Study On A Cellulolytic Strain Actinomycete Sp. SX-3and Its Cellulolytic Characteristics

Cellulose is widely distributed in nature.The purpose of low cost, no pollution and highreturns will achieve by using micro-biological degradation. But there is little strain that candegrade cellulose effectively. So singling out high-efficiency strains has great significance.We have singled out a strain of actinomycetes from soil which has good growth and highefficiency degradation. There is a series of researches.The results are illustrated as follows:1.A new strain of cellulolytic was isolated from soil. According to the strain’smorphological characteristics, physiological and biochemical characteristics,"theactinobacteria appraisal manual" and related documents, the strain was identified asActinomycetal, Streptomycetaceae, Streptomyces, named Streptomyces sp.SX-3.2. Results of research in the bacteria’s liquid fermentation conditions showed that: cornskin as carbon source, yeast cream as nitrogen source, pH7, temperature28℃-30℃,40mlculture medium,3%inoculation amount,3d cell age were the best conditions.3.The results of the research in the strain’s solid fermentation conditions showed that: thecorn skin particles size had little influence on the cellulase production, the optimum nitrogensource was peptone, distilled water was the optimal medium, the optimal leach liquor wasphysiological saline, the optimum inoculation amount was3ml, the best culture temperaturewas28℃, the optimum incubation time was the4d, the optimum water content was20ml.4.Results of liquid cultivation with filter paper, corn skin and glucose as sole carbonsource showed that the pH increased with the first two, but decreased with the last. Results ofculturing the actinomyces in liquid cultivation with paper or corn skin as sole carbon source todetect the quantity of the reducing sugar amount showed that the reducing sugar amountincreased in the former, but decreased in the later. CMCase was higher when the ratio ofsupernatant to substrate was1:3. FPase was higher when it was1:1. FP without beingprocessed produced more reducing sugar than FP with being processed did.5.We obtained rough enzyme powder by extraction filtration, ultrafiltration, ammoniumsulfate fractionation, dialysis and freeze-dying. The analysis showed that the optimum pH was5.8, the optimal buffer was acetic acid sodium buffer, the enzyme was the most stable in thepH6.0, the optimum temperature was45℃, the most stable temperature was between40℃-50℃.