6+ January - February 2015
Enhancing Quality of Ultisols through Phototropic Bacteria
Institute of Bio-Product Development, Universiti Teknologi Malaysia, 81310 Johor, Malaysia.
Department of Bioprocess Engineering, Faculty of Chemical Engineering, University Teknologi Malaysia, 81310 Johor, Malaysia.
* Correspondent author: firstname.lastname@example.org
The agriculture sector in Malaysia relies heavily on chemical fertilizers to forecast their production yields. Use
of the chemical fertilizers increases production cost, and prolonging their use destroys the natural soil ecosystem and
deteriorates soil health. In this study, an attempt to improve the fertility of Malaysian soils known as Ultisols was done
by applying phototropic bacterium, Rhodopseudomonas palustris. R. palustris is considered to be a “versatile bacterium”. The bacterium has the ability to fix carbon dioxide to form biomass, converts nitrogen to ammonia, and produces
hydrogen (as a by-product of nitrogen fixation). Experiments were carried out by introducing amounts of 1, 2.5 and 5 %
v/w ofR. palustris to the Malaysian Ultisols (Bungor) and they were allowed to ferment for 30 days under an anaerobic
condition. Deionized water was poured to the soils to increase the soil moisture to have approximately 30% humidity.
During the experiment, light exposure, temperature and moisture of soil were controlled. After the fermentation period,
the elementary analysis was performed to quantify the C/N ratio, soil pH, cation exchange capacity (C.E.C) and soil
electrical conductivity (EC). The analysis of CO
2 uptake rate (OUR) was also recorded to monitor the R.
palustris respiration in soil. Based on the findings, the optimum results obtained were pH 5.5, C/N ratio 3, C.E.C 38.62
meq/100g, EC 314 ?S and OUR 1.59 x 10-5 moles of O
/mass of soil (kg) x Time (h). Experimental results from this
study have proven that the use ofR. palustris had positively improved the Malaysian Ultisols quality in terms of nutrient
content uptake capability.
Keywords : Ultisols, R. palustris, C/N ratio, C.E.C, Malaysia.