Marzena Jędrzejczak-Krzepkowska

Complete genome sequence of Gluconacetobacter xylinus E25 strain—Valuable and effective producer of bacterial nanocellulose ☆

This study reports the release of complete genome sequence of the producer of bacterial nanocellulose (BNC) - Gluconacetobacter xylinus E25, a vinegar-isolated strain. Preliminary sequence analysis revealed complexity of the genome structure and familiarized genetic basis of productive properties of E25 strain. The genome consists of one chromosome and five plasmids. Whole genome sequencing has opened up new perspectives for further bioinformatics and experimental studies allowing the elucidation of molecular mechanisms responsible for regulation of production of BNC - a valuable biomaterial.

Application of byproducts from food processing for production of 2,3-butanediol using Bacillus amyloliquefaciens TUL 308

ABSTRACT A nonpathogenic bacterial strain Bacillus amyloliquefaciens TUL 308 synthesized minor 2,3-butanediol (2,3-BD) amounts from glucose, fructose, sucrose, and glycerol, and efficiently produced the diol from molasses and hydrolysates of food processing residues. Batch fermentations yielded 16.53, 10.72, and 5 g/L 2,3-BD from enzymatic hydrolysates of apple pomace, dried sugar beet pulp, and potato pulp (at initial concentrations equivalent to 45, 20, and 30 g/L glucose, respectively), and 25.3 g/L 2,3-BD from molasses (at its initial concentration equivalent to 60 g/L saccharose). Fed-batch fermentations in the molasses-based medium with four feedings with either glucose or sucrose (in doses increasing their concentration by 25 g/L) resulted in around twice higher maximum 2,3-BD concentration (of about 60 and 50 g/L, respectively). The GRAS Bacillus strain is an efficient 2,3-BD producer from food industry byproducts.

Medical Devices Regulation

Bacterial nanocellulose (BNC), thanks to its properties, can be used for the production of a wide range of medical devices. Medical devices made from pure bacterial nanocellulose or in association with other substances or materials must meet certain legal requirements while placed onto the market. The legislation in force concerning medical devices aims to eliminate undesirable products and to ensure that only such products are on the market and in use that meet all of the European Union requirements. This chapter provides the necessary definition and classification of a medical device, essential requirements, conformity assessment procedures, obligation of manufacturers (authorized representatives), and other information related to these issues.

Medical and Cosmetic Applications of Bacterial NanoCellulose

Abstract Bacterial nanocellulose, a natural, chemically pure biopolymer produced by microorganisms, is being well recognized as a highly biocompatible material. It has been already successfully applied as wet wound dressing and cosmetic facial mask, but its internal uses as artificial vessels, heart valves, and hernia meshes have been also conducted. Specific modifications of BNC make possible production of cartilage-like substitutes of meniscus, auricular, and nasal concha or even tubes for nerves regeneration. The final products are similar to natural tissues, with biocompatibility, moldability, biophysical, and chemical properties fitting the needs of regenerative medicine. Some of these biotechnological products have been already subjected to intensive in vivo investigation; some others, such as porous scaffolds for tissue engineering, are still under development. Recently, a lot of attention has been put into drug delivery systems production based on bio-cellulose. Continually, microbial cellulose offers a large field for systematic research on its new biomedical applications.

Taxonomic Review and Microbial Ecology in Bacterial NanoCellulose Fermentation

Abstract Acetic acid bacteria (AAB) have a long history of use in several fermentation processes. Their exploitation gradually emerged in biotechnologic applications, especially in the biosynthesis of useful chemicals and processes for the manufacture of several fermented food products. Taxonomic studies, from traditional to polyphasic approaches, have gradually allowed the proper classification of several ABB into distinct genera and species, among them, the bacterial nanocellulose (BNC) producers, notably Komagataeibacter xylinus. Despite the advantages in using specific (isolated) strains for biotechnologic processes toward controlling the kinetics and process yield, mixed culture fermentations may provide an interesting approach to tailoring the properties of BNC and to increase the product yield when aiming at industrial scale. Microbial population dynamics may play a synergistic role in the coordinative substrate consumption and metabolites’ production, especially if using complex media (as is the case with low cost substrates, eg, residues from other processes). This chapter will first review the main historic steps involved in the taxonomic classification of AAB. It will then address the lying potential behind mixed microbial fermentations, from kombucha to nata de coco, both sharing in common, the contribution of cellulose-producing bacteria for the fermentation process.

