Pectin Degradation in Fruit Juices by Pectinase from Meyerozyma sp. VITPCT75 Isolated from Phyllanthus emblica

B Meena,V.G Sowmeya,D Naga Sarath Chandra,M Kavitha,A Swetha,Archa B Praveen

doi:10.22207/jpam.15.2.51

Abstract

This study aimed to identify and characterize a pectinase-producing novel yeast from the fermented juice of Phyllanthus emblica and apply the enzyme for fruit juice clarification. Among the five pectinase-producing yeasts, isolate-1 exhibited the highest pectinase activity and was further used in this study. Based on morphological, physiological, and 18SrRNAanalyses, isolate-1 was recognized as a new strain sharing 99% sequence homology with other Meyerozyma strains and was thus designated as Meyerozyma sp. VITPCT75. The strain produced pectinase optimally at a temperature and pH of 25oC and 7, respectively. Maximum pectinase production was observed after 4-days incubation. The enzyme exhibited optimum activity at the temperature of 25 °C and pH 7.0. The enzyme was more stable at a temperature and pH of 20 °C and 7, respectively. Storage stability studies revealed that the enzyme was stable at -20 °C. The cell-free supernatant was partially purified using ammonium sulfate and solvent precipitation. Acetone at a concentration of 20% assured an adequate partial purification. The molecular weight of pectinase was determined as 6 kDa. The enzymatic metal ion preference-related studies revealed that Ca²z, Kz, Cu²z, Fe²z, and Ba²z ions enhanced, Ni²z ions moderately inhibited, and Mn²z ions intensely inhibited the enzymatic activity. Neither Na+ and Mg2+ ions nor EDTA affected the enzyme activity. When subjected to fruit juice clarification, the enzyme significantly reduced the viscosity of the juice.

Highlights

Pectinases (EC 3.2.1.15) are hydrolytic enzymes that cleave the b-1,4 glycosidic bonds linking galacturonic acids in pectin present in the plant cell walls[1,2]
This study aimed to identify and characterize a pectinase-producing novel yeast from the fermented juice of Phyllanthus emblica and apply the enzyme for fruit juice clarification
The fermented juice obtained was used to screen for pectinaseproducing yeast, which was screened based on the utilization of pectin as the only carbon source in the screening medium, yeast extract peptone pectin agar (YPPA) containing (g/l) yeast extract 10, peptone 20, pectin 20, and agar 2027

Summary

Introduction

Pectinases (EC 3.2.1.15) (polygalaturonases) are hydrolytic enzymes that cleave the b-1,4 glycosidic bonds linking galacturonic acids in pectin present in the plant cell walls[1,2]. Pectinases play a vital role in the usual ripening processes of certain fruits by altering the nature of pectin substances[3,4]. They are extensively used in the food industry, plant tissue maceration, degumming of natural fibers, textiles, and wastewater treatment[5,6]. Pectinases improve liquefaction, clarification, filterability, color release, and flavor compounds from the fruits into boost wine quality[8]. Pectinases of microbial origin are classified into enzymes with depolymerizing and saponifying activities. Polymethyl galacturonases, pectin lyases, pectate lyases, and polygalacturonases are depolymerizing enzymes, whereas pectin esterases are saponifying enzymes[9]

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