CHAPTER n 



OUTLINES OF BACTERIOLOGICAL TECHNIQUE 



BACTERIOLOGICAL and enzyme chemistry is essentially the 

 chemistry of the single cell : biological chemistry and physio- 

 logical chemistry in the wider sense deal with the changes 

 taking place in higher organisms, which consist of collections 

 of ceDs of varying and interdependent functions. We have 

 tfcffffmr only to consider the chemical changes brought 

 about by the simplest organisms, which if not actually 

 unicellular are only very slightly differentiated ; or with 

 tie chemistry of specific cells of higher organisms. More- 

 over, from the chemical point of view, the form of the 

 organism, and its method of growth and development, are 

 of leas importance than the chemical changes it brings 

 about. 



The following pages deal with the methods of recognition 

 and cultivation of the simplest organisms, the subject being 

 treated in quite a general manner. For the detailed methods 

 used in the irrognitinn of specific organisms, text books on 

 bacteriology should be consulted. 



The micro-organisms whose chemical activities have to be 

 studied may be divided into three groups, viz. : 



L Bacteria; 

 IL Yeasts ; 

 IIL Moulds. 



Bacteria (Fig. 3, 1. and I A ). These are the lowest forms of 



