Construction and Practice of a Teaching Model for the Bacterial Gram Staining Experiment from a Project-Based Perspective

Abstract

In alignment with the talent development goals of Environmental Engineering under the framework of Emerging Engineering Education, this study aims to improve the practical relevance and overall effectiveness of microbiology laboratory teaching. Using the bacterial Gram staining experiment as a representative case, an integrated teaching model was designed and implemented by combining project-based learning, experimental inquiry, result presentation, and feedback-oriented evaluation. The model was applied to second-year undergraduate students majoring in Environmental Engineering within an authentic project context related to soil microbial analysis. Students completed a structured sequence of tasks, including soil sample collection, microbial isolation and cultivation, Gram staining, and microscopic observation. A multi-dimensional assessment system was established to evaluate students’ experimental operation skills, the quality of laboratory reports and group presentations, and learning attitudes, enabling a comprehensive evaluation of teaching outcomes. The results indicate that the proposed model standardized experimental procedures and enhanced the clarity, coherence, and rigor of laboratory records and reports. Compared with traditional teaching methods, both pass rates and excellence rates in experimental assessments improved. Students reported higher motivation, stronger problem-solving ability, better teamwork, and clearer understanding of engineering applications.