Figure 7. A 1-inch-long holothurian (sea cucumber) found in 
a sediment sample. 
Antibiotic-Producing Marine Bacteria 
A bacteriological analysis was made of a sediment sample obtained from a 
depth of 1,500 feet of water off the coast of Port Hueneme during the early phase 
of this study. On one of the Petri dishes (pour plate) inoculated with the sediment 
sample and incubated for several days at 15°C, a relatively clear area surrounding 
one of the bacterial colonies was observed, The orange-pigmented bacteria had 
apparently produced an antimicrobial agent known as an antibiotic which inhibited 
the growth of other microorganisms, It plays an important role in regulating the 
microbial population of bottom sediment. The 3/16-inch-diameter colony had 
produced a 5/16-inch-wide clear area surrounding the colony. A few small yellow- 
pigmented bacterial colonies were not affected by the antibiotic substance and 
were growing inside the clear area. 
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