEIA. Additionally, a convenient and rapid colloidal gold immunochromatographic assay for β2-MG detection was preliminarily established. The monoclonal antibody pair 5H7/6H9-AP was developed into the CLEIA, demonstrating a linear range of 0.14-120.00 μg/L (extended to 60.00 mg/L). The serum β2-MG CLEIA results showed excellent correlation with the latex enhanced immunoturbidimetry assay conducted in hospitals (R²: 0.96, P<0.000 1). The established colloidal gold immunochromatographic assay exhibited good sensitivity for detecting recombinant β2-MG, with test strips capable of detecting a minimum concentration of 0.20 mg/L. The prepared monoclonal antibodies for β2-MG, along with the established quantitative and qualitative immunoassay methods, hold significant potential for clinical diagnostic applications.

Steroids are the second-largest category of clinical drugs following antibiotics, with significant physiological functions such as anti-inflammatory, antiviral, antitumor, and antihypertensive effects, bearing a huge market demand. Currently, the mainstream industrial approach for steroid drugs production is microbial semi-synthesis, which involves microbial degradation of phytosterols into steroid-drug intermediates (precursors) followed by chemical modification. This review focuses on Mycobacterium sp., a representative strain used for synthesizing steroid-drug intermediates, and outlines the key steps in its steroid metabolic pathway, including sterol uptake, initial oxidation of sterol nucleus, side chain degradation, further oxidation of sterol nucleus, and nucleus cleavage, along with the key enzymes involved. Furthermore, the genetic modification systems of gene overexpression, knockout and knockdown applicable to Mycobacterium are summarized. However, the identification and characterization of complex enzyme systems in the degradation process of sterol side chain remains a major challenge in current research and a key bottleneck restricting the development of novel steroid-drug intermediates. Therefore, accelerating the analysis of sterol metabolic pathways by high-throughput sequencing, bioinformatics analysis and site-directed saturation mutagenesis is essential for the rational design of mycobacterial cell factories and for the construction of strains with high-yield of new steroid intermediates.

Long-term excessive application of chemical fertilizers in agricultural production has led to soil quality degradation and environmental problems, which to some extent restricts the green development of modern agriculture. Microbial fertilizers can enhance crop yield and quality, improve stress resistance, and reduce environmental pollution. This paper provides an overview of the characteristics, development history, and classification of microbial fertilizers, with a focus on elucidating their mechanisms which include regulating plant hormones (such as salicylic acid and auxin) to influence plant immunity and development, improving soil aggregation through physical entanglement and secretion of extracellular polymers, as well as activating soil nutrients by secreting siderophores, solubilizing phosphates, and participating in nitrogen fixation and nitrification processes. The application prospects and trends in technology development of microbial fertilizers are analyzed and summarized from macro, market, and technical perspectives. Considering the agricultural context of Liaoning Province as a major grain-producing region, the current status and regional advantages of microbial fertilizer development in Liaoning are examined. Finally, future development directions for China's microbial fertilizer industry are discussed, aiming to provide references for the research and application of microbial fertilizers.

Polycyclic aromatic hydrocarbons (PAHs), as a typical class of organic pollutants, are difficult to naturally degrade in the environment. However, microorganisms, by virtue of their environmental adaptability, play an irreplaceable role in the degradation process of PAHs. Therefore, the development of efficient laboratory isolation and cultivation techniques for PAHs-degrading microorganisms has become a research direction. This article reviews the types of PAHs-degrading microorganisms, as well as their cultivation techniques and methods. It points out the different mechanisms of microbial degradation of polycyclic aromatic hydrocarbons, including bacteria, fungi, algae (specifically microalage belonging to the category of microorganisms), and actinomycetes, etc., and their metabolic pathways for degrading PAHs under aerobic or anaerobic conditions. Additionally, it discusses different types of traditional and novel cultivation techniques, and makes a comparative analysis of the characteristics and applications of traditional cultivation techniques (such as optimizing the composition of the culture medium and adjusting the structure of the culture medium, etc.) and novel cultivation techniques (such as cell sorting technology, etc.). This is helpful for screening more effective cultivation methods, exploring more PAHs-degrading microorganisms, further promoting the research on polycyclic aromatic hydrocarbon-degrading microorganisms, and providing theoretical basis and technical support for solving the problem of PAHs pollution.

