Composition and nutritional value of biofloc
·
Biofloc is a heterogeneous aggregate of suspended
particles and variety of microorganisms associated with extracellular polymeric
substances.
·
It is composed of microorganisms such as bacteria,
algae, fungi, invertebrates and detritus, etc. It is a protein-rich live feed
formed as a result of conversion of unused feed and excreta into a natural food
in a culture system on exposure to sunlight.
·
Each floc is held together in a loose matrix of
mucus that is secreted by bacteria and bound by filamentous microorganisms or
electrostatic attraction.
·
Large flocs can be seen with the naked eye, but
most of them are microscopic. Floc size range from 50 – 200 microns.
· A good
nutritional value is found in biofloc. The dry weight protein ranges from 25 –
50 percent, fat ranges 0.5 – 15 percent. It is a good source of vitamins and
minerals, particularly phosphorous.
· It also
has an effect similar to probiotics. The dried biofloc is proposed as an
ingredient to replace the fishmeal or soybean in the feed. The nutritional
quality is good; however, only limited qualities are available.
· Furthermore,
the cost-effectiveness of producing and drying biofloc solids at a commercial
scale is a challenge