Bacterial NanoCellulose Synthesis, Recent Findings

Abstract In this chapter we attempted to summarize recent reports on molecular biology and metabolism of bacteria belonging to the genus Gluconacetobacter with focus on its application for cellulose synthesis. The following issues were addressed: (1) the taxonomy of cellulose-producing Gluconacetobacter species; (2) cellulose synthase operons and flanking sequences from BNC producers, their role in biosynthesis of cellulose, and differences with other microorganisms; (3) recent advances in studies on three-dimensional structure of cellulose synthase subunits and their impact on Bacterial NanoCellulose (BNC) biosynthesis; (4) conditions of BNC production by Gluconacetobacter species from various substrates, including a variety of agro-industrial wastes; (5) metabolic pathways operating in Gluconacetobacter species verified as crucial for BNC synthesis by metabolic flux analysis; (6) the state of genome sequences data availability, concerning BNC-producing strains and their closest relatives; (7) genetic modifications of Ga. xylinus and Ga. hansenii and their effect on biosynthesis of cellulose with emphasis on methods and vectors used for these modifications.

Stable composite of bacterial nanocellulose and perforated polypropylene mesh for biomedical applications: BNC Based Composites for Biomedical Applications

The article presents the method of preparation of new, stable bacterial cellulose composites with perforated solid materials for biomedical applications, comprising reconstructive surgery of soft and hard tissues. The composites were obtained in specially designed bioreactors equipped with a set of perforated mesh stripes threaded vertically to the culture medium, ensuring perpendicular growth of bacterial nanocellulose synthesized by Komagataeibacter xylinus E25 in stationary culture. The developed biocomposites have been tested for stability and mechanical strength, as well as for their in vitro inflammatory responses shown as mast cell degranulation with N-acetyl-β-d-hexosaminidase release and mast cell adhesion. The obtained results indicate that the composites components are well integrated after the process of cultivation and purification. Bacterial nanocellulose does not negatively influence mechanical properties of the polypropylene porous mesh, preserving its tensile strength, elasticity, and load. Moreover, application of bacterial cellulose makes the composites less immunogenic as compared to polypropylene itself. Therefore, the composites have the great potential of application in medicine, and depending on the applied porous material, might be used either in hernioplasty (if porous hernia mesh is used), cranioplasty (if perforated metal or polymeric cranial implant is applied), or as a protective barrier in any application that requires biocompatibility or antiadhesive properties improvement.

Improvement of efficiency of brown coal biosolubilization by novel recombinant Fusarium oxysporum laccase

Clean coal technologies (e.g. coal biosolubilization) are of essential value, especially in Europe, where coal is the national wealth and other energy sources like crude oil are not available. Fusarium oxysporum LOCK 1134, the strain isolated from brown coal, efficiently biosolubilizes lignite. The obtained liquefied products contain 50% less sulfur and over 99% less mercury than the crude coal. Moreover, the liquefied coal can be modified further by laccase. In this study F. oxysporum laccase was expressed in Pichia pastoris for the first time and was assessed as an additional agent for coal degradation. The novel laccase contributes to humic and fulvic acids release from liquefied coal due to introduction of oxygen into coal structure. The effect is increased when a natural redox mediator, sinapic acid, is present in the reaction mixture—up to 30% and 80% respectively. Humic acids obtained by biological process are environmentally friendly fertilizers that may have stimulating effects on crop growth.