Page 299 - Trends in Science and Technology fo Sustainable Living

260 Fakultas Sains dan Teknologi
Universitas Terbuka (2023)

Wastewater from fish farming is high in dissolved and particulate
matter, including excess nitrogen. Microorganisms utilize this extra
nitrogen as a protein source by manipulating the C and N ratios
(Das & Mandal, 2018).
Biofloc technology is a fish farming method that focuses
on developing and using “flocs,” or colonies of microorganisms
that coexist with fish in a culture system. This flock is made up of a
variety of microorganisms, including bacteria, algae, protozoa, and
other microscopic species. They dwell in aggregates with complex
structures, often brown or orange, giving the water in biofloc systems
a distinct appearance.
Biofloc technology works by utilizing microorganisms’ ability
to transform waste products produced by fish into a source of high-
value nutrients. When fish excrete waste such as ammonia, urea,
and other organic chemicals, the microorganisms in the biofloc
convert the waste into a safer and easier form for fish to ingest,
such as nitrate and microbial protein. These processes, which
include interactions between distinct types of bacteria, are known
as nitrification and denitrification.
Microorganism colonies coexist with fish in the biofloc
system. These microbes get nourishment from fish waste, and the
fish get extra food from them. The presence of biofloc maintains the
water quality in the aquaculture system because microorganisms
assist in eliminating toxic compounds such as ammonia, which can
damage fish.
The basic idea behind this technique is to create a nitrogen
cycle by stimulating the growth of heterotrophic microorganisms,
which digest nitrogenous wastes that can be used as feed by
aquatic species being cultivated. Biofloc technology not only treats
waste effectively, but it also feeds aquatic wildlife. The C:N ratio
must be kept high by adding a supply of carbohydrates (molasses),
and water quality is improved by producing high-quality single-cell
microbial protein. Solid microorganisms proliferate and operate as
water quality control bioreactors and protein food sources in these