Practical 5 : Propagation of seaweed in enrichment media

     INTRODUCTION

Each group was given the same species of seaweed, Glacilaria changii but different group need to use different media which is each of them consists of 3 replicates.

Seaweed

Glacilaria changii

Media

Sterile seawater,VSE,PES

Bacterial cultures

17 different bacteria

Aquaflora : SS,VSE,PES,B 

Phytoteam : B1,B2,B3,B4 (SS)

Floratic :  B5,B6,B7,B8

Greendot :  B9,B10,B11,B12

Floria :  B13,B14,B15,B16

*SS = sterile seawater

SW = seaweed

B = bacteria

 METHODOLOGY

o   The seaweed was placed in a container filled with seawater.

o   Seaweed was rinsed in a series of containers by submerging and shaking vigorously underwater several times.

o   The wet weight of seaweed was recorded.

o   Seaweed was introduced in beaker containing Von Stosch’s Enrichment (VSE) and Provasoli Enrichment Seawater (PES) media.

o   Seaweed was incubated for a photoperiod of 12hr light and 12hr dark with aeration.

o   The growth was compared by determining the gain / loss of the seaweed wet weight.

o   Any changes  that can be observed were recorded.

1)Wash with tap water

2)Cut 1cm-1cm

3)Weight

4)Wash with sterile seawater (30 s)

5)Fill well-plate with sterile seawater

6)Add 10^4 cfu/ml of selected bacteria

7)Put seaweed

8)Observe 7 days-7 days

RESULTS

Sterile seawater + seaweed
Before After
1 0.02 g
2 0.04 g
3 0.03 g
VSE + seaweed
Before After 
4 0.02 g
5 0.02 g
6 0.02 g
PES + seaweed
Before After 
7 0.03 g
8 0.05 g
9 0.04 g
Sterile seawater + bacteria + seaweed
Before After 
10 0.04 g
11 0.05 g

12 0.04 g

It was shown that almost all of the seaweed grow bud on it. 

DISCUSSION

. Low PES strength was also found to be more suitable for Gracilaria species in the previous study as reported by Ursi et al. (2008). This work indicated that growth promotion effects were seen using lower concentration of PES. Ferreira et al. (2006) reported that higher growth rate was observed for low strength media such as PES.However, G. changii is an indigenous seaweed species in Malaysia and adapted to tropical oliogotrophic water which contains lower nutrient concentration compared to temperate sea (Eppley, 1972; Phang, 2006). Dilution of PES media demonstrated to be ideal for achieving better growth rate for G. changii.