|Title||Onderzoekingen over de aerobe celluloseontleding in den grond|
|Source||University. Promotor(en): J. Smit. - Groningen : Wolters|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||bodembiologie - koolhydraten - degradatie - soil biology - carbohydrates - degradation|
|Abstract||Harmsen detected and isolated nearly all of the microbes previously mentioned in the literature: 1. The Cellvibrio group did not form a unit but only represented cellulose-decomposing strains within a large morphological group; 2. The Cytophaga group was mainly dependent upon cellulose as a foodstuff; 3. Polyangides, belonging to the Myxobacteriaceae; 4. Bacilli were not strictly specific cellulose-decomposers although some strains preferred cellulose to soluble carbohydrates; 5. Actinomycetes were the chief cellulose-disintegrators in most soils; 6. Proactinomyces and Mycobacteria or Corynebacteria.
Harmsen also studied the distribution of cellulolytic microbes and their function in the soil. Nearly all groups of microbes appeared to play their special part in the decomposition of cellulose. The different groups formed a succession during decomposition. After manuring most soils with material rich in cellulose, only a few species proved quantitatively important (alkaline soils: actinomycetes cellvibrios or polyangides; acid soils: fungi).
On almost synthetic cellulose agar, many cellulolytic bacteria were markedly stimulated in their growth by extracts of plant or animal origin, by soil or by stable manure, and often by metabolic products of several other microbes. For this reason mutual stimulation, such as of celIvibrios by actinomycetes or of Cytophagae by Bacilli, was frequent in cellulose decomposition.