Beneficial effects, challenges and opportunities of the filamentous fungus, Aspergillus niger with special reference to the shrimp feed industry - A review

Abstract

The shrimp industry, including its culture and feed sectors, exhibited steady growth over the years with a reduced cost–benefit ratio due to increasing production costs attributed mainly to enhanced feed costs. The unsustainable availability and rapid increase in fishmeal cost have forced the aquafeed sector to reduce dietary inclusion levels. The filamentous fungus, Aspergillus niger plays an important role in utilising plant protein sources for formulating cost-effective shrimp feed. A. niger has been reported to produce numerous hydrolytic enzymes to degrade the limiting factors of plant proteins such as antinutrients and fibre fractions. This fungus enhanced not only the quantity but also the quality of proteins and amino acids, especially methionine and lysine. Likewise, it also increased the availability of soluble minerals, particularly phosphorous, by degrading the phytic-phosphorus, thereby helping to replace dietary fishmeal up to 80% in penaeid shrimps. Consequently, this fungus could reduce feed formulation cost significantly. However, the mycotoxins produced by this fungus pose difficulties during large-scale fermentation, and its implications on the workers and environment cast doubt about its efficacy and utility. However, recent developments indicate that A. niger could be an alternative choice in reducing the pressure on fishmeal demand by enhancing the nutrient utilization of plant-based materials leading to the formulation of, cost-effective feeds that can sustain shrimp culture and production in the future.