Pectinolytic Activity of Mutagenic Strain of Leuconostoc Mesenteroides Isolated From Orange and Banana Fruit Waste

Adeleke Bartholomew Saanu

doi:10.21767/2576-1412.100007

Abstract

The aim of this study was to isolate pectinolytic bacteria from fermented banana and orange peels. The bacterial isolates were identified using standard biochemical method. The bacteria isolates were screened on pectin agar plates. All the isolates showed pectinolytic activity in terms of making zone surrounding their colony on pectin agar medium. Pectinase activity was determined by dinitrosalicylic (DNS) acid method while protein concentration in the fermentation broth was quantified by Lowry method. The screened isolate designated OP6 tentatively identified as Leuconostoc mesenteroides with highest pectinase activity was subjected to mutagen (Ethidium bromide). The mutants of Leuconostoc mesenteroides generated were screened for pectinase production in comparison with the parent (wild) type in submerged state fermentation. All the mutant strains generated from Leuconostoc mesenteroides had their pectinolytic activities repressed in comparison with the wild strain. Out of mutants screened, mutant designated AB4 have the highest pectinolytic activity 1.54 U/mg. The pectinase activity produced by AB4 was approximately 32% lower than the wild strain. The pretreatment of Leuconostoc mesenteroides with Ethidium bromide caused enzyme repression. The appreciable yield in pectinase activity displayed by the mutant strains when compared with the wild type suggests its industrial relevance. Therefore, use of other chemical mutagens can be tested for further strains improvement.

Highlights

Many countries today, especially Africa depend on agriculture as sole bedrock of its economy [1]
The microbial counts from banana peels increased from 25 × 106 cfu/ml to 83 × 106 cfu/ml while fermented orange peels increased from 11 × 106 cfu/ml to 63 × 106 cfu/ml from orange peel respectively
The increase in microbial population in the fermenting substrates might be due to the bioavailability and utilization of nutrients required by microorganisms to grow, contamination arising from the indiscriminate disposal of wastes to the environment and favourable growth conditions [29]

Summary

Introduction

Especially Africa depend on agriculture as sole bedrock of its economy [1]. Most fruits peels are prone to microbial spoilage; there by-products could be of use as functional ingredients in the production of functional foods, since they are good sources of dietary fiber and bioactive compounds [8]. The citrus peel and seeds are very rich in phenolic compounds, such as phenolic acids and flavonoids, the peel is richer in flavonoids than seeds [10,11] These peels contain macro and micronutrients with several therapeutic, antiseptic, analgesic, anti-inflammation and nutritional values. They can be processed as ingredients and essential additives to many preparations like as juices, cocktails and cooking’s [12]

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Conclusion