Study On Ecological Distribution Of Actinomcetes And Resources Of Antaagonistic Actinomycetes In Salty Environments

By taking various kinds of salt lake and saline soil as the research objects, ecological distribution of actinomycetes and stimulation effect on isolation method of halophilic and halotolerant actinomycete were discuessed. Taking animal pathogens as organism, which damage seriously in animal husbandry culture, we screened excellent antagonistic actinomycetes, and used polyphasic taxonomy technique including form character, physiology and biochemistry determine, chemistry component analysis and the comparability contrast of 16Sr DNA gene sequence to identify parts of strains of actinomycetes which had special morphology and physiology and excellent antagonistic effect. The research results indicated:1. The separation method of halophilic and salt tolerance Actinomycetes in Chaerhan lake, Qinghai were preliminary established.There were obvious difference in actinomycetes species and quantity among different treatments. The quantities and species of actinomycetes were the most under modified starch- casein medium and when the salt concentration was 30 %, the most species and quantity were obtained. There were the most of species and quantities of actinomycetes after the pretreatment of microwave irradiated at 120W,2450 HZ for 3min, CA 10g/kg, HA 20g/kg, vibrated at 40℃for 20 minutes. 935.46 doubles higher than the quantity of actinomycetes at initialize separate medium and 13 more species were obtained without undesired microbes.2. Composition of actinomycetes populations in Tibet and Gansu saline soil or in Chaerhan lake were revealed.211 strains of actinomycetes were obtained from Tibet selincuo lakeside and Gansu. There were obvious difference actinomycetes species and quantity between different location and the different samples. Albosporus and Cinerogriseus was the dominant group in tibet selincuo lakeside where has more streptomyces groups than Gansu which Flavus and Albosporus was the dominant. 27 halophilic or halotolerant actinomycetes were abtained from Chaerhan lake Qinghai provice. All the tested strains have strong salt tolerance and all the salt-tolerant level are moderate or above, among which appropriate salt concentration were above 30%.3. Tolerance difference between different salts for 27 strains of actinomycetes abtained from Chaerhan lake were made clear.There were distinct tolerance difference between NaCl and KCl for 27 strains of actinomycetes abtained from Chaerhan lake. As for NaCl of 27 strains obtained from Chaerhan lake. For NaCl there were 1, for KCl there were 5 and for local mine salt there were 6, which highest tolerance salt gradient was 30%; There were 1 strains can't survive in the salty culture medium that without KCl and they may be the addictive-K actinomycetes. 8 halophilic actinomycetes were obtained. For NaCl, there were 7 moderate halophilic actinomycetes , while for KCl, there were 6 extreme halophilic actinomycetes, and for local mine salt there were extreme halophilic actinomycetes. What's more, 1 strain may be a extreme addictive-K actinomycete.4. Screening 14 strains of antagonistic actinomycetes against animal pathogen were screened.370 strains of antagonistic actinomycetes were screened and 34.05 % of the test strains had antagonistic activity, in which 14 antagonistic actinomycetes with broad spectrum, which accounted for 3.78%. In all actinomycetes which antagonized bacteria, actinomycetes which had strong inhibiting activity to avian Escherichia coli and bovine Streptococcus agalactiae than to swine Escherichia coli and swine Staphalococcus aureus.5. Fermentation conditions of strain 16 were optimized.The optimum fermentation condition which can produce the most effective ferment filtrate is seed age 36 h and 72 h for rotational culture time. The inhibition diameter of the optimal fermentation liquid exceed 38 mm, which improved 13mm more than that came from original fermentation conditions.6. The classified status of 17 strains which had special morphology and physiology and excellent antagonistic effect were identified.17 strains which had special morphology and physiology and excellent antagonistic effect were identified by polyphasic taxonomy technology such as morphological, physiological and biochemical characteristics, cell chemistry, as well as the 16S rDNA sequence analysis. Strains 3C, 201Y, 211Y are likely to be the new species.