Abstract:
Nannochloropsis sp. was widely used in aquaculture as it has a great source of protein,
lipid and carbohydrate. Microalgae's major applications for aquaculture are related to
nutrition, being used fresh as a sole component, as a food additive to basic nutrients,
for coloring the flesh of salmonids and for other biological activities. Study on
Nannochloropsis sp .. was conducted to determine the growth and the proximate
composition of Nannochloropsis sp. cultured using different media in indoor and
outdoor culture condition. This study was conducted at Universiti Malaysia
Terengganu. Marine rnicroalgae, Nannochloropsis sp., was collected and cultured in
two different media - Conway and KW2 l; and two different culture conditions -
indoor and outdoor. The growth and proximate composition - protein, lipid and
carbohydrate; of all culture treatments were determined. Nannochloropsis sp. was
grown best in both culture media even though growth in KW2 l was slightly higher
(P>0.05) when compared to Conway medium. Nannochloropsis sp. culture in indoor
(laboratory) condition was significantly shown higher growth (P<0.05) when
compared to the outdoor (natural) culture condition. The protein production seems to
be significantly high (P>0.05) in KW21 culture medium (39.58% and 32.99% for
indoor and outdoor respectively) when compared to Conway medium (26. 74% and
19.05% for indoor and outdoor respectively). However, rnicroalgae culture under
indoor culture condition (26.74% and 39.58% for Conway and KW21 media
respectively) has shown significantly high (P>0.05) percentage of protein as
compared to outdoor condition (19.05% and 32.99% for Conway and KW21 media
respectively). Lipid accumulation in Nannochloropsis sp. was significantly high
(P>0.05) when cultured under indoor condition (27.2% and 25.6% for Conway and
KW21 respectively) when compared to outdoor condition (18.13% and 12. 73% for
Conway and KW21 respectively). The percentage (%) of carbohydrate in microalgae
cultured in Conway medium for indoor condition (34.01 %) was slightly high (P<0.05)
compared to outdoor condition (32.29%). All of the results obtained might be affected
by some physical factors such as light intensity and temperature; as well as nutrient
composition such as nitrogen, phosphate and trace metals. From the results obtain, we
also can make a conclusion that Nannochloropsis sp. can grow best in both Conway
and KW2 l media under indoor culture condition.
