Protein remains the most expensive component of shrimp feeds, with fish meal (FM) traditionally serving as the primary source. However, rising costs and sustainability concerns have driven the search for alternative protein sources, including terrestrial animal by-products and plant-based ingredients. While plant proteins can partially replace fish meal, they often introduce anti -nutritional factors that impair feed digestibility and shrimp performance. Recent attention has shifted toward novel, high-quality, and sustainable protein sources capable of replacing FM without compromising production efficiency. One such alternative is methano troph bacteria protein (MBP), derived from Methylococcus capsulatus through controlled fermentation process. MBP offers a consistent nutritional profile, high digestibility, and a markedly lower environmental footprint in terms of land use compared to other protein alternatives . Several feeding trials with Litopenaeus vannamei juveniles (0.3 – 1.1 g initial body weight ; 7 – 8 weeks in length ) have demonstrated the potential of MBP as both partial and total replacement for FM (Table 1).
The results summarised in Table 1 highlight that dietary inclusion of MBP at inclusion levels up to 15% can maintain growth and feed conversion ratios equivalent to FM-based feeds . Moreover, shrimp fed MBP exhibited enhanced gut and hepatopancreas morphology, and beneficial shifts in haemolymph biochemical parameters. Beyond performance, MBP supplementation supported oxidative stress resilience, as reflected in higher SOD and GPX activities, while also stimulating immune responses and improved survival under Vibrio challenges. Notably, total FM replacement with 15% MBP still yielded comparable growth while significantly increasing survival rates after pathogen exposure.
In conclusion, MBP represents a next-generation feed ingredient with the capacity to reduce dependence on marine resources, improve shrimp health, and support more resilient and responsible shrimp farming systems.