Microbiological features and bioactivity of a fermented manure product (preparation 500) used in biodynamic agriculture

J Microbiol Biotechnol. 2013 May;23(5):644-51. doi: 10.4014/jmb.1212.12004.


The fermented manure derivative known as Preparation 500 is traditionally used as a field spray in biodynamic agriculture for maintaining and increasing soil fertility. This work aimed at characterizing the product from a microbiological standpoint and at assaying its bioactive properties. The approach involved molecular taxonomical characterization of the culturable microbial community; ARISA fingerprints of the total bacteria and fungal communities; chemical elemental macronutrient analysis via a combustion analyzer; activity assays for six key enzymes; bioassays for bacterial quorum sensing and chitolipooligosaccharide production; and plant hormonelike activity. The material was found to harbor a bacterial community of 2.38 × 10(8) CFU/g dw dominated by Grampositives with minor instances of Actinobacteria and Gammaproteobacteria. ARISA showed a coherence of bacterial assemblages in different preparation lots of the same year in spite of geographic origin. Enzymatic activities showed elevated values of beta-glucosidase, alkaline phosphatase, chitinase, and esterase. The preparation had no quorum sensing-detectable signal, and no rhizobial nod gene-inducing properties, but displayed a strong auxin-like effect on plants. Enzymatic analyses indicated a bioactive potential in the fertility and nutrient cycling contexts. The IAA activity and microbial degradation products qualify for a possible activity as soil biostimulants. Quantitative details and possible modes of action are discussed.

MeSH terms

  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Bacteria / metabolism*
  • Fermentation
  • Fungi / classification
  • Fungi / genetics
  • Fungi / isolation & purification
  • Fungi / metabolism*
  • Manure / analysis
  • Manure / microbiology*
  • Phylogeny
  • Soil / analysis
  • Soil Microbiology


  • Manure
  • Soil