PMID- 15248481
OWN - NLM
STAT- MEDLINE
DCOM- 20040809
LR  - 20240109
IS  - 0019-5189 (Print)
IS  - 0019-5189 (Linking)
VI  - 41
IP  - 8
DP  - 2003 Aug
TI  - Bacterial dynamics associated with algal antibacterial substances during post 
      harvest desiccation process of Sargassum stolonifolium Phang et Yoshida.
PG  - 837-45
AB  - Brown algae of genus Sargassum are known to produce relatively higher amount of 
      alginic acid. Optimal extraction of this algalcolloid for local consumption 
      requires in-depth studies on post-harvest treatment of the algal fronds. Present 
      investigation endeavors to establish the dynamics and inter-relationship of 
      moisture content and bacteria found on the surface of the alga and alginic acid 
      content during post-harvest desiccation of Sargassum stolonifolium Phang et 
      Yoshida. Harvested fronds were subjected to desiccation for 31 days and bacterial 
      dynamics were monitored with relation to moisture content and water activity 
      index (a(w)). There was 85% decrease in moisture content, however, a(w) showed a 
      more gradual decrease. Total bacterial count increased during the first week and 
      attained maximal value on day 7. Thereafter, a drastic decrease was seen until 
      day 14, followed by a gradual decline. Six species of bacteria were isolated and 
      identified, i.e. Azomonas punctata, Azomonas sp., Escherichia coli, Micrococcus 
      sp., Proteus vulgaris and Vibrio alginolyticus. Calculated ratios for increase in 
      alginic acid content and decrease in moisture content were almost the same 
      throughout the desiccation process, implying that extracellular 
      alginase-producing bacteria did not use the alginic acid produced by the algae as 
      its carbon source. It became apparent that drastic decrease in bacterial count 
      after day 7 could not be attributed to salinity, moisture content, a(w) or lack 
      of carbon source for the bacteria. The possible exposure of these bacteria to 
      algal cell sap which is formed due to the rupture of algal cells was seen as the 
      most likely reason for the drop in bacterial population. Scanning electron 
      microscope (SEM) micrograph taken on day 10 of desiccation showed the presence of 
      cracks and localities where bacteria were exposed to algal cell sap. In vitro 
      antibacterial tests were carried out to verify the effect of algal extracts. 
      Separation and purification of crude algal extracts via bioassay guided 
      separation methodology revealed the identity of active compounds (i.e. 
      gylcolipids and free fatty acids) involved in this inherently available 
      antibacterial defense mechanism during algal desiccation.
FAU - Vairappan, Charles Santhanaraju
AU  - Vairappan CS
AD  - Borneo Marine Research Institute, Universiti Malaysia Sabah, Locked Bag 2073, 
      Kota Kinabalu, 88999 Sabah, Malaysia. csv@ums.edu.my
LA  - eng
PT  - Journal Article
PL  - India
TA  - Indian J Exp Biol
JT  - Indian journal of experimental biology
JID - 0233411
RN  - 0 (Alginates)
RN  - 0 (Anti-Bacterial Agents)
RN  - 0 (Hexuronic Acids)
RN  - 8A5D83Q4RW (Glucuronic Acid)
SB  - IM
MH  - Alginates/isolation & purification/*pharmacology
MH  - Anti-Bacterial Agents/isolation & purification/*pharmacology
MH  - *Desiccation
MH  - Glucuronic Acid/isolation & purification/*pharmacology
MH  - Gram-Negative Bacteria/drug effects/growth & development
MH  - Gram-Positive Bacteria/drug effects/growth & development
MH  - Hexuronic Acids/isolation & purification/*pharmacology
MH  - Microbial Sensitivity Tests
MH  - *Sargassum/chemistry/growth & development/microbiology
EDAT- 2004/07/14 05:00
MHDA- 2004/08/10 05:00
CRDT- 2004/07/14 05:00
PHST- 2004/07/14 05:00 [pubmed]
PHST- 2004/08/10 05:00 [medline]
PHST- 2004/07/14 05:00 [entrez]
PST - ppublish
SO  - Indian J Exp Biol. 2003 Aug;41(8):837-45.