potential of bioflocculant-producing bacteria as
for biofloc based systems
Harun1, N.A. Ghazali1, N.F.C. Hashim1,
N.A.H. Mohammad1, Mhd. Ikhwanuddin1,2, N. Ismail3,
Z. Ibrahim4 and N.A. Kasan1,2*
Tropical Aquaculture, Universiti Malaysia Terengganu, 21030 Kuala Terengganu,
Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu, 21030
Kuala Terengganu, Terengganu, Malaysia
Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu,
Biological Science, Faculty of Bioscience and Bioengineering, Universiti
Teknologi Malaysia, 81300, Skudai, Johor, Malaysia
Author E-mail: firstname.lastname@example.org
Paper received : 25.07.2017
Revised received : 20.08.2017
Re-revised received :
Accepted : 28.12.2017
flocculants has been widely used around the world to replace the usage of
synthetic flocculants for wastewater treatment. A new green technology using
biological flocculant known as biofloc system was developed which offers zero
water exchanged, low feed conversion ratio (FCR) and high nutritional
profile. This study was conducted to determine the most potential
bioflocculant-producing bacteria isolated from biofloc sample in Pacific
Whiteleg shrimp, P. vannamei culture pond.
Methodology: Biofloc sample was
collected using Imhoff cone and bacteria was isolated. The most abundant
bacteria isolated throughout P. vannamei culture period was selected
for screening of bioflocculant-producing bacteria using YPG medium and
flocculation activity using floc-jar test.
Results: Screening of
bioflocculant-producing bacteria showed that B. infantis, N.
aquimarinus, B. cereus, H. venusta, Pseudoalteromonas
sp., and B. safensis were characterized as highly mucoid and ropy
colony morpologies. The highest flocculation activity with 93% was showed by B.
infantis followed by N. aquimarinus (91%), B. cereus (87%),
H. venusta (79%), Pseudoalteromonas (78%), while the lowest
flocculation activity was showed by B. safensis with 69%.
Interpretation: As bacteria grew,
extracellular polymeric substances (EPS) produced were involved in
flocculation process. Each bacteria produced different EPS composition which
differed their ability in flocculation process. Therefore, bacteria with high
flocculation activity are potentially used as inoculum to increase flocculation
process in biofloc production.