The comprehensive experimental course of microbial engineering is one of the core courses of the National Characteristic Major and the National First-class Undergraduate Major in biotechnology. The course content is closely integrated with the needs of national and local industries, based on practical production and scientific problems, and consists of eight comprehensive research-based experimental projects. The teaching process is principally based on students' independent experimentation, supplemented by teacher guidance, and implemented in six stages:pre-class mobilization, plan formulation and demonstration, independent experimentation and process management, experiment summary and analysis, report writing, and academic evaluation. The course places emphasis on cultivating students' program design ability, comprehensive practical ability, problem analysis ability, and other pertinent skills. It fosters an environment characterized by cooperative learning, joint exploration, and mutual assistance, thereby enhancing students' comprehensive practical innovation ability and their capacity to address complex engineering challenges. The teaching reform of the course has achieved marked effect, laying an important foundation for the teaching reform and innovation of comprehensive research-based experimental courses. The objective of this initiative is to serve as a valuable reference point for colleagues engaged in the instruction of associated course offerings. This objective is to be realized through the development and enhancement of a novel, integrated experimental curriculum in microbial engineering.

The starch-binding domains (SBDs) are structurally and functionally independent non-catalytic protein module widely found in carbohydrate active enzymes (CAZymes), and they play an important role in the degradation process of raw starch in ecological environment. In nature, SBDs effectively lead the catalytic domain to the substrate surface by specifically binding to starch granules or other polysaccharides, significantly enhancing the hydrolytic efficiency of enzymes. In addition to the non-hydrolytic disruptive activity on the structure of starch granules, SBDs widely influence many catalytic properties of host enzymes, including substrate specificity, environmental adaptability (thermostability, salt tolerance, and cold adaptation), and oligomerization state. These roles demonstrate their adaptive function in helping host microorganisms to compete for carbon sources in complex habitats. Here, we summarized the distribution characteristics, functional mechanisms, and multiple effects of SBDs on host enzyme functions in terrestrial and marine ecosystems. The main experimental methods for studying SBD functions, including domain deletion, functional characterization of binding and disruption, are also introduced. A broader and deeper understanding of SBDs enhances our knowledge of microbial competition for carbon sources in natural environments, as well as provides novel approaches for the rational design of industrial enzymes.

Biopolymers have significant influences and regulatory effect on microbial mineralization processes and precipitate characteristics. In this study, xanthan gum (XG) served as the biopolymer, and Klebsiella aerogenes was utilized as the carbonate mineralizing bacterium, the regulatory effects and mechanisms of XG concentrations on the precipitation yield, particle size, crystalline polymorph, and morphological characteristics of calcium carbonate precipitation induced by K. aerogenes were explored systematically. The results showed that when the calcium concentrations were 0.25 mol/L and 0.50 mol/L, and the XG concentrations were 0.50 g/L and 0.75 g/L, respectively, the precipitation yield of calcium carbonate was 25.00% and 9.60% greater than that of the control group, respectively. With the amount of XG addition increasing, at low calcium concentrations (0.25 mol/L), the proportion of calcite decreases and the proportion of vaterite increases, and gradually to be stabilizing. At high calcium concentration (0.50 mol/L), the proportion of calcite tends to increase first and then to decrease, whereas the proportion of vaterite tends to decrease and then gradually to stabilize. Compared with those of the control group, the average particle sizes of the calcium carbonate crystals in the two calcium concentrations groups decreased by 44.50% (0.25 mol/L) and 64.40% (0. 50 mol/L). Meanwhile, the addition of XG promoted the formation of spherical or spheroidal-like calcium carbonate morphology. These findings provide a new strategy for the precise and customized regulation of microbial mineralization.

