ZoBell — 4 — Marine Microbiology 



dance of bacteria was associated with plankton organisms either in coastal 

 waters or far from land at the borders of two convergent ocean currents. 

 The prevalence of bacteria in such places is now attributed to larger quan- 

 tities of organic matter from the remains of dead organisms or to upwelling 

 which brings nutrient-rich water to the surface. 



On the Humboldt Plankton Expedition, Fischer (1894a) isolated 

 nine new species of photogenic bacteria including Photohacterium annulare, 

 Ph. caraibicum, Ph. coronatum, Ph. degenerans, Ph. delagadense, Ph. gluti- 

 nosum, Ph. hirsutum, Ph. papillare, and Ph. tuberosum. He also described 

 seven other new species of heterotrophic bacteria to which he assigned the 

 generic name, Halibacterimn, the prefix hali denoting salt or sea. Hali- 

 bacteriuni aurantiacum, E. liguefaciens, H. pellucidum, H. polymorphum, 

 H. purpureum, H. roseum, and H. rubrofuscum were isolated from sea 

 water or other marine materials. 



Most of the marine bacteria grew only, or preferentially, in nutrient 

 media prepared with sea water or water rendered isotonic with sea water 

 by the addition of sodium chloride. Helicoidal-shaped spirilla or vibrio 

 and pleomorphic rods predominated. Fischer failed to find any strepto- 

 cocci or sarcinae. Most of the bacteria were actively motile and gram- 

 negative. When stained with aniline dyes, some of the bacteria showed 

 polar bodies. Sporeformers were not observed but no exhaustive search 

 was made for them. Mold fungi were often found, particularly near land, 

 and yeasts were regularly encountered. 



A full account of his observations and conclusions together with a re- 

 view of the early literature has been summarized by Fischee (1894a) 

 in an 82-page monograph entitled "Die Bakterien des Meeres." 



During the time that Fischer's classical studies were in progress, 

 FoRSTER (1887) isolated from plaice, flounder, and other marine fish 

 photogenic bacteria which would grow on fish gelatin prepared with as 

 much as 6 to 7 per cent sodium chloride. They failed to grow in distilled 

 water media. The cultures were physiologically active at temperatures 

 ranging from 0° to 20° C. Foester (1892) also demonstrated the occur- 

 rence throughout the year of bacteria in the North Sea and the Zuider 

 Zee. The bacteria were able to multiply at 0° C. 



In the Gulf of Naples, Russell (1891) collected samples of sea water 

 and bottom deposits from depths as great as 11 00 meters and at distances 

 up to about ten miles from land. Bacteria were found in all samples. Bot- 

 tom slime contained 25,000 to 300,000 bacteria per ml. while the bacterial 

 population of the overlying water rarely exceeded 100 per ml. Slime from 

 shallow bottoms generally contained more bacteria than that from 

 greater depths, but there was little difference in the bacterial content of 

 water with depth. 



Although a few soil forms belonging to the Bacillus subtilis-mesentericus 

 group were found in the Gulf of Naples, Russell believed most of the 

 bacteria which live in the sea to be autochthonous marine species. Cer- 

 tain typical bacteria inhabiting the mud were never found in the overly- 

 ing water. This, together with the fact that the bacteria can multiply in 

 the mud, indicated to Russell that the mud was their native habitat, 

 thereby discounting the view held by some that the bacteria find their 

 way there merely by sedimentation. He expressed the opinion that the 

 low temperatures characteristic of great depths might inhibit the growth 

 of bacteria, but those which he observed grew best at temperatures lower 

 than 25° C. Very few of the bacteria tolerated temperatures as high as 

 37° C. 



