Adaptive laboratory evolution of nanocellulose‐producing bacterium

Abstract

Adaptive laboratory evolution through 12 rounds of culturing experiments of the nanocellulose-producing bacterium Komagataeibacter hansenii ATCC 23769 in a liquid fraction from hydrothermal pretreatment of corn stover resulted in a strain that resists inhibition by phenolics. The original strain generated nanocellulose from glucose in standard Hestrin and Schramm (HS) medium, but not from the glucose in pretreatment liquid. K. hansenii cultured in pretreatment liquid treated with activated charcoal to remove inhibitors also converted glucose to bacterial nanocellulose and used xylose as carbon source for growth. The properties of this cellulose were the same as nanocellulose generated from media specifically formulated for bacterial cellulose formation. However, attempts to directly utilize glucose proved unsuccessful due to the toxic character of the lignin-derived phenolics, and in particular, vanillan and ferulic acid.Adaptive laboratory evolution at increasing concentrations of pretreatment liquid from corn stover in HS medium resulted in a strain of K. hansenii that generated bacterial nanocellulose directly from pretreatment liquids of corn stover. The development of this adapted strain positions pretreatment liquid as a valuable resource since K. hansenii is able to convert and thereby concentrate a dilute form of glucose into an insoluble, readily recovered and value-added product-bacterial nanocellulose.

Moving from residual lignocellulosic biomass into high‐value products: Outcomes from a long‐term international cooperation

“…4). 80 The adapted strain was able to produce 48% more BC when cultivated in the LHW pretreated corn‐stover‐derived liquid fraction. The final product also maintained the same desired properties of crystallinity and thermal stability found in BC produced with the standard culture medium.…”

“…The high purity and organized structure give bacterial cellulose (BC) remarkable properties such as thermal stability, high crystallinity, and a degree of polymerization, while also being biocompatible and biodegradable 79 . Usually, BC is produced in glucose‐rich culture medium with other nutrient sources, resulting in high production cost, and limiting its use in biotechnological applications 80,81 . One of the key measures to reduce BC production costs is the use of alternative feedstocks, especially plant waste.…”

Production and characterization of Komagataeibacter xylinus SGP8 nanocellulose and its calcite based composite for removal of Cd ions

“…The cellulose pellicle was harvested by decanting the culture media, the pellicle was then repeatedly rinsed with distilled water and treated with 0.5 N NaOH for 1 h under constant shaking at 65°C. Alkali treatment was done to remove the media components and the attached bacterial cells from the pellicles (Vasconcellos et al 2019). Thereafter, the pellicle was taken out and washed with distilled water till the pH of washing solution become neutral.…”

“…The nascent polymers are extruded out through complex pores or complex terminals of the cell membrane and assembled to form subfibrils which are interconnected to form complex structure in the form of cellulose pellicles (Cacicedo et al 2016). Owing to various aforementioned unique properties of BNC, it has been used for preparation of tissue scaffold, as a drug delivery agent, surgical implants, and for wound dressing (Dubey et al 2017; Responsible editor: Tito Roberto Cadaval Jr Vasconcellos et al 2019). Indeed large numbers of patents involving the usage of BNC in biomedicine as a drug delivery agents and medical implants have been obtained by various researchers (Charreau et al 2013;Charreau et al 2020).…”

Developing rapid growing Bacillus subtilis for improved biochemical and recombinant protein production

“…Adaptive laboratory evolution (ALE) is an important strategy to improve the fitness of microorganisms through selected environmental conditions and was widely used in metabolic engineering ( Papapetridis et al., 2018 ; Lee et al., 2016 ; Choe et al., 2019 ; Phaneuf et al., 2019 ; Gibson et al., 2020 ). Five major application areas of ALE are growth rate optimization ( Sandberg et al., 2014 ; Pfeifer et al., 2017 ), increasing tolerance of the strain ( Qi et al., 2019 ; Wang et al., 2018 ; Pereira et al., 2019 ), increase of substrate utilization ( Kawai et al., 2019 ; Gonzalez-Villanueva et al., 2019 ), increase of product yield/titer ( Gibson et al., 2020 ; Lee et al., 2019 ; Vasconcellos et al., 2019 ) and mechanism discovery ( Tenaillon et al., 2012 ; Kang et al., 2019 ). Fast growth phenotypes of Escherichia coli have been obtained through ALE, and the underlying mechanism has been studied ( LaCroix et al., 2015 ; Long et al., 2017 ; McCloskey et al., 2018 ; Wannier et al., 2018 ; Sandberg et al., 2016 ).…”