Abstract
Bacillus species are highly regarded as probiotics in aquaculture due to their positive impact on host health and disease prevention. This chapter provides a comprehensive overview of the physiological aspects and optimization strategies involved in the production of Bacillus spp. probiotics for aquaculture that contributes to the development of efficient and sustainable aquaculture practices. It highlights the significance of Bacillus spp. as probiotic, their potential in enhancing aquaculture productivity, and the importance of understanding the physiological characteristics of Bacillus spp. to optimize their growth and spore production. The chapter discusses several key factors that influence Bacillus spp. spore production and growth. It explores the effects of carbon sources, lignocellulosic growth substrates, nitrogen sources, medium pH, agitation and aeration, and microelements on the physiology and productivity of Bacillus species. Additionally, the chapter emphasizes the importance of selecting the appropriate cultivation method for scaled-up Bacillus spp. probiotic production in aquaculture. Different cultivation methods, such as batch, continuous, and fed-batch cultures, are evaluated, taking into account their impact on growth, spore formation, and overall probiotic yield. It enables the cultivation of high-quality probiotics with enhanced benefits, including disease prevention, improved nutrient utilization, and growth promotion, thereby enhancing the health and productivity of aquaculture organisms.