Fan-Chiang H.-J.,Danisco United States Inc. |
Wrolstad R.E.,Oregon State University
Journal of AOAC International | Year: 2010
Sugar and nonvolatile acid analyses were conducted on 52 samples of blackberries (Rubus spp), the objective being to develop a compositional database for evaluating authenticity and quality. ̊Brix ranged from 6.88 to 16.83, with a mean of 10.82. Titratable acidity ranged from 0.52 to 2.24 g citric acid/100 mL, with a mean of 1.35. Sucrose levels (range, 0-12.9%; mean, 4.6%) were highly variable. The overall glucose:fructose ratio ranged from 0.81 to 1.17, with a mean of 1.01. Malic, isocitric, lactoisocitric, citric, shikimic, and fumaric acids were identified, with succinic acid being present in some samples. Malic acid ranged from 5.2 to 35.3% of total acids (87.5-603 mgIIOO g), with a mean of 16.4% (280 mg/I 00 g). Isocitric acid ranged from 4.7 to 71.6%, with a mean of 34.7% (599 mg/100 g), and lactoisocitric acid ranged from 3.4 to 32.6% with a mean of 17.3% (293 mgIlOO g). Citric acid ranged from 1.3 to 80.2%, with a mean of 31.6 (572 mg/I 00 g). Shikimic, fumaric, and succinic were present in trace quantities. Two patterns of nonvolatile acid compositions were evident. Ten commercial blackberry juice samples were analyzed, and it was possible to determine whether they were Marion, Evergreen, or a mixture of the two from their acid profiles.
Recombinant expression of two bacteriophage proteins that lyse clostridium perfringens and share identical sequences in the c-terminal cell wall binding domain of the molecules but are dissimilar in their n-terminal active domains
Simmons M.,U.S. Department of Agriculture |
Donovan D.M.,U.S. Department of Agriculture |
Siragusa G.R.,Danisco United States Inc. |
Seal B.S.,U.S. Department of Agriculture
Journal of Agricultural and Food Chemistry | Year: 2010
Clostridium perfringens is a Gram-positive anaerobic spore-forming bacterium capable of producing four major toxins that are responsible for disease symptoms and pathogenesis in a variety of animals, humans, and poultry. The organism is the third leading cause of human foodborne bacterial disease, and C. perfringens is the presumptive etiologic agent of necrotic enteritis among chickens, which in the acute form can cause increased mortality among broiler flocks. Countries that have complied with the ban on antimicrobial growth promoters (AGP) in feeds have had increased incidences of C. perfringens-associated necrotic enteritis in poultry. To address this issue, new antimicrobial agents, putative lysins from the genomes of bacteriophages, are identified. Two putative phage lysin genes (ply) from the clostridial phages phiCP39O and phiCP26F were cloned and expressed in Escherichia coli, and the resultant proteins were purified to near homogeneity. Gene and protein sequencing revealed that the predicted and chemically determined amino acid sequences of the two recombinant proteins were homologous to N-acetylmuramoyl-L-alanine amidases. The proteins were identical in the C-terminal putative cell-wall binding domain, but only 55% identical to each other in the presumptive N-terminal catalytic domain. Both recombinant lysins were capable of lysing both parental phage host strains of C. perfringens as well as other strains of the bacterium in spot and turbidity reduction assays. The observed reduction in turbidity was correlated with up to a 3 log cfu/mL reduction in viable C. perfringens on brain-heart infusion agar plates. However, other member species of the clostridia were resistant to the lytic activity by both assays. © 2010 American Chemical Society.
Namal Senanayake S.P.J.,Danisco United States Inc.
Journal of Functional Foods | Year: 2013
Green tea is one of the most popular and extensively used dietary supplement in the United States. Diverse health claims have made for green tea as a trendy ingredient in the growing market for nutraceuticals and functional foods. Green tea extract contains several polyphenolic components with antioxidant properties, but the predominant active components are the flavanol monomers known as catechins, where epigallocatechin-3-gallate and epicatechin-3-gallate are the most effective antioxidant compounds. Additional active components of green tea extract include the other catechins such as epicatechin and epigallocatechin. Among these, epigallocatechin-3-gallate is the most bioactive and the most scrutinized one. Green tea polyphenols are also responsible for distinctive aroma, color and taste. Green tea extract can also be used in lipid-bearing foods to delay lipid oxidation and to enhance the shelf-life of various food products. This review outlines the chemistry, flavour components, antioxidant mechanism, regulatory status, food applications, and stability of green tea extract in food. © 2013 Elsevier Ltd.
Sinkunas T.,Vilnius University |
Gasiunas G.,Vilnius University |
Fremaux C.,Danisco |
Barrangou R.,Danisco United States Inc. |
And 2 more authors.
EMBO Journal | Year: 2011
Clustered regularly interspaced short palindromic repeat (CRISPR) is a recently discovered adaptive prokaryotic immune system that provides acquired immunity against foreign nucleic acids by utilizing small guide crRNAs (CRISPR RNAs) to interfere with invading viruses and plasmids. In Escherichia coli, Cas3 is essential for crRNA-guided interference with virus proliferation. Cas3 contains N-terminal HD phosphohydrolase and C-terminal Superfamily 2 (SF2) helicase domains. Here, we provide the first report of the cloning, expression, purification and in vitro functional analysis of the Cas3 protein of the Streptococcus thermophilus CRISPR4 (Ecoli subtype) system. Cas3 possesses a single-stranded DNA (ssDNA)-stimulated ATPase activity, which is coupled to unwinding of DNA/DNA and RNA/DNA duplexes. Cas3 also shows ATP-independent nuclease activity located in the HD domain with a preference for ssDNA substrates. To dissect the contribution of individual domains, Cas3 separation-of-function mutants (ATPase+/nuclease- and ATPase-/nuclease+) were obtained by site-directed mutagenesis. We propose that the Cas3 ATPase/helicase domain acts as a motor protein, which assists delivery of the nuclease activity to Cascade-crRNA complex targeting foreign DNA. © 2011 European Molecular Biology Organization. All Rights Reserved.
Francl A.L.,Urbana University |
Francl A.L.,Danisco United States Inc. |
Thongaram T.,Urbana University |
Miller M.J.,Urbana University
BMC Microbiology | Year: 2010
Abstract. Background. Lactobacilli can utilize a variety of carbohydrates which reflects the nutrient availability in their respective environments. A common lactobacilli in the human gastrointestinal tract, Lactobacillus gasseri, was selected for further study. The currently available annotation of the L. gasseri ATCC 33323 genome describes numerous putative genes involved in carbohydrate utilization, yet the specific functions of many of these genes remain unknown. Results. An enzyme I (EI) knockout strain revealed that a functional phosphotransferase transporter system (PTS) is required to ferment at least 15 carbohydrates. Analysis of the L. gasseri ATCC 33323 genome identified fifteen complete (containing all of the necessary subunits) PTS transporters. Transcript expression profiles in response to various carbohydrates (glucose, mannose, fructose, sucrose and cellobiose) were analyzed for the fifteen complete PTS transporters in L. gasseri. PTS 20 was induced 27 fold in the presence of sucrose and PTS 15 was induced 139 fold in the presence of cellobiose. No PTS transporter was induced by glucose, fructose or mannose. Insertional inactivation of PTS 15 and PTS 20 significantly impaired growth on cellobiose and sucrose, respectively. As predicted by bioinformatics, insertional inactivation of PTS 21 confirmed its role in mannose utilization. Conclusions. The experiments revealed the extensive contribution of PTS transporters to carbohydrate utilization by L. gasseri ATCC 33323 and the general inadequacy of the annotated sugar specificity of lactobacilli PTS transporters. © 2010 Francl et al; licensee BioMed Central Ltd.