Undergraduate students exploring microorganisms in fermented milk products using basic microscopes and smartphone cameras

Students of an undergraduate class were trained to explore microorganisms in milk products. Fermented curd/yogurt prepared at home was compared with commercial milk products for the presence of bacteria and yeast. Students visualized Gram-stained samples with a basic microscope and captured images by adjusting their smartphone on the eyepiece. They estimated the dimensions of the organisms using the images, after factoring in the smartphone's magnification and the microscope's field of view (FOV). Students could appreciate the health benefits of fermented milk products prepared at home by monitoring the prevalence of Gram-positive bacilli. Undergraduate teachers can readily adopt this pedagogy approach to give hands-on training to students in large labs, even within economically constrained setups.