Antibacterial Effects of Aqueous Ethanolic Leaf Extracts of Ocimum gratissimum, Cymbopogon citratus, Vernonia amygdalina and Annona muricata on the Isolated Pathogenic Organism of Citrus Canker from Citrus sinensis (Sweet Orange)

Eneh Frank Uchenna,Okeke Chidi Benjamin,Nwachukwu Godslove Pephel,Igbokwe Gabriel Ejike,Okpala Chukwuemeka Obumneme

doi:10.32861/jbr.58.64.68

Abstract

The aqueous ethanolic extracts of Vernonia amygdalina, Ocimum gratissimum, Cymbopogon citrates and Annona muricata were screened for antibacterial activities at 200mg/ml concentration. Antibacterial efficacy of extracts against the bacteria were identified by gram staining techniques, coagulase and catalase tests and the bacterial isolate was indicated by the appearance of clear zones of inhibition around the disks. The extracts of Vernonia amygdalina and Ocimum gratissimum showed inhibitory activities against the bacterial isolate with zones of inhibition of 12mm and 8.5mm respectively while extracts of C.citratus and A.muricata showed no zone of inhibition. Result of the antimicrobial activity of the extracts compared effectively with the activity of standard fumigant with extract of V. amydalina showing the highest potency which was used in preparation of a local fumigant. The minimum inhibitory concentration of V.amygdalina and O.gratissimum were 25mg/ml and 50mg/ml respectively which were not determined in C.citratus and A.muricata. In conclusion, the results of this investigation showed that the aqueous ethanolic leaf extracts of V. amygdalina and O. gratissimum can be used as an effective control measure for the elimination of citrus canker of Citrus sinensis.

Highlights

The aquatic ecosystem was a combination of interconnected species that are reacting to each other of habits and habitats
Many studies have shown that the direct discharge of untreated wastewater into aquatic environment containing anionic surfactants causes significant damage to the aquatic environment due to the growth of algae that consume oxygen needed for the life of aquatic organisms
These damages in the aquatic environment are caused by the presence of anionic surfactants (SLS), and by their interaction with other pollutants in the aquatic environment, which increases their toxic effect on aquatic organisms

Summary

Introduction

The aquatic ecosystem was a combination of interconnected species that are reacting to each other of habits and habitats. The discharging of many different types of synthetic chemicals (i.e., fertilizers, pesticides, and detergents) into the marine environment causes several adverse effects on biodiversity of aquatic ecosystem [1, 2]. Most contaminants show specific mechanisms of toxicity, for example, impairing the nervous system or the liver. These effects may acutely or chronically reduce population sizes in wildlife by weakening individuals, culling young, or initiating disease processes, for example [5]. Sweeping or systematic reduction in genetic variability has been called a bottleneck effect [7, 8] and could lead to inbreeding depression [9, 10], which could exacerbate the effects of direct contaminant damage by further reducing overall population size and genetic polymorphisms

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Discussion

Conclusion