Characterization of Bacterial Isolates

Oct 13, 2025 by wbrum.org 97 views

Introduction

The production of crude palm oil (CPO) in oil palm plantations has been a significant contributor to the global economy. However, the process of CPO production generates a substantial amount of liquid waste known as Palm Oil Mill Effluent (POME). This waste has a detrimental impact on the environment, and its management is a pressing concern for oil palm companies. One of the methods used to manage POME is through anaerobic processes that produce biogas, but the biogas sludge produced from this process has not been utilized effectively. The high diversity of microbial populations in biogas sludge can contribute to soil fertility and plant productivity. Therefore, research on the characteristics of biogas sludge is essential to be applied in the field, enabling oil palm companies to manage waste from POME processing more effectively.

Background

Palm Oil Mill Effluent (POME) is a byproduct of the CPO production process, and its management is a critical issue for oil palm companies. POME contains high levels of organic matter, nutrients, and pathogens, making it a significant environmental pollutant. The anaerobic digestion of POME produces biogas, which can be used as a renewable energy source. However, the biogas sludge produced from this process has not been utilized effectively, and its potential as a source of biofertilizer has not been fully explored.

Research Methodology

This study is divided into two stages. The first stage involves a pre-researching phase to identify several chemical characteristics of the biogas sludge and measure the number of useful bacterial populations, which can later be used as a source of isolates. Sludge samples were taken from anaerobic biogas tanks in palm oil mills in Labuhanbatu Selatan Regency, North Sumatra, and analysis was conducted in January to February 2020 using analytical descriptive methods. The results showed that the biogas sludge has a pH of 7.41, which meets quality standards, and BOD and COD levels that are lower than POME. The number of nitrogen-inhibiting bacterial populations was found to be more than phosphate solvent bacteria, indicating the potential of biogas sludge as a useful source of microbes.

Characterization of Bacterial Isolates

In the first stage of research, the focus was on obtaining the characteristics of superior bacterial isolates from biogas sludge that can increase N-total and P-Available, and molecular identification of the bacterial isolates. This study was conducted at the Biology Laboratory of Soil, Faculty of Agriculture, University of North Sumatra between March and August 2020. The results showed that nitrogen (N3) bacterial isolates have significant nitrogenase activity, able to increase N-total ultisol soil to 62.56%. On the other hand, phosphate solvent isolates (P7) can increase P-Ultisol soil-soil levels up to 36.21%. Morphological characteristics of these bacteria indicate that nitrogen-inhibiting bacteria are gram-negative with round cells, while phosphate solvent bacteria are gram-negative with stem cells.

Evaluation of Bacterial Isolates and Biogas Sludge on Plant Growth

The second stage of this study aims to evaluate the effect of superior bacterial isolates and biogas sludge on the growth and production of up Gogo rice plants in ultisol soils. The study was conducted on farmers' land on Jl. Ikahi, Medan Selayang District, Medan City, between October 2020 and March 2021. The experimental design used a random group design with two factors. The results showed that the use of superior bacterial isolates and biogas sludge at certain doses increases various plant growth parameters, including dry weight, N absorption, and total nitrogen-inhibiting bacterial population.

Conclusion

From the analysis conducted, it appears that the interaction between nitrogen-inhibiting bacterial isolates and biogas sludge at high doses can significantly increase total N-Soil and support the growth of Gogo rice. The conclusion of this study is that biogas sludge contains a favorable population of bacteria, such as nitrogen-inhibiting bacteria and phosphate solvents, which have the potential to improve soil quality and support plant production effectively.

Implications and Recommendations

With the results of this study, it is hoped that oil palm companies can use biogas sludge not only as part of the waste process but also as a source of biofertilizer that is beneficial to agriculture, as well as reducing the negative environmental impact of industrial waste. The use of biogas sludge as a biofertilizer can be a sustainable solution that supports food security and environmental sustainability. Therefore, it is recommended that oil palm companies adopt this approach and explore the potential of biogas sludge as a biofertilizer.

Future Research Directions

Future research should focus on scaling up the production of biogas sludge as a biofertilizer and exploring its potential applications in various agricultural systems. Additionally, further research is needed to understand the long-term effects of using biogas sludge as a biofertilizer on soil health and plant productivity.

Q1: What is Palm Oil Mill Effluent (POME) and how is it managed?

A1: Palm Oil Mill Effluent (POME) is a byproduct of the crude palm oil (CPO) production process. It is managed through anaerobic processes that produce biogas, which can be used as a renewable energy source. However, the biogas sludge produced from this process has not been utilized effectively.

Q2: What are the characteristics of biogas sludge?

A2: Biogas sludge has a pH of 7.41, which meets quality standards, and BOD and COD levels that are lower than POME. It also contains a high diversity of microbial populations, including nitrogen-inhibiting bacteria and phosphate solvents.

Q3: What are the benefits of using biogas sludge as a biofertilizer?

A3: Biogas sludge can be used as a biofertilizer to improve soil quality and support plant production effectively. It contains nitrogen-inhibiting bacteria and phosphate solvents that can increase N-total and P-Available in soil.

Q4: How does biogas sludge affect plant growth?

A4: Biogas sludge can increase various plant growth parameters, including dry weight, N absorption, and total nitrogen-inhibiting bacterial population. It can also support the growth of Gogo rice plants in ultisol soils.

Q5: What are the implications of using biogas sludge as a biofertilizer?

A5: Using biogas sludge as a biofertilizer can reduce the negative environmental impact of industrial waste and support food security and environmental sustainability. It can also provide a sustainable solution for oil palm companies to manage waste from POME processing.

Q6: What are the future research directions for biogas sludge as a biofertilizer?

A6: Future research should focus on scaling up the production of biogas sludge as a biofertilizer and exploring its potential applications in various agricultural systems. Additionally, further research is needed to understand the long-term effects of using biogas sludge as a biofertilizer on soil health and plant productivity.

Q7: How can oil palm companies adopt biogas sludge as a biofertilizer?

A7: Oil palm companies can adopt biogas sludge as a biofertilizer by implementing anaerobic digestion processes to produce biogas and utilizing the biogas sludge as a biofertilizer. They can also explore partnerships with research institutions and agricultural experts to develop and implement sustainable agricultural practices.

Q8: What are the potential challenges and limitations of using biogas sludge as a biofertilizer?

A8: Potential challenges and limitations of using biogas sludge as a biofertilizer include the need for further research on its long-term effects on soil health and plant productivity, the potential for contamination of soil and water, and the need for proper handling and application of biogas sludge.

Q9: How can biogas sludge be applied to agricultural fields?

A9: Biogas sludge can be applied to agricultural fields through various methods, including injection, broadcasting, and incorporation into soil. It is essential to follow proper application guidelines and ensure that the biogas sludge is handled and applied safely to avoid contamination of soil and water.

Q10: What are the potential economic benefits of using biogas sludge as a biofertilizer?

A10: The potential economic benefits of using biogas sludge as a biofertilizer include reduced costs associated with purchasing synthetic fertilizers, increased crop yields and productivity, and improved soil health and fertility.