In this study, fungal diversity was analyzed and antimicrobial activity isolates were screened from Eling Lake to enrich the fungi diversity in the extreme environment and to provide basic materials for subsequent development of biocontrol agents. Ten sediment samples were collected from shoreside of Eling Lake, and fungi were isolated by dilution separation method using seven selective mediums. The isolated fungi were identified by morphological characteristics and rDNA-ITS sequence phylogenetic analysis, and antimicrobial activity isolates were screened by confront culture method. One hundred and forty-four fungi isolates were obtained, belonging to totally 22 genera of Ascomycota, Mucoromycota and Zygomycota. Seven high antimicrobial activity isolates were screened from one hundred and forty-four fungi isolates, they had a broad spectrum of antimicrobial activity on eight fungi pathogens from maize, highland barley and wheat. Moreover, they were Phaeosphaeria and Emericellopsis, respectively. These results showed that sediment fungi resource in Eling Lake was abundant and have certain biocontrol and utilization value.

To reduce nitrogen loss during aerobic composting, enhance compost fertility, and minimize environmental pollution, this study used cattle manure as the material to isolate a highly efficient heterotrophic nitrifying strain of NB-2. Through morphological characterization and 16S rRNA gene sequence analysis, the strain was identified as Alcaligenes faecalis. Further research showed that NB-2 exhibited significantly enhanced ammonia oxidation capacity under the conditions of sodium citrate as the carbon source, C/N ratio of 15, temperature of 35 ℃, and pH of 9.0. The ammonia nitrogen () removal rate reached 100% at 32 hours, with a removal rate as high as 33.38 mg/(L·h). This study demonstrated the potential of strain NB-2 in composting applications to reduce nitrogen losses while improving fertilizer quality and efficiency, thereby promoting the sustainable development of the livestock industry.

In this study, we performed 16S rRNA high-throughput sequencing to examine the diversity of endophytic bacterial communities in Gymnadenia conopsea growing at four different locations on Mount Sejila. The results revealed that a total of 715 920 effective sequences were obtained from all samples, which were associated with 2 365 operational taxonomic units, classified within five phyla, 38 families, and 62 genera. Proteobacteria was identified as the dominant bacterial phylum and the predominant genera were Pseudomonas, Methylbacterium, and Sphingomonas. Diversity analysis revealed that among the collected samples, the stem samples（LHS）collected at the Linhai Observation Deck were characterized by the highest endophytic bacterial community richness, whereas the richness of fruit samples（LDF）collected from the Radar Station was the lowest. The stem samples（FMS）from the Abandoned Wood Factory site were found to have the highest diversity of endophytic bacterial communities, and the diversity indices of communities in the stems, leaves, and fruits of plants growing at this sampling point（FM）at a lower altitude were higher than those recorded at the other three sampling points. Among the four types of tissue collected, the richness of endophytic bacterial communities in the stems, leaves, and roots was higher than that in the fruits, and we found that the diversity and richness of endophytic bacterial communities in fruits declined with increasing altitude, with the values obtained for the endophytic bacteria in fruit pods（LDF）being the lowest. Furthermore, we detected significant differences in the diversity of endophytic bacterial communities in the same tissue in different habitats, whereas there were differences in the diversity of endophytic bacteria within the different tissues of plants growing in the same habitat. Principal coordinate analysis indicated that the composition of endophytic bacterial communities was influenced by environmental factors and tissue types, and redundancy analysis and correlation heatmaps provided evidence to indicate that total phosphorus, total potassium, pH, and altitude were the main influencing factors, significantly correlated with the composition of these endophytic bacterial communities. Moreover, PICRSt prediction analysis revealed that the endophytic bacteria in G. conopsea were mainly enriched in three primary metabolic pathways, namely, metabolism, environmental information processing, and genetic information processing, and the activity of most of the identified metabolic pathways was found to show a declining trend with increasing altitude. This study employed high-throughput sequencing technology to analyze the effects of environmental factors and tissue types on the diversity and community structure of endophytic bacteria in G. conopsea. It aims to enrich and improve the resources of endophytic bacteria in wild G. conopsea, laying a foundation for the future resource development of beneficial endophytic bacteria and the protection of wild G. conopsea.