464 



PRINCIPLES OF SOIL MICROBIOLOGY 



bacteria, including Staph, pyogenes aureus, Bad. prodigiosum, Bad. 

 pyocyaneum, Bad. fluorescens, Bad. lipolyticum. 115 



It is possible, however, that some fat may also be decomposed under 

 anaerobic conditions. The chemical processes involved may be differ- 

 ent, Bach and Sierp 116 having shown that, under anaerobic conditions, 

 CO2 is split off and the fatty acids change into hydrocarbons. This 

 results in the formation of products of a lower saponification and 

 higher iodine number than the original fat. 



Waxes are chemically related to the fats, being esters of higher alco- 

 hols and fatty acids. For example, flax wax consists of phytosterol 

 and ceryl alcohol, as well as of palmitic-, stearic-, oleic-, linolic-, and 

 linoleic acids. These substances are even more resistant to decomposi- 



TABLE 41 

 Influence of age of culivre vpon the fat content of Asp. niger 11 - 

 350 cc. Raulin's solution containing 4.7 per cent invert sugar 



DRY WEIGHT OF 

 MYCELIUM 



mgm. 



0.29 



5.10 



6.30 



4.1 



1.7 



1.3 



FAT CONTENT 



per cent 



2.11 

 12.0 

 7.5 

 4.0 

 1.6 

 0.6 



116 Schenker, R. Zur Kenntniss der Lipase von Aspergillus niger (van Tiegh). 

 Biochem. Ztschr., 120: 164-196. 1921; Derx, H. G. Der oxydative Abbau der 

 Fette durch Schimmel. Konigl. Akad. Wiss. Amsterdam, 33: 545-558. 1924; 

 Sohngen, N. L. Lipase production of microbes. Konink. Acad. Wetenschap. 

 Amsterdam., 19: 698. 1910; 20: 126. 1911; Eijkman, C. Uber Enzyme bei 

 Bakterien und Schimmelpilzen. Centrbl. Bakt. I, 29: 841-848. 1901 ; de KruyfT, 

 E. Les bacteries hydrolysant et oxydant les graisses. Bull. dept. agr. Ind. 

 norland. IX. Buitenzorg. 1907. (Centrbl. Bakt. II, 20: 610-611. 1908); 

 Huss, H. Eine fettspaltende Bakterie (Bactridiurn lipolyticum n. sp.). Centrbl. 

 Bakt. II, 20: 474-484. 1908; Stephenson, M., and Whetham, M. D. Fat metab- 

 olism of the timothy hay bacillus. Proc. Roy. Soc. B., 93: 262-280. 1922; 

 Shibata, N. Zur Frage der Fettzersetzung einiger Saprophyten. Jour. Biochem. 

 Tokyo, 1: 249-260. 1922. 



118 Bach and Sierp. Untersuchungen iiber den anaeroben Abbau organischer 

 Stoffe durch Bakterien des Klarschlammes. Centrbl. Bakt. II, 62: 24-76. 1924. 

 A detailed review of the formation and decomposition of fats by microorganisms 

 is given by Seliber, G. The formation and decomposition of fats by micro- 

 organisms. Glavnauka. Leningrad. 1926. 



