Antibacterial potency of the coat of Citrus sinensis (orange) on Bacillus species

Document Type : Original Article


1 Science Laboratory Technology, Faculty of Science, Biological Sciences Unit, The Oke Ogun Polytechnic, Saki. Department of Zoology, Cellular Parasitology Programme, University of Ibadan, Nigeria

2 Department of Science Laboratory Technology, and Microbiology Option, The Oke-Ogun Polytechnic, Saki Oyo state, Nigeria

3 Department of Zoology, Parasitology Unit, University of Ibadan,Nigeria

4 Department of Microbiology, The Oke-Ogun Polytechnic, Saki, Nigeria.


Background: In other to curb the resurgence of drug resistance, there is need to find cheaper, environmental friendly and readily available alternative chemotherapy for all patients for all ages. Extracts from plants has proven to be potent against wide range of pathogen such as bacteria, viruses, fungi and parasites of which Citrus sinensis is an important example. Both the aqueous and ethanoic extracts of Citrus sinensis were evaluated on some Bacillus species which were isolated from vegetables in nearby farm around the Oke Ogun Polytechnic Saki. Aim: The aim of this study was to evaluate the phytocompounds and antimicrobial activities of the coat of Citrus sinensis on some Bacillus species. Methods: The aqueous and ethanoic extract of the dried plant coat was evaluated for its antimicrobial activities on the isolated organisms using Kirby bauer disc diffusion method. The isolates were subjected to molecular identification using the polymerase chain reaction and subsequent Sanger sequencing techniques. There was high correlation between the isolates’ identity at all the levels and sequencing except in few. The FASTA format of the nucleotides sequences were submitted at the GenBank at NCBI database for accession numbers which were MW362290 (Bacillus cereus), MW362291 (Bacillus cereus), MW362292 (Bacillus weidmanii), MW362293 (Bacillus cereus), MW362294 (Bacillus cereus) and MW362295 (Bacillus thuringiensis). Results: The active phytocompounds present in the aqueous and ethanol solvent were saponin, alkaloid, flavonoid, tannin, coumarin, steroid, terpenoid, cardiac glycosides, quinones, anthraquinones and phenol while Anthocyanin was present only in aqueous extract. These extracts both showed high antibiotics activities on all the isolated organisms. All the extracts recorded considerable antibiotic potency against all the isolates making the extracts of Citrus sinensis coat a suspect containing active biocidal agents. Conclusion: The coat of Citrus sinensis showed high antimicrobial properties against some Bacillus species, the antimicrobial effects was as a result of active phytochemicals present in the coat. This study established biocidal activities in both aqueous and ethanolic extracts. Its utilization for its pharmaceutical would be of great advantage both economically and environmentally.


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