Biotechnology

Karl Popper, Forensic Science, and Nested Codes
This paper utilizes the framework of Karl Popper’s 3-world ontology to make the case that forensic science is a specialized coding system that establishes meaningful connections between the world of biology (world 1) and the world of human society (world 3). Forensic science is a cross-disciplinary endeavor that uses scientific methods to determine what transpired in a crime so the legal syst...


Enhanced phytate dephosphorylation by using Candida melibiosica yeast-based biofuel cell
We report for the first time that Candida melibiosica expresses enhanced phytase activity when grown under biofuel cell polarization in a nutrient-poor medium, containing only fructose as a carbohydrate source. Phytase activity during the cultivation under polarization reached up to 25 U per g dry biomass, exceeding with 20 ± 3 % those of the control. A participation of the enzyme in the ad...
High pH (and not free ammonia) is responsible for Anammox inhibition in mildly alkaline solutions with excess of ammonium
Ammonium is a substrate of the anaerobic ammonium oxidation (Anammox) process but it has been suggested as a substrate-inhibitor because of the action of its unionized form, free ammonia. High pH of the medium is also an important limiting factor of the Anammox bacteria. Both effects are difficult to discriminate. In this work the inhibitory effects of high pH, total ammonia (TA) and NH3 on the...


Mycoparasitism studies of Trichoderma harzianum against Sclerotinia sclerotiorum: evaluation of antagonism and expression of cell wall-degrading enzymes genes
Trichoderma spp. are known for their biocontrol activity against several plant pathogens. A specific isolate of Trichoderma harzianum, 303/02, has the potential to inhibit the growth of Sclerotinia sclerotiorum, an important agent involved in several crop diseases. In this study, the interaction between T. harzianum 303/02 and mycelia, sclerotia and apothecia of S. sclerotiorum was studied by s...
Deletion of a KU80 homolog enhances homologous recombination in the thermotolerant yeast Kluyveromyces marxianus
Targeted gene replacement in the thermotolerant yeast Kluyveromyces marxianus KCTC 17555 has been hampered by its propensity to non-homologous end joining (NHEJ). To enhance homologous recombination (HR) by blocking NHEJ, we identified and disrupted the K. marxianus KU80 gene. The ku80 deletion mutant strain (Kmku80∆) of K. marxianus KCTC 17555 did not show apparent growth defects under sever...


Direct patterning of poly(acrylic acid) on polymer surfaces by ion beam lithography for the controlled adhesion of mammalian cells
Poly(acrylic acid) (PAA)-patterned polystyrene (PS) substrates were prepared by ion beam lithography to control cell behaviors of mouse fibroblasts and human embryonic kidney cells. Thin PAA films spin-coated on non-biological PS substrates were selectively irradiated with energetic proton ions through a pattern mask. The irradiated substrates were developed with deionized water to generate neg...
Degradation of polyphosphates by polyphosphate kinases from Ruegeria pomeroyi
Polyphosphate kinases 2 (PPK2) are key enzymes for polyphosphate utilisation in bacteria. The genome of Ruegeria pomeroyi, a marine α-proteobacterium, includes three Pseudomonas aeruginosa PPK2 homologs. We expressed these homologs in Escherichia coli as soluble proteins, purified the protein products and compared their metal, pH and nucleotide preferences. The optimal pH was 8.0 for SPO1727 a...

Characterization of putative glycosylphosphatidylinositol-anchoring motifs for surface display in the methylotrophic yeast Hansenula polymorpha
Bioinformatic analysis of the genome of the methylotrophic yeast Hansenula polymorpha revealed 39 putative glycosylphosphatidylinositol-anchored proteins (GPI-proteins). Notably, dibasic motifs in the proximal ω-site, that has been reported as a plasma membrane retention signal in Saccharomyces cerevisiae GPI-proteins, were not found in any of the predicted GPI-proteins of H. polymorpha. To ev...
The operating performance of a biotrickling filter with Lysinibacillus fusiformis for the removal of high-loading gaseous chlorobenzene
Removal of gaseous chlorobenzene (CB) by a biotrickling filter (BTF) filled with modified ceramics and multi-surface hollow balls during gas–liquid mass transfer at the steady state was by microbial degradation rather than dissolution in the spray liquid or emission into the atmosphere. The BTF was flexible and resistant to the acid environment of the spray liquid, with the caveat that the sp...

Distance effect of matrix attachment regions on transgene expression in stably transfected Chinese hamster ovary cells
The β-globin matrix attachment regions (MARs) were inserted into the 5′-site of the eukaryotic expression vector cassette and DNA fragments 350 and 750 bp in length were inserted into the site to generate expression vectors with varying distances between the expression cassette and MAR. The vectors containing MARs increased chloramphenicol acetyltransferase (CAT) expression levels compared ...
Microgrooved poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) affects the phenotype of vascular smooth muscle cells through let-7a-involved regulation of actin dynamics
Cell–substrate interaction is important in tissue engineering. Vascular smooth muscle cells (VSMCs) cultured on the microgrooved surface of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) showed a distinctive polarized morphology and a high expression level of let-7a compared with the flat substrates. LIMK2, a crucial regulator of actin dynamics, was identified as a new target of let-7...

Enhanced production techniques, properties and uses of coenzyme Q10
Coenzyme Q10 (CoQ10) is an essential component of the respiratory chain which produces ATP. It is formed from the conjugation of a benzoquinone ring with a hydrophobic isoprenoid chain. Efforts on the production of CoQ10 by microorganisms focus on the development of potent strains by conventional mutagenesis and metabolic engineering especially in Escherichia coli, analysis and modification of ...
Method for the stabilization and immobilization of enzymatic extracts and its application to the decolorization of textile dyes
Peroxidases from Pleurotus eryngii have been investigated for their ability to degrade recalcitrant, phenolic pollutants. The use of crude enzymatic extracts can reduce the high costs associated with enzyme purification, and enzyme immobilization can enhance enzyme stability and recovery. The present study tests the effectiveness of various conditions for crude enzyme stabilization in polyethyl...
An ice nucleation protein from Fusarium acuminatum: cloning, expression, biochemical characterization and computational modeling
Ice nucleation proteins (INP) are a major cause of frost damage in plants and crops. Here, an INP gene from Fusarium acuminatum was optimized, synthesized, expressed in E.coli and subsequently purified and characterized. The protein belongs to the second class of ice nucleation proteins with an optimum pH 5.5, relative activity and stability between pH 5 and 9.5 and up to 45 °C. The protein w...
Introduction of two mutations into AroG increases phenylalanine production in Escherichia coli
L-Phenylalanine is an important amino acid commercially, and therefore optimization of its manufacture is of interest. We constructed a range of mutant alleles of AroG, the enzyme involved in the first step of phenylalanine biosynthesis. Three single-site mutant alleles were constructed (aroG8, aroG15, and aroG29), which were then combined to generate three double-site aroGfbr mutant alleles (a...