A Mini-Review on the Progress of Spherical Bacterial Cellulose Production

2017 ◽  
Vol 45 ◽  
pp. 142-154 ◽  
Author(s):  
Ricardo Brandes ◽  
Claudimir Carminatti ◽  
Alexandre Mikowski ◽  
Hazim Al-Qureshi ◽  
Derce Recouvreux
Keyword(s):  
Bacterial Cellulose ◽  
Weight Control ◽  
Processing Parameters ◽  
Culture Conditions ◽  
Ex Situ ◽  
Cellulose Production ◽  
Static Culture ◽  
Agitated Culture ◽  
Made In

Bacterial cellulose (BC) is a polymer produced by some bacteria and it is highly pure when compared to plant cellulose. Its structure and properties are unique, which makes it a material of a large commercial interest due to its broad potential of applications. The biosynthesis of BC may be carried out in two ways either static or agitated culture. Static culture usually generates BC membranes whereas agitated tends to produce spherical shapes. The production in agitated culture often enables an increase of yield for cellulose production. However, it provides a material with lower mechanical properties compared to static culture. The processing parameters and the phenomena governing the formation of BC in agitated cultivation have not fully established. A greater understanding of the phenomena and parameters inherent in the production of BC in agitated culture is necessary to achieve a technological progress. Some limitations concerning molecular weight control and BC structure made in agitated culture can improve with a better understanding of the culture conditions and the biosynthesis evolution. The ex-situ or in-situ insertion of additives may be performed to increase some specific properties of BC over agitated culture. Thus, the principal objective of this work is to discuss and provide a broad literature review on the techniques of BC production by agitated culture.

scholarly journals Multifrequency target strength of northern krill (Meganyctiphanes norvegica) swimming horizontally

2011 ◽  
Vol 69 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Lucio Calise ◽  
Tor Knutsen
Keyword(s):  
Length Distribution ◽  
Ex Situ ◽  
Target Strength ◽  
Acoustic Backscatter ◽  
Acoustic Measurements ◽  
Acoustic Beams ◽  
Meganyctiphanes Norvegica ◽  
Acoustic Identification ◽  
Made In

Abstract Calise, L., and Knutsen, T. 2012. Multifrequency target strength of northern krill (Meganyctiphanes norvegica) swimming horizontally. – ICES Journal of Marine Science, 69: 119–130. Multifrequency acoustic measurements on ex situ horizontally swimming krill were made in a novel experimental setting. An ensemble of northern krill (Meganyctiphanes norvegica) was introduced to a large enclosure (a mesocosm), and acoustic backscatter was sampled using a multifrequency (70, 120, and 200 kHz) echosounder (Simrad EK60). Two submerged lamps were placed at opposite sides of the mesocosm and switched on and off to induce the krill, by light attraction, to swim horizontally through the acoustic beams. By tracking echoes, animal displacement, swimming speed, and target strength (TS) by frequency were estimated. The dominant and secondary modes of the total-length distribution were 21.8 ± 3.0 and 27.8 ± 2.7 mm, respectively. Although krill orientation was assumed stable and the ping rate was high, the range and inter-ping variability of the average TS values were large, decreasing and increasing with frequency, respectively. The overall TS frequency response observed and concurrent measurements at 120 and 200 kHz confirm the theoretical expectation that the acoustic backscatter from the investigated organisms were confined to the Rayleigh and Geometric scattering regions, a finding that might both aid acoustic identification and size-group separation of in situ northern krill.

Potential Applications of Bacterial Cellulose in Environmental and Pharmaceutical Sectors

2020 ◽  
Vol 26 (45) ◽  
pp. 5793-5806
Author(s):  
Mazhar Ul-Islam ◽  
Salman Ul-Islam ◽  
Sumayia Yasir ◽  
Atiya Fatima ◽  
Md. Wasi Ahmed ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
3D Structure ◽  
Three Dimensional ◽  
Base Material ◽  
Advanced Materials ◽  
Ex Situ ◽  
Potential Applications ◽  
Wide Readership ◽  
Water Filters

Biopolymers and their composites have been extensively investigated in recent years for multiple applications, especially in environmental, medical, and pharmaceutical fields. Bacterial cellulose (BC) has emerged as a novel biomaterial owing to its nontoxic, high-liquid absorbing and holding capacity, drug-carrying ability, and pollutant absorbing features. Additionally, its web-shaped three-dimensional (3D) structure and hydrogen bonding sites have incited a combination of various nanoparticles, polymers, and other materials with BC in the form of composites. Such BC-based composites have been developed through in-situ, ex-situ, and solution casting methods for targeted applications, such as air and water filters, controlled drug delivery systems, wound dressing materials, and tissue regeneration. This review details the production and development of BCbased composites with different materials and by various methods. It further describes various applications of BC-based composites in the environmental and pharmaceutical sectors, with specific examples from the recent literature. This review could potentially appeal a wide readership in these two emerging fields, where novel and advanced materials for different applications have been developed on a regular basis using BC as the base material.

scholarly journals Preparation of Graphene Oxide/Bacterial Cellulose Nanocomposite via in situ Process in Agitated Culture

2018 ◽  
Vol 30 (7) ◽  
pp. 1564-1568 ◽  
Author(s):  
S.A. Amaturrahim ◽  
S. Gea ◽  
D.Y. Nasution ◽  
Y.A. Hutapea
Keyword(s):  
Graphene Oxide ◽  
Bacterial Cellulose ◽  
Agitated Culture

scholarly journals In Situ and Ex Situ Designed Hydroxyapatite: Bacterial Cellulose Materials with Biomedical Applications

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4793
Author(s):  
Adrian Ionut Nicoara ◽  
Alexandra Elena Stoica ◽  
Denisa-Ionela Ene ◽  
Bogdan Stefan Vasile ◽  
Alina Maria Holban ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Composite Materials ◽  
Bacterial Cellulose ◽  
Antibacterial Properties ◽  
Antimicrobial Effect ◽  
Absorption Capacity ◽  
Coprecipitation Method ◽  
Ex Situ ◽  
Degradation Rates

Hydroxyapatite (HAp) and bacterial cellulose (BC) composite materials represent a promising approach for tissue engineering due to their excellent biocompatibility and bioactivity. This paper presents the synthesis and characterization of two types of materials based on HAp and BC, with antibacterial properties provided by silver nanoparticles (AgNPs). The composite materials were obtained following two routes: (1) HAp was obtained in situ directly in the BC matrix containing different amounts of AgNPs by the coprecipitation method, and (2) HAp was first obtained separately using the coprecipitation method, then combined with BC containing different amounts of AgNPs by ultrasound exposure. The obtained materials were characterized by means of XRD, SEM, and FT-IR, while their antimicrobial effect was evaluated against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and yeast (Candida albicans). The results demonstrated that the obtained composite materials were characterized by a homogenous porous structure and high water absorption capacity (more than 1000% w/w). These materials also possessed low degradation rates (<5% in simulated body fluid (SBF) at 37 °C) and considerable antimicrobial effect due to silver nanoparticles (10–70 nm) embedded in the polymer matrix. These properties could be finetuned by adjusting the content of AgNPs and the synthesis route. The samples prepared using the in situ route had a wider porosity range and better homogeneity.

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