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Marine microorganisms are of great interest as novel and rich sources of biologically
active products. The micro-organisms living in both sea water and sand must be able
to survive and grow under harsh conditions. Due to these adaptations, the metabolites
produced by marine micro-organisms possess unique features and they serve as
promising choices for many different biotechnological applications. The aforesaid
micro-organisms are referred to as 'microbial treasures' at present.
In this study, preliminary screening for different culturable bacteria present in
shoreline sand was carried out and tested for different biological activities.
Morphologically different bacterial isolates were identified using the standard
morphological and biochemical characterization procedures in microbiology. The
results indicated that the majority ofthe isolates belong to the genus Bacillus and the
others were the species of Micrococcus, Aerococcus, Pseudomonas, and
Staphylococcus. The degradation oftwo dyes, crystal violet and saffranin were tested
and the degradation was only observed for crystal violet with two Bacillus isolates
i.e. SSMA-15 and SSPC-16. Some isolated bacteria accumulated the dyes in their
cells. The highest indole acetic acid (IAA) production was observed for the BacillusSSPC-ll. Antagonistic effect against all three selected bacteria, i.e. S. aureus, B.
subtilis and E. coli was only shown by the Pseudomonas-SSMA-7. Along with the
antagonistic effects, it also produced the protease and cellulase enzymes. The
bacterial isolate-SSMA-9 belonging to the family Enterobacteriaceae exhibited the
highest number of positive activities during this study. It included the production of
cellulase, laccase, amylase and protease enzymes and the accumulation of the
saffranin and crystal violet dyes. The Bacillus-SSPC-3 showed positive production
of three enzymes; amylase, protease and cellulase. Staphylococcus-SSPC-12 has the
ability to accumulate the two dyes in addition to the production of the two enzymes
amylase and protease. Based on the positive activities and produced components,
bacterial isolates SSMA-9, SSMA-7 and SSPC-12 were identified as possible
bacterial treasures.
