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Background: Biofilm is described as an accumulation of microbial organisms connected to a living or unmoving surface mainly through self-secreted polymeric materials. With a complete understanding of biofilm behaviors and the role of rhamnolipids in its stability or dispersion, a new path could be designed in the treatment of infections like Pseudomonas aeruginosa (P. aeruginosa). The purpose of this study was to investigate the role and function of rhamnolipids in P. aeruginosa velocity and biofilm formation ability.
Materials & Methods: In this study, 68 P. aeruginosa clinical samples were isolated from February 2022 to 2023 and confirmed based on culture and molecular methods. The presence of genes associated with di-rhamnolipid (rhlC) and mono-rhamnolipid (rhlA and rhlB) biosynthesis was detected by PCR method. For velocity assay, bacterial cultures on Bushnell Haas medium were monitored for 24 and 72 hours (0.5%).
Findings: The results showed that the distribution of biofilm strength among P. aeruginosa strains was normal. The frequency of rhlC was significantly different from those of rhlA and rhlB (p= .01). In the first 24 hours, the velocity of P. aeruginosa on Bushnell Haas with glucose was 2 µm/min and decreased during 72 hours. But after 72 hours, the velocity of moderate and weak biofilm-producing strains on solid medium with glycerol was constant.
Conclusion: In this study, rhamnolipids produced from different carbon sources showed different behaviors on colony shape, velocity, and strength of bacterial biofilms.

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This study focuses on the significant lines of development characterizing the history of educational research methodology in Iran. A “historical case study” employed to collect, verify, and synthesize evidence about the same as such appeared in the Quarterly Journal of Education. The results indicated that the educational research in Iran has experienced five, distinct yet, overlapping and simultaneously operating historical moments. The first is the pre-methodology (1919- 1985) stage, during which scholars carried out their investigations without a distinct systematic scientific method. The second (1985- 1994) is a period of rising quantitative approach, during which quantitative methods were becoming central in the education field. The third (1995- 2004) is characterized by insistence on the monopoly of quantitative, during which educational and other social science researchers relied primarily on quantitative methods and statistical inference understood as a means to test the proposed hypotheses. The fourth (2005–2014), is a replacement stage started with the wave of qualitative taking over the traditional and provoked the appearance of a new hegemony. The concern for quality stage (2015-2019) is the fifth when the threat of losing credibility and leaving a relativistic impression were considered by members of the research community. It is concluded that Iran’s educational research urgently requires mobilized and rationalized methodological pluralism with the ultimate goal of improving on existing pedagogical practices.