Bacterial Nanocellulose Derived from Banana Leaf Extract: Yield and Variation Factors

Manuel Fiallos-Cárdenas,Hugo Romero Bonilla,Marco Ordoñez-Viñan,Omar Ruiz-Barzola,Simón Pérez-Martínez,Miguel A Reinoso,Angel D Ramirez

doi:10.3390/resources10120121

Abstract

Bananas are one of the most important crops worldwide. However, a large amount of residual lignocellulosic biomass is generated during its production and is currently undervalued. These residues have the potential to be used as feedstock in bio-based processes with a biorefinery approach. This work is based on the valorization of banana leaf and has the following objectives (i) to determine the effect of certain physical and environmental factors on the concentration of glucose present in banana leaf extract (BLE), using a statistical regression model; (ii) to obtain Bacterial Nanocellulose (BNC), using BLE (70% v/v) and kombucha tea as fermentation medium. In addition, the physicochemical properties of BNC were evaluated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The results indicate that storage time, location, leaf color, and petiole type are factors related to BLE concentration, which is reduced by approximately 28.82% and 64.32% during storage times of five days. Regarding BNC biosynthesis, the results indicate that the highest yield, 0.031 g/g, was obtained at 21 days. Furthermore, it was determined that the highest production rate was 0.11 gL−1h−1 at 11 days of fermentation. By FTIR, it was determined that the purification step with NaOH (3M) should be carried out for approximately two hours. This research supports the development of a circular bioeconomy around the banana value chain, as it presents a way of bioprocessing residual biomass that can be used to produce bioproducts.

Highlights

Banana is a perennial tropical crop belonging to the Musaceae family and is one of the most important crops in the world in terms of metric tons harvested [1,2]
Tan et al [7] used the juice extracted from banana frond (JEBF), which contains a total sugar of 14% with the amount of glucose (18.9 gl−1), sucrose (13.29 gl−1), and fructose (15.63 gl−1) with a total volume of 0.33 l JEBF/kg banana leaf with a theoretical yield of 65% for obtaining bioethanol. These results demonstrate the potential of banana leaf extract as a carbon source in the fermentation process of different microorganisms
This work aims to: (i) determine the relationship between the morphological characteristics of banana leaves and the content of reducing sugars in the extracts obtained from them and, (ii) characterize the bacterial nanocellulose formed from banana leaf extract (BLE) as the sole carbon source for fermentation according to its physicochemical properties

Summary

Introduction

Banana is a perennial tropical crop belonging to the Musaceae family and is one of the most important crops in the world in terms of metric tons harvested [1,2]. The banana production system generates different by-products as (i) starchy material, rejected fruits that do not reach the commercial standard [4,5], this by-product is used for the production of flour, cattle feed, or snacks; and (ii) lignocellulosic biomass: rachis, leaf, and pseudostem [2]. These lignocellulosic residues are usually not valorized [6,7,8]. This practice is thought to benefit the crop; it has been determined that it can cause a nutritional imbalance in the plant [10], in addition to generating environmental and health problems [11,12]

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Results