Distribution and characteristics of microorganisms from tropical peat grown to oil palm and pineapple
1998
Halimi Mohd Saud | Jadol, J. | M.Y. Mohd Fairuz | Ahmad Husni Mohd Hanif
Two experiments were conducted to determine the population of bacteria and their characteristics in peat cultivated to oil palm. Bacterial counts from the peat grown to oil palm were determined. Peat were sampled at 0-50, 50-100 and 100-150 cm depths. The average bacterial count was 1.01 x 10 superscript 7 c.f.u. (colony forming units), 4.55 x 10 superscript 5 c.f.u. and 3.25 x 10 superscript 5 c.f.u gE-1 peat at 0-50, 50-100 and 100-150 cm depth, respectively. Nutrient Agar media pH 7.0 is most suitable for determining bacterial counts using the total plate counts technique. Seven strains were isolated on the basis of colony characteristics and were characterized by cell morphology and Gram`s staining. Two strains were Gram-positive short rods in chains and one was Gram-positive diplo/streptococcus. The remainder was Gram-negative showing short rods, long rods and coccus-shaped. The strains were tested for their ability to hydrolyse starch, cellulose and urea. Of the seven strains, one strain could not degrade any of the substances tested while another strain can degrade all three substances, whilst the rest were considered starch and urea degraders. Only three strains could degrade cellulose. Three treatments were tested on peat under pineapple. Microbial counts were monitored for a period of seventy days and samples taken from a depth of 0-15 and 15-30 cm. The bacterial counts fluctuated during the first two weeks, but stabilized after the fourth week. Most of the bacteria were found at the upper layer in the third treatment where a count of 6.13 x 10 superscript 6 c.f.u. gE-1 peat was counted. The least number of bacteria was found in the treatment without any pineapple leaves residue, having a count of 3.33 x 10 superscript 5 c.f.u. gE-1 peat. Four strains were isolated in which three strains were Gram-negative either with short rods or intermediate rods. The other strain was a Gram-positive short pod. None of the four strains from this experiment was able to hydrolyse starch, cellulose or urea unlike bacteria from peat grown with oil palm.
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