[P002] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P01-056] Light-Modulated Regulatory Control of Morphogenesis and Lipstatin Biosynthesis in Streptomyces toxytricini

○Deepanshi .¹, Kashyap Kumar Dubey¹ (1. School of Biotechnology, Jawaharlal Nehru University (India))

Keywords:

Streptomyces,Bacteriophytochrome,Lipstatin,Anti-Obesity Drug,Light

The production of secondary metabolites in Streptomyces toxytricini is intricately associated with its complex life cycle and responsiveness to environmental cues. Among these factors, light remains an underexplored regulator of both morphological differentiation and metabolite biosynthesis. The present study evaluates the spatiotemporal influence of light on biomass accumulation, pellet morphology, and lipstatin production under submerged cultivation conditions. Growth kinetics analysis demonstrated that exposure to red light significantly enhanced biomass accumulation relative to dark (control) conditions by approximately 4-fold. Microscopic observations (10×) and scanning electron microscopy revealed pronounced morphological alterations, including a 200 % reduction in pellet size under red light compared to dark and white light conditions, indicating modulation of mycelial architecture. These morphological and physiological changes were accompanied by a marked enhancement in lipstatin production under red light, resulting in a 5-fold increase compared to dark controls. The observed correlation between biomass, morphology, and metabolite yield suggests coordinated regulation of growth and secondary metabolism. Genome mining and conserved domain analysis identified two putative bacteriophytochromes, StBphP1 (1488 bp) and StBphP2 (3180 bp), which were further validated through gene amplification. In silico characterization indicated that StBphP1 (~52.1 kDa) and StBphP2 (~111.6 kDa) lack signal peptides and possess conserved domains consistent with light-sensing histidine kinases. Structural prediction and phylogenetic analysis support their potential role as photoreceptors mediating light-responsive regulation. Furthermore, systems-level analysis integrating protein–protein interaction mapping, functional clustering, and pathway annotation revealed interconnected modules comprising two-component regulatory systems, lipstatin biosynthetic gene clusters, and morphological differentiation regulators. These findings indicate a multi-layered regulatory framework governing metabolite production. Collectively, the study's findings demonstrate that red light serves as a critical environmental signal that influences both developmental and metabolic processes in Streptomyces. The identification of candidate photoreceptors and associated regulatory networks provides a foundation for targeted strategies to enhance lipstatin production through metabolic and process engineering. Future studies focusing on transcriptomic, proteomic, and biophysical characterization of identified photoreceptors will further elucidate the mechanistic basis of light-mediated regulation and enable rational strain improvement.