Optimization and characterization of bacterial nanocellulose produced by Komagataeibacter rhaeticus K3

Paulina Jacek,Francisco A.G Soares Da Silva,Fernando Dourado,Stanisław Bielecki,Miguel Gama

doi:10.1016/j.carpta.2020.100022

Paulina Jacek, Francisco A.G Soares Da Silva + Show 3 more

Open Access

https://doi.org/10.1016/j.carpta.2020.100022

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Abstract

In this work, a novel Bacterial NanoCellulose (BNC) producing strain, from Kombucha tea, was isolated and characterized. Based on 16S rRNA analysis the strain was identified as Komagataeibacter rhaeticus. Under static culture, K. rhaeticus K3 produces membranes with a relaxed structure, as observed by Scanning Electron Microscopy (SEM). The addition of 2% (v/v) ethanol to the culture media enhanced by more than 3-fold of the BNC yield.Response surface methodology (RSM) was performed with K. rhaeticus K3, using a new low cost Eucalyptus Biomass Hydrolysate (EBH). The maximum experimental BNC yield was of 5.46 g/L, obtained with the following composition: 31.4 g/L of EBH; 2.89% (v/v) of ethanol and 10.8 g/L of Yeast extract/peptone.Texture Profile Analysis (TPA) of BNC membranes obtained using Hestrin-Schramm culture (HS) medium and optimized medium from EBH showed that membranes from EBH had higher resistance to compression, higher cohesiveness and resilience.

Highlights

Bacterial Nanocellulose (BNC) is a form of cellulose naturally synthesized by several species of Acetobacteraceae
The microorganism Komagataeibacter rhaeticus was labelled as K3 and it was deposited in Institute of Agricultural and Food Biotechnology (IAFB), Collection of Industrial Microbial Cultures, Warsaw, Poland with the registration number 2955
A BLAST search of the GenBank database using 1486 bp 16 S rRNA gene sequence of strain K3 showed its similarity with many members of the genus Komagataeibacter

Summary

Introduction

Bacterial Nanocellulose (BNC) is a form of cellulose naturally synthesized by several species of Acetobacteraceae. Despite the unique properties and interesting application potential, there are still strong limitations associated with its industrial production due to the high operational costs and low BNC yields. Extensive research has been done to promote higher productivities/yield by using low-cost raw materials such as rotten fruits, milk whey, carob and haricot bean and corn steep liquor as nitrogen source, molasse as carbon source, waste beer yeast, beverage industrial waste, fruit peels, rice bark and fruit juices as food industrial waste (Bilgi, Bayir, Sendemir-Urkmez & Hames, 2016; Campano et al, 2016; Fan et al, 2016; Jozala et al., 2016, Jozala et al, 2015). The use of wastewaters from textiles, pulp and paper and agricultural has been reported (Campano et al, 2016; Chen et al, 2017; Cheng, Yang, Liu, Liu & Chen, 2017; Jahan, Kumar & Saxena, 2018; Jozala et al, 2016; Yan et al, 2012)

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