Wordnet 3.0
ADJECTIVE (2)
1. 
 produced by living organisms or biological processes; 
- Example: "fermentation is a biogenic process"2. 
 essential for maintaining the fundamental life processes; 
- Example: "sleep and food and water are among the biogenic needs of the organism"
The Collaborative International Dictionary of English v.0.48:
biogenic \bi`o*gen"ic\, a. [Gr. bi`os life + -gen + -ic.]
   produced by living organisms; as, biogenic methane.
   [PJC]
WordNet (r) 3.0 (2006):
biogenic
    adj 1: produced by living organisms or biological processes;
           "fermentation is a biogenic process"
    2: essential for maintaining the fundamental life processes;
       "sleep and food and water are among the biogenic needs of the
       organism"