Microbial products in terms of isolates, whole-cell biomass, and live organisms as aquafeed ingredients: production, nutritional values, and market potential-a review

Utilizing microbial products could be considered a novel approach to sustain the present growth of the aquafeed sector due to dwindling availability and high cost of fishmeal. Various microbial products in terms of isolates, whole-cell biomass, and live organisms are mainly derived from algae, bacteria, fungi, and yeast through the process of fermentation. They have a balanced amino acid profile and contain several minerals and vitamins. However, essential amino acid index (EAAI) of fungal-based microbial meal was comparatively lower (0.57-0.67) than the other three microbes (0.77-0.90). Microbes were deployed in the production of microbial products ranked as algae > fungus/yeast > bacteria based on their nucleic acid content. The global production of microbial products was valued at US$5.3 billion in 2017 and is predicted to increase by 8.6% in 2018-2023. They could substitute fishmeal by 25-50% in feeds for aquatic species. Notwithstanding, they act as a potential growth promoter, a viable immunostimulant and can control infectious diseases in various aquatic species. The present review reiterates the utilization of microbial products in ameliorating the issues related to the global aquafeed industry, in particular fishmeal demand. However, newer approaches need to be established with regard to fermentation technology and genetic engineering to overcome the present limitations to make them an economical one.

Automated summary

Microbial products are a potential alternative to fishmeal in aquafeed industry, offering benefits such as growth promotion and disease control. However, certain microbial products have limitations in terms of amino acid content that require further research and technological improvements.