Chapter 64 



Nutritional Patterns in Marine 

 Bacterial Populations 



T. M. Skerman 

 INTRODUCTION 



I 



t has been stated that among the most important activities of 

 bacteria in the sea is the minerahzation or modification of organic 

 matter (22). Heterotrophic bacteria, of which the majority are 

 probably saprophytes, appear to outnumber autotrophic varieties 

 in the sea, their abundance closely parallels the distribution of 

 organic matter and they seem capable of utilizing virtually all 

 types of organic compounds (26). Yet accompanying the de- 

 gradation of such a variety of organic molecules are many intri- 

 cate biochemical relationships including such phenomena as 

 symbiosis, antagonism and syn trophism, which impart a com- 

 plex history to the mineralization process. Fundamental to studies 

 of marine bacteria concerned in these activities is an understand- 

 ing of the molecular relationships between each organism and 

 its environment: experimental observations designed to elucidate 

 some of these relationships of marine heterotrophic bacteria have 

 been initiated by the author. 



The Indigenous Heterotrophic Flora 



Up to the present, valuable data have accrued from numerous 

 studies of known biochemical processes such as ammonification, 

 nitrification and those concerned with the transformation of sul- 

 phur and other elements. Some detailed investigations have 

 been made of the types of marine bacteria taking part in such 

 processes as well as of those engaged in the decomposition of 

 residues such as cellulose, agar, chitin and lignin. Comparatively 

 less attention has been de\otcd to heterotrophs whose functions 

 are less well understood, but which doubtless comprise a large 



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