By Rita Okoye
An expert in biochemistry, Chukwuemeka Obumneme Okpala, has opened up about his innovative research on the antibacterial effects of aqueous ethanolic leaf extracts from four plants—Vernonia amygdalina, Ocimum gratissimum, Cymbopogon citratus, and Annona muricata—against the isolated pathogen responsible for citrus canker in Citrus sinensis (sweet orange).
This study, which contributes significantly to the field of biochemistry, sheds light on how plant-based remedies could potentially be used to combat a persistent agricultural problem.
The research, which was carried out in collaboration with fellow scientists Eneh Frank Uchenna, Okeke Chidi Benjamin, Igbokwe Gabriel Ejike, and Nwachukwu Godslove Pephel, focused on evaluating the antibacterial activity of these plant extracts at a 200mg/ml concentration. The findings, which were published in a prominent scientific journal, demonstrate the potential of local plant extracts as alternative solutions to combat citrus canker—a disease that has long affected citrus production globally.
In their investigation, the researchers applied various microbiological techniques, including gram staining, coagulase and catalase tests, to identify the bacterial isolates. The results revealed that the aqueous ethanolic extracts of Vernonia amygdalina and Ocimum gratissimum exhibited strong antibacterial effects, with clear zones of inhibition measuring 12mm and 8.5mm, respectively.
This was in stark contrast to Cymbopogon citratus and Annona muricata, whose extracts did not show any inhibitory activity.
The study’s lead author, Okpala, emphasized the significance of these findings in addressing the growing challenges in agriculture.
“Citrus canker is a serious threat to citrus farming, and our research offers an environmentally friendly and sustainable alternative to chemical pesticides,” he explained. “By exploring the antibacterial properties of these plants, we can potentially offer safer solutions that reduce the environmental footprint of agricultural practices.”
The research team’s work further explored the minimum inhibitory concentration (MIC) of the plant extracts, an important metric for determining the lowest concentration of a substance needed to inhibit bacterial growth. The MIC for Vernonia amygdalina was found to be 25mg/ml, while that of Ocimum gratissimum was 50mg/ml.
This provides a clear indication that Vernonia amygdalina was the most potent antibacterial agent among the plants tested.
Okpala and his team noted that the findings of the study were particularly important in the context of sustainable agricultural practices.
“With the growing concern over the environmental impact of synthetic pesticides, it is crucial that we look into natural alternatives like plant-based extracts that are safer for both the environment and human health,” Okpala added.
The results of this study could serve as a foundation for future research into the use of natural plant extracts in agricultural pest control.
The antibacterial activity of Vernonia amygdalina and Ocimum gratissimum opens up new possibilities for their use as active ingredients in the development of natural pesticides.
These plants, commonly known in traditional medicine for their healing properties, could now be considered for large-scale agricultural applications.
The study suggests that these extracts can be used in the development of eco-friendly fumigants that could help in mitigating the spread of citrus canker.
Okpala’s research builds on previous studies that have investigated the antibacterial properties of various plants, but what sets his work apart is the specific focus on citrus canker, a disease that directly impacts food security in many regions.
“Our goal is to ensure that our findings contribute not only to the scientific community but also to farmers who are struggling with diseases like citrus canker,” Okpala said.
The study also compared the effectiveness of the plant extracts to that of a standard fumigant.
Vernonia amygdalina stood out as the most effective, aligning with its traditionally recognized antibacterial properties. This comparison adds further credence to the potential application of these plant extracts as natural alternatives to conventional fumigants.
In addition to the antibacterial findings, the research also explored the feasibility of using these plant extracts in the form of fumigants.
Okpala and his colleagues noted that the use of such extracts in fumigants could provide an added layer of protection for citrus crops, reducing the dependency on chemical-based treatments while preserving the health of the soil and surrounding ecosystem.
Okpala’s work on the antibacterial properties of plant extracts highlights his broader research goals, which are centered on biochemistry’s practical applications in real-world challenges.
“My research aims to create sustainable and cost-effective solutions to agricultural problems,” he stated. “I believe that by tapping into the potential of nature, we can provide farmers with tools that are not only effective but also environmentally conscious.”
For Okpala, this research is just the beginning. As he continues his doctoral studies at Auburn University, he is focused on further exploring the uses of natural substances in agricultural biotechnology.
His work could eventually contribute to the development of green, sustainable agricultural products that are safer for consumers and more effective for farmers.
The publication of this research has not only brought attention to Okpala’s innovative work but also to the growing need for environmentally friendly solutions in the fight against plant diseases.
His study on Vernonia amygdalina and Ocimum gratissimum is a reminder of the untapped potential that exists in nature and the critical need for scientific exploration to harness these resources for the betterment of global agriculture.
Okpala’s research on the antibacterial effects of plant extracts on citrus canker stands as a testament to the power of biochemistry in solving pressing agricultural challenges.
Further findings however showed that as the field of biochemistry continues to evolve, Okpala’s work may pave the way for future advancements in natural pest control and the development of sustainable agricultural practices.