Lignin Degradation and Acid Precipitable Polymeric Lignin (APPL) Accumulation by Selected Streptomyces Strains in Submerged and Solid State Culture Systems

Abstract

Lignin has connective effect between cell wall components. Therefore, lignin polymer leads to less biological usefulness of substrate. In this study, it has been aimed to decrease lignin proportion in wheat straw by selected actinomycetes strains. For this purpose, the effect of different actinomycetes strains which incubated during six weeks with solid state and submerged culture systems on wheat straw have been investigated. Besides, actinomycetes strains and controls have been compared for lignin loss and production of “Acid Precipitable Polymeric Lignin” (APPL) values. A strong correlation was observed between lignin loss from substrate and APPL production in both culture systems. The maximum lignin loss values for solid state and submerged cultures by Streptomyces 07 – 05 strain were determined as 53.22% and 61.03%, respectively. After 3 weeks of growth, the APPL production by this strain reached maximum, 65.52 and 84.12 mg/g substrate for solid state and submerged culture, respectively. It has been determined that, in both of culture systems, amount of APPL which was produced by Phanerochaete chrysosporium did not reach any of actinomycetes strains’ values

Keywords

• Actinomycetes, APPL, Lignin, Wheat Straw