Query: Bacterial cellulose in static culture

title: Mango waste as a culture medium for bacterial cellulose production by Komagateibacter xylinus in static culture

title: Static Culture Condition for Production of Bacterial Cellulose, Environment Friendly Functional Material, by Acetic Acid Bacteria
abstract: Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7% soytone 12% K 2 HPO 4 0.2% NaH 2 PO 4 U 2H 2 O 0.2% lactic acid 0.05% and ethanol 0.3% respectively. The strain F15 was able to produce BC at 26 36 with a maximum at 32 BC production occurred at pH 4.5 8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3 fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

title: Production of bacterial cellulose in static conditions by a simple fed batch cultivation strategy
abstract: The current study investigated fed batch cultivation for the increased productivity of bacterial cellulose (BC) sheets by Gluconacetobacter hansenii PJK in static conditions using chemically defined medium and waste from beer fermentation broth. Fermentations were carried out in a 3 L jar fermenter without any impeller for 30 days. In the proposed fed batch cultivation, 500 mL of the medium was initially inoculated with pre culture in a jar fermenter while a fresh medium was fed periodically. BC production was also done by using batch cultivation which was used as a control for comparison. The results obtained revealed an overall of 2 3 times increase in BC production in fed batch cultivation compared to batch cultivation after 30 days of cultivation. During these experiments, it was found that waste from beer fermentation broth is a superior medium for the BC production using fed batch cultivation. The production of water soluble oligosaccharides as useful by products was also monitored during these investigations. Fed batch cultivation and waste from beer fermentation was also found superior for the production of these by products. According to literature search and to the best of our knowledge, it is the first report of using fed batch cultivation for BC production in static conditions.

title: Physical structure variations of bacterial cellulose produced by different Komagataeibacter xylinus strains and carbon sources in static and agitated conditions
abstract: The morphology, crystallinity, crystallite size, and production yield of bacterial cellulose (BC) produced with six different carbon sources (glucose, fructose, lactose, maltitol, sucralose, and xylitol) in static and agitated fermentation conditions by five strains of Komagataeibacter xylinus (KX, TISTR 086, 428, 975, and 1011) which are locally available, were studied. In static condition, the BC pellicle was formed as a membrane sheet at the medium surface exposed to air, while in agitated condition, the spherical or asterisk like shape BC particles were obtained in the culture media. The XRD and FT IR analyses found no significant differences in the cellulose crystallinity, crystallite size or polymorphic distribution within the carbon sources. However, changes in crystallinity and mass fraction of the Ia allomorph were observed in BC produced from the different bacterial strains and incubation conditions. The BC samples produced by the same bacterial strain with the varying culture conditions showed the alteration of physical properties more clearly than the BC samples prepared by the opposite situation. These findings suggested that the strains of bacteria and fermentation conditions strongly affected on the physical structures of BC.

title: EFECTO DE DIFERENTES CONCENTRACIONES DE FRUCTOSA SOBRE LA PRODUCCION DE CELULOSA BACTERIANA EN CULTIVO ESTATICO EFFECT OF DIFFERENT CONCENTRATIONS OF FRUCTOSE ON BACTERIAL CELLULOSE PRODUCTION IN STATIC CULTURE
abstract: In the synthesis of bacterial cellulose have used various carbon sources, various configurations and strategies of bioreactor cultivation. In this study we compared the production of bacterial cellulose evaluating the effect of different concentrations of fructose in the production of bacterial cellulose (BC) by Gluconacetobacter xylinus IFO static culture. The study was carried out in bioreactors of 750ml cylinder, 200 ml of medium containing initial concentrations of 1, 5, 10, 15 p/v of fructose at pH 5.6. The inoculum volume was 10% v v of culture medium volume. Cellulose synthesis was performed at room temperature and at different incubation times ranging from 1.5 to 28 days, which time is determined on the physicochemical and mechanical properties of bacterial cellulose, as well as fructose consumption versus time for different initial concentrations of fructose. The results indicate that 10% w/v fructose highest value obtained for the synthesis of BC in grams per liter of moist cellulose culture medium and the maximum thickness was obtained with a volume decrease of remnant; furthermore, fructose consumption observed until 90% of the initial concentration. The compressibility was less than a greater thickness of the cellulose film. The medium pH was kept in a region for optimal synthesis of BC.

title: Influence of lignosulfonate on crystal structure and productivity of bacterial cellulose in a static culture
abstract: The influence of lignosulfonate on bacterial cellulose (BC) structure and productivity was studied using six strains of Gluconacetobacter xylinus Acetobacter xylinum (ATCC 10245, IFO 13693, 13772, 13773, 14815 and 15237) The BC productivity of all strains was improved almost 57% in the presence of (1% w/v) lignosulfonate. FT IR result showed that the BC produced in the presence of lignosulfonate displayed the higher crystallinity index and I a rich cellulose. Furthermore, X ray diffractogram confirmed the FT IR results and showed no remarkable change in d spacing. From CP/MAS 13 C NMR spectra, the amorphous region in the presence of lignosulfonate was relatively lower, that means the lignosulfonate enhanced the crystallinity of BC. These results indicate that the increase in the BC yield is due to the inhibition of gluconic acid formation in the presence of the antioxidant, polyphenolic compounds in the lignosulfonate.

title: Bacterial cellulose modification using static magnetic field
abstract: Bacterial cellulose (BC) has known as a cellulose material produced by bacteria, which is characterized by its purity, high porosity and randomly cellulose fibrils network arrangement. Static magnetic field (SMF) is a promising method, which can be used to modify the structure of BC. The aim of this study was to investigate the influence of an SMF on the morphology and the physical and chemical properties of BC by varying the intensity of the SMF (45 mT, 110 mT and 140 mT) through the culture medium. The results showed that the SMF did not disturb the cellulose production yield of the BC. Changes between SMF modified and conventional BC were shown on the side section perpendicular and parallel to SMF. The porous structure of SMF modified BC recorded under Scanning Electron Microscopy was more aligned. The changes of cellulose fibrils arrangement and porous structure resulted in the increase of mechanical property of the SMF modified BC. Feature characteristic of high porosity and crystallinity of BC maintained under an SMF. This study suggested a novel method to modify BC by the use of an SMF.

title: Enhanced production of bacterial cellulose in Komagataeibacter xylinus via tuning of biosynthesis genes with synthetic RBS.
abstract: Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is Komagataeibacter xylinus. However, due to limited tools of expression, this host is difficult to engineer metabolically to improve BC productivity. In this study, a regulated expression system for K. xylinus with synthetic ribosome binding site (RBS) was developed and used to engineer a BC biosynthesis pathway. A synthetic RBS library was constructed using green fluorescent protein (GFP) as a reporter, and three synthetic RBS (R4, R15, and R6) with different strengths were successfully isolated by fluorescence activated cell sorting (FACS) Using synthetic RBS, the expression of three homologous genes, pgm, galU, and ndp, responsible for BC production were optimized, and BC production was greatly increased under both static and shaking culture conditions. The final titer of BC under static and shaking conditions was 5.28 and 3.67 g/L, respectively. Our findings demonstrate that reinforced metabolic flux towards BC through quantitative gene expression represents a practical strategy for the improvement of BC productivity.

title: Enhanced mechanical properties of bacterial cellulose nanocomposites produced by co culturing Gluconacetobacter hansenii and Escherichia coli under static conditions.
abstract: Including additives in the culture media during bacterial cellulose (BC) biosynthesis is a traditional method to produce BC based nanocomposites. This study examines a novel fermentation process, which is to co culture Gluconacetobacter hansenii (G. hansenii) with Escherichia coli (E. coli) under static conditions, to produce BC pellicles with enhanced mechanical properties. The mannose rich exopolysaccharides (EPS) synthesized by E. coli were incorporated into the BC network and affected the aggregation of co crystallized microfibrils without significantly changing the crystal sizes of BC. When co culturing G. hansenii ATCC 23769 with E. coli ATCC 700728, which produced a low concentration of EPS at 3.3 0.7 mg/L, the BC pellicles exhibited a Young's modulus of 4,874 1144 MPa and a stress at break of 80.7 21.1 MPa, which are 81.9% and 79.3% higher than those of pure BC, respectively. The growth dynamics of the two co cultured strains suggested that the production of BC and EPS were enhanced through co culturing fermentation.

title: High Rate Production in Static Culture of Bacterial Cellulose from Sucrose by a Newly Isolated Acetobacter Strain
abstract: For the industrial production of bacterial cellulose from sucrose in static cultures, the possibility of a high rate of cellulose production was investigated. An Acetobacter strain, S 35, which had been isolated from a grape, was selected from 1500 isolates. This strain was found to produce a large amount of cellulose from either glucose or fructose. Using this strain, high cellulose production rates of 3.3g/liter/d or 40g/m2/d from sucrose were seen in static culture.