Biomedical Engineering and Bioengineering Commons^™

A Highly Versatile Fungal Glucosyltransferase For Specific Production Of Quercetin-7-O-Β-D-Glucoside And Quercetin-3-O-Β-D-Glucoside In Different Hosts, Jie Ren, Wenzhu Tang, Caleb Don Barton, Owen M. Price, Mark Wayne Mortensen, Alexandra Phillips, Banner Wald, Simon Elgin Hulme, Logan Powell Stanley, Joan Hevel, Jixun Zhan

Biological Engineering Faculty Publications

Glycosylation is an effective way to improve the water solubility of natural products. In this work, a novel glycosyltransferase gene (BbGT) was discovered from Beauveria bassiana ATCC 7159 and heterologously expressed in Escherichia coli. The purified enzyme was functionally characterized through in vitro enzymatic reactions as a UDP-glucosyltransferase, converting quercetin to five monoglucosylated and one diglucosylated products. The optimal pH and temperature for BbGT are 35 ℃ and 8.0, respectively. The activity of BbGT was stimulated by Ca2+, Mg2+, and Mn2+, but inhibited by Zn2+. BbGT enzyme is flexible and can glycosylate a variety of substrates such as curcumin, …

Discovery And Engineering Of An Endophytic Pseudomonas Strain From Taxus Chinensis For Efficient Production Of Zeaxanthin Diglucoside, Ozkan Fidan, Jixun Zhan

Biological Engineering Faculty Publications

Background

Endophytic microorganisms are a rich source of bioactive natural products. They are considered as promising biofertilizers and biocontrol agents due to their growth-promoting interactions with the host plants and their bioactive secondary metabolites that can help manage plant pathogens. Identification of new endophytes may lead to the discovery of novel molecules or provide new strains for production of valuable compounds.

Results

In this study, we isolated an endophytic bacterium from the leaves of Taxus chinensis, which was identified as Pseudomonas sp. 102515 based on the 16S rRNA gene sequence and physiological characteristics. Analysis of its secondary metabolites revealed …

Identification Of New Glutamate Decarboxylases From Streptomyces For Efficient Production Of Γ-Aminobutyric Acid In Engineered Escherichia Coli, Haina Yuan, Hongbo Wang, Ozkan Fidan, Yong Qin, Gongnian Xiao, Jixun Zhan

Biological Engineering Faculty Publications

Background

Gamma (γ)-Aminobutyric acid (GABA) as a bioactive compound is used extensively in functional foods, pharmaceuticals and agro-industry. It can be biosynthesized via decarboxylation of monosodium glutamate (MSG) or L-glutamic acid (L-Glu) by glutamate decarboxylase (GAD; EC4.1.1.15). GADs have been identified from a variety of microbial sources, such as Escherichia coli and lactic acid bacteria. However, no GADs from Streptomyces have been characterized. The present study is aimed to identify new GADs from Streptomyces strains and establish an efficient bioproduction platform for GABA in E. coli using these enzymes.

Results

By sequencing and analyzing the genomes of three Streptomycesstrains, …

Engineered Production Of Fungal Anticancer Cyclooligomer Depsipeptides In Saccharo-Myces Cerevisiae, Dayu Yu, Fuchao Xu, Jiachen Zi, Siyuan Wang, David Gage, Jia Zeng, Jixun Zhan

Biological Engineering Faculty Publications

Two fungal cyclooligomer depsipeptide synthetases (CODSs), BbBEAS (352 kDa) and BbBSLS (348 kDa) from Beauveria bassiana ATCC 7159, were reconstituted in Saccharomyces cerevisiae BJ5464-NpgA, leading to the production of the corresponding anticancer natural products, beauvericins and bassianolide, respectively. The titers of beauvericins (33.82±1.41 mg/l) and bassianolide (21.74±0.08 mg/l) in the engineered S. cerevisiae BJ5464-NpgA strains were comparable to those in the native producer B. bassiana. Feeding D-hydroxyisovaleric acid (D-Hiv) and the corresponding L-amino acid precursors improved the production of beauvericins and bassianolide. However, the high price of D-Hiv limits its application in large-scale production of these cyclooligomer depsipeptides. Alternatively, we …

An Indigoidine Biosynthetic Gene Cluster From Streptomyces Chromofuscus Atcc 49982 Contains An Unusual Indb Homologue, Dayu Yu, Fuchao Xu, Jonathan Valiente, Siyuan Wang, Jixun Zhan

Biological Engineering Faculty Publications

A putative indigoidine biosynthetic gene cluster was located in the genome of Streptomyces chromofuscus ATCC 49982. The silent 9.4-kb gene cluster consists of five open reading frames, named orf1, Sc-indC, Sc-indA, Sc-indB, and orf2, respectively. Sc-IndC was functionally characterized as an indigoidine synthase through heterologous expression of the enzyme in both Streptomyces coelicolor CH999 and Escherichia coli BAP1. The yield of indigoidine in E. coli BAP1 reached 2.78 g/l under the optimized conditions. The predicted protein product of Sc-indB is unusual and much larger than any other reported IndB-like protein. The N-terminal portion of this enzyme resembles IdgB and the …