Nitrogen oxide (N₂O) gas which has a global warming impact 296 times higher than CO₂ can now be suppressed through the application of nitrate-reducing bacteria. Prof Iman Rusmana, Professor at the Department of Biology, IPB University, revealed that this breakthrough can simultaneously improve agricultural productivity and the quality of shrimp pond culture.
“The gas molecule produced in the process of nitrogen metabolism gets attention because it affects climate change is nitrous oxide gas (N₂O). The gas is one of the greenhouse gases that contribute to global warming, because it is 296 times higher than CO₂ and can erode the ozone layer,” said Prof Iman at the Press Conference of Pre Scientific Oration of Professor of IPB University, 5/22.
As a Professor of the Faculty of Mathematics and Natural Sciences, Prof Iman explained that rice fields are a significant contributor to greenhouse gas emissions. About 15,8 percent of N₂O emissions come from agricultural land, and the number increases with the use of nitrogen fertilizers. In waterlogged land such as rice fields, denitrifying bacteria contribute 85-90 percent of N₂O emissions.
Nitrogen is one of the main components of cell macromolecules such as proteins, nucleic acids and other organic molecules. In the nitrogen cycle, microorganisms, especially bacteria, play an important role in several nitrogen metabolism reactions.
“The application of selected nitrate-reducing bacteria that have high N₂O-reducing activity can reduce N₂O emissions in rice fields. The application of nitrate-reducing bacteria Ochrobactrum anthropi combined with methanotroph bacteria (25 percent recommended NPK fertilizer) can reduce N₂O and CH₄ gas emissions in rice fields,” he explained.
Based on productivity parameters, bacterial treatment on plants showed encouraging results. The bacterial treatment on plants was 24,5 percent higher than the comparison, proving that this environmentally friendly solution is also economically beneficial.
Not only in paddy fields, the application of nitrate-reducing bacteria also provides significant benefits for shrimp pond culture. Prof Iman said that in shrimp ponds, ammonia and nitrite compounds are toxic metabolites for shrimp.
“These ammonia and nitrite compounds are the result of protein decomposition from the remaining unconverted feed from shrimp feces. High ammonia content affects the increase in oxygen consumption by tissues and reduces the ability of blood to bind oxygen,” he said.
In brackish water environments such as shrimp ponds, nitrate-reducing bacteria compete in the nitrate reduction process. The main end product of nitrate reduction at high temperatures is 65-78 percent nitrogen, indicating that denitrification still has an important role in the end product of nitrate reduction, although it is not the dominant species in the estuary.
“The application of selected nitrate-reducing bacteria can keep ammonia and nitrite levels low, so that pond water quality is maintained well which supports shrimp health and growth. Therefore, this selected nitrate reducing bacteria formulation can be applied by shrimp farmers to maintain the success of shrimp farming,” concluded Prof Iman. (Lp) (IAAS/LAN)
