This book serves as a comprehensive summary of the priority program SPP 1934, which focused on understanding the dispersity, structure, and phase changes of proteins and bio-agglomerates in biotechnological processes. Through contributions from various research groups, the program explored how sensitive proteins and bio-agglomerates are affected by the process environment during fermentation, downstream processing, and formulation. It investigated these effects across three size scales: microscale, encompassing single proteins, clusters, crystals, and virus-like particles; mesoscale, focusing on cells and cell clusters; and macroscale, examining overall process dynamics. The main objective was to enhance biotechnological process chains by elucidating the mechanical, thermal, and chemical stresses that impact protein and bio-agglomerate structures. By gaining insights into these stressors, the program aimed to enable precise control measures to mitigate denaturation and unfavorable growth of proteins and cells. This compilation seeks to contribute to the optimization of biotechnological processes, facilitating advancements in various industries.