Mochamad Alqi Harlianto1 and I Nyoman P. Aryantha1,2
1Microbiology-Genetics-Cell Molecular Biology Division School of Life Sciences and Technology
2Center for Life Sciences
Institut Teknologi Bandung
Jalan Ganesha 10, Bandung 40132
Email : nyoman@sith.itb.ac.id
ABSTRACT
Nitrogen is the most important fertilizer for plant growth, and it is required in large quantity as the main component of protein, nucleic acid, and other cell components. Plant can only absorb nitrogen in form of ammonium and nitrate. Azotobacter chroococcum can provide ammonium for plant by nitrogen fixation from atmosphere by non-symbiotic interaction (free living). In order to develop biofertilizer (nitrogen fixing agent), this research was aimed to find out the maximum growth of Azotobacter chroococcum in coconut water based medium. The focuse of research was to determine the concentration of coconut water and inoculum to produce maximum Azotobacter chroococcum cell biomass. The experiment was conducted by substrate optimization with various coconut water concentration i.e: 25%, 50%, 75%, and 100% (v/v). Six inoculum concentration were evaluated i.e: 2,5%, 5,0%, 7,5%, 10,0%, 12,5%, and 15,0% (v/v). Cell biomass was measured with Optical Density method using spectrophotometer, pH with pH meter, and reducing sugar by using Somogyi-Nelson method. Cell number was obtained by converting OD value into cell number by using a standard curve. The result indicates that coconut water concentration of 25%v/v was the best with a growth rate maximum of 1,45 cell/hour. The best inoculum concentration was 2,5% (v/v) with maximum growth rate of 0,85 cell/hour. This result approves that coconut water can be used as growth medium for Azotobacter chroococcum production to develop biofertilizer.
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Keyword : Azotobacter chroococcum , coconut water, non-symbiotic bacteria, nitrogen fixation.
1Microbiology-Genetics-Cell Molecular Biology Division School of Life Sciences and Technology
2Center for Life Sciences
Institut Teknologi Bandung
Jalan Ganesha 10, Bandung 40132
Email : nyoman@sith.itb.ac.id
ABSTRACT
Nitrogen is the most important fertilizer for plant growth, and it is required in large quantity as the main component of protein, nucleic acid, and other cell components. Plant can only absorb nitrogen in form of ammonium and nitrate. Azotobacter chroococcum can provide ammonium for plant by nitrogen fixation from atmosphere by non-symbiotic interaction (free living). In order to develop biofertilizer (nitrogen fixing agent), this research was aimed to find out the maximum growth of Azotobacter chroococcum in coconut water based medium. The focuse of research was to determine the concentration of coconut water and inoculum to produce maximum Azotobacter chroococcum cell biomass. The experiment was conducted by substrate optimization with various coconut water concentration i.e: 25%, 50%, 75%, and 100% (v/v). Six inoculum concentration were evaluated i.e: 2,5%, 5,0%, 7,5%, 10,0%, 12,5%, and 15,0% (v/v). Cell biomass was measured with Optical Density method using spectrophotometer, pH with pH meter, and reducing sugar by using Somogyi-Nelson method. Cell number was obtained by converting OD value into cell number by using a standard curve. The result indicates that coconut water concentration of 25%v/v was the best with a growth rate maximum of 1,45 cell/hour. The best inoculum concentration was 2,5% (v/v) with maximum growth rate of 0,85 cell/hour. This result approves that coconut water can be used as growth medium for Azotobacter chroococcum production to develop biofertilizer.
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Keyword : Azotobacter chroococcum , coconut water, non-symbiotic bacteria, nitrogen fixation.
