Komagataeibacter rhaeticus as an alternative bacteria for cellulose production

Abstract

A strain isolated from Kombucha tea was isolated and used as an alternative bacterium for the biosynthesis of bacterial cellulose (BC). In this study, BC generated by this novel bacterium was compared to Gluconacetobacter xylinus biosynthesized BC. Kinetic studies reveal that Komagataeibacter rhaeticus was a viable bacterium to produce BC according to yield, thickness and water holding capacity data. Physicochemical properties of BC membranes were investigated by UV-vis and Fourier transform infrared spectroscopies (FTIR), thermogravimetrical analysis (TGA) and X-ray diffraction (XRD). Additionally, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were also used for morphological characterization. Mechanical properties at nano and macroscale were studied employing PeakForce quantitative nanomechanical property mapping (QNM) and dynamic mechanical analyzer (DMA), respectively. Results confirmed that BC membrane biosynthesized by Komagataeibacter rhaeticus had similar physicochemical, morphological and mechanical properties than BC membrane produced by Gluconacetobacter xylinus and can be widely used for the same applications.

Komagataeibacter rhaeticus grown in sugarcane molasses-supplemented culture medium as a strategy for enhancing bacterial cellulose production

“…3F0) presented thin nanofibers and, consequently, less dense nanofibers structure comparing to BC membranes produced in SCM medium (Fig. 3F6) corroborating BC yield and WHC results (Velásquez-Riaño and Bojacá, 2017;Lazarini et al, 2016;Machado et al, 2016;Çakar et al, 2014). The average nanofiber thickness were 92 and 119 nm for F0 and F6 samples, respectively.…”

“…Hence, the investigation of BC production by K. rhaeticus bacterium isolated of Kombucha tea and grown in static SCM-supplemented culture media were evaluated in order to reach an alternative carbon source, in addition to adding value to this important by-product of Brazilian agroindustry. As already described by Machado et al (2016), comparative studies using both G. xylinus and K. rhaeticus showed BC membranes produced with similar physicochemical, morphological, thermal and mechanical properties. From these results, K. rhaeticus emerged as a suitable and viable alternative bacterium to produce BC membranes.…”

“…The thermal degradation of BC membranes occurs in two subsequent steps: first step of weight loss in the range of 200-400°C (of around 60%) were ascribed to the BC depolymerization in small glucose units. The second step from 400 to 600°C (about 20%) corresponds to the dehydration and decomposition of the glucose units into gases (water, carbon monoxide and carbon dioxide) (Barud et al, 2008b(Barud et al, , 2011De Salvi et al, 2014;Machado et al, 2016). It is worth pointing up that the T onset (around 350°C) obtained from DTG curves (Fig.…”

“…Five samples of each different medium were analysed. The water holding capacity (WHC) was calculated by the following formula (Machado et al, 2016;Shezad et al, 2010):…”

“…Recently, Machado et al (2016) and Dos Santos et al (2014) isolated a strain from Kombucha tea for BC production, which occurred in a rate 50% higher, besides showing similar physicochemical, morphological and mechanical properties than those BC synthesized by G. xylinus. This set of findings makes the Komagataeibacter rhaeticus a more viable alternative for BC production, leading to benefits that range from time production optimization to costs reduction.…”