Biotechnology

Application of Statistically Based Experimental Designs to Optimize Cellulase Production and Identification of Gene
A natural bacterial strain identified as Bacillus amyloliquefaciens MBAA3 using 16S rDNA partial genome sequencing has been studied for optimization of cellulase production. Statistical screening of media components for production of cellulase by B. amyloliquefaciens MBAA3 was carried out by Plackett–Burman design. Plackett–Burman design showed CMC, MgSO4 and pH as significant components in...


Anaerobic Fluidized Membrane Bioreactor Polishing of Baffled Reactor Effluent During Treatment of Dilute Wastewater
This is illustrated in the current study where an anaerobic fluidized bed membrane bioreactor (AFMBR) is added as a second stage to an operating anaerobic baffled bioreactor (ABR) termed the staged anaerobic baffled-fluidized membrane bioreactor (SAB-FMBR) at ambient temperature. The ABR first stage was operated at a 3 h hydraulic retention time (HRT) and was followed by AFMBR operated at 0.9...
One-carbon substrate-based biohydrogen production: microbes, mechanism, and productivity
Among four basic mechanisms for biological hydrogen (H2) production, dark fermentation has been considered to show the highest hydrogen evolution rate (HER). H2 production from one-carbon (C1) compounds such as formate and carbon monoxide (CO) is promising because formate is an efficient H2 carrier, and the utilization of CO-containing syngas or industrial waste gas may render the industrial bi...


Rapid Prototyping of Microbial Cell Factories via Genome-scale Engineering
Advances in reading, writing and editing genetic materials have greatly expanded our ability to reprogram biological systems at the resolution of a single nucleotide and on the scale of a whole genome. Such capacity has greatly accelerated the cycles of design, build and test to engineer microbes for efficient synthesis of fuels, chemicals and drugs. In this review, we summarize the emerging te...
Recent Advances in Micro/Nanotechnologies for Global Control of Hepatitis B Infection
The control of Hepatits B virus (HBV) infection is a challenging task, specifically in developing countries where there is limited access to diagnostics and antiviral treatment mainly due to high costs and insufficient healthcare infrastructure. Although current diagnostic technologies can reliably detect HBV, they are relatively laborious, impractical and expensive for resource-limited setting...


Ferulic acid: a key component in grass lignocellulose recalcitrance to hydrolysis
In the near future, grasses must provide most of the biomass for the production of renewable fuels. However, grass cell walls are characterized by a large quantity of hydroxycinnamic acids such as ferulic and p-coumaric acids, which are thought to reduce the biomass saccharification. Ferulic acid (FA) binds to lignin, polysaccharides and structural proteins of grass cell walls cross-linking th...
Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds
Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PH...

Β-Catenin as a Tension Transmitter Revealed by AFM Nanomechanical Testing
Β-Catenin, a component of adherens junction (AJ), transmits forces between cells and stabilizes their balance, thereby contributing to AJ maturation. A previous study based on a single-molecule experiment has suggested that β-catenin unfolds under tension with low mechanical stability, while another study showed its mechanical behavior bearing to high forces. Such discrepancy in mechanical be...
Gene dynamics of core transcription factors for pluripotency in embryonic stem cells
Embryonic stem cell (ESC) pluripotency is maintained by core transcription factors (TFs). Although the expression of these TFs is well documented, their expression dynamics is poorly evaluated. Here, we visualized the dynamics of Nanog and Oct3/4 expression in ESC using fluorescent reporters and found that expression of these TFs change dramatically during culture.

Effective stimulating factors for microbial levan production by Halomonas smyrnensis AAD6T
Levan is a bioactive fructan polymer that is mainly associated with high-value applications where exceptionally high purity requirements call for well-defined cultivation conditions. In this study, microbial levan production by the halophilic extremophile Halomonas smyrnensis AAD6T was investigated systematically. For this, different feeding strategies in fed-batch cultures were employed and fe...
Comparative study of fungal strains for thermostable inulinase production
Fructose and fructo-oligosaccharides (FOS) are important ingredients in the food industry. Fructose is considered an alternative sweetener to sucrose because it has higher sweetening capacity and increases iron absorption in children, and FOS's are a source of dietary fiber with a bifidogenic effect. Both compounds can be obtained by enzymatic hydrolysis of inulin. However, inulin presents limi...

Effects of temperature on the astaxanthin productivity and light harvesting characteristics of the green alga Haematococcus pluvialis
The green alga Haematococcus pluvialis, which accumulates astaxanthin at an optimal temperature of 20°C, was cultivated under temperatures of 20°C, 23.5°C, 27°C, and 30.5°C, in order to assess the effects on algal metabolism during the growth phase. The culture growth rate declined with above-optimal increases in temperature, and the final maximum cell concentration at 30.5°C reached only...
Substrate specificity of β-glucosidase from Gordonia terrae for ginsenosides and its application in the production of ginsenosides Rg3, Rg2, and Rh1 from ginseng root extract
A β-glucosidase from Gordonia terrae was cloned and expressed in Escherichia coli. The recombinant enzyme with a specific activity of 16.4 U/mg for ginsenoside Rb1 was purified using His-trap chromatography. The purified enzyme specifically hydrolyzed the glucopyranosides at the C-20 position in protopanaxadiol (PPD)-type ginsenosides and hydrolyzed the glucopyranoside at the C-6 or C-20 posit...
Titer of trastuzumab produced by a Chinese hamster ovary cell line is associated with tricarboxylic acid cycle activity rather than lactate metabolism
Achieving high productivity and quality is the final goal of therapeutic antibody development, but the productivity and quality of antibodies are known to be substantially dependent on the nature of the cell lines expressing the antibodies. We characterized two contrasting cell lines that produce trastuzumab, namely cell line A with a high titer and a low aggregate content and cell line B with ...
Optimization of isopropanol production by engineered cyanobacteria with a synthetic metabolic pathway
Cyanobacterium is an attractive host for the production of various chemicals and alternative fuels using solar energy and carbon dioxide. In previous study, we succeeded to produce isopropanol using engineered Synechococcus elongatus PCC 7942 under dark and anaerobic conditions (0.43 mM, 26.5 mg/l). In the present study, we report the further optimization of this isopropanol producing conditi...