Paper Information

Journal:   IRANIAN JOURNAL OF SOIL AND WATERS SCIENCES   2004 , Volume 18 , Number 2; Page(s) 0 To 0.
 
Paper: 

STUDY OF THIOBACILLI SURVIVAL ON DIFFERENT CARRIERS

 
 
Author(s):  BESHARATI H., SALEH RASTIN N., MALAKOUTI M.J., ALI ZADEH A.
 
* 
 
Abstract: 

A major requirement in utilizing elemental sulfur to lower soil pH is the presence and activity of sulfur oxidizing bacteria (especially the Thiobacilli) in the soils. The beneficial effects of sulfur application along with Thiobacillus bacteria for soil reclamation and improvement of soil nutrient availability have been demonstrated in various fields as well as in greenhouse studies. In all such investigations, either pure cultures of Thiobacillus suspension or Thiobacillus bearing soils were utilized as inoculants, neither of which is applicable on large scale. On the other hand, the acid produced as a result of the oxidation of the sulfur material during the growth cycle or long-term maintenance phase of Thiobacillus would cause limitation on their growth and sharp declines in their population densities. The present research was aimed at the development of a carrier, suitable for a long-term maintenance of Thiobacillus bacteria as well as a source of inoculants to be used in the greenhouse and field experiments. Several easily available, inexpensive materials that are capable of sustaining the Thiobacilli were selected and some of their physical and chemical properties were measured. Then, these materials were mixed in different ratios and 6 carriers were selected. After sterilizing them, 100 ml Thiobacilli suspension was added to the carriers. The surviving abilities of the bacteria in various carriers were tested using a completely randomized split-split-plot design with 12 treatments, 8 sampling times, and 3 replications. Colony count and pH measurements were made by taking samples at 0, 14, 30, 60, 90, 120, 150 and 180 days intervals after the start of the experiment. The effect of all treatments on the carrier pH and bacterial population measured at constant time intervals during a 6-month period for different materials showed significant differences (1% level). At these time intervals, the pH values were higher at 4 oC than at 25 oC, but bacterial population were higher at 25 oC then at 4 oC. Carrier 3 contained the highest number of bacteria at 25oC while at 4oC it did not significantly differ from carriers 2, 4, and 5 in this respect. Carrier 3 maintained a large population of bacteria for a longer period of time, and, in contrast to the other carriers, it contained a larger population during the 6-month trial at 25oC than at 4oC. Therefore, it was selected as the superior carrier. Carrier 6 showed the lowest numbers of bacteria at both temperatures and, consequently had the lowest rank.

 
Keyword(s): CARRIER, INOCULANTS, SULFUR, THIOBACILLUS
 
References: 
  • ندارد
 
  Yearly Visit 52
 
Latest on Blog
Enter SID